2007 Cotton Research Report Research Report No. 32 March 2008 Alabama Agricultural Experiment Station Richard Guthrie, Director Auburn University Auburn, Alabama Printed in cooperation with the Alabama Cooperative Extension System (Alabama A&M University and Auburn University) ACKNOWLEDGMENTS This publication is a joint contribution of Auburn University, the Alabama Agricultural Experiment Station, and the USDA Agricultural Research Service. Research contained herein was partially funded through the Alabama Cotton Commission and private industry grants. All donations, including the Alabama Cotton Commission grants and private industry funding, are appreciated. CONFIDENTIAL REPORT Publication, display, or distribution of data contained herein should not be made without prior written approval. Mention of a trademark or product does not constitute a guarantee of the product by Auburn University and does not imply its approval to the exclusion of other products. This report can be found on the Web at http://www.ag.auburn.edu/aaes/communications/researchreports/07cottonrr.pdf Information contained herein is available to all persons regardless of race, color, sex, or national origin. Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex. age, veteran status, or disability. CONTENTS page Editors, Contributors ...........................................................................................................................................................................5 IRRIGATION Cotton Income Gains Due to Irrigation—2007 Report.......................................................................................................................7 Subsurface Drip Irrigation (SDI) Fertigation for Site-Specific, Precision Management of Cotton....................................................8 Sprinkler Irrigation for Site-Specific, Precision Management of Cotton .........................................................................................10 Evaluating Pressure-Compensating Subsurface Drip Irrigation (SDI) for No-Till Row Crop Production on Rolling, Irregular Terrain......................................................................................................................................................11 WEED CONTROL Early Season Pigweed Control in Conservation Tillage Cotton .......................................................................................................13 Influence of Tillage and Herbicides on Weed Control on Cotton .....................................................................................................15 INSECTICIDES Identifying Different Chemicals or Combinations for Managing the Sucking–Bug Complex in Cotton Research in the Southeast Region .............................................................................................................................17 Identifying Practical Knowledge and Solutions for Managing the Sucking–Bug Complex in Cotton Research in the Southeast Region .............................................................................................................................18 FERTILITY Evaluation of Surface Application of Nitrogen Fertilizer Sources in a Conservation Tillage Cotton System .................................20 Nitrogen and Plant Growth Regulator Rates on Cotton Yield and Fiber Quality ............................................................................21 Nitrogen Fertilizer Source, Rates, and Timing for a Cover Crop and Subsequent Cotton Crop ......................................................23 GPS/GIS Use of Remote Sensed Thermal Imagery for In-Season Stress Detection and Site-Specific Management of Cotton .....................26 Evaluation of Variable-Rate Seeding for Cotton...............................................................................................................................27 CROP ROTATION AND VARIETY SELECTION Crop Rotation for the Control of Reniform Nematodes ...................................................................................................................29 Screening Commercial Cotton Varieties Against Fusarium Wilt ......................................................................................................31 Cotton Cultivar Response to Temik 15G plus Avicta in Two Tillage Regimes in Alabama, 2007 ...................................................31 Cotton Cultivar Response to Telone II for Reniform Nematode Management in Cotton in South Alabama, 2007 .........................32 Breeding Cotton for Yield and Quality in Alabama ..........................................................................................................................33 Irrigation on The Old Rotation..........................................................................................................................................................34 Fertilization of Cotton on Black Belt Prairie Soils in Alabama ........................................................................................................36 Ammonia Losses from Surface-Applied Urea-Based Nitrogen Fertilizer ........................................................................................39 FUNGICIDES Effect of Selected Fungicide Seed Treatment Combinations on Cotton Seedling Disease in North Alabama, 2007.......................41 Evaluation of Agriliance Cotton Seed Treatments in North Alabama, 2007 ....................................................................................42 Efficacy of Experimental Seed Treatments on Early Season Cotton Diseases in North Alabama, 2007 .........................................43 Evaluation of Cotton Seedling Disease Management in North Alabama, 2007 ...............................................................................44 Evaluation of Agriliance Cotton Seed Treatments in Central Alabama, 2007 ..................................................................................46 Efficacy of Experimental Seed Treatments on Early Season Cotton Diseases in Central Alabama, 2007 .......................................46 Evaluation of Cotton Seedling Disease Management in Central Alabama, 2007.............................................................................49 Nematicide Combination Effects on Selected Nematode Species in Central Alabama, 2007..........................................................50 CONTENTS, CONTINUED NEMATICIDES On-Farm Field Trials to Test the Effectiveness of Seed Nematicides for Managing Reniform and Root-Knot Nematodes on Cotton in Alabama, 2007 ..........................................................................................................51 Evaluation of Avicta Formulation Variants for Reniform Nematode Management in Cotton in North Alabama, 2007 ..................52 Evaluation of Avicta Variants Alone and in Combinations With Vydate C-LV or Temik 15G for Reniform Nematode Management in Cotton in North Alabama, 2007 ...............................................................................53 Evaluation of the Experimental AGST06012 Alone and in Combination with Avicta CP, InHibit, or Temik 15G for Reniform Nematode Management in Cotton in North Alabama, 2007........................................................54 Avicta, Aeris, Temik 15G, and Vydate C-LV Management Options for Reniform Nematode Management in Cotton in North Alabama ......................................................................................................................................................55 Evaluation of Avicta Formulation Variants for Reniform Nematode Management in Cotton in South Alabama, 2007 ..................56 Evaluation of Avicta Variants Alone and in Combinations with Vydate C-LV or Temik 15G for Reniform Nematode Management in Cotton in South Alabama, 2007 ...............................................................................57 Evaluation of Avicta CP, InHibit, or Temik 15G with the Experimental AGST06012 for Reniform Nematode Management in Cotton in South Alabama, 2007 ...............................................................................58 Efficacy of Aeris Seed Treatment in Combination with Biological GB 126 for Reniform Nematode Management in Cotton in South Alabama, 2007 ............................................................................................................................................59 Evaluation of the Biological Muscodor for Reniform Nematode Management in Cotton in South Alabama, 2007 .......................60 Efficacy of Aeris Seed Treatment in Combination with Biological GB 126 for Root-Knot Nematode Management in Cotton in Alabama, 2007.......................................................................................................................................................61 NemOut Seed Treatment for Reniform Nematode Management .....................................................................................................62 Nematicide Combination Effects on Selected Nematode Species in Central Alabama, 2007 ..............................................................................................................................................................63 MOLECULAR Facilitating Breeding Cotton for Reniform Nematode Resistance ...................................................................................................65 Breeding New Varieties of Cotton for Heat and Drought Tolerance: Elite Germplasm Development Using Molecular Markers..........................................................................................................................................................65 Production and Characterization of Bt Resistance in Cotton Bollworm, Helicoverpa zea ..............................................................66 Contributors Index ............................................................................................................................................................................68 EDITORS K. S. Lawrence Associate Professor Entomology and Plant Pathology Auburn University C.D. Monks Professor and Extension Specialist Agronomy and Soils Auburn University D.P. Delaney Extension Specialist IV Agronomy and Soils Auburn University CONTRIBUTORS J. R. Akridge Director Brewton Agricultural Research Unit Brewton, Alabama F. J. Arriaga Affiliate Assistant Professor Agronomy and Soils, Auburn University USDA-National Soil Dynamics Lab. K. S. Balkcom Affiliate Assistant Professor Agronomy and Soils, Auburn University USDA-National Soil Dynamics Lab. J. Bergtold Affiliate Assistant Professor Agronomy and Soils, Auburn University USDA-National Soil Dynamics Lab. W. C. Birdsong Regional Agronomist Southeast Alabama Alabama Cooperative Extension System C. Brodbeck Engineer II Biosystems Engineering, Auburn University C. H. Burmester Extension Agronomist Tennessee Valley Research and Extension Center, Belle Mina, Alabama J. Clary Regional Extension Agent Alabama Cooperative Extension System L. M. Curtis Professor and Extension Spec., Emeritus Biosystems Engineering, Auburn University D. P. Delaney Extension Specialist IV Agronomy and Soils, Auburn University B. Dillard Regional Extension Agent Alabama Cooperative Extension System C. Dillard Agricultural Program Associate Agronomy and Soils, Auburn University M. P. Dougherty Assistant Professor Biosystems Engineering, Auburn University F. Ducamp Graduate Research Assistant Agronomy and Soils, Auburn University B. Durbin Director, Field Crops Unit, E.V. Smith Research Center Shorter, Alabama B. Durham Agricultural Program Associate Tennessee Valley Research and Extension Center, Belle Mina, Alabama J. P. Fulton Assistant Professor Biosystems Engineering, Auburn University W. S. Gazaway Professor and Extension Spec., Emeritus Entomology and Plant Pathology Auburn University K. Glass Agricultural Program Associate Agronomy and Soils, Auburn University R. W. Goodman Associate Professor Agricultural Economics and Rural Sociology Auburn University W. G. Griffith Regional Extension Agent Fayette County Alabama Cooperative Extension System M. H. Hall Regional Extension Agent Madison County Alabama Cooperative Extension System D. H. Harkins Agricultural Program Assistant Tennessee Valley Research and Extension Center, Belle Mina, Alabama J. Holliman Director, Black Belt Research and Extension Center, Marion Junction, Alabama G. Huluka Associate Professor Agronomy and Soils, Auburn University L. Kuykendall Regional Extension Agent Autauga County Alabama Cooperative Extension System G. W. Lawrence Entomology and Plant Pathology Mississippi State University K. S. Lawrence Associate Professor Entomology and Plant Pathology Auburn University R. D. Locy Professor Biological Sciences, Auburn University P. L. Mask Assistant Director, Ag, For, Nat. Res. Alabama Cooperative Extension System C. C. Mitchell Professor and Extension Agronomist Agronomy and Soils, Auburn University W. J. Moar Professor Entomology and Plant Pathology Auburn University C. D. Monks Professor and Extension Specialist Agronomy and Soils, Auburn University S. R. Moore Graduate Research Assistant Entomology and Plant Pathology Auburn University S. Nightengale Director, Plant Breeding Unit E. V. Smith Research Center Tallassee, Alabama B. E. Norris Director Tennessee Valley Research and Extension Center, Belle Mina, Alabama CONTRIBUTORS, CONTINUED S. H. Norwood Regional Agent, Tennessee Valley REC Alabama Cooperative Extension System M. G. Patterson Professor Agronomy and Soils, Auburn University H. Potter former Regional Extension Agent Alabama Cooperative Extension System A. J. Price Affiliate Assistant Professor Agronomy and Soils, Auburn University USDA-National Soil Dynamics Lab. R. Raper Affiliated Professor Agronomy and Soils, Auburn University USDA–National Soils Dynamic Lab T. Reed Extension Specialist Tennessee Valley REC Alabama Cooperative Extension System N. S. Sekora Graduate Research Assistant Entomology and Plant Pathology Auburn University D. Schrimsher Agriculture Technician I Tennessee Valley Research and Extension Center, Belle Mina, Alabama J. N. Shaw Professor Agronomy and Soils, Auburn University N. K. Singh Professor Biological Sciences, Auburn University R. H. Smith Professor and Extension Spec., Emeritus Entomology and Plant Pathology Auburn University D. Sullivan Soil Scientist USDA–ARS, Southeast Watershed Research Lab, Tifton, Georgia D. B. Weaver Professor Agronomy and Soils, Auburn University A. Winstead Regional Agent, Tennessee Valley REC Alabama Cooperative Extension System R. P. Yates Regional Extension Agent Marengo County Alabama Cooperative Extension System IRRIGATION COTTON INCOME GAINS DUE TO IRRIGATION – 2007 REPORT The 2006 and 2007 growing seasons were progressively dryer at the Tennessee Valley Research and Extension Center (TVREC), Belle Mina, Alabama, with decreasing precipitation and increasing evaporation during both years (see figure). The most recent 10-year average rainfall at Belle Mina for June through August is 10.5 inches; and the 78-year average is 11.5 inches. Comparable season rainfall in 2006 and 2007 was less than 7 inches. Only four previous years on record had such low rainfall during these months; and only one year on record, 1954, had less rainfall than 2007. Not only was rainfall low, but evapotranspiration (approximated by pan evaporation in figure) was extremely high throughout the growing season of both years. As M. P. Dougherty, J. P. Fulton, C. H. Burmester, L. M. Curtis, D. H. Harkins, B. Durham, B. E. Norris, and C. D. Monks a result, cotton producers with adequate irrigation had the potential to realize significant yield gains in 2006 and 2007, similar to the excellent response to irrigation observed in 1999 and 2000. This report evaluates irrigated cotton income gains over comparable dryland cotton using yield and irrigation data for overhead sprinkler plots at TVREC during two back-to-back drought years, 2006 and 2007. Total annual irrigation system ownership costs of $87.95 per acre and irrigation operating costs of $9.39 per acre-inch for a 140-acre pivot are taken from Timely Information Series publication BSEN-IRR-07-01 (May 2007) (http://www.aces.edu/dept/irrig/anIRR-01.php). Table 1 shows increasing seasonal operating costs for irrigation as larger depths of water are applied. During the 2006 and 2007 drought, 100 percent of pan evaporation, adjusted 30 for canopy cover, was required in sprinkler research plots to 25 achieve maximum yields (Table 20 1). Total seasonal irrigation depths were extremely high 15 during 2006 and 2007 (approximately 20 inches). 10 Table 2 shows that in 2006, if estimated irrigation ownership 5 and operating costs are charged against 2006 gross receipts, 0 overhead sprinkler irrigation re1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 sults in a net income gain of $26 per acre over dryland (irrigaSeasonal precip (Jun-Aug) Seasonal PAN evap (Jun-Aug) Seasonal irrigation (Jun-Aug) tion replaces 50 percent of pan Ten-year seasonal water balance (June through August only), TVREC, Belle Mina, Alabama. An- evaporation, adjusted for crop nual seasonal irrigation is calculated as 90 percent x seasonal pan evaporation x crop canopy canopy). A maximum net infactor. come gain of $144 per acre over Inches TABLE 1. COMPARATIVE YIELDS, GROSS RECEIPTS, AND ESTIMATED OPERATING COSTS FOR OVERHEAD SPRINKLER IRRIGATION, 2006 AND 2007, TVREC, BELLE MINA, ALABAMA1 Source: TVREC record: 2006-2007 2006 Lint yield bales/A2 1.2 1.7 2.0 2.2 2.8 2.9 2007 Lint yield bales/A2 1.0 2.2 3.4 3.8 4.0 3.9 2006 Gross receipts $/A3 $312 $438 $521 $574 $736 $774 2007 Gross receipts $/A3 $260 $589 $895 $1,000 $1,058 $1,040 2006 Operating costs $/A4 $0 $46 $95 $143 $192 $236 2007 Operating costs $/A4 $0 $40 $90 $138 $181 $229 Sprinkler plots (actual 2006, 2007 irrigation depths): Dryland / winter cover (0.0”, 0.0”) 25% x PAN x canopy cover factor (4.9”, 4.3”) 50% x PAN x canopy cover factor (10.1”, 9.6”) 75% x PAN x canopy cover factor (15.2”, 14.7”) 100% x PAN x canopy cover factor (20.4”, 19.3”) 125% x PAN x canopy cover factor (25.2”, 24.4”) 1 2 Operating costs do not include irrigation annual ownership costs. 2006: 38% turnout; 2007: 41 percent turnout. 3 Gross receipts $0.55 / pound lint (includes resale of $200/ton seed). 4 Operatiing cost for 101 horsepower diesel motor for irrigation pump; Estimated pumping costs for a 140-ac pivot-irrigated cotton field are $9.39/acin. Source: http://www.aces.edu/dept/irrig/anIRR-01.php. 8 ALABAMA AGRICULTURAL EXPERIMENT STATION dryland would be realized if irrigation replaced 100 percent of pan evaporation, adjusted for crop canopy. In 2007, a higher response to irrigation was observed in all sprinkler research plots. As a result, when estimated irrigation ownership and operating costs are charged against 2007 gross receipts, net income gain due to irrigation is $201 per acre over dryland even if irrigation replaces only 25 percent of pan evaporation, adjusted for crop canopy. Based on 2007 field trial data, a maximum net income gain of $529 per acre would be realized if irrigation replaced 100 percent of pan evaporation, adjusted for crop canopy. A separate report discusses reasons for the higher irrigation response in 2007 sprinkler trials at TVREC. TABLE 2. ESTIMATED NET INCOME GAIN OVER DRYLAND DUE TO OVERHEAD SPRINKLER IRRIGATION, 2006 AND 2007, TVREC, BELLE MINA, ALABAMA Source: TVREC record: 2006-2007 2006 2007 2006 2007 Total Total ownership ownership + + Operating Operating costs costs $/A2 $/A2 $0 $134 $183 $231 $280 $324 $0 $128 $178 $226 $269 $317 2006 Net income gain over dryland $/A --($7) $26 $31 $144 $138 2007 Net income gain over dryland $/A --$201 $457 $515 $529 $463 Gross receipts $/A1 Sprinkler plots (actual 2006, 2007 irrigation depths): Dryland / winter cover (0.0”, 0.0”) 25% x PAN x canopy cover factor (4.9”, 4.3”) 50% x PAN x canopy cover factor (10.1”, 9.6”) 75% x PAN x canopy cover factor (15.2”, 14.7”) 100% x PAN x canopy cover factor (20.4”, 19.3”) 125% x PAN x canopy cover factor (25.2”, 24.4”) 1 2 Gross receipts bales/A1 $260 $589 $895 $1,000 $1,058 $1,040 $312 $438 $521 $574 $736 $774 Gross receipts $0.55 / pound lint (includes resale of $200/ton seed). Ownership costs = $87.95/ac; Operating costs = $9.39/ac-in (Table 1). Estimated costs include a 140-ac pivot system, with pump and motor. Source: http://www.aces.edu/dept/irrig/anIRR-01.php. SUBSURFACE DRIP IRRIGATION (SDI) FERTIGATION FOR SITE-SPECIFIC, PRECISION MANAGEMENT OF COTTON M. P. Dougherty, J. P. Fulton, C. H. Burmester, B. E. Norris, D. H. Harkins, L. M. Curtis, and C. D. Monks Since 2006, an SDI study at the Tennessee Valley Research and Extension Center (TVREC) has evaluated four precision fertigation management scenarios. Approximately 7,500 feet of SDI tape and four positive displacement liquid fertilizer injectors were used to evaluate four replications of five nutrient timing treatments. The twenty treatment plots were made up of eight, 345-foot rows of cotton on 40-inch row spacing, with drip tape between every other row of cotton. The four fertigation treatments and one non-fertigated control are described in Table 1. Yield results for 2006 and 2007, two of the driest consecutive years on record at TVREC, are shown in the figure. Significant yield, quality, and nutrient differences are presented in Tables 2 and 3. Fertigated plot yields were comparable in 2007 and 2006 (2.9 bales and 3.0 bales, respectively). In 2007, the non-fertigated control (treatment 1) was the highest yielding treatment, but was not significantly different from the two highest fertigated treatments (treatments 2 and 5). The three highest yielding treatments in 2007 received at least 20 pounds of sur- Treatment1 1. Control – drip irrigated, but all fertilizers are surface applied. 2. Timing 1 – with surface preplant 3. Drip timing 1 – no preplant 4. Drip timing 2 – no preplant “spoon-fed” 5. Timing 2 – with surface preplant TABLE 1. TREATMENT DESCRIPTION, FERTIGATION MANAGEMENT TRIALS, 2006-2007 Description Preplant 60 pounds N and K 60 (surface) Post-Plant N (75 lb/A) sidedressed at early square. Preplant 20 pounds of N and K (surface). Drip 40 pounds N,K – square to bloom (25 days) Drip 75 pounds N,K – bloom to 25 days Planting Drip 20 pounds N,K Drip 40 pounds N,K – square to bloom (25 days) Drip 75 pounds N,K – bloom to 25 days Planting Drip 20 pounds N,K Drip 40 pounds N,K – square to bloom (25 days) Drip 75 pounds N,K – bloom to 40 days Preplant 40 pounds of N and K (surface). Drip 95 pounds N,K – square through bloom (50 days) 1 All treatments received 135 pounds per acre of nitrogen and potassium (K2O), 20 pounds per acre of sulfur, and l.0 pound per acre of boron. Phosphorus fertilizer was surface-applied to maintain P at high soil test levels. Drip fertilizer was 8-0-8-1.2S-0.06B made using 32 percent liquid N, potassium thiosulfate, fertilizer grade KCL, solubor, and water. 2007 COTTON RESEARCH REPORT 9 face-applied, preplant nitrogen and potassium (K2O). In 2006, the non-fertigated control (treatment 1) was the lowest yielding treatment, with highest fertigated yields observed where fertigated nutrients were applied within 50 days of square (treatments 2 and 5). The non-fertigated control treatment responded much better in 2007, possibly due to beneficial downward movement of surface-applied fertilizer early in the season as a result of 4.55 inches of rain from May through July. A comparable number of storm events in 2006 delivered only 2.87 inches of rain over the same May through July period. As a result, in spite of near- ly equal total seasonal rainfall in the 2007 and 2006 growing seasons (6.1 inches and 6.6 inches, respectively), higher early season rainfall in 2007 may have assisted delivery of surfaceapplied nutrients. Several large convectional storms later in the 2007 season may have further moved surface-applied nutrients into the soil horizon, while leaching fertigated nutrients farther out of reach of roots. Increased soil moisture monitoring is being installed in 2008. In both 2007 and 2007, plant tissue nutrients were generally higher in the highest yielding treatments, with plant tissue boron, manganese, and sodium (results not shown) generally lower in the surface-applied control treatment (treatment 1). Seed cotton yield, lb/ac 4,000 3,800 3,600 3,400 3,200 3,000 2,800 1 2 3 4 5 2006 2007 Fertigation treatments Seed cotton yield, lb/A, drip tier fertigation management study, Belle Mina, AL, 2006-2007. N=4. Turnout = 41 percent. trt1 1 2 3 4 5 TABLE 2. YIELD AND QUALITY ANALYSIS, COTTON FERTIGATION MANAGEMENT TRIALS, 2007 Lbs/A 3636 a2 3328 ab 3164 b 3266 b 3333 ab Mic Length Strength Uniformity 4.40 a 1.11 ab 31.1 a 84.0 a 4.53 a 1.11 ab 30.7 ab 84.2 a 4.48 a 1.10 b 29.6 b 83.9 a 4.45 a 1.09 b 30.8 ab 83.9 a 4.40 a 1.13 a 30.9 ab 84.4 a N% 4.65 a 4.12 b 3.95 b 3.49 c 4.14 b Ca% 3.30 a 3.09 ab 2.83 b 2.99 b 3.07 ab K% 1.74 a 1.58 ab 1.47 b 1.47 b 1.57 ab Mg% 0.57 a 0.42 bc 0.38 c 0.41 bc 0.44 b P% 0.44 b 0.54 a 0.47 b 0.49 ab 0.47 b 1 1. Surface-applied N-P-K with drip irrigation (control). 2. Preplant 20 lb. N-K surface with 2 N-K drip timings. 3. 20 lb. N-K drip at planting with 2 N-K drip timings (to 25 days after bloom). 4. 20 lb. N-K at planting with 2 N-K drip timings (to 40 days after bloom). 5. Preplant 40 lb. N-K surface with 1 N-K drip timing (square through bloom). 2 Different subscripts denote statistical difference (α=0.10). N=4. Turnout = 41percent. trt1 1 2 3 4 5 TABLE 3. YIELD AND QUALITY ANALYSIS, COTTON FERTIGATION MANAGEMENT TRIALS, 2006 Lbs/A 3160 c2 3780 a 3528 ab 3430 bc 3606 ab Mic 4.83 a 4.63 b 4.60 b 4.65 b 4.58 b Length Strength Uniformity 1.13 ab 31.1 a 84.3 a 1.15 a 30.8 ab 84.4 a 1.12 b 30.6 ab 84.2 a 1.13 b 30.1 b 83.8 a 1.13 b 30.2 b 83.9 a N% 3.88 ab 3.92 a 3.62 bc 3.59 c 3.80 abc Ca% 2.06 a 2.01 ab 1.86 c 2.07 a 1.87 bc K% 1.48 a 1.45 a 1.28 b 1.44 a 1.31 b Mg% 0.35 a 0.32 b 0.32 b 0.31 b 0.32 b P% 0.28 a 0.29 a 0.24 b 0.30 a 0.26 ab 1 1. Surface-applied N-P-K with drip irrigation (control). 2. Preplant 20 lb. N-K surface with 2 N-K drip timings. 3. 20 lb. N-K drip at planting with 2 N-K drip timings (to 25 days after bloom). 4. 20 lb. N-K at planting with 2 N-K drip timings (to 40 days after bloom). 5. Preplant 40 lb. N-K surface with 1 N-K drip timing (square through bloom). 2 Different subscripts denote statistical difference (α=0.10). N=4. Turnout = 41percent. 10 ALABAMA AGRICULTURAL EXPERIMENT STATION SPRINKLER IRRIGATION FOR SITE-SPECIFIC, PRECISION MANAGEMENT OF COTTON M. P. Dougherty, J. P. Fulton, C. H. Burmester, B. E. Norris, D. H. Harkins, L. M. Curtis, and C. D. Monks The sprinkler scheduling study initiated in 2006 at the Ten- 2008, a canola-soybean-cotton rotation will be incorporated into nessee Valley Research and Extension Center (TVREC) was 24 of the 48 sprinkler test plots to assess the economic feasibility continued during 2007 on a randomized block design of 48 plots of adding two oil crops to a northern Alabama cotton rotation. (39’x39’) to test the soil and plant response of cotton grown usTable 2 provides estimated operating costs for pivot irrigation ing six irrigation treatments. Treatments ranged from 0 percent based on overhead sprinkler trials at TVREC during two back-to(dryland) to 125 percent of calculated pan evaporation adjusted back drought years, 2006 and 2007. Total irrigation operating costs for percent canopy cover. Of note, 2007 was the driest growing of $9.39 per acre-inch are taken from Timely Information Series season on record at Belle Mina since 1954. June through August publication BSEN-IRR-07-01 (May 2007), assuming a 140-acre rainfall was less than 7 inches during both 2006 and 2007 growing pivot. In a separate report, net income gain due to irrigation in seasons, with pan evaporation surpassing 23 inches each year. 2006 and 2007 is estimated by deducting total estimated irrigation Yield results from 2006 and 2007 (see figure) provided costs (ownership + operating) from estimated gross receipts and benchmarks indicating the response of various irrigation sched- then comparing the results with estimated dryland receipts. ules on yield and operating cost. Sprinkler irrigated cotton yields averaged 2.3 bales in 2006 and 3.5 bales in 2007 5,000 (Table 1). From 2006 to 2007, dryland yield decreased while 4,000 sprinkler-irrigated treatments increased. The highest yield3,000 ing sprinkler treatment in 2007 (irrigation at 100 percent 2006 of calculated pan evaporation 2,000 2007 x canopy cover adjustment) yielded four bales per acre. 1,000 Significantly increased 2007 sprinkler plot yields may have 0 been due to a change in ex0 25 50 75 100 125 perimental method in 2007, which included deeper, less % Pan evaporation x CC frequent irrigations, or due to a higher number of total heat- Seed cotton yield, precision sprinkler irrigation cotton trials, lb/A, for 2006 and 2007. Different degree days in 2007, especial- subscripts denote statistical difference. In 2006, N=4, turnout = 38 percent. In 2007, N=8, turnout ly during the month of July. In = 41 percent. In 2006, four out of eight replications were discarded due to irrigation malfunction. CC=canopy cover factor, where 100 percent equals closed canopy. Seed cotton yield, lb/ac TABLE 1. YIELD AVERAGES PER TREATMENT FOR 2006 AND 2007, SPRINKLER SCHEDULING TRIALS Treatment 125% pan evaporation x canopy cover factor 100% pan evaporation x canopy cover factor 75% pan evaporation x canopy cover factor 50% pan evaporation x canopy cover factor 25% pan evaporation x canopy cover factor 0% pan evaporation (dryland) ————2006———— Seed cotton Bales lbs/A bales/A 3704 a1 3520 a 2748 b 2491 b 2098 c 1492 d 2.9 2.8 2.2 2.0 1.7 1.2 ————2007———— Seed cotton Bales lbs/A bales/A 4612 a1 4692 a 4437 a 3970 b 2613 c 1151 d 3.9 4.0 3.8 3.4 2.2 1.0 1 Different subscripts denote statistical difference (α=0.10). In 2006, N=4, turnout 38 percent. In 2007, N=8, turnout 41 percent. 2007 COTTON RESEARCH REPORT 11 TABLE 2. IRRIGATION AMOUNTS AND ESTIMATED CENTER PIVOT OPERATING COSTS, BASED ON 2006 AND 2007 TVREC SPRINKLER IRRIGATION TRIALS Treatment 125% pan evaporation x canopy cover factor 100% pan evaporation x canopy cover factor 75% pan evaporation x canopy cover factor 50% pan evaporation x canopy cover factor 25% pan evaporation x canopy cover factor 0% pan evaporation (dryland) 1 ————2006———— Irrigation Operating depth costs in $/A1 25.17 20.44 15.24 10.07 4.87 0.00 $236.35 $191.93 $143.10 $94.56 $45.73 $0.00 ————2007———— Irrigation Operating depth costs in $/A 1 24.42 19.31 14.71 9.63 4.29 0.00 $229.30 $181.32 $138.13 $90.43 $40.28 $0.00 Operating cost for 101 horsepower diesel motor for irrigation pump; Estimated operating costs based on a 140-ac pivot-irrigated cotton field are $9.39/ac-in. Source: http://www.aces.edu/dept/irrig/anIRR-01.php. EVALUATING PRESSURE-COMPENSATING SUBSURFACE DRIP IRRIGATION (SDI) FOR NO-TILL ROW CROP PRODUCTION ON ROLLING, IRREGULAR TERRAIN J. P. Fulton, M. P. Dougherty, J. N. Shaw, L. M. Curtis, C. H. Burmester, R. Raper, C.Brodbeck, B. Durham, D. H. Harkins, A. Winstead, and S. H. Norwood The study was conducted on a 12-acre field located at the Tennessee Valley Research and Extension Center (TVREC), Belle Mina, Alabama. The two major objectives were to evaluate cotton production on rolling terrain irrigated with SDI in conjunction with cover crops and to evaluate spatial yield variability as related to water distribution and topography. The experimental design was a randomized block design with two irrigation treatments (Irr – irrigated; No Irr – non-irrigated) and two cover crop treatments (C – Cover; NC – No Cover) with four replications. Plots measured 27 feet by 1250 feet with SDI tape laid out in 1250-foot runs on 80-inch spacing (every other row of 40-inch cotton) and buried at an average depth of 13 inches. Plots receiving a cover crop treatment were planted with rye at a 2007 accumulated monthly pan evaporation, rainfall, and irrigation during the growing season. rate of 90 pounds per acre on October 23, 2006. Cotton, variety ST 4554 B2RF, was planted on April 23, 2007. In 2007, irrigated treatments were to be scheduled based on daily application of 90 percent of daily pan evaporation, with the application amount adjusted for percent crop canopy cover. However, in mid-June, the water application amount was increased to more than two times the 90 percent level due to obvious plant development problems caused by extremely low soil moisture in the developing root zone. The figure presents the accumulated rainfall, pan evaporation, and irrigation over the growing season. During the 2007 growing season, a total of 19.8 inches of water was applied with only 8.1 inches of rain. All plots were harvested on October 3 and 4, 2007. Mean yields per treatment and statistical significance for the 2007 growing season are provided in Table 1. Lint turnout data indicated that irrigated treatments averaged 44 percent while non-irrigated plot treatments averaged 40 percent. Significant yield differences were measured between the irrigated and non-irrigated treatments. As in 2006, irrigated yields were significantly higher than non-irrigated yields with 2007 treatment yields 66 percent higher than non-irrigated yields. Irrigated treatment yields averaged approximately three bales per acre in 2007. These yields were impressive considering the exceptional drought conditions experienced during the growing season and the questionable adequacy of irrigation early in the season. No significant differences existed between cover and nocover plots in 2007 although there was a numerical increase in yield for plots with cover crops compared to those without. It should be noted that the 16 percent difference between cover treatments in 2006 was partly caused by water application issues in the no-cover plots. For example, there was about a 3-week 12 ALABAMA AGRICULTURAL EXPERIMENT STATION period in June where, due to a scheduling error, the irrigated/nocover plots did not receive water probably causing a difference. Numerically higher yields in the 2007 cover crop treatment suggested that cover crops have potential yield benefits. A quality analysis was conducted by harvesting 50 cotton bolls collected at six locations within each plot (96 total samples; six locations x 16 plots) in 2007. Quality factors considered were micronaire, strength, uniformity, and lint length (Table 2). There were significant differences between the irrigated and non-irrigated treatments for all quality factors which also existed in the 2006 quality data (Table 3). Micronaire values were below 3.5 for the non-irrigated plots, signifying a discount. Strength and uniformity were significantly higher on the irrigated plots with a high strength classification and an average to high uniformity, whereas the non-irrigated plots produced average strength and low to average uniformity. No significant differences existed between the irrigated/cover treatments compared to irrigated/nocover. Micronaire, uniformity, and lint length were significantly different for the cover and no-cover, non-irrigated treatments. Uniformity and lint length had higher values (not always significant) in the no-cover treatments. In summary, irrigated treatments in the 2007 growing season had significantly higher yields (66 percent greater) than nonirrigated treatments and compared to similar yield differences (60 percent) observed in 2006. While not significant, the winter cover crop did provide a 6 percent yield benefit in 2007. Results of the 2007 quality data indicated that repeatable differences existed, with micronaire, lint strength, lint uniformity, and lint length being significantly higher on irrigated than non-irrigated plots, a result also observed in 2006. TABLE 1. YIELD AVERAGES PER TREATMENT FOR 2006 AND 2007 Treatment Irrigated / Cover Irrigated / No-Cover Non-Irrigated / Cover Non-Irrigated / No-Cover 1 ————2006———— Seed cotton Bales lbs/A bales/A 2853 a1 2.6 2396 b 2.1 1098 c 1.0 941 c 0.8 ————2007———— Seed cotton Bales lbs/A bales/A 3574.8 a 3.1 3350.0 a 2.9 1187.9 b 1.0 1119.3 b 1.0 Mean yields with similar letters indicate they are not statistically different at the 90 percent confidence level. Treatment TABLE 2. 2007 QUALITY AVERAGES PER TREATMENT Micronaire lbs/A 1 4.7 a2 4.6 a 3.3 b 3.1 c Strength g/Tex 30.0 a 29.4 a 26.3 b 26.1 b Uniformity % 82.9 a 83.0 a 79.6 b 80.9 c Irrigated / Cover Irrigated / No-Cover Non-Irrigated / Cover Non-Irrigated / No-Cover 1 2 Length in 1.10 a 1.11 a 1.05 b 1.08 c Values between 3.5 and 4.9 are not discounted at the gin. Mean yields with similar letters indicate they are not statistically different at the 90 percent confidence level. Treatment TABLE 3. 2006 QUALITY AVERAGES PER TREATMENT Micronaire lbs/A 1 4.4 a2 3.9 b 4.1 b 4.1 b Strength g/Tex 28.5 a 28.0 a 26.1 b 25.2 c Uniformity % 83.5 a 82.8 b 81.8 c 81.2 c Irrigated / Cover Irrigated / No-Cover Non-Irrigated / Cover Non-Irrigated / No-Cover 1 2 Length in 1.1 a 1.1 a 1.0 b 1.0 b Values between 3.5 and 4.9 are not discounted at the gin. Mean yields with similar letters indicate they are not statistically different at the 90 percent confidence level. WEED CONTROL EARLY SEASON PIGWEED CONTROL IN CONSERVATION TILLAGE COTTON A. J. Price, C. D. Monks, and M. G. Patterson Cotton acreage in conservation tillage systems is estimated to approach 60 percent in the southeastern United States. The use of cover crops in conservation tillage offers many advantages, one of which is weed suppression through physical as well as chemical allelopathic effects. Cereal rye (Secale cereale L.) is one of the most common winter cover crops recommended for cotton production in the United States. Recently, glyphosate-resistant Palmer amaranth (Amaranthus palmerii) has been discovered in Arkansas, Georgia, North Carolina, South Carolina, and Tennessee, and populations in Alabama may also be resistant. Current resistant Palmer amaranth control recommendations in Georgia rely on soil applied herbicides. However, conservation tillage systems are disadvantaged due to herbicide interception by winter cover residue. Banding herbicides over the drill may protecting cotton yield while reducing inputs. High amounts of residue can inhibit weed germination and emergence. Pigweed control may be higher in high-residue systems versus low-residue systems and at control levels equivalent to conventional tillage systems utilizing soil applied herbicides. Field studies were conducted to evaluate pigweed density, biomass, and cotton yield provided by two tillage systems containing four winter residue amounts in the conservation tillage system and four herbicide systems. In the fall of 2006, field experiments were established at the E.V. Smith Research Center (EVSRC) located near Shorter, Alabama, and at the Tennessee Valley Research and Extension Center (TVREC) near Bella Mina, Alabama. The experimental design was a randomized complete block, having a split block restriction on randomization, with three replicates. Native populations of Palmer amaranth and redroot pigweed (Amaranthus hybridus) were present at EVSRC and TVREC locations, respectively. However, an additional 120,000 seed of each respective pigweed species was broadcast early spring over each plot. Parallel strips consisted of four conservation-tillage treatments: high (PD1), medium (PD2), and low (PD3) amounts of cereal rye plus a winter fallow treatment, as well as a conventional tillage treatment that was left fallow. Three cereal rye residue amounts were generated by utilizing three fall planting dates: 2 and 4 weeks prior to and on the historical average first frost. The rye was established with a no-till drill at a seeding rate of 100 kg/ha; 56 kg of nitrogen (N) as ammonium nitrate was applied to rye in the fall. Additionally, perpendicular strips consisted of four herbicide regimes. In the spring, the rye cover crop as well as weeds in the winter fallow treatment were terminated using glyphosate at 1.12 kg ae/ha and a mechanical roller-crimper. Cover biomass from each plot was measured immediately before termination; the aboveground rye cover was sampled, dried, and weighed. The cotton variety DP 555 BG/RR was seeded at EVSRC following within-row subsoiling of all plots with a narrowshanked parabolic subsoiler. The cotton variety DP 444 BG/RR was direct-seeded at TVREC. The conventional tillage treatment was prepared with multiple disk passes and cotton was seeded with a four-row planter equipped with row cleaners and double-disk openers at both locations. Both experimental areas were exposed to extreme drought, and the experimental area at EVSRC received minimal supplemental irrigation. At both locations, plots consisted of four 6-m rows spaced 102 cm apart. Evaluations also included pigweed density, dry weight and fresh weight before and after postemergence and layby herbicide applications, cotton stand establishment, and height. Cotton seed lint yields were determined by machine-harvesting the middle two rows of each plot with a spindle picker. Due to space limitations, results from the herbicide regimes are not discussed here. Winter cover crop biomass and weed density. At both locations, the highest rye biomass was attained following the earliest planting date and the lowest biomass was attained following the latest planting date (Figures 1 and 2). At TVREC, biomass yields of 8,680, 7,390, and 6,430 kg/ha were attained for planting dates one, two and three, respectively (Figure 1). At TVREC, the highest pigweed density (1,073,000 plants/ha) was observed following the winter fallow conservation-tillage (WF) treatment. The second highest densities were observed following the third planning date (493,000 plants/ha) and the conventionaltillage (CT) (560,000 plants/ha) treatments. The lowest densities followed the first (90,000 plants/ha) and second planting dates (123,000 plants/ha). At EVSRC, biomass yields of 8,430, 6,050, and 4,170 kg/ha were attained for planning dates one, two, and three, respectively (Figure 2). At EVSRC, the highest pigweed density again followed the winter fallow conservation-tillage treatment (797,000 plants/ha). The second highest density followed the conventional-tillage treatment (580,000). All three conservation-tillage systems provided lower densities ranging between 210,000 and 230,000 plants/ha compared to both the winter fallow conservation tillage and conventional tillage treatments. 14 ALABAMA AGRICULTURAL EXPERIMENT STATION Winter cover crop biomass and pigweed biomass. Differences between location and pigweed species biomass were significant. At TVREC, redroot pigweed biomass generally reflected pigweed density, with the highest pigweed biomass (270 kg/ha) attained in winter fallow conservation tillage and conventional tillage (200 kg/ha) treatments (Figure 3). Planting date three resulted in 20 kg biomass/ha while planting dates one and two resulted in less than 3 kg biomass/ha. At EVSRC, similar Palmer amaranth biomasses were observed in the winter fallow conservation tillage (85 kg/ha) and conventional tillage treatments (95 kg/ha) (Figure 4). Densities of 60 kg/ha and 55 kg/ha were observed in planting date treatments one and two, respectively. However, the third planting date, which provided similar pigweed density compared to planning dates one and two, provided the lowest pigweed biomass (25 kg/ha). Because the experimental area experienced severe drought stress throughout Rye Biomass (kg/ha) 10000 8000 6000 4000 2000 0 PD1 PD2 PD3 Treatment WF CT 1200000 1000000 800000 600000 400000 200000 0 the season, the larger pigweed in the earlier planting dates may be due to increased moisture conservation provided by the higher mulch residue attained in these treatments, resulting in larger plants. Cotton yield. At TVREC and EVSRC, cotton yield was not dependent on pigweed density (Figures 5 and 6) or pigweed biomass (data not shown). Additionally, all conservation-tillage treatments yielded more seed cotton than the conventional tillage treatment. In conclusion, increasing amounts of winter cover biomass can decrease early season pigweed density in conservation-agriculture systems, thus allowing for a size differential between pigweed and crop for future herbicide applications. Weed control provided by shallow tillage is similar to conservation-agriculture systems that have moderate amounts of residue. Rye Biomass (kg/ha) 10000 8000 6000 4000 2000 0 PD1 PD2 PD3 Treatment WF CT 300 250 200 150 100 50 0 Figure 1. Cover biomass vs. early season pigweed density, TVREC, 2007. Bars represent rye biomass, dots represent pigweed density. Rye Biomass (kg/ha) 10000 8000 6000 4000 2000 0 PD1 PD2 PD3 Treatment WF CT 1000000 800000 600000 400000 200000 0 Figure 3. Cover biomass vs. early season pigweed biomass, TVREC, 2007. Bars represent rye biomass, dots represent pigweed density. 10000 Rye Biomass (kg/ha) 8000 6000 4000 2000 0 PD1 PD2 PD3 Treatment WF CT 120 100 80 60 40 20 0 Figure 2. Cover biomass vs. early season pigweed density, EVSRC, 2007. Bars represent rye biomass, dots represent pigweed density. Figure 4. Cover biomass vs. early season pigweed biomass, EVSRC, 2007. Bars represent rye biomass, dots represent pigweed density. 2007 COTTON RESEARCH REPORT Seed Cotton Yield Seed Cotton Yield (kg/ha) 15 1200000 1000000 800000 600000 400000 200000 0 2500 2000 (kg/ha) 1500 1000 500 0 PD1 PD2 PD3 Treatment WF CT 3000 2500 2000 1500 1000 500 0 PD1 PD2 PD3 Treatment WF CT 1000000 800000 600000 400000 200000 0 Figure 5. Cotton yield vs. early season pigweed density by cover crop treatment, TVREC, 2007. Bars represent rye biomass, dots represent pigweed density. Figure 6. Cotton yield vs. early season pigweed density by cover crop treatment, EVSRC, 2007 Bars represent rye biomass, dots represent pigweed density. INFLUENCE OF TILLAGE AND HERBICIDES ON WEED CONTROL IN COTTON Mike Patterson and C. D. Monks Tillage systems—including (1) moldboard plowing followed by disking with Prowl at 2 pints per acre followed by field cultivation, (2) disking twice with Prowl followed by field cultivation, (3) no-till with Prowl preemergence after planting, and (4) no-till without Prowl—were initiated in the spring of 2006 at the E.V. Smith Research Center. The trial was planted in Roundup Ready Flex cotton. Preemer100 gence herbicides including Cotoran, Cap90 arol, or none were applied after planting. 80 Postemergence herbicides used following 70 preemergence herbicides included either Cot Pre 60 Roundup Weathermax at 22 fluid ounces Cot fb Rdup 50 Rdup only per acre or none. The trial area was in40 None fested with annual grasses (goosegrass 30 and crabgrass) and spiny pigweed. Visual 20 weed control and seed cotton yields were 10 obtained. The test area was replanted in 0 Invert, Disk+P Disk 2X+P Notill+P Notill 2007 using no-till planting across the entire test area to determine the residual efFigure 1. Effect of tillage and herbicides on weed control in cotton, 2006 (percent fects of tillage conducted in 2006. control). (P=Prowl, Cot=Cotoran, Rdup=Roundup) Weed control and seed cotton yields in 2006 were higher overall for the plots that 3500 received moldboard plowing, regardless 3000 of the preemergence or postemergence 2500 herbicides applied after tillage operations Cot Pre (Figures 1 and 2). No-till without Prowl 2000 Cot fb Rdup resulted in lower overall weed control and Rdup only 1500 cotton yield. This tillage influence carNone ried over somewhat in 2007 with the same 1000 yield trend as 2006 (Figure 3). Continuing 500 the trial in 2008 will provide more infor0 mation on the potential residual benefits Invert, Disk+P Disk 2X+P Notill+P Notill of primary tillage as an occasional break Figure 2. Effect of tillage and herbicides on seed cotton, 20086(seed cotton pounds from reduced tillage. per acre). (P=Prowl, Cot=Cotoran, Rdup=Roundup) 16 ALABAMA AGRICULTURAL EXPERIMENT STATION 3000 2500 2000 1500 1000 500 0 Invert, Disk+P Disk 2X+P Notill+P Notill Cot Pre Cot fb Rdup Rdup only None Figure 3. Effect of tillage and herbicides on seed cotton, 2007 (seed cotton pounds per acre). (P=Prowl, Cot=Cotoran, Rdup=Roundup) INSECTICIDES IDENTIFYING DIFFERENT CHEMICALS OR COMBINATIONS FOR MANAGING THE SUCKING–BUG COMPLEX IN COTTON RESEARCH IN THE SOUTHEAST REGION R. H. Smith This test was conducted to validate sampling technique and treatment thresholds for stink bugs on cotton field borders adjacent to peanuts. Peanuts were chosen since they provide a good host for stink bugs and movement out of this crop occurs over a long period of the growing season. Many cotton fields in Alabama and the southeastern United States are planted adjacent to peanut fields and, therefore, incur this movement from peanuts to cotton throughout much of the fruiting season. This test was designed by planting eight rows of cotton through the middle of a peanut field. Fifteen different chemicals or combinations were evaluated for residual control (Table 1). One application was made when the bug-damaged boll count reached 46 percent. Evaluations were then made at 7,14, and 21 days after application by selecting 25 quarter diameter bolls per treatment and examining them for internal injury. Adjacent strips (nonreplicated) of four rows by 250 feet TABLE 1. TREATMENTS FOR STINK BUG TRIAL, WIREGRASS RESEARCH CENTER, were utilized for this test. One HEADLAND, AL, 2007 application was made on AuNo. Treatment Formulation Rate lbs ai/A (product/A) gust 14 with evaluations made 1 NUP 05077 (lambda cyhalothrin) 24.8% WDG 0.03 on August 22, 28, and Septem2 Karate (pyrethriod) 2.08 CS 0.03 (1.8 oz) ber 8 (7, 14, and 21 days after 3 Trimax Pro (imidacloprid) 4.4 SC 0.06 (1.8 oz.) application [DAA]) (Table 2). 4 Trimax Pro + Diamond (IGR) 4.4 SC + 0.83 EC 0.06 + 0.04 (1.8 + 6 oz.) The stink bug population in this 5 Trimax Pro + Bidrin (phosphate) 4.4 SC + 8 EC 0.06 + 0.33 (1.8 + 5.3 oz.) 6 Trimax Pro + Baythroid (pyrethroid) 4.4 SC + 1 EC 0.06 + 0.016 (1.8 + 2.1 oz.) test was about 50:50 southern 7 Endigo (Karate + Centric) 2.06 SC (9.48% + 12.6 %) 0.065 (4 oz.) green and brown species. 8 Diamond + Bidrin (threshold) 0.83 EC + 8 EC 0.04 + 0.33 (6+ 5.3 oz.) About one half (46 per9 Diamond + Bidrin (schedule) 0.83 EC + 8 EC 0.04 + 0.33 (6+ 5.3 oz.) cent) of the quarter diameter 10 Bidrin 8 EC 0.33 (5.3 oz.) bolls had internal stink bug 11 Diamond 0.83 EC 0.06 (9.0 oz.) 12 Salt (Sodium Chloride) — 1.0 injury when this test was initi13 Bidrin + Discipline 8 EC + 2 E 0.33 + .083 (5.3 + 5.3 oz.) ated on August 14. Most treat14 Discipline (pyrethroid) 2E 0.1 (6.4 oz.) ments had reduced injury on 15 Centric (Thiamethoxam) 40 WG 0.05 (2 oz.) the first evaluation at 7 DAA. 16 Untreated — — The weakest treatments at 7 DAA were Trimax Pro, Trimax Pro + Diamond and salt. TABLE 2. EVALUATION OF SELECT INSECTICIDES FOR RESIDUAL CONTROL OF STINK BUGS, Bug injury in the salt treatment was higher than the untreated, WIREGRASS RESEARCH CENTER, 2007 % internal boll injury which would raise the question of an attractant property. The Aug. Aug. Sep. 22 28 4 most effective treatments after No. Treatment Rate lbs ai/A (product/A) (7 (14 (21 7 days posttreatment were EnDAA) DAA) DAA) digo (Centric + Karate), Dia1 NUP 05077 (lambda cyhalothrin) 0.03 20 20 32 mond + Bidrin, Bidrin + Disci2 Karate (pyrethriod) 0.03 (1.8 oz) 28 28 36 pline, Discipline, and Centric. 3 Trimax Pro (imidacloprid) 0.06 (1.8 oz.) 48 20 32 4 Trimax Pro + Diamond (IGR) 0.06 + 0.04 (1.8 +6 oz.) 32 20 52 Treatments that showed 5 Trimax Pro +Bidrin (phosphate) 0.06 + 0.33 (1.8 + 5.3 oz.) 24 32 36 improved control at the 14 6 Trimax Pro + Baythroid (pyrethroid) 0.06 + 0.016 (1.8 + 2.1 oz.) 20 24 20 DAA evaluation were Trimax 7 Endigo (Karate + Centric) 0.065 (4 oz.) 12 12 24 Pro, Trimax Pro + Diamond, 8 Diamond + Bidrin (threshold) 0.04 + 0.33 (6+ 5.3 oz.) 12 20 28 Bidrin, and salt. At 14 DAA 9 Diamond + Bidrin (schedule) 0.04 + 0.33 (6+ 5.3 oz.) 20 32 48 10 Bidrin 0.33 (5.3 oz.) 28 20 44 the salt treatment was more 11 Diamond 0.06 (9.0 oz.) 16 24 36 like the untreated, even though 12 Salt (Sodium Chloride) 1.0 76 44 48 the damage was less than at 7 13 Bidrin+ Discipline 0.33 +0 .083 (5.3 + 5.3 oz.) 12 24 20 DAA. Treatments that showed 14 Discipline (pyrethroid) 0.1 (6.4 oz.) 8 16 36 similar control at 14 DAA as 15 Centric (Thiamethoxam) 0.05 (2 oz.) 12 20 48 16 Untreated — 56 56 76 they did at 7 DAA were NUP 05077, Karate, Trimax Pro + 18 ALABAMA AGRICULTURAL EXPERIMENT STATION Baythroid and Endigo. The better treatments at 14 DAA were Endigo, Discipline, Centric, Bidrin, Diamond + Bidrin, Trimax Pro + Diamond, Trimax Pro, and NUP 05077. Most treatments showed reduced effectiveness at the 21 DAA evaluation. The two exceptions were Trimax Pro + Baythroid and Bidrin + Discipline. The most residual treatments at 21 DAA were Trimax Pro + Baythroid, Endigo, and Bidrin +Discipline. Damage in the untreated area and several treatments increased approximately 50 to 100 percent between the 14- and 21-day evaluation. This might indicate the movement of additional stink bugs into the test area along with a loss in residual control of these treatments. It is thought that most stink bugs in this test area were migrant adults. Therefore, the IGR products such as Diamond would have been at a disadvantage. Based on these results, it appears that pyrethroids, at moderate to high rates, alone or in combinations, offer the best residual control of stink bugs when migration from nearby crops or hosts is the situation. Cotton in this test area was bordered at one end by peanuts and the other end by corn. Both crops are known as good stink bug hosts. Yields were collected from this test (Table 3). However, it is doubtful that the stink bug pressure present in this test had a significant or measurable impact on yields. This is based on the fact that the untreated and some of the less effective treatments, such as salt, yielded as much as some of the more effective treatments. If the natural stink bug population had continued to increase in late season, requiring more treatments, the likelihood of treatment impacts on yield would have been greater. TABLE 3. SEED COTTON YIELDS: STINK BUG TEST # 1, HEADLAND, AL 2007 Treatment NUP 05077 (lambda cyhalothrin) Karate (pyrethriod) Trimax Pro (imidacloprid) Trimax Pro + Diamond (IGR) Trimax Pro +Bidrin (phosphate) Trimax Pro + Baythroid (pyrethroid) Endigo (Karate + Centric) Diamond + Bidrin (threshold) Diamond + Bidrin (schedule) Bidrin Diamond Salt (Sodium Cloride) Bidrin+ Discipline Discipline (pyrethroid) Centric (Thiamethoxam) Untreated 1 Actual lbs. Calculated seed cotton lbs. seed harvested1 cotton/A 194 3162 213 3472 201 3276 210 3423 208 3390 206 3358 214 3488 179 2918 199 3244 210 3423 204 3325 204 3325 180 2934 210 3423 194 3162 190 3097 Harvested entire plot (4 rowsx220 ft.) by machine on 10/17/07. Weights taken by dumping into a boll buggy modified with scales. IDENTIFYING PRACTICAL KNOWLEDGE AND SOLUTIONS FOR MANAGING THE SUCKING–BUG COMPLEX IN COTTON RESEARCH IN THE SOUTHEAST REGION Ron H. Smith Peanuts serve as a host crop for stink bugs throughout the summer months. Many cotton fields in the southeastern United States are planted adjacent to these crops. In this situation, stink bugs appear to migrate weekly throughout the cotton fruiting season from corn/peanuts to cotton. Much knowledge has been gained in recent years about improved management and control of stink bugs in cotton. However, cotton field borders (approximately 50 to 60 feet) adjacent to other host crops face a unique situation with continuous reinfestation. More knowledge is needed as to how these borders can be protected from economic stink bug injury. The study site consisted of an irrigated field 250 feet in length where the rows ran from corn on one end to a peanut field on the other. Four replicates consisting of eight rows by 80 feet planted to DP 555BG/RR were utilized. For the threshold study, the test was initiated on week 7 of bloom when the damage level reached 20 percent. Two applications were made on an automatic schedule while three applications were made on a “sliding” threshold. Bidrin at a rate of 1 gallon to 24 acres was used as the insecticide. The ratio of southern green to brown stink bug species was about 80:20 in this test. Treatment thresholds evaluated: 1. Untreated 2. Automatic (Week 3,5,7 of bloom) Note: due to lack of stink bug pressure, first application was not made until week 6 of bloom (August 1). Second application was made 1 week later due to the rapid build up of stink bugs. 3. University sliding threshold as shown below: Week of bloom % Boll damage threshold 1 20 2 20 3 10 4 10 5 10 6 20 7 20 8 30 9 30 Treatments made: #2 (Automatic) 8/1/07 Bidrin 5.3oz (Wk.6) 8/7/07 Bidrin 5.3oz (Wk.7) #3 (University) 8/1/07 Bidrin 5.3oz (Wk.6) 8/7/07 Bidrin 5.3oz (Wk.7) 8/14/07 Bidrin 5.3oz (Wk.8) 2007 COTTON RESEARCH REPORT 19 The protocol for this trial was modified due to the late arrival of a natural infestation of stink bugs at treatable levels. Once the bug population was present, the cotton plants in this test fields had begun to abort squares and small bolls. As a result, bolls that were susceptible to stink bug injury were present for about 3 weeks. Several points might be learned from the results of this trial. One, tremendous variability existed between replicates within the same treatment threshold based on our sample size of 25 bolls per plot (see table). Two, large sample sizes were prohibitive time wise, requiring four persons from 2 to 3 hours (8 to 12 man hours) to examine for internal injury. Three, based on the results of this test, it appears that a phosphate insecticide, such as Bidrin, does not offer growers the residual control needed for field borders with daily or continuous migration from other crops such as peanuts. There was more variability between replicates than between treated and untreated plots in this trial. Some of this variability could have been due to sampling differences between those collecting the samples. Furthermore, there could easily be differences between samplers in the process of crushing and examining the bolls internally for bug injury. All of these possibilities define the complexities of sampling and making treatment deci- sions for stink bugs. When these points are added to the short residual control of some of our most common treatments, much work remains to be done in managing this insect. When reviewing the damage level in this test by date it is difficult to see consistent trends (see table). On August 7 (7DAA), the difference between damage levels of the various treatments was erratic. After application #2 (August 14) the untreated began to separate from the treated. However, there was great variability between replicates receiving the same treatment. By week 3 (August 22) following the initial application, the treated plots had about one-half the damage as the untreated. However, the treated plots did not show acceptable levels of stink bug control. It was unfortunate that the test had to be terminated due to the lack of stink bug susceptible bolls. In many ways, this test raised more questions than provided answers. It is difficult to determine exactly how much the heat, drought, lack of mid-season stink bug pressure, and the lack of late season bolls had on the results of this trial. Plans are to repeat this test again in 2008 and hopefully gain further insight into the management of stink bugs on the borders of cotton fields that interface with good alternate hosts for stink bugs, such as peanuts. Yields will be taken in this trial but they may or may not provide additional information for the 2007 season. STINK BUG THRESHOLD STUDY, HEADLAND, AL, 2007 Treatment threshold Untreated Replicate 1 2 3 4 Ave. 1 2 3 4 Ave. 1 2 3 4 Ave. July 10July 17July 24July 31- % Quarter diameter bolls with internal injury1 Aug 7 Aug 14 Aug 22 48 56 52 16 48 84 20 20 76 24 88 44 27 53 64 24 20 32 52 32 12 16 24 32 21 0% 8% 12% 30% 12 0 16 32 15 24 36 40 20 30 3rd week of bloom 4th week of bloom 5th week of bloom 6th week of bloom 20 16 8 64 27 40 16 32 36 31 Automatic University Pretreatment Damage: (% Quarter diameter bolls with internal damage) 1 Sample size: 25 bolls per plot. FERTILITY EVALUATION OF SURFACE APPLICATION OF NITROGEN FERTILIZER SOURCES IN A CONSERVATION TILLAGE COTTON SYSTEM C. H. Burmester Surface application of nitrogen (N) fertilizer sources was evaluated for two seasons on cotton grown in a conservation tillage system. The tests were conducted at the Tennessee Valley Research and Extension Center in Belle Mina, Alabama. Cotton was planted in late April each season into a heavy rye residue that was terminated approximately three weeks prior to cotton planting. The test area received 20 and 30 pounds per acre of preplant N fertilizer in 2006 and 2007, respectively. At early squaring, all N fertilizer sources were surface applied. In 2006, 60 and 90 pounds per acre of N fertilizer were applied, while in 2007 N fertilizer rates were reduced to 50 and 80 pounds per acre because of an increase in preplant N fertilizer. In 2006 only granular fertilizer products were tested. Fertilizer products tested included (1) ammonium nitrate, (2) urea, (3) urea + Agrotain (1gallon per ton), (4) urea + 4.5 percent calcium thiosulfate (Cats), and (5) urea + 7.0 percent calcium thiosulfate. In 2007, the 7.0 percent calcium thiosulfate product was not tested, but four liquid fertilizer products were added. The four liquid fertilizer products included (1) 32 percent UAN, (2) 32 percent UAN + calcium chloride (50 percent), (3) 32 percent UAN +agrotain, (1 gallon per ton), and (4) Georgia Pacific 300-0 (GP). All fertilizer products were applied at early squaring. The granular products were hand applied along each side of the cotton row. The liquid fertilizer products were applied with a CO2 pressurized sprayer that dribble applied the fertilizer rate along one side of each cotton row. The residue from the rye cover crop provided thick residue each season. No rainfall occurred for 7 days following fertilizer application in 2006. In 2007, 0.11 inches of rain was recorded 3 days after fertilizer application, and irrigation (0.5 inches) was applied 7 days after application. Cotton leaf samples were collected after 3 weeks of blooming. Very hot dry weather dominated both growing seasons in Alabama, but 2007 was especially severe. However, with 6.5 and 9.5 inches of irrigation applied to the test area in 2006 and 2007, respectively, cotton yields were excellent. Cotton yields averaged close to 2.5 bales in 2006 and close to three bales in 2007 (Tables 1 and 2). Responses to increasing N fertilizer rates were generally greater in 2006 than in 2007. In 2006 all granular fertilizers tested significantly increased cotton yields and leaf-N content as N rates were increased from 60 to 90 pounds per acre. In 2006 urea alone produce significantly lower yields than all other fertilizers tested at 90 pounds per acre and also significantly lower yields than ammonium nitrate when applied at 60 pounds per acre (Table 2). In 2006 the urea + Agrotain, and urea + calcium thiosulfate products produced yields similar to yields produced by ammonium nitrate at both N rates (Table 1). In 2007 all fertilizers products tested produced numerically higher yields when N rates were increased from 50 to 80 pounds per acre. However, these increases were only significantly different for ammonium nitrate, UAN + calcium chloride, and the 30-0-0 product from Georgia Pacific (Table 2). Leaf-N values were also numerically higher as N rates were increased from 60 to 90 pounds per acre for all fertilizers tested in 2007. The only significant increase in leaf N with increasing N rates, however, was found with the urea + calcium thiosulfate, and urea + agrotain fertilizers (Table 2). Cotton quality samples were ginned and analyzed for lint percent, micronaire, staple length, and uniformity. In both seasons no significant differences could be found between these cotton quality measurements and the different N fertilizer sources or rates applied. Apparently N fertilizer loss through volatilization was a greater problem in 2006 than 2007. Wetter soil conditions at application in 2006 may be the primary reason for this difference, TABLE 1. SEED COTTON YIELDS AND LEAF-NITROGEN, 2006 Treatments Source Rate (lb/A) 60 Amm Nitrate 60 Urea 60 Urea + Cats 4.5% 60 Urea + Cats 7.0% 60 Urea + Agrotain 90 Amm Nitrate 90 Urea 90 Urea Cats 4.5% 90 Urea Cats 7.0% 90 Urea + Agrotain LSD (P≤0.05) Seed cotton yield lb/A 3550 b 3078 c 3258 bc 3183 bc 3308 bc 3748 a 3347 b 3622 a 3637 a 3622 a 269 Leaf-N % 3.67 cd 3.41 e 3.43 e 3.41 e 3.48 de 3.98 ab 3.85 abc 3.93 ab 3.81 bc 4.04 a 0.23 TABLE 2. SEED COTTON YIELDS AND LEAF-NITROGEN, 2007 Treatments Source Rate (lb/A) 50 Amm Nitrate 50 Urea 50 Urea Cats 4.5% 50 Urea + Agrotain 50 UAN 32% 50 UAN + CaCl2 50 UAN + Agrotain 50 GP 30-0-0 80 Amm Nitrate 80 Urea 80 Urea Cats 4.5% 80 Urea + Agrotain 80 UAN 32% 80 UAN + CaCl2 80 UAN + Agrotain 80 GP-30-0-0 LSD (P≤.0.05) Seed cotton yield lb/A 3528 c 3479 c 3520 c 3518 c 3625 bc 3540 c 3730 bc 3589 bc 3832 abc 3627 bc 3659 bc 3793 abc 3717 bc 3942 ab 3867 abc 4079 a 232 Leaf-N % 3.64 abc 3.63 abc 3.47 c 3.53 bc 3.65 abc 3.66 abc 3.69 abc 3.59 abc 3.94 a 3.80 abc 3.90 ab 3.97 a 3.79 abc 3.83 abc 3.75 abc 3.81 abc 0.23 2007 COTTON RESEARCH REPORT 21 combined with the extremely dry weather in 2007. These data support the possibility of N loss through volatilization. In both years granular urea alone produced the lowest numerical yield with both N fertilizer rates. These data also support previous research on the use of Agrotain to reduce N loss on surface-applied urea. Several of the other combination urea fertilizer products also showed promise when applied in a high-residue conservation-tillage system. Further research and product pricing will determine if they are viable fertilizers for the future. Total N fertilizer rates tested in this study (80 and 110 pounds ) support previous work indicating an N recommendation of 100 to 120 pounds per acre is sufficient on irrigated cotton on these soil types. NITROGEN AND PLANT GROWTH REGULATOR RATES ON COTTON YIELD AND FIBER QUALITY K. S. Balkcom and C. D. Monks were collected at each location approximately 3 weeks before anticipated cotton planting dates. Biomass production averaged 3765 pounds per acre at WREC and 6400 pounds per acre at EVSRC. This difference in biomass production can be attributed to the different cover crop species and different termination dates. Immediately prior to cotton planting, all plots were in-row subsoiled with a KMC Ripper Stripper® equipped with rubber pneumatic tires to minimize surface disruption. The cotton variety DP 555® BG/RR was planted on May 21, 2007 at WREC and May 8, 2007 at EVSRC. Rates of PGR application (Mepex Ginout®) were selected based on the label directions and the growing conditions. Table 1 summarizes the total amounts of PGR applied, which ranged from 0 to 22 ounces per acre across the six PGR strategies examined at the WREC. The initial low rate, frequent application consisted of 4 to 6 ounces per acre per application, while the high rate, infrequent application consisted of 12 ounces per acre per application. The late season application consisted of a single 8 ounces per acre application. Table 1 also summarizes the total amounts of PGR applied, which ranged from 0 to 32 ounces per acre across the six PGR strategies examined at EVSRC. The initial low rate, frequent application consisted of 4 to 8 ounces per acre per application, while the high rate, infrequent application consisted of 12 ounces per acre per application. The late season application consisted of a single application of 8 ounces per acre. Immediately prior to defoliation, plant heights, whole plant biomass, and final node counts were collected from each plot. Plant heights were the average TABLE 1. PLANT GROWTH REGULATOR (PGR) AMOUNTS AND APPLICATION TIMES ACROSS of 10 randomly selected plants within each plot. The nodes on SIX PGR STRATEGIES DURING THE 2007 GROWING SEASON each of the 10 randomly seApplication time ——Low rate—— ——High rate—— —Late season application— None many applications few applications None Low rate High rate lected plants were counted at ————————————————oz/A———————————————— the time of plant height meaWiregrass Resarch and Extension Center, Headland, Alabama surement collection to estimate 52 DAP1 4 4 final node production. Whole 64 DAP 4 12 4 12 plant biomass consisted of 71 DAP 6 6 85 DAP 8 8 8 clipping the aboveground porTotal 0 14 12 8 22 20 tion of all the plants within a E.V. Smith Research Center,Shorter, Alabama 3.28 feet section of a non-har63 DAP† 4 4 vest row from each plot. The 71 DAP 8 12 8 12 plant material collected was 78 DAP 8 8 85 DAP 4 4 dried at 55 degrees Celsius for 92 DAP 8 8 8 72 hours and weighed to estiTotal 0 24 12 8 32 20 mate the plant biomass of each 1 Days after planting. plot. The experimental area at The project objective was to determine the effect of plant growth regulator (PGR) strategies, with and without a high application PGR rate prior to harvest, on cotton yield and fiber quality across two N rates for a cotton conservation-tillage system. Nitrogen rates and PGR strategies were implemented at the Wiregrass Research and Extension Center (WREC) in Headland, Alabama, and the Field Crops Unit of the E.V. Smith Research Center (EVSRC) near Shorter, Alabama. Treatments arranged in a split-plot design with four replications were as follows: Nitrogen rates 1. 90 pounds per acre 2. 120 pounds per acre Plant Growth Regulator Strategies 1. No PGR 2. Low rate, multiple PGR applications according to label directions 3. High rate, infrequent PGR applications according to label directions 4. No PGR plus a late season PGR application 5. Low rate, multiple PGR applications plus a late season PGR application 6. High rate, infrequent PGR applications plus a late season PGR application A rye cover crop was drilled across both experimental areas in early November 2005 at the WREC and the EVSRC. Both were seeded at 90 pounds per acre. In early spring, 30 pound per acre, as NH4NO3, were applied to the cover crop at both locations to enhance biomass production. Biomass samples 22 ALABAMA AGRICULTURAL EXPERIMENT STATION WREC was defoliated with 1.5 pints per acre Finish® and 5 TABLE 2. LEAST SIGNIFICANT DIFFERENCE FOR PLANT ounces per acre Ginstar® on September 28, 2007 and harvested HEIGHTS, BIOMASS AT DEFOLIATION, AND FINAL NODE with a spindle picker equipped with a bagging attachment. The COUNT ACROSS NITROGEN RATES AND PLANT GROWTH seed cotton was collected from the two center rows of each 40REGULATOR STRATEGIES AT THE E.V. SMITH RESEARCH foot plot and weighed on October 1, 2007 at EVSRC and Oct. CENTER NEAR SHORTER, AL, AND THE WIREGRASS 12, 2007 at WREC. A subsample of seed cotton from each plot RESEARCH AND EXTENSION CENTER IN HEADLAND, AL, was ginned in a 20-saw tabletop micro-gin to determine ginning DURING THE 2007 GROWING SEASON Plant height Biomass Final nodes percentage. Lint yields were determined by weighing lint and seed collected from each plot and multiplying corresponding E.V. Smith Research Center 1 Nitrogen NS 136 NS seed cotton by the ginning percentage of each plot. Plant growth strategy 1.6 NS 1.1 Nitrogen rates had no effect on the observed plant heights, Nitrogen*PGR NS NS NS whole plant biomass, or final node counts at defoliation for either Wiregrass Research and Extension Center NS NS NS location with the exception of whole plant biomass measured at Nitrogen 4.5 NS 0.8 EVSRC (Table 2). The additional N resulted in higher whole Plant growth strategy Nitrogen*PGR NS NS NS plant biomass for that location (Table 3). The PGR strategy did 1Not significant at 0.05 level of probability. affect plant heights and final node counts for both locations (Table 2). At both locations, the tallest plants were observed TABLE 3. PLANT HEIGHTS, BIOMASS AT DEFOLIATION, AND FINAL NODE COUNT ACROSS where no PGR was applied NITROGEN RATES AND PLANT GROWTH REGULATOR STRATEGIES AT THE E.V. SMITH or the late season application RESEARCH CENTER NEAR SHORTER, AL, AND THE WIREGRASS RESEARCH AND EXTENSION was applied alone (Table 3). CENTER IN HEADLAND, AL, DURING THE 2007 GROWING SEASON The high PGR rate applied ——Plant growth regulator strategies—— infrequently resulted in taller Nitrogen rate, plants compared to the low ——lb/A—— Late season application 90 120 None Low High None Low High rate applied more frequently, E.V. Smith Research Center but the difference was only Plant height, inches 42.6 44.0 47.0 40.7 43.3 45.6 40.3 43.0 significant at EVS (Table 3). Biomass at defoliation, lb/A 1002 1146 1017 1004 1067 1072 1249 1035 The late season application of Final nodes, no. 19.6 20.1 20.5 19.4 20.0 20.2 19.3 19.5 PGR used in conjunction with Wiregrass Research and Extension Center 44.0 45.2 51.0 41.1 42.0 47.9 43.2 42.3 the low- and high-application Plant height, inches Biomass at defoliation, lb/A 1253 1376 1390 1231 1122 1403 1276 1467 strategies produced no eviFinal nodes, no. 21.3 21.7 22.8 21.0 21.2 22.0 21.0 21.0 dence to indicate that the late season application controlled plant heights better (Table 3). TABLE 4. LINT YIELDS MEASURED ACROSS NITROGEN The final node count was analogous to plant height with more RATES AND PLANT GROWTH REGULATOR STRATEGIES AT nodes present on the taller plants, which resulted when no PGR THE E.V. SMITH RESEARCH CENTER NEAR SHORTER, AL, or the late season application was applied alone (Table 3). AND THE WIREGRASS RESEARCH AND EXTENSION CENTER Neither nitrogen nor PGR strategy had any effect on obIN HEADLAND, AL, DURING THE 2007 GROWING SEASON served lint yields at either location (Table 4). However, there ———Lint yield——— was a strong trend (P>F = 0.0597) that indicated PGR strategy Treatment EVSRC WREC influenced lint yields to some extent at EVSRC. At this location, ———lb/A——— PGR applied at low frequent rates tended to produce the highest Nitrogen 90 lb/A 1357 1501 lint yields (Table 4). In contrast, lint yields measured at WREC 120 lb/A 1453 1581 with no PGR applied were equivalent to lint yields observed folPlant growth regulator strategy lowing low- and high-application rates and with or without a None 1381 1504 late season application. The experiments at both locations were Low rate 1479 1507 irrigated to maximize yield potential, but despite the irrigation, High rate 1370 1586 Late application 1332 1592 extremely dry conditions were experienced during the growing Low rate + late application 1431 1569 season. Although some differences were observed among selectHigh rate + late application 1438 1488 ed plant measurements, the final yields indicate that PGRs were ———P > F——— not beneficial, regardless of application strategy. Nitrogen 0.2717 0.3556 Extremely dry conditions made the evaluation of PGRs dif- Plant growth regulator strategy 0.0597 0.7785 0.8285 0.3447 ficult. Although each location could be irrigated, the dry weather Nitrogen x PGR strategy controlled excess growth much better than PGRs could. As a result, the benefit of PGR applications was minimally observed at only one location during the 2007 location. If costs of the product and the expense of application were factored into the analysis, the advantage of PGR applications would be certainly diminished. 2007 COTTON RESEARCH REPORT 23 NITROGEN FERTILIZER SOURCE, RATES, AND TIMING FOR A COVER CROP AND SUBSEQUENT COTTON CROP K. S. Balkcom, F. J. Arriaga, C. C. Mitchell, D. P. Delaney, and J. Bergtold The project objective was to (1) compare N fertilizer sources, rates, and time of application for a rye winter cover crop to determine optimal biomass production for conservation tillage cotton production; (2) compare recommended and no additional N fertilizer rates across different biomass levels for cotton; and (3) determine the effect of residual N applied to the cover crop across two N fertilizer rates for cotton. Nitrogen sources, rates, and time of application were implemented at the Wiregrass Research and Extension Center (WREC) in Headland, Alabama. Biomass cover treatments were arranged in a split-split-plot design with four replications. At cotton planting, the eight row plots were split with one side receiving 90 pounds of N per acre at sidedress and the other side receiving no additional N. Time of application 1. Fall 2. Spring Nitrogen Source 1. Commercial fertilizer 2. Poultry litter Nitrogen rates Commercial fertilizer 1. 0 lb/A 2. 30 lb/A 3. 60 lb/A 4. 90 lb/A Poultry litter 1. 0 ton/A 2. 1 ton/A 3. 2 tons/A 4. 3 tons/A A rye cover crop was drilled across the experimental area on November 9, 2006 at the WREC. Rye was seeded at 90 pounds per acre. Plots consisted of eight 36-inch rows, 24 feet wide and 40 feet long. Fall poultry litter treatments were applied on the same day the cover crop was planted. Commercial fertilizer was applied on December 4, 2006 after stand establishment. The spring applications of commercial fertilizer and poultry litter were applied on February 7, 2007. Poultry litter application rates were designed to approximate commercial fertilizer rates based on total and estimated available N supplied in the litter (Table 1). Biomass samples were collected on April 16, 2007 by collecting all aboveground plant biomass from two 2.7 square foot areas within each plot. Immediately prior to cotton planting, all plots, were in-row subsoiled TABLE 1. TOTAL AND AVAILABLE N APPLIED IN THE FALL AND SPRING FROM POULTRY LITTER ON A DRY WEIGHT BASIS AT THE WIREGRASS RESEARCH AND EXTENSION CENTER with a KMC Ripper Stripper® equipped with rubber pneumatic IN HEADLAND, AL, DURING THE 2006-2007 GROWING SEASON ————Rate (tons /A)———— ————Rate (tons /A)———— tires to minimize surface disrupTime of 0 1 2 3 0 1 2 3 tion. The cotton variety DP 555® application Total N Available N1 BG/RR was planted on May 2, ----------------------------------------------lb /A---------------------------------------------2007. The eight row plots were Fall 0 53 106 159 0 27 53 80 split and corresponding cotton Spring 0 69 138 207 0 35 69 104 1 Available N based on an estimate of 50 percent total N available during the first year of applica- plots were sidedressed on June tion. 20, 2007 with 90 pounds of N per acre, while other plots were not fertilized, in order to estimate any residual effects from the 8000 poultry litter. Fall application 7000 Nitrogen uptake at mid-bloom was determined by collectSpring application ing whole plant biomass from the aboveground portion of all 6000 plants within a 3.28 foot section of a non-harvest row from each plot. The plant material collected was dried at 55 degrees Cel5000 sius for 72 hours and weighed to estimate plant biomass of each 4000 plot. A subsample from each plot was analyzed for total N by dry combustion on a LECO CHN-600 analyzer. Corresponding 3000 N contents and biomass were used to calculate N uptake at mid2000 bloom. The plot area was defoliated with 1.5 pints per acre of Fin1000 ish® and Ginstar® at 5 ounces per acre on September 26, 2007. 0 All plots were harvested with a spindle picker equipped with a -1 -1 -1 60 lb ac 90 lb ac 30 lb ac bagging attachment on October 3, 2007. A subsample of seed No N -1 -1 -1 cotton from each plot was ginned in a 20-saw tabletop micro-gin 2 Ton ac 3 Ton ac 1 Ton ac Nitrogen Rate to determine ginning percentage. Lint yields were determined by weighing lint and seed collected from each plot and multiplyFigure 1. Rye biomass production measured between N rates, ing corresponding seed cotton by the ginning percentage of each regardless of source and time of application during the 2006plot. 2007 winter growing season at the Wiregrass Research and Extension Center in Headland, AL. -1 Rye biomass, lb ac 24 ALABAMA AGRICULTURAL EXPERIMENT STATION Biomass levels measured TABLE 2. COTTON LINT YIELDS AND N UPTAKE MEASURED AT MID-BLOOM ACROSS in 2007 produced a timing COVER CROP FERTILIZER TIMING, COVER CROP N RATES AND SIDEDRESS COTTON N x rate interaction (Pr > F = RATES DURING THE 2007 COTTON GROWING SEASONS AT THE WIREGRASS RESEARCH 0.0440), which indicates that AND EXTENSION CENTER IN HEADLAND, AL —————2007————— biomass levels increased with Treatment Lint yields N uptake fall application of N (Figure ————lb /A———— 1). Timing of N fertilizer had Timing cover crop fertilizer no effect on measured biomass Fall 1192 47.1 levels during the previous Spring 1233 48.9 Cover crop N rate year of this study, but biomass Poultry litter (tons /A) Commercial fertilizer (lb /A) levels following fall-applied 0 0 1011 46.2 N averaged over sources and 1 0 1267 48.7 rates for both crop years in2 0 1288 54.9 dicated 25 percent higher 3 0 1393 57.4 0 30 1136 41.7 biomass levels compared to 0 60 1182 45.7 spring applied N. This would 0 90 1211 41.5 indicate that if growers choose Sidedress Cotton N rate (lb /A) to maximize biomass produc0 912 36.0 tion by utilizing some form 90 1513 60.0 of N fertilizer, that fertilizer would be more beneficial to 1800 the cover crop if applied in the fall. Fall cover crop N timing a 1600 In 2007, time of appliSpring cover crop N timing a cation and cover crop N rate 1400 influenced cover crop biomass levels (Table 2). Significant 1200 interactions between time of b application and sidedress N 1000 rates, as well as cover crop c N rates and sidedress N rates 800 were observed in 2007 and are illustrated in Figures 2 600 and 3. As expected, regardless of cover crop N timing, 400 lint yields were increased with 90 pounds of N per acre com200 pared to 0 pounds of N per acre; however, when N was 0 applied to the cover crop in the 0 90 spring, superior yields were -1 produced compared to fall apCotton Sidedress N rate, lb ac plied N at the 0 pounds per N Figure 2. Cotton lint yields measured following fall and spring applied N to the cover crop and per acre sidedress rate (Figtwo cotton sidedress N rates (0 and 90 lb N /A) during the 2007 growing season at the Wireure 2). Nitrogen applied in the grass Research and Extension Center in Headland, AL. spring to the cover crop would be less susceptible to loss, prior to cotton uptake, which could ex- ence between sources was not as great, but lint yields following plain this difference. Depending on how quickly the poultry litter poultry litter were higher (Figure 3). These data indicate there is mineralized, spring applications could also synchronize better is no advantage to cover crop N rates greater than 30 pounds of with cotton uptake. N per acre as commercial fertilizer or 1 ton per acre as poultry Figure 3 illustrates the interaction between cover crop litter when 90 pounds of N per acre is supplied at sidedress to N rate and sidedress N rate observed during the 2007 growing the cotton. However, due to the organic fraction of poultry litter, season. By examining only N applied to the cover crop (0 pounds utilizing higher poultry litter rates to the cover crop with lower of N per acre sidedress), the residual effects of the poultry lit- sidedress N rates could provide some cost savings to growers ter are apparent. Regardless of N source, lint yields increased without sacrificing yields. as cover crop N rate increased, but poultry litter improved lint In 2007, only cover crop N rate and sidedress cotton N rate yields compared to commercial fertilizer (Figure 3). At the rec- influenced uptakes at mid-bloom (Table 3). Measured uptakes at ommended 90 pounds of N per acre sidedress rate, the differ- mid-bloom were lowest from plots receiving 90 pounds of N per -1 Lint yield, lb ac 2007 COTTON RESEARCH REPORT 2000 Poultry Litter Commercial Fertilizer 25 1750 1500 -1 Lint yield, lb ac 90 lb N ac-1 sidedress 1250 1000 0 lb N ac-1 sidedress 750 500 No N -1 30 lb ac -1 1 Ton ac 60 lb ac -1 -1 90 lb ac -1 -1 2 Ton ac 3 Ton ac Cover crop N rate Figure 3. Cotton lint yields measured across two sources of N (commercial fertilizer and poultry litter) applied to the cover crop and two cotton sidedress N rates (0 and 90 lb N /A) during the 2007 growing season at the Wiregrass Research and Extension Center in Headland, AL. acre to the cover crop, while the highest observed uptakes were measured from plots receiving 3 tons per acre of poultry litter (Table 2). Generally, higher measured uptakes were observed from plots receiving poultry litter compared to plots receiving commercial fertilizer (Table 2). As in 2006, measured uptakes at mid-bloom in 2007 were greater following plots that received the recommended 90 pounds of N per acre at sidedress compared to no additional N at sidedress (Table 2). Poultry litter can be considered a slow release fertilizer and preliminary results indicate that when applied in the fall it benefits the cover crop and the cotton crop. Cover crop biomass is maximized and cotton N rates could be at least partially reduced by using poultry litter. Future work in this area should focus on comparing poultry litter supplied to the cover crop combined with lower cotton N side-dress rates to the current cotton conservation-tillage systems that utilize approximately 30 pounds of N per acre to the cover crop and maintain recommended side-dress N rates. These scenarios could maximize biomass, maintain yields, and decrease costly commercial N use. GPS/GIS USE OF REMOTE SENSED THERMAL IMAGERY FOR IN-SEASON STRESS DETECTION AND SITE-SPECIFIC MANAGEMENT OF COTTON J. P. Fulton, J. N. Shaw, D. Sullivan, M. P. Dougherty, and C. Brodbeck This project was conducted on a 12-acre field at the Tennessee Valley Research and Extension Center (TVREC), Belle Mina, Alabama. Treatments included two irrigations treatments (Irr – irrigated; No Irr – non-irrigated) and two cover crop treatments (C – Cover; NC – No-Cover). Subsurface drip irrigation (SDI) was buried on 80-inch spacing at a depth of 13 inches. Plots receiving a cover crop treatment were planted with winter wheat (Triticum aestivum L.) on October 28, 2006. Cotton was planted on April 18, 2007 using a 40-inch row spacing. Irrigation was initiated on May 26. Irrigation was scheduled based on pan evaporation and adjusted for canopy closure, triggering an irrigation event at 60 percent pan evaporation. Airborne thermal infrared (TIR) imagery was acquired inseason using an unmanned aerial system equipped with a TIR sensor on July 18 at 10:13 AM central standard time, under clear conditions. Cotton was between first and peak flower with percent canopy ranging from 15 to 72 percent. TIR data were collected using an unmanned aerial vehicle equipped with a TIR sensor (Figure 1a). Ground truth data (soil water content, stomatal conductance, and digital photographs; Figure 1b) across the field were also collected. Comparisons were made to determine the relationship between TIR emittance, stomatal conductance, soil water content or plant available water, crop residue management, and canopy closure. Since integrated effects of surface characteristics (canopy closure, percent actively transpiring vegetation, crop residue cover, and bare soil) impact observed emittance, variability in surface characteristics at the time of TIR acquisition were evaluated. Results indicated differences in soil water content between treatments. No significant interaction between treatments was observed. The impact of irrigation on canopy closure was most significant having 40 percent canopy closure on irrigated treatments and 26 percent canopy closure on non-irrigated treatments. Differences in canopy closure between covered and no-covered treatments were less significant; however, greater canopy closure was observed on cover crop treatments compared to no-cover treatments. The relationships between observed TIR emittance and ground truth parameters were evaluated using Pearson linear correlation coefficients. Emittance spectra were negatively correlated with stomatal conductance (r = -0.48, alpha = 0.05), providing evidence that observed emittance was related to variability in canopy response to irrigation and cover treatments. Additionally, a negative linear relationship was observed between TIR emittance and canopy closure (r = -0.44, alpha = 0.05), indicating cooler surface conditions as canopy closure increased. As transpiration rates increased, TIR emittance decreased. Although soil water content was correlated with stomatal conductance (r = 0.58, alpha = 0.05), no significant correlation was observed between TIR emittance and soil water content at the time of data acquisition. SDI uniformity issues, including crimped distribution lines, were detected in some plots using TIR imagery (Figure 2). The crimped lines are quite evident, spanning the length of the image as a very bright feature within two irrigated treatments. At the time of data collection, these differences were not noticeable at ground level. Comparing the areas along either side of the crimped lines with adjacent rows of well-watered cotton, emittance was more than two times greater along the crimped lines, as would be expected. Water distribution problems are evident in Figure 2 as an area of very bright surface features (canopy stress), bounded on either side by dark surface features (actively transpiring canopy). Yield monitor data indicated yield losses up to 35 percent due to the crimped SDI tape. Based on observed results, SDI performance problems can be rapidly and easily identified using the UAV and TIR imagery, thereby allowing correction in a timely fashion during the growing season to minimize yield loss. (A) (B) Figure 1. (A) UAV equipped with TIR sensor and (B) ground truth data collection on July 18 of leaf temperature and stomatal conductance. Crim ped SDI Lines Poor Water Distribution Figure 2. Thermal infrared image showing crimped SDI tape and an area of poor water distribution on July 18, 2007. Lighter or white rows heading N-S indicate stressed cotton plants (nonirrigated) while darker rows illustrate irrigated cotton which was less stressed during the time of data collection. 2007 COTTON RESEARCH REPORT 27 In conclusion, TIR shows promise for in-season evaluation of crop stress and SDI performance. Further, thermal imagery could be used for site-specific management of cotton and provide a management tool for SDI. This study is being continued at the same location in 2008 and 2009 to further evaluate the use of TIR imagery to monitor agronomic factors and real-time data collection methods for cotton production. EVALUATION OF VARIABLE-RATE SEEDING FOR COTTON The objective of this project was to evaluate opportunities for increased yield or profits through variable-rate (VR) seeding for cotton production. The cooperative farmer identified in 2005 allowed the on-farm study in Northern Alabama to continue during the 2006 and 2007 growing seasons. This farmer utilizes a cotton and corn rotation while also managing center pivot irrigation on a select portion of farmland permitting the comparison of irrigated and dryland cotton production. Selected seeding rates, based on the farmer’s traditional seeding rates and recommendations from consultants for both dryland and irrigated fields, included 35K, 50K, 65K, and 80K seeds/ac. A 24-row planter equipped with a VR drive system was used in this study. A study site within each field was blocked to provide four replications of the cotton treatments. Treatments were then randomly assigned within each block with a single pass of the planter representing a specific population treatment within the block. After planting, stand counts were measured to determine the actual germinated population. Stand count measurements were gathered on each of the 12-row sections of the planter; counts were collected at three or more places along the 12 rows depending upon terrain variability. A cotton picker equipped with an AgLeader yield monitor was used to obtain spatial performance data for each plot. Analyses included summarizing stand counts along with spatially segregating yields based on the various seeding treatments to determine the effect of seeding rate on cotton yields. Yield and stand count data were statistically analyzed, using T-tests and Least Significant Difference (α = 0.1) to determine if differences existed between seeding treatments. Results showed that stand counts were all significantly lower, in both irrigated and non-irrigated fields, than the targeted J. P. Fulton, S. H. Norwood, J. N. Shaw, C. H. Burmester, C. Brodbeck, R. W. Goodman, P. L. Mask, M. H. Hall, and C. Dillard seeding rate with the exception of one (35,000 seeds per acre treatment within the non-irrigated plot). The seed populations being consistently lower than the target application rate may be tied to calibration and planter setup along with poor emergence. However, the reason for the lower than expected actual populations is unknown. Statistically comparing the actual populations indicated significant differences between the four average populations for field 1 (non-irrigated); however, differences were reported in field 2 (irrigated) (see table). In field 2, the actual population of the 35K treatment was significantly different that the actual population of the 50K and 65K treatments. These results for each field were expected considering the differences between the seeding rate treatments. In the non-irrigated field, there was not a significant difference in lint yield between the four seeding rates (see table). These results reflect the same outcomes as in 2005 and 2006 for the non-irrigated field. For the irrigated plots, a correlation existed between yield and actual population indicating the importance of seedling emergence on final yield (see table). As expected, irrigated cotton yields were significantly higher than dryland cotton yields. They were around 49 percent higher for the various treatments. The value of the average yield response for irrigated cotton was slightly greater than the increased cost, returning on average $0.50 for every dollar spent on additional 1,000 seeds, while yield response on dryland cotton was poor, returning on average, a profit loss ($-1.25 per 1000 seeds). The change in seeding rate response from one year to the next has been statistically significant; however, extrapolation outside the range of the experiment is not recommended. Profit increase and decrease were determined using the following cost breakdown: Treatment seeds/A 35,000 50,000 65,000 80,000 1 2 ———————————2007——————————— ———————————2006——————————— ——Non-Irrigated—— ——Irrigated—— ——Non-Irrigated—— ——Irrigated—— Actual Yield Actual Yield Actual Yield Actual Yield plants/A1 lbs lint/A3 plants/A1 lbs lint/A3 plants/A2 lbs lint/A3 plants/A2 lbs lint/A3 38,714 a 662 a 27,080 a 984 a 33,251 d 660 c 26,455 d 1383 ab 32,815 a 657 a 31,508 b 1098 ab 40,874 c 621 c 37,679 c 1093 b 39,986 a 761 a 42,979 b 1145 b 54,813 b 624 c 47,335 b 1171 b 56,701 b 765 a 52,490 b 1140 b 62,944 a 645 c 52,199 a 1592 a IRRIGATED AND NON-IRRIGATED DATA FOR THE 2006 AND 2007 GROWING SEASONS Means with similar letters in this column for 2007 indicates they are not statistically different at the 90 percent confidence level. Means with similar letters in this column for field 2 indicates they are not statistically different at the 90 percent confidence level. 3 Mean lint yields with similar letters in each column for fields 1 and 2 indicates they are not statistically different at the 90 percent confidence level. 28 ALABAMA AGRICULTURAL EXPERIMENT STATION • Irrigated Cotton: Cost of seed: $2 per 1000; Yield response: 5 pounds of lint per 1000; Profit increase ($.50 cotton): $2.50-$2 = $.50 per 1000 • Dryland Cotton: Cost of seed: $2 per 1000; Yield response: 1.5 pounds of lint per 1000; Profit increase ($.50 cotton): $0.75-$2 = -$1.25 per 1000 In summary, similarities were reported for the 2005, 2006 and 2007 growing seasons. On the non-irrigated treatments the actual plant populations were all significantly less than the target population during the three growing seasons except for the lowest seeding rate (35K) in the 2006 and 2007 growing season. While some significant differences between actual populations did exist in the non-irrigated treatments (80K in 2006), no significant differences in lint yields were reported for the 2005, 2006, and 2007 growing seasons. For the irrigated treatments, a linear correlation existed between lint yields and actual populations and lint yields differing from the non-irrigated results. Finally, lint yields were at least 49 percent higher on irrigated treatments compared to non-irrigated treatments. Due to the atypical growing conditions in 2007, it has been decided to repeat this study in 2008 in an effort to draw more conclusive results, particularly within irrigated treatments. CROP ROTATION AND VARIETY SELECTION CROP ROTATION FOR THE CONTROL OF RENIFORM NEMATODES W. S. Gazaway, K. S. Lawrence, J. R. Akridge, and C. D. Monks 449BG/RR) was treated with Cruiser® for early season insect control. Corn (Pioneer 33M53RR), peanut (AP3), and soybean (DP5634RR) were planted in the non-host plots on the same day as cotton. Nematode samples were collected at planting and at harvest. Twenty soil cores, 1 inch in diameter and 6 inches deep, were collected using a zig-zag sampling pattern. Nematodes were extracted from the soil by combined gravity screening and sucrose centrifugal flotation and enumerated with a stereo-microscope. Cotton yields were harvested with a mechanical plot cotton picker from the two center rows of each four-row cotton plot. For statistical purposes, ANOVA was performed on all data on each trial and treatment effects considered significant where P ≤ 0.10. Within each trial, treatment effects were examined utilizing LSD and data were combined where no interactions occurred. Where there was an absence of treatment interactions on nematode population or seed cotton yield, the main effects were compared. In 2006, Telone, at a rate of 3 gallons per acre, improved cotton yields in all rotations except where cotton followed corn (Table 2). It increased yields the most (368 pounds per acre when applied to cotton following cotton (Table 2). When applied to cotton following soybean or peanut, Telone produced an increase in yield of 195 pounds per acre and 170 pounds per acre, respectively. Following a 1-year rotation with corn, Telone-treated cotton yielded only slightly greater numerically (64 pounds per acre) than the untreated cotton following corn. Cotton treated with Telone following peanut in 2005 produced the highest cotton yield in 2006 (Table 2). In 2007, Telone failed to improve cotton yields significantly (Table 3). Looking at the impact of non-host crops alone, a 1-year TABLE 1. ROTATION SCHEME FOR CROP ROTATION STUDY peanut or corn rotation proRotation Telone1 2005 2006 2007 2008 2009 duced significantly larger cotton Corn 1 year +/cotton corn cotton corn cotton yields than a 1-year soybean roPeanut 1 year +/cotton peanut cotton peanut cotton Soybean 1 year +/cotton soybean cotton soybean cotton tation with cotton or continuous Corn 2 year +/corn corn cotton corn corn cotton in 2006 (Table 2). The Peanut 2 year +/peanut peanut cotton peanut peanut Soybean 2 year +/soybean soybean cotton soybean soybean first year that yields from the 1year and 2-year rotation could Cont. cotton +/cotton cotton cotton cotton cotton be compared directly was 2007. Corn 1 year +/corn cotton corn cotton corn Peanut 1 year +/peanut cotton peanut cotton peanut Both the 1- and 2-year rotations Soybean 1 year +/soybean cotton soybean cotton soybean improved cotton yields signifiCorn 2 year +/cotton corn corn cotton corn cantly over continuous cotton. Peanut 2 year +/cotton peanut peanut cotton peanut Soybean 2 year +/cotton soybean soybean cotton soybean The 2-year rotation was numerically but not significantly Corn 2 year +/cotton cotton corn corn cotton Peanut 2 year +/cotton cotton peanut peanut cotton superior to the 1-year rotation Soybean 2 year +/cotton cotton soybean soybean cotton (Table 3). The yield increase 1 Telone, a nematicide, was applied to designated cotton plots. was reflected in smaller 2006 The reniform nematode (Rotylenchulus reniformis) replaced the root-knot nematode (Meloidogyne incognita) as the major nematode cotton pest in Alabama. Cotton farmers have been able to manage moderate to heavy reniform populations with nematicides, but have been unsuccessful managing extremely high reniform populations. Only rotation with nonsusceptible summer crops has been successful in these extreme cases. To address the growing economic damage of the reniform nematode in fields with extremely high reniform nematode populations, a series of rotation studies were conducted. These included non-host crop rotations with and without nematicides applied to cotton following a non-host crop. The test was designed to compare cotton yield and reniform nematode populations following 1 or 2-year rotations with non-host crops the same year beginning in 2007 and continuing indefinitely (Table 1). The soil was a Ruston Very Fine Sandy Loam (49 to 56 percent sand, 15 to 34 percent silt, 12 to 17 percent clay, 2.2 to 1.9 percent organic matter, and pH 6.0 to 6.2) that has been cropped continuously with cotton for several years. The field trial was a split-plot design with nematicides as the primary factor and summer non-host crops as the secondary factor with four replications. All non-host crop plots and continuous cotton plots were eight rows wide and 40 feet long. Cotton plots were split into two four-row subplots; one subplot was selected at random and treated with the fumigant Telone II. The entire field was planted in the winter with a rye cover which was cut in the spring, plowed and disked 6 weeks prior to planting the summer crops. Telone II was injected 18 inches deep, at a rate of 3 gallons per acre into raised seedbeds to designated nematicide plots three weeks before planting. Cotton seed (DP 30 ALABAMA AGRICULTURAL EXPERIMENT STATION fall populations of reniform nematode following one season of peanut and corn (Table 2). It is also noteworthy that in the fall of 2006 the lowest reniform populations occurred in the plots following 2 years of peanut and corn, but there were no significant differences in reniform populations between the 1- and 2-year rotations in the fall of 2007 (Table 4). This test has undergone severe drought conditions during both the 2006 and 2007 growing seasons. In 2007, the test received 16 inches of rain for the entire growing season. Consequently, both cotton yields and reniform nematode populations have been adversely impacted due to the lack of soil moisture. A real response to crop rotation and nematicide treatment has been undoubtedly compromised both years as a result of these unfavorable growing conditions. We will not have an accurate measure of the real affect of crop rotation and nematicide treatments until more normal growing conditions return. TABLE 2. EFFECT OF CROP ROTATION AND NEMATICIDE TREATMENT ON RENIFORM NEMATODES AND COTTON YIELD IN 2006 Rotation 2005 2006 Cotton Cotton Cotton Corn Cotton Peanut Soybean Cotton Corn Cotton Cotton Soybean Peanut Cotton ——Comparison only1—— Corn Corn Peanut Peanut Soybean Soybean Pr>F Pr>F Pr>F LSD (P≤0.10) C.V. (%) ———2006——— Spring Fall nematode nematode population population ——no./100 cc—— 1140 3450 1087 367 1081 383 856 3235 753 2592 528 315 257 2321 219 335 798 61 106 256 0.0001 0.1072 0.5202 766 49 0.0001 0.0073 0.1809 0.0649 151 13 Seed cotton yield lb/A 2006 2007 1739 1597 1540 1541 0.0579 0.5898 NA 123 76 13 –Seed cotton yield– ————lb/A———— Nematicide No nematicide 1734 NA2 NA 1619 1767 NA 1838 1366 NA NA 1424 1702 NA 1668 Rotation 0.011 Nematicide 0.4438 Rotation x Nematicide 407 58 Nematicide Nematicide No nematicide Pr>F LSD (P≤0.10) C.V. (%) 1 Not included in the statistical analysis. Comparisons included for information only. NA=not applicable. TABLE 3. EFFECT OF CROP ROTATION AND NEMATICIDE TREATMENT ON COTTON YIELD IN 2007 —————Crops————— 2005 2006 2007 Cotton Corn Cotton Cotton Peanut Cotton Cotton Soybean Cotton Corn Corn Cotton Peanut Peanut Cotton Soybean Soybean Cotton Cotton Cotton Cotton LSD (P≤0.05) Pr>F Rotation Pr>F Nematicide Pr>F Rotation x Nematicide ——2007—— Seed cotton yield lbs/A 1535 1512 1536 1726 1705 1651 1319 257 0.0001 0.5898 0.9848 —————Crops————— 2005 2006 2007 Corn Cotton Corn Peanut Cotton Peanut Soybean Cotton Soybean Cotton Corn Corn Cotton Peanut Peanut Cotton Soybean Soybean Cotton Corn Cotton Cotton Peanut Cotton Cotton Soybean Cotton Corn Corn Cotton Peanut Peanut Cotton Soybean Soybean Cotton Cotton Cotton Cotton LSD (P≤0.05) TABLE 4. EFFECT OF CROP ROTATION AND NEMATICIDE TREATMENT ON RENIFORM NEMATODE POPULATIONS IN 2007 Reniform/100cc soil Telone No Telone 322 de 190 e 369 de 242 e 199 e 317 de 149 e 175 e 225 e 368 de 334 de 297 de 953 b-e 1450 ab 836 b-e 1293 abc 918 b-e 1397 abc 802 b-e 1197 a-d 667 b-e 1371 abc 867 b-e 1830 a 1382 abc 1887 a 511 2007 COTTON RESEARCH REPORT 31 SCREENING COMMERCIAL COTTON VARIETIES AGAINST FUSARIUM WILT W. S. Gazaway and K. Glass The purpose of this study was to identify commercial cotton varieties currently grown in Alabama that are susceptible or have tolerance to Fusarium wilt. Results are also published in a tabular form online and in the Alabama Cotton IPM guide each year. Fifteen of the most commonly grown cotton varieties were planted late (June 14) due to lack of rain. The field was extremely dry and had to be irrigated to obtain a stand. Rowden, an extremely susceptible cotton variety, was planted as a control. Plots were 20 feet long and 16 rows wide. The test consisted of five replicates. Plants were evaluated for wilt soon after they reached the first true leaf stage. Plants showing Fusarium wilt symptoms were counted and removed. Plots were checked for wilt on a weekly basis and evaluated as symptoms appeared throughout the growing season. Very little wilt occurred during the 2007 growing season due to the extreme drought and heat. Root-knot nematode damage, which is critical for Fusarium wilt to occur, was very light in 2007. Consequently, there was insufficient wilt in the plots during 2007 to separate cotton varieties’ reaction to Fusarium wilt (see table). Variety Rep 1 Rep 2 Rep 3 Rep 4 Av wilt % Rowden 8 6 5 3 6 PhytoGen PHY 480WR 6 5 0 0 3 Fiber Max FM 9063B2F 3 4 1 1 2 Deltapine DP 454BG/RR 5 0 1 3 2 Fiber Max FM 1735LLB2 0 5 0 3 2 Deltapine DP 445BG/RR 3 2 0 0 1 DynaGro DG 2520B2RF 0 1 2 0 1 Deltapine DP 555BG/RR 0 1 2 0 1 Fiber Max FM 960BR 1 0 1 0 1 Stoneville ST 4664RF 0 2 0 0 0 Deltapine DP 143B2RF 0 1 0 0 0 PhytoGen PHY 485WRF 1 0 0 0 0 Stoneville ST 6611B2RF 0 0 0 0 0 Crop. Gen. CG 3020B2RF 0 0 0 0 0 Deltapine DP 515BG/RR 0 0 0 0 0 Deltapine DP 444BG/RR 0 0 0 0 0 2007 COMMERCIAL VARIETY FUSARIUM WILT, PLANT BREEDING UNIT,TALLASSEE, AL COTTON CULTIVAR RESPONSE TO TEMIK 15G PLUS AVICTA IN TWO TILLAGE REGIMES IN ALABAMA, 2007 K.S. Lawrence, K. S. Balkcom, and B. Durbin Six cotton cultivars were evaluated for yield response to the root-knot nematode in a naturally infested field at E. V. Smith Research and Education Center, near Shorter, Alabama. The field had a long history of root-knot nematode infestation, and the soil type was classified as a sandy loam. Plots consisted of four rows, 50 feet long, with 3-foot row spacing and were planted in a factorial arrangement in a randomized complete block design with five replications. Blocks were separated by a 20-foot wide alley. Avicta was applied to the seed by the manufacturer. Temik 15G (5 pounds per acre) was applied at planting on May 16 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S (0.12 pound per acre) was applied to all plots as needed for thrips control. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the rootknot nematode were determined approximately 30 days after emergence. Ten soil cores, 1 inch in diameter and 6 inches deep, were collected from the center two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Nematode eggs were extracted from the root systems of five plants collected at random across each plot using a 0.6 percent sodium hypochlorite separation. Plots were harvested on September 24. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). Rainfall was the limiting factor in the 2007 season; thus, root-knot nematode pressure was moderate under these conditions. Only 17.7 in of rain were recorded for the entire growing season. At planting, root-knot nematode numbers averaged 107 J2s per 150 cm3 of soil. Seed cotton stand was uniform for cultivars with or without nematicide. The ST5599BR cultivar produced a greater (P ≤ 0.10) stand than DP 143B2RF or DP515BG/RR with the nematicide applications. Seedling vigor was also similar for each cultivar regardless of nematicide application. However, differences in vigor were observed between cultivars with ST5599BR and DP117B2RF being more vigorous in growth at 30 DAE than DP 555BG/RR when treated with a nematicide. Root-knot numbers of J2 from the soil and eggs from the roots varied between varieties and nematicide application. ST 5599BR root-knot numbers were numerically lower than all other cultivars, and all cultivars exhibited numerically greater numbers of root-knot nematodes in the control plots compared to the nematicide plots. ST 5599BR, DP 117B2RF, and DP 143B2RF did not produce a numerical yield increase with the nematicide combination of Temik 15G and Avicta; thus, tolerance is a possibility under the environmental conditions of this growing season. DP 555BG/RR and DP 515BG/RR did increase yields (P ≤0.10) with the application of the nematicides. 32 ALABAMA AGRICULTURAL EXPERIMENT STATION COTTON CULTIVAR RESPONSE TO TEMIK 15G PLUS AVICTA IN TWO TILLAGE REGIMES IN ALABAMA, 2007 Stand/10 ft row1 N2 CK 3 41.6 41.5 40.3 40.9 38.0 38.4 36.8 40.4 33.8 37.8 33.4 36.1 6.8 ——Vigor—— N CK 4.4 4.0 4.4 4.0 3.9 3.6 3.7 3.6 4.3 4.1 4.1 4.3 0.6 Plant height N CK 8.1 7.5 8.4 7.2 7.1 6.6 7.7 7.6 7.0 6.3 8.1 6.9 1.1 Meloidogyne incognita —J2 and eggs— N CK 10459 37809 26631 150924 34821 126303 45309 188556 11447 65908 69194 164616 144221 —Lint lb/A— N CK 433.7 473.8 456.5 460.0 496.2 486.1 549.1 480.1 456.5 509.5 549.3 509.1 59 ST 5599BR DP 117B2RF STM DP 555BG/RR DP 143B2RF DP 515BG/RR LSD (P≤ 0.10) 1 Numbers in columns followed by the same letter are not significantly different by Fisher’s LSD at P ≤ 0.05. 2 N is the application of the nematicides Avicta and Temik 15G. 3 C stands for the non treated control plots. COTTON CULTIVAR RESPONSE TO TELONE II FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA K. S. Lawrence, S. R. Moore, G. W. Lawrence, and J. R. Akridge Nine cotton cultivars were evaluated for yield response Rainfall was the limiting factor in the 2007 season; thus, to reniform nematodes in a naturally infested producer’s field reniform nematode pressure was low to moderate under near Huxford, Alabama. The field had a long history of reniform these conditions. Only 15.3 inches of rain was recorded for nematode infestation, and the soil type was classified as a loam. the entire growing season. At planting, reniform nematode Plots consisted of four rows, 25 feet long, with a 3-foot row numbers averaged 127 and 208 vermiform life stages per 150 spacing and were planted in a factorial arrangement in a ran- cm3 of soil in the Telone II and DiSyston plots, respectively. domized complete block design with five replications. Blocks Seed cotton stand was uniform between treatments (data not were separated by a 20-foot wide alley. Telone II was applied at shown). Reniform numbers increased by 170 and 110 per3.0 gallons per acre and compared with at-planting applications cent in the Telone II and DiSyston plots at harvest (see table). of Di-Syston 8EC at 5.0 pounds per acre. Telone II was applied The lowest reniform populations in the Telone II plots were with a modified ripper hipper. A CO2 system was used to inject observed in the DP 161B2RF, DP 174RF, and DP 121RF culthe fumigant through flow regulators mounted on stainless steel tivars. DP 174RF, DP 121RF, DP 555BG/RR, and DP 515BG/ delivery tubes attached to the trailing edge of forward-swept RR supported the lowest populations in the DiSyston plots. chisels. The fumigant was placed 12 in. deep 21 days prior to Telone II numerically increased the yield of seven of the nine planting. Rows were immediately hipped to seal and prevent cultivars. DP 117B2RF was the highest yielding cultivar in rapid loss of the fumigant. All remaining rows were subsoiled both the Telone II and DiSyston plots, although yield was 12 in. deep and hipped without applying the fumigant. All plots increased by 245 pounds per acre in the Telone II plots. DP were maintained throughout the season with standard herbicide, 515BG/RR and DP 174RF did not produce a yield increase in insecticide, and fertility production practices as recommended response to Telone II and, thus, may possess some tolerance by the Alabama Cooperative Extension System. Population to the reniform nematode under drought conditions. densities of the reniform nematode were determined at monthly intervals. Orthene 90S at 0.12 pound per acre was applied to EFFECT OF TELONE II AND DISYSTON ON CULTIVAR RESPONSE all plots as needed for thrips TO ROTYLENCHULUS RENIFORMIS AND SUBSEQUENT COTTON YIELD control. Ten soil cores, 1 inch ——Rotylenchulus reniformis/150cc soil—— —Seed cotton lb/A— in diameter and 6 inches deep, Telone II DiSyston Telone II DiSyston Telone II DiSyston were collected from the two Cultivar ——5/8/2007—— ——10/31/2007—— rows of each plot in a system- 1 DP 445BG/RR 176 192 2689 a1 3461 a 1680 ab 1475 b atic sampling pattern. Nema- 2 DP 555BG/RR 109 207 3044 a 1406 b 1540 ab 1199 bc todes were extracted using the 3 DP 515BG/RR 129 223 2750 a 1437 b 1517 ab 1539 b 125 218 2148 ab 3152 a 2102 a 1856 a gravity sieving and sucrose 4 DP 117B2RF 5 DP 141B2RF 109 203 2055 ab 3492 a 1071 b 982 c centrifugation technique. Plots 6 DP 161B2RF 140 172 1638 b 1947 ab 1382 b 1222 bc were harvested on October 7 DP 174RF 140 203 1144 b 1762 b 1104 b 1136 bc 31. Data were statistically 8 DP 121RF 94 223 1561 b 1653 b 1733 ab 1505 b analyzed by GLM and means 9 ST 5599BR 124 239 3461 a 2410 ab 1724 ab 1423 b compared using Fisher’s pro- LSD (P≤ 0.10) 152 141 1537 1714 427 245 tected least significant differ- 1 Numbers in columns followed by the same letter are not significantly different by Fisher’s LSD at P ≤ 0.10. ence test (P ≤ 0.10). 2007 COTTON RESEARCH REPORT 33 BREEDING COTTON FOR YIELD AND QUALITY IN ALABAMA David B. Weaver There are three major aspects to this project: (1) development of cotton germplasm or cultivars with improved yield and fiber properties; (2) evaluation and development of cotton germplasm for resistance to reniform nematode; (3) and evaluation and development of cotton germplasm for resistance to abiotic stresses, particularly heat and drought. For the first objective, experimental breeding lines from seven different cotton populations were developed using bulk and pedigree methods. In 2007, we evaluated 280 experimental lines (roughly 40 lines per population) for yield and fiber properties at two locations, Tallassee and Prattville. Plots were two rows, 20 feet in length, with a spacing of 36 inches between rows, replicated three times. Data were collected by sampling 50 bolls from each plot for determining lint percentage, boll size, lint weight per seed, and fiber quality. Fiber quality was analyzed by HVI at Cotton, Inc., Cary, NC. The entire plot was spindle-harvested to determine seed and lint yield. No data were collected at Prattville due to extreme drought. Supplemental irrigation, plus some very timely rainfall late in the season, resulted in good data from Tallassee; however, and fiber analysis is in progress. Five advanced lines were evaluated in the Regional Breeders Testing Network at 12 locations across the Cotton Belt. These are the first entries from the Auburn program since its inception. All locations have not reported, however, the top performing line at the Tallassee location (29 entries plus three checks) was an Auburn experimental line (Au04-6207, from the cross Miscot 8001 × Suregrow 747), with a lint yield of 1371 pounds per acre. Test average was 1123 pounds per acre. Fiber quality of this line was good, with 42.7 percent lint, micronaire of 4.4, 50 percent span length of 1.12 inches, and strength of 29.25 g/tex. Other Auburn lines are performing well at other locations, but all data have not been submitted. We have cooperated in this test for the past five growing seasons. Further work is being done to develop new populations for generating experimental cotton lines for future testing. We have made significant progress developing advanced populations from crosses between four adapted lines (FM966, SG747, PM1218, and DeltaPearl) and two germplasm lines (TX245 and TX1419) identified as having a moderate level of resistance to reniform nematode. Three types of populations have been developed: Adapted × resistant accession (F2:3 lines); (adapted × resistant accession) × adapted (BC1:2 lines); and (adapted × resistant accession) × resistant accession (BC1:2 lines). We have a total of 1200 lines representing 25, 50, and 75 percent adapted germplasm, and these lines are ready for evaluation for nematode resistance in 2008. Evaluation and incorporation of genes for resistance into adapted types will be a longterm process. We are continuing along the same path in development of similar type populations using genotypes identified as heat tolerant. We have identified seven accessions as having significantly greater vegetative heat tolerance than Deltapine 90. Development of these populations is progressing more slowly, due to the difficulty of crossing with these materials. These lines are photoperiodic, with long juvenile periods and can take over a year between planting and flowering. We were unable to make crosses in the winter nursery in 2007, and lines also failed to flower in the field during 2007. However, plants that were planted in the greenhouse in spring of 2007 are now flowering, and we are making crosses with the adapted Deltapine 90. We hope to have F2 populations developed by fall 2008; however, it is highly probable that the F1 hybrids will also have a long juvenile period, so it may take until 2009 before F2 populations are available for evaluation. During the upcoming year, we will continue to work with these lines to determine the level of expression of this trait and hope to identify genes that are responsible. 34 ALABAMA AGRICULTURAL EXPERIMENT STATION IRRIGATION ON THE OLD ROTATION C. C. Mitchell, K.S. Balkcom, and D.P. Delaney The Old Rotation (circa 1896) is the oldest, continuous cot- fered under a severe drought in both 2006 and 2007. However, ton experiment in the world. Its 13 plots on one acre of land the site of the Old Rotation received some timely rains during on the campus of Auburn University continue to document the 2006 which it did not get in 2007 (Figure 2). In fact, 2007 was long-term effects of crop rotations with and without winter le- the worse drought in more than 50 years for the Auburn, Alagumes (e.g., crimson clover) as a source of N for cotton, corn, bama, area. Cotton that was planted on May 17, 2007 did not soybean, and wheat. Irrigation was installed on half of each plot emerge until late June except where the plots were irrigated. in 2003 and both irrigated and non-irrigated yields have been Cotton on plots low in soil organic matter due to a lack of longmonitored since then (Figure 1). For more information on the term rotations (e.g. plots 1, 6, and 13) never emerged because of history of the Old Rotation, visit the website at soil crusting. Previous research has shown that soil organic mathttp://www.ag.auburn.edu/agrn/cotton.htm ter on these plots is less than 0.5 percent. Surface soil organic The eastern half of each of the 13 plots on the Old Rotation matter is as high as 2.5 percent on plots with rotations, winter can be irrigated separately using a system of eight 8-foot risers cover crops, and high residue management. Irrigation in 2007 in each plot. Scheduling irrigation, on the other hand, is tricky. resulted in large yield differences and an all-time record cotIdeally, irrigation should be based on soil moisture in the rooting ton lint yield on plot 9 (2-year cotton–corn rotation with legume depth plus the stage of growth of the crop. Because this system plus 120 pounds of N per acre) of 1940 pounds of lint per acre. can be programmed to apply water on a regular schedule to each Plot size = 21' x 139' Field Plot Design plot, we estimate evapotranspiration and preset the system to N (3' alley) apply supplemental water. We adjust the timing and rate of irrigation based upon the weather, crop, and stage of growth. In Irrigated half general, during tasseling of corn and peak boll fill of cotton, we apply between 1 and 2 inches of irrigation per week if no rain occurs. In most years, the irrigation system is not turned on until 1 2 3 4 5 6 7 8 9 10 11 12 13 June so cotton and corn crops are established without irrigation. Because of the extreme drought of 2007, irrigation was necessary to assure a uniform stand of cotton and soybeans. In 2007, II. Cotton rotations I. Cotton every year irrigation began in mid-May and continued to early September. • Corn + winter legumes (4,7) • No N/no legume (1,6) Most of the cotton plots received a total of 20 to 25 inches of • Corn + winter legumes + • Winter legumes (2,3,8) 120 lb. N/acre/yr (5,9) irrigation. This was twice the total amount applied in previous • 120 lb. N/acre/yr (13) • 3-yr Cotton-Corn-soybean rotation with wheat & winter years. Winter wheat and winter legumes are not irrigated. legumes (10, 11, 12) From its inception in 1896 through 1996, all crops on the Old Rotation were produced with conventional tillage, e.g., moldboard Figure 1. Field plot diagram of Old Rotation experiment showing irrigated half since 2003. plowing, disking, harrowing, and cultivation. Since 1997, all 9 crops have been produced using conservation tillage which 8 leaves a maximum of crop residue on the soil surface. Prior to 7 planting, all crops receive in2003 row subsoiling or para-tilling, 6 which is the only soil distur2004 bance used. Since 1997 and the 5 advent of genetically modified 2005 crops, the use of insecticides 4 2006 and herbicides have been dra3 matically reduced and overall 2007 crop yields have increased. Re2 cord yields of all crops grown on the Old Rotation have been 1 produced since 1997. Cotton. There were no 0 differences due to irrigation during the first 4 years after irApril May June July Aug. Sept. rigation was installed, 20032006. Most of Alabama suf- Figure 2. Monthly precipitation during the growing season for the Old Rotation site, 2003-2007. Precipitation (inches)_ 2007 COTTON RESEARCH REPORT 35 Potassium deficiency, which has not been observed on the Old Rotation by any of the authors, was observed on plots 7, 8, and 9 in 2007. This was attributed to the very high irrigated cotton yields. Because of the dramatic yield increase due to irrigation in 2007, the 5-year average yield increase due to irrigation was 22 percent (Figure 3). In conclusion, irrigated cotton on the Old Rotation has resulted in a positive yield response in only one year out of five, and that was the severe drought year of 2007. Irrigated yields in 2007 were so dramatically higher than the non-irrigated cotton yields that over the 5-year period, irrigation resulted in a 22 percent average yield increase over all plots. Irrigation with corn and soybean resulted in higher grain yields each year with average increases of 47 and 44 percent, respectively, over all treatments. EFFECT OF IRRIGATION ON OLD ROTATION MEAN CROP YIELDS, 2003-2007 Treatment (plots) Cotton every year No N/no legume (plots 1 & 6) Legume N only (plots 2, 3 & 8) 120 lb. N/acre (plot 13) Cotton Rotations Cotton-Corn rotation, legume N only (plots 4&7) Cotton-Corn rotation, +legume, + 120 lb N/acre (plots 5&9) 3-yr rotation, Cotton (winter legume)-Corn (wheat)-Soybean (plots 10, 11 , 12) Soybean mean yield (irrigated) = 56 bu/acre Soybean mean yield (non-irrigated) = 39 bu/acre Wheat mean yield (non-irrigated) = 51 bu/acre 1 ——Corn grain—— ——Cotton lint—— NonNonIrrigated irrigated Irrigated irrigated ———bu/A——— ———lbs/A——— ---69 c 166 a 119 b ---54 c 116 a 71 b 470 d1 1020 c 1330 ab 1190 bc 1530 a 1210 bc 300 d 1000 b 940 bc 1150 b 1380 a 750 c Values followed by the same letter within a column are not significantly different at P≤0.05. (lb/acre)_ 1400 1200 1000 800 600 400 200 Irr Non Lint yield 2003 2004 2005 2006 2007 Year Figure 3. Mean cotton lint yields by year over all treatment/plots on the Old Rotation experiment as affected by irrigation (Irr) and non-irrigation (Non). LSD (P≤0.05) =400. 36 ALABAMA AGRICULTURAL EXPERIMENT STATION FERTILIZATION OF COTTON ON BLACK BELT PRAIRIE SOILS IN ALABAMA C.C. Mitchell, D.P. Delaney, R. P.Yates, G. Huluka, and J. Holliman Soil fertility research with cotton has not been conducted on the fine-textured, often calcareous soils of the Alabama Black Belt Prairie region in several decades although as much as 30,000 acres are being planted on these soils. Most fine-textured, Black Belt soils test “low” in P and “high” or “very high” in K if recognized analytical techniques are used that are appropriate for these highly buffered, often calcareous soils. Nevertheless, cotton growers in this area sometime suspect K deficiency in spite of following the soil test recommendation. Very little research has been conducted to verify soil test calibration or recommendations for cotton on these soils. These soils have a much higher cation exchange capacity compared to adjacent soils of the Coastal Plain or Tennessee Valley region. They generally have poor internal drainage, low saturated hydraulic conductivity, poor infiltration and may be calcareous with a soil pH above 7.0. Nitrogen management is also a concern for cotton on these slowly permeable soils where N denitrification may be more of a concern than nitrate leaching. On-farm research has suggested higher N rates are needed for corn on these soils Very little research has been conducted with cotton on these soils in Alabama. Standard N recommendations are based on research conducted on sandier, Coastal Plain soils or finer textured soils of the Tennessee Valley in northern Alabama. The purpose of this experiment is to identify optimum rates of N, P2O5, and K2O for cotton on Black Belt soils on a permanent site for soil fertility research at the Black Belt Research and Extension Center in Marion Junction, Alabama. Initial soil tests from the site indicated a very uniform site typical of unfertilized Black Belt area cropland (Table 1). Phosphorus was rated low using the Mississippi/Lancaster extract, which is the preferred method for these soils and is used by both the Auburn University and Mississippi State University soil testing laboratories. Potassium was rated “very high.” Soil samples have been taken from each plot every year of this experiment but are not included in this paper. This experiment was laid out in 2004 and was designed to complement the “Rates of NPK Experiment” (circa 1929) on other outlying units of the Alabama Agricultural Experiment Station. The site is on an acid, Vaiden clay (very fine, smetitic, TABLE 1. INITIAL, MEAN PLOW-LAYER SOIL YEST VALUE (N=4) FROM SITE TAKEN IN 2004 Extract used Mehlich-1 Miss/Lancaster 1 Soil pHw 6.0 6.0 P K Mg Ca —————————mg/kg and rating1———————— 4 Very Low 88 High 35 High 2330 (not rated) 16 Low 180 V. High 60 High 10,000+ Adams et al., 1994. TABLE 2. FERTILIZER TREATMENTS AND COTTON LINT YIELDS ON A VAIDEN CLAY IN WEST ALABAMA, 2005-2007 Treatment no. description N rates 1 No N 2 Low N 3 Intermediate N 5 Control 4 High N 6 No S/VH N P rates 7 No P 8 Very low P 9 Low soil P 10 Intermediate P 5 Control K rates 11 No K 12 Very low K 13 Low K 14 Intermediate K 15 High K 5 Control Other treatments 16 No lime 17 Nothing L.S.D P<0.1 Rate of nutrients applied 2005 2006 2007 N P2O5 K2O Lint yield Lint yield Lint yield ————————————lb/A———————————— 0 30 60 90 120 150 90 90 90 90 90 90 90 90 90 90 90 90 0 100 100 100 100 100 100 0 20 40 60 100 100 100 100 100 100 100 100 0 100 100 100 100 100 100 100 100 100 100 100 0 20 40 60 80 100 100 0 177 214 265 388 237 320 280 205 274 233 388 157 170 253 341 319 388 196 160 135 311 380 403 393 400 387 378 394 375 388 393 353 324 295 335 349 393 413 300 ns 870 1040 990 1076 1037 1040 910 940 1091 1027 1076 585 784 803 922 806 1076 1027 649 220 2007 COTTON RESEARCH REPORT 37 thermic, Vertic Hapludalfs) and is the only soil fertility experiment in Alabama on Black Belt soils. The experiment consists of six N rates, four P rates, five K rates and a no-lime treatment and an unfertilized treatment replicated four times in a randomized block design (Table 2). Plot size was 15 x 25 feet laid out in five 36-inch wide rows. Because of disappointing yields in 2005 when cotton was planted no-till into a rye cover crop and excessive rainfall occurred, the decision was made to switch to a ridge tillage system with no cover crop for 2006 and 2007. All the P and K and half of the total N were applied within 1 week of planting in late April. The remainder of N was applied in mid-June. Lint yields were estimated by hand-picking 20 feet from the two middle rows in each plot. Relative yields are yields compared to the mean yield of treatment no. 5, the control treatment, which received 90-100-100 pounds N-P2O5-K2O per acre each year. Excessive rainfall from several tropical storms and anaerobic soil conditions dramatically limited cotton lint yields in 2005. The following two years have been described as the worst summer droughts and highest temperatures in more than 50 years (Figure 1). The drought severely limited yields in 2006, but critical rainfall in July resulted in somewhat higher yields in 2007. Yields were from hand-picked plots. If the 2006 and 2007 crops had been machine harvested, very little of the lint would have been saved because of hard locks and weak bolls. Cotton lint quality was measured in 2006 and 2207 on four different treatments by USDA AMS Cotton Program Birmingham Classing Office, No N (treatment 1), No P (treatment 7), No K (treat ment 11) and the complete fertilized control (treatment 5). There were no differences in mean fiber quality due to soil fertility treatment. 2006 2007 Micronaire 4.6 3.97 Length 97 1.02 Strength 26.9 26.4 Uniformity 81.9 81.9 Because of the higher yields and significant differences in treatment on yield in 2007, 2007 data are probably more relevant to producers (Table 2). N rates. Optimum total N rates in the two dry years, 2006 and 2007, appeared to be around 60 pounds N per acre, although rates above 30 pounds N per acre produced relative yields above 95 percent of maximum. Although there was a more dramatic response to N rates in 2005, yields were low because excessive rainfall resulted in severe denitrification losses on these poorly drained soils. On-farm tests in 2003 when excessive rainfall also limited yields, showed that delaying N application until sidedressing could almost double the yield potential of cotton. In these tests, optimum N rate when denitrification was a problem was 120 pounds N per acre as a sidedress. P2O5 rates. One would have anticipated more dramatic responses to rates of P than we found in these tests because of the low soil test P rating. Except for the low-yielding, wet year of 2005, there was very little yield response to added P. This calls into question the current “low” rating for this soil test value for cotton. The definition of a “low” soil test rating indicates that the soil will produce less than 75 percent of its potential without fertilization of that nutrient. Without P in 2006 and 2007, relative cotton lint yields were above 80 percent. K2O rates. In spite of the fact that this soil initially tested “very high” in K, there were significant increases in yield with higher rates of K2O up to 100 pounds per acre in 2005 and 2007. These results provide credibility to grower’s claims that additional K seems to increase yields even though the soils are rated “very high” for K. There may be justification to change soil test K ratings for these soils and increase K recommendations for cotton. Additional studies are on-going related to this issue. Three years of extreme weather conditions and very poor cotton yields at this site preclude any major conclusions regarding soil fertility. Significant differences in 2007 due to treatments suggest a need for modification of soil test ratings for both P and K on these soils. Phosphorus may be currently rated too low and potassium may be rated too high for cotton on these soils. Since these are the only established soil fertility variable plots on the Black Belt Research and Extension Center, we hope that they will be maintained indefinitely as is the “Rates of NPK” experiment at six other Alabama locations to provide more conclusive evidence for changes in soil test calibration for similar Alabama soils. 38 ALABAMA AGRICULTURAL EXPERIMENT STATION Rainfall, 2005 Rainfall (inches)_ 5.0 4.0 3.0 2.0 1.0 0.0 4/1 7/8 8/5 4/15 4/29 5/13 5/27 6/10 6/24 7/22 8/19 9/2 9/16 9/16 9/16 9/30 9/30 9/30 Date Rainfall, 2006 Rainfall (inches)_ 5.0 4.0 3.0 2.0 1.0 0.0 4/1 7/8 8/5 4/15 4/29 5/13 5/27 6/10 6/24 7/22 8/19 8/19 9/2 9/2 Date Rainfall, 2007 Rainfall (inches)_ 5.0 4.0 3.0 2.0 1.0 0.0 4/1 7/8 4/15 4/29 5/13 5/27 6/10 6/24 7/22 8/5 Date Figure 1. Precipitation at the Black Belt Research and Extension Center, 2005-2007. 2007 COTTON RESEARCH REPORT 39 AMMONIA LOSSES FROM SURFACE-APPLIED UREA-BASED NITROGEN FERTILIZERS F. Ducamp, C.C. Mitchell, F.J. Arriaga, K.S. Balkcom Ammonia volatilization is the major process responsible for N losses from surface-applied urea-based fertilizers, with losses accounting up to 50 percent of the N applied The use of N stabilizers mixed with urea-based N fertilizers decreases the rate of urea hydrolysis and reduces ammonia volatilization losses, allowing the use of less expensive sources of N. The objective of this study was to examine the effect of two N stabilizers on ammonia volatilization from surface-applied urea-based N fertilizers. 35 140 120 30 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 100 80 60 40 20 0 Days after fertilizer application Precipitation Temperature Figure 1. Average air temperature and precipitation for the experimental period. 0.7 a a b b bc cd bc cc cd d a aa c d cd cd bc c a c The experiment was conducted at the E.V. Smith Research Center, in central Alabama, during August of 2007. Two N stabilizers (Agrotain® and calcium chloride) were evaluated on ammonia volatilization from urea and urea-applied nitrogen (UAN) fertilizers (applied at a rate of 134 kg N ha-1) under two field conditions (soil covered with rye residue and bare soil). Treatments for each situation were (1) Control (no N added), (2) urea, (3) urea+Agrotain®, (4) UAN, (5) UAN+Agrotain®, and (6) UAN+calcium chloride. Atmospheric ammonia was measured at 0, 1, 2, 3, 5, 8, and 17 days after the fertilizer application, following a methodology similar to the one proposed by the GRACEnet Protocol. Daily average temperature and precipitation data during the study period are shown in Figure 1. The statistical analysis was performed using the ANOVA procedure of SAS, considering effects as significant when P≤0.05. Results are presented in Figures 2 through 5. Agrotain significantly reduced the rate of ammonia volatilization from dry urea applied to either a bare soil or soil with a heavy rye residue, but Agrotain significantly decreased the accumulated ammonia loss only in the rye residue covered soil. There was not a consistent effect of Agrotain or CaCl2 on the rate of ammonia volatilization from UAN. Neither Agrotain nor CaCl2 significantly affected the accumulated ammonia loss from UAN when applied to a heavy residue or a bare soil. Accumulated ammonia losses from a bare soil were about half those with a heavy residue. Average temperature ( C) Precipitation (mm) o hour ) hour ) -1 0.6 a a ab -1 a 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 c c c b b a -1 N loss (kg N-NH 3 ha 0.4 0.3 0.2 0.1 0 0 bc bc a b a bc bc bc aa a aaa N loss (kg N-NH 3 ha a -1 0.5 ab a a ab a aa d bc ab a ab cd b a a a bb bb a aa a aa b bb a a aa a b a 1 2 3 5 8 17 1 2 3 5 8 17 Days after fertilizer application Control Urea Urea+Agrotain UAN UAN+Agrotain UAN+CaCl2 Control Urea Days after fertilizer application Urea+Agrotain UAN UAN+Agrotain UAN+CaCl2 Figure 2. Ammonia volatilization rate as affected by treatments and time (rye residue covered soil). Urea+Agrotain had a lower ammonia volatilization rate than urea (days 1, 2, and 3), and Agrotain and CaCl2 did not have a consistent effect on the ammonia volatilization rate of UAN. Columns with different letters (for each day) are significantly different at P≤ 0.05. Figure 3. Ammonia volatilization rate as affected by treatments and time (bare soil). Urea+Agrotain had a lower ammonia volatilization rate than urea (days 2 and 3), and Agrotain and CaCl2 did not have a consistent effect on the ammonia volatilization rate of UAN. Columns with different letters (for each day) are significantly different at P≤ 0.05. 40 ALABAMA AGRICULTURAL EXPERIMENT STATION 60 30 Accumulated N loss (kg N-NH 3 ha ) -1 50 Accumulated N loss (kg NH 3 ha ) a a a -1 25 20 15 10 5 0 ab 40 30 20 ab bc ab b b c 10 0 Urea Urea+ Agrotain UAN UAN+ Agrotain UAN+ CaCl2 Urea Urea+ Agrotain UAN UAN+ Agrotain UAN+ CaCl2 Figure 4. Accumulated net ammonia loss 8 days after applying the fertilizer (rye residue covered soil). Agrotain significantly reduced accumulated ammonia losses from urea but neither Agrotain nor CaCl2 influenced accumulated ammonia losses from UAN. Columns with different letters are significantly different at P≤ 0.05. Figure 5. Accumulated net ammonia loss 8 days after applying the fertilizer (bare soil). Ammonia losses from bare soil were about half those with a heavy residue. Agrotain reduced the N volatilized from urea by 30 percent. Neither Agrotain nor CaCl2 significantly reduced N volatilized from UAN. Columns with different letters are significantly different at P≤ 0.05. FUNGICIDES EFFECT OF SELECTED FUNGICIDE SEED TREATMENT COMBINATIONS ON COTTON SEEDLING DISEASE IN NORTH ALABAMA, 2007 K. S. Lawrence, D. Schrimsher, and B. Norris A cotton seedling disease test was established at the Tennessee Valley Research and Education Center in Belle Mina, Alabama. The field selected had a history of seedling disease and the soil type was a Decator silt loam. On April 12, 2007 the soil was 60 degrees F at a 4-inch depth measured at 10 a.m. with adequate soil moisture. All fungicide seed treatments were applied by the manufacturers. High disease incidence plots were infested with autoclaved millet seed inoculated with Pythium ultimum and Rhizoctonia solani. Temik 15G (5 pounds per acre) was applied at planting in the seed furrow using chemical granular applicators attached to the planter. Orthene 90S (0.12 pound per acre) was applied to all plots as needed for thrips control. Plots consisted of four rows, each 25 feet long with a 40-inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts and skip index ratings were recorded 3 and 5 weeks after planting (WAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 20, 2007. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. The average monthly maximum temperatures for April through September were 69, 69, 91, 88, 98, and 87 degrees F, respectively, with average minimum temperatures of 46, 59, 66, 69, 72, and 72 degrees F. The total monthly rainfall from April through September was 4.27, 0.86, 0.49, 2.89, 0.93, and 0.23 inches for a total rainfall of 9.67 inches. Seedling disease pressure was high for the early planted cotton in 2007. Less than 25 percent of the cotton seed planted in the high density seedling disease pressure plots emerged (see table). Fifty-four and 85 percent of the seeds produced seedlings in the low density plots at 3 and 5 WAP, respectively. Plant stand was increased (P ≤ 0.05) in the high density plots at 5 WAP by the RTU Baytan Thiram + Trilex Advance + Vortex FL seed treatment as compared to the control. In the low disease density plots, plant stand was increased (P ≤ 0.05) by all fungicide seed treatment combinations over the control. RTU Baytan Thiram alone or in combination with Trilex Advanced + Vortex FL or Dynasty CST produced similar stands which were greater than the control. Seed cotton yields varied by 2019 and 599 pounds per acre over all treatments in the high and low density plots, respectively. In the high disease pressure plots, RTU Baytan Thiram in combination with Trilex Advanced and Vortex FL or Dynasty CST produced an average of 1199 pounds per acre increase in yield over the RTU Baytan Thiram alone. Yields were not different between the fungicide seed treatments and the control in the low seedling disease plots. SEED TREATMENT FUNGICIDE’S EFFECTS ON PLANT STAND AND COTTON YIELD Treatment 1 RTU Baytan Thiram 2 RTU Baytan Thiram Trilex Advanced 3 RTU Baytan Thiram Trilex Advanced Vortex FL 4 RTU Baytan Thiram Dynasty CST 5 Untreated LSD (P ≤ 0.05) 1 2 Rate/ oz cw 3.0 + 0.75 3.0 + 0.75 1.64 3.0 + 0.75 1.64 0.34 3.0 + 0.75 3.95 ——————Stand 10 ft row1—————— May 4 May 4 May 18 May 18 High Low High Low 4.6 a2 34.2 a 3.0 ab 30.8 a 4.2 a 25.6 a 2.0 ab 21.6 bc 31.8 a 29.6 a 17.8 b 6.94 9.0 a 4.6 ab 0.0 b 5.42 —Seed cotton lb/A— Sep 20 Sep 20 High Low 822.6 b 4.8 995.8 b 5477.5 a 5195.5 a 5298.5 a 5540.8 a 585.5 10.0 a 7.8 a 4.4 a 7.45 26.6 ab 29.8 a 17.6 c 6.62 2052.3 a 2164.8 a 146.3 b 860.6 Plant stand based on the number of seedlings/10 ft row. Numbers in columns followed by the same letter are not significantly different by Fisher’s LSD at P ≤ 0.05. 42 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF AGRILIANCE COTTON SEED TREATMENTS IN NORTH ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected seed treatments were evaluated to determine their efficacy against early season cotton disease in north Alabama. The soil was a Decatur silt loam that had a history of seedling disease. Soil temperature was 60 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. High incidence disease plots were infested with millet seed inoculated with Rhizoctonia solani and Pythium ultimum. Temik 15G (5 pounds per acre) was applied at planting on April 12 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of four rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 19. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was high for early planted cotton in 2007. At 21 DAP, 87 percent of the seeds planted in the high disease pressure plots did not emerge compared to 40 percent in the low disease pressure plots. Under low disease pressure, cotton seedling stand was increased by all treatments as compared to the untreated control (P≤0.10). All fungicides yielded as well as the untreated control (P≤0.10) with an average of 4906.8 pounds per acre seed cotton produced over all fungicide treatments. Under high disease pressure, all fungicides also increased cotton seedling stand as compared to the untreated control (P≤0.10). Catapult XL increased yield by an average of 776.1 pounds per acre over AGST06012 and Dynasty CST under high disease pressure. All treatments increased yield as compared to the untreated control (P≤0.10) by an average of 1879.7 pounds per acre seed cotton produced over all fungicide treatments. YIELD AND STAND COUNT OF COTTON IN NORTH ALABAMA TRIAL, 2007 Treatment Low Disease Pressure 1 Untreated Control 2 Catapult XL 3 AGST06012 4 Dynasty CST LSD (P≤0.10) High Disease Pressure 1 Untreated Control 2 Catapult XL 3 AGST06012 4 Dynasty CST LSD (P≤0.10) 1 Rate Rate unit ml/kg seed ml/kg seed mg/seed ——Stand/10ft row1—— 21 DAP2 35DAP 16.0 b 23.0 a 28.2 a 29.0 a 5.65 0.2 c 8.8 a 4.6 b 7.4 a 2.6 16.0 b 21.0 a 24.2 a 23.4 a 4.37 0.2 c 8.0 a 5.4 b 4.6 b 2.6 Seed cotton yield lb/A 4919 a 5750 a 5566 a 5768 a 911.69 206 c 2894 a 1889 b 2158 b 452.4 7.65 2.08 0.03 7.65 2.08 0.03 ml/kg seed ml/kg seed mg/seed Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. Means within columns followed by different letters are significantly different according to Fisher’s LSD (P ≤ 0.10). 2007 COTTON RESEARCH REPORT 43 EFFICACY OF EXPERIMENTAL SEED TREATMENTS ON EARLY SEASON COTTON DISEASES IN NORTH ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected experimental seed treatments were evaluated to determine their efficacy against early season cotton disease in north Alabama. The soil was a Decatur silt loam that had a history of seedling disease. Soil temperature was 60 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. High incidence disease plots were infested with millet seed inoculated with Rhizoctonia solani and Pythium ultimum. Temik 15G (5 pounds per acre) was applied at planting on April 12 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of four rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 19. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was high for early planted cotton in 2007. At 21 DAP, 74 percent of the seeds planted in the high disease pressure plots did not emerge as compared to 34 percent in the low disease pressure plots. Under low disease pressure, cotton seedling stand was increased by all treatments as compared to the Cruiser control (1) at 35 DAP. All treatments yielded as well as the Cruiser control (1) (P≤ 0.10) except for treatment 6 (Apron + Maxim + Systhane + A14911 + Cruiser). Under high disease pressure, cotton seedling stand was increased by all treatments as compared to the Cruiser control (1) at 35 DAP. All treatments produced higher yields (P≤ 0.10) than the Cruiser control (1) by an average of 1833.7 pounds per acre. Treatment two (Apron + Maxim + Systhane + Cruiser) had a lower yield (P≤ 0.10) than all other treatments, which did not differ (P≤ 0.10). YIELD AND STAND COUNT OF COTTON IN NORTH ALABAMA TRIAL, 2007 Treatment Low Disease Pressure 1. Cruiser 5 FS 2. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Cruiser 5 FS 3. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A15701 + Cruiser 5 FS 4. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A15423 + Cruiser 5 FS 5. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A13012 + Cruiser 5 FS 6. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A14911 + Cruiser 5 FS 7. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Cruiser 5 FS 8. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + STP27159 + Cruiser 5 FS 9. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Vortex 3.77 FS + Cruiser 5 FS LSD (P≤0.10) Rate 0.34 3.4 + 1.14 9.54 + 0.34 3.4 + 1.14 9.54 + 15.67 0.34 3.4 + 1.14 9.54 + 14.99 0.34 3.4 + 1.14 9.54 0.03 + 0.34 3.4 + 1.14 9.54 + 24.53 0.34 3.4 + 1.14 9.54 + 6.81 2.27 + 4.54 0.34 3.4 + 1.14 9.54 + 61.78 0.34 3.4 + 1.14 9.54 + 6.81 2.27 + 4.54 0.91 0.34 Rate unit mg/seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed g/lb seed g/lb seed mg/seed Seed cotton ——Stand/10ft row1—— yield 21 DAP2 35DAP lb/A 21.8 b 28.2 ab 29.8 a 26.0 ab 27.0 ab 29.8 a 29.6 a 4471 a 4309 ab 4232 ab 3957 ab 3964 ab 3603 b 4427 a 21.4 b3 31.4 a 25.2 ab 25.2 ab 30.0 ab 25.8 ab 32.0 a 24.0 ab 24.0 ab 26.2 ab 29.0 a 4353 ab 3876 ab 5.73 4.5 508.31 continued 44 ALABAMA AGRICULTURAL EXPERIMENT STATION YIELD AND STAND COUNT OF COTTON IN NORTH ALABAMA TRIAL, 2007 (CONT.) Treatment High Disease Pressure 1. Cruiser 5 FS 2. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Cruiser 5 FS 3. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A15701 + Cruiser 5 FS 4. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A15423 + Cruiser 5 FS 5. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A13012 + Cruiser 5 FS 6. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + A14911 + Cruiser 5 FS 7. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Allegiance LS Baytan 150 SC + Trilex Flowable Cruiser 5 FS 8. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + STP27159 Cruiser 5 FS 9. Apron XL 3LS + Maxim 4FS + Systhane 40 WP + Allegiance LS Baytan 150 SC + Trilex Flowable Vortex 3.77 FS Cruiser 5 FS LSD (P≤0.10) 1 Rate 0.34 3.4 + 1.14 9.54 + 0.34 3.4 + 1.14 9.54 + 15.67 0.34 3.4 + 1.14 9.54 + 14.99 0.34 3.4 + 1.14 9.54 0.03 + 0.34 3.4 + 1.14 9.54 + 24.53 0.34 3.4 + 1.14 9.54 + 6.81 2.27 + 4.54 0.34 3.4 + 1.14 9.54 + 61.78 0.34 3.4 + 1.14 9.54 + 6.81 2.27 + 4.54 0.91 0.34 Rate unit mg/seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed mg/seed g/lb seed g/lb seed g/lb seed g/lb seed mg/seed ——Stand/10ft row1—— 21 DAP2 35DAP 1.4 c 6.0 b 10.6 ab 11 ab 13.8 a 12.6 ab 12.6 ab 0d 2.6 cd 5.2 bc 8.2 ab 11.2 11.6 a 5.2 bc Seed cotton yield lb/A 161 d 1261 c 2006 ab 2294 a 2221 a 2459 a 1969 ab 8.4 ab 15.6 a 4.6 bc 8.6 ab 1587 bc 2147 a 4.42 3.4 420.08 Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. 3Means within columns followed by different letters are significantly different according to Fisher’s LSD (P ≤ 0.10). EVALUATION OF COTTON SEEDLING DISEASE MANAGEMENT IN NORTH ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected fungicides were evaluated to determine their efficacy against early season cotton disease in north Alabama. The soil was a Decatur silt loam that had a history of seedling disease. Soil temperature was 60 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. High incidence disease plots were infested with millet seed inoculated with Rhizoctonia solani and Pythium ultimum. Temik 15G (5 pounds per acre) was applied at planting on April 12 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of 4 rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 19. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was high for early planted cotton in 2007. At 21 DAP, 82 percent of the seeds planted in the high disease pressure plots did not emerge as compared to 35 percent in the low disease pressure plots. Under low disease pressure, stands did not differ with the untreated control (P≤0.10) at 35 DAP. All treatments yielded as well as the untreated control (P≤ 0.10) with an average of 4763.8 pounds per acre seed cotton produced over all fungicide treatments. Under high disease pressure stands were increased (P≤0.10) by RTU Baytan Thiram + Allegiance + Trilex + Vortex + Allegiance + Gaucho and RTU Baytan Thiram + Allegiance + Dynasty + Gaucho as compared to the untreated control and the remaining fungicide combinations. All treatments increased yield as compared to the untreated control (P≤0.10) at an average of 1574.8 pounds per acre seed cotton produced over all fungicide treatments. 2007 COTTON RESEARCH REPORT 45 YIELD AND STAND COUNT OF COTTON IN NORTH ALABAMA TRIAL, 2007 Treatment Low Disease Pressure 1. Untreated + Gaucho 2. RTU Baytan Thiram + Allegiance + Gaucho 3. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Vortex FL + Gaucho 4. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Gaucho 5. RTU Baytan Thiram + Allegiance + Trilex Vortex FL + Allegiance Gaucho 6. RTU Baytan Thiram + Allegiance + DynastyCST + Gaucho LSD (P≤0.10) High Disease Pressure 1. Untreated + Gaucho 2. RTU Baytan Thiram + Allegiance + Gaucho 3. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Vortex FL + Gaucho 4. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Gaucho 5. RTU Baytan Thiram + Allegiance + Trilex Vortex FL + Allegiance Gaucho 6. RTU Baytan Thiram + Allegiance + DynastyCST + Gaucho LSD (P≤0.10) 1 Rate 2.08 1.95 0.49 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 0.06 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 2.08 1.95 0.49 + 0.42 0.22 + 0.49 2.08 1.95 0.49 2.57 + 2.08 2.08 1.95 0.49 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 0.06 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 2.08 1.95 0.49 + 0.42 0.22 + 0.49 2.08 1.95 0.49 2.57 + 2.08 Rate unit ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg Seed cotton ——Stand/10ft row1—— yield 21 DAP2 35DAP lb/A 19.8 b3 27 ab 26.6 ab 19.4 a 22.2 a 27.8 a 4674 a 4849 a 4867 a 30.6 a 28.8 a 5055 a 26.2 ab 24.8 a 4617 a 25.8 ab 5.63 0.2 c 4.4 b 7.6 b 19.8 a 6.56 0c 2 bc 2.4 bc 4498 a 573.91 128 c 1119 b 1485 b 6.8 b 3.2 bc 1457 b 13.6 a 8.2 a 2035 a 11.2 a 2.92 6.6 ab 3.43 2412 a 402.06 Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. 3Means within columns followed by different letters are significantly different according to Fisher’s LSD (P ≤ 0.10). 46 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF AGRILIANCE COTTON SEED TREATMENTS IN CENTRAL ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected experimental seed treatments were evaluated to determine their efficacy against early season cotton disease in central Alabama. The soil was a Compass loamy sand that had a history of seedling disease. Soil temperature was 72 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. Temik 15G (5 pounds per acre) was applied at planting on April 4 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of 4 rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Coopera- tive Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 6. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was moderate for early planted cotton in 2007. At 21 DAP, 37.7 percent of the seed planted did not emerge. No difference (P≤0.10) was observed in stand counts between the untreated control and the fungicide combinations at 35 DAP. Skip indexes taken at 35 DAP were also observed to be the same (P≤0.10) for all fungicide combinations and the untreated control. All fungicide treatments yielded as well as the untreated control (P≤0.10) with an average of 3193.4 pounds per acre of seed cotton produced over all fungicide treatments. STAND COUNT, SKIP INDEX, AND YIELD IN CENTRAL ALABAMA, 2007 Treatment 1. Untreated 2. Dynasty CST + Cruiser 5FS 3. AGST06012 + Cruiser 5FS 4. AGST06012 + AGI07004 5. AGST06012 + AGI07007 LSD (P≤0.10) 1 Rate 0.03 0.34 2.28 0.34 0.03 0.13 0.03 0.13 Rate unit mg/seed mg/seed ml/kg seed mg/seed oz/lb seed oz/lb seed oz/lb seed oz/lb seed —Stand/10ft row1— 21 DAP2 35 DAP 56.0 57.4 69.8 69.2 68.2 63.0 54.4 14.9 61.8 66.4 57.6 12.4 Skip Index3 35DAP 7.0 2.8 6.4 4.6 6.2 4.4 Seed cotton yield lb/A 3039 3134 3402 3528 3144 301.6 Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. 3 Skip index rating is equal to the footage of row greater than 1 foot not occupied by seedling. EFFICACY OF EXPERIMENTAL SEED TREATMENTS ON EARLY SEASON COTTON DISEASES IN CENTRAL ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected experimental seed treatments were evaluated to determine their efficacy against early season cotton disease in central Alabama. The soil was a Compass loamy sand that had a history of seedling disease. Soil temperature was 72 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. High incidence disease plots were infested with millet seed inoculated with Rhizoctonia solani and Pythium ultimum. Temik 15G (5 pounds per acre) was applied at planting on April 4 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of 4 rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production prac- tices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 6. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was moderate for early planted cotton in 2007. At 21 DAP, 48.3 percent of the seeds planted in the high disease pressure plots did not emerge as compared to 20.5 percent in the low disease pressure plots. Under low disease pressure, all fungicide combinations increased seedling stand at 35 DAP as compared to the Cruiser control (P≤ 0.10). All fungicides also produced a lower skip index rating as compared to the Cruiser control (P≤ 0.10) at 35 DAP indicating more evenly spaced plants. All fungicides yielded as well as the 2007 COTTON RESEARCH REPORT 47 Cruiser control with an average of 3061.3 pounds per acre of seed cotton produced over all fungicide treatments. Under high disease pressure, all fungicide combinations increased seedling stand at 35 DAP as compared to the Cruiser control (P≤ 0.10) except for the Apron + Maxim + Systhane + Cruiser combina- tion which did not differ. All fungicides produced a lower skip index compared to the Cruiser control (P≤ 0.10) at 35 DAP. All fungicides yielded as well as the Cruiser control with an average of 2146.6 pounds per acre of seed cotton produced over all fungicide treatments. STAND COUNT, SKIP INDEX, AND YIELD IN CENTRAL ALABAMA, 2007 Treatment Low Disease Pressure 1. Cruiser 5 FS 2. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Cruiser 5 FS 3. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A15701 + Cruiser 5 FS 4. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A15423 + Cruiser 5 FS 5. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A13012 + Cruiser 5 FS 6. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A14911 + Cruiser 5 FS 7. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Cruiser 5 FS 8. Apron XL 3LS Maxim 4FS + Systhane 40 WP + STP27159 Cruiser 5 FS 9. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Vortex 3.77 FS + Cruiser 5 FS LSD (P≤ 0.10) Rate 0.34 28.4 9.5 79.5 0.34 28.4 9.5 79.5 130.6 0.34 28.4 9.5 79.5 124.9 0.34 28.4 9.5 79.5 0.03 0.34 28.4 9.5 79.5 204.4 0.34 28.4 9.5 79.5 56.8 18.9 37.9 0.34 28.4 9.5 79.5 514.8 0.34 28.4 9.5 79.5 56.8 18.9 37.9 7.6 0.34 Rate unit mg/seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed mg/seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed —Stand/10ft row1— 21 DAP2 35 DAP 47.2b 68.8 a 43.6 b 66.0 a Skip Index3 35DAP 12.2 a 9.0 b Seed cotton yield lb/A 3544 a 3434 a 77.6 a 65.0 a 5.2 c 3112 a 81.2 a 72.0 a 3.8 c 2992 a 77.2 a 69.0 a 4.8 c 3021 a 69.2 a 77.6 a 5.6 c 2869 a 74.8 a 70.0 a 4.6 c 3155 a 80.2 a 79.2 a 4.2 c 2415 a 77.0 a 73.4 a 4.4 c 2988.a 12.35 11.8 2.14 802.82 continued 48 ALABAMA AGRICULTURAL EXPERIMENT STATION STAND COUNT, SKIP INDEX, AND YIELD IN CENTRAL ALABAMA, 2007 (CONT) Treatment High Disease Pressure 1. Cruiser 5 FS 2. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Cruiser 5 FS 3. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A15701 + Cruiser 5 FS 4. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A15423 + Cruiser 5 FS 5. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A13012 + Cruiser 5 FS 6. Apron XL 3LS Maxim 4FS + Systhane 40 WP + A14911 + Cruiser 5 FS 7. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Cruiser 5 FS 8. Apron XL 3LS Maxim 4FS + Systhane 40 WP + STP27159 Cruiser 5 FS 9. Apron XL 3LS Maxim 4FS + Systhane 40 WP + Allegiance LS + Baytan 150 SC + Trilex Flowable + Vortex 3.77 FS + Cruiser 5 FS LSD (P≤ 0.10) 1 Rate 0.34 28.4 9.5 79.5 0.34 28.4 9.5 79.5 130.6 0.34 28.4 9.5 79.5 124.9 0.34 28.4 9.5 79.5 0.03 0.34 28.4 9.5 79.5 204.4 0.34 28.4 9.5 79.5 56.8 18.9 37.9 0.34 28.4 9.5 79.5 514.8 0.34 28.4 9.5 79.5 56.8 18.9 37.9 7.6 0.34 Rate unit mg/seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed mg/seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed l/kg seed mg/seed —Stand/10ft row1— 21 DAP2 35 DAP 21.8 a 45.4 a 6.4 c 20.2 bc Skip Index3 35DAP 21.2 a 13 b Seed cotton yield lb/A 2046 a 2622 a 52.8 a 42.4 a 8.6 b 2633 a 54.2 a 52.8 a 8.4 b 2267 a 66.6 a 48.6 a 9.6 b 2216 a 57.6 a 46.6 a 8.0 b 1603 a 52.0 bc 32.4 ab 8.6 b 2437 a 62.4 a 30.0 ab 9.8 b 1233 a 52.2 a 36.4 ab 9.8 b 2245 a 8.48 14.59 3.4 819.45 Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. 3 Skip index rating is equal to the footage of row greater than 1 foot not occupied by seedling. Means within columns followed by different letters are significantly different according to Fisher’s LSD (P ≤ 0.10). 2007 COTTON RESEARCH REPORT 49 EVALUATION OF COTTON SEEDLING DISEASE MANAGEMENT IN CENTRAL ALABAMA, 2007 S. R. Moore and K. S. Lawrence Selected fungicides were evaluated to determine their efficacy against early season cotton disease in south Alabama. The soil was a Compass loamy sand that had a history of seedling disease. Soil temperature was 72 degrees F at a 4-inch depth on the day of planting, with adequate soil moisture. All fungicide treatments were applied to the seed by the manufacturer. Temik 15G (5 pounds per acre) was applied at planting on April 4 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of 4 rows, each 25 feet long with 40 inch row spacing, and were arranged in a randomized complete block design with five replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Stand counts were recorded 21 and 35 days after planting (DAP) to determine stand density and percent seedling loss resulting from cotton seedling disease. Plots were harvested on September 6. Data were statistically analyzed by GLM, and means compared using Fisher’s protected least significant difference (LSD) test. Seedling disease pressure was moderate for early planted cotton in 2007. At 21 DAP, 27.3 percent of the seeds planted did not emerge. At 35 DAP the RTU Baytan Thiram + Allegiance + Trilex + Vortex + Allegiance + Gaucho and the RTU Baytan Thiram + Allegiance + Dynasty + Gaucho combinations increased seedling stands (P≤0.10) as compared to the control and all other fungicide combinations. Skip indexes were lowered by all fungicide treatments compared to the control (P≤0.10) at 35 DAP indicating more evenly spaced plants. All fungicide combinations yielded as well as the untreated control (P≤0.10) with an average of 3162.7 pounds per acre of seed cotton produced over all fungicide treatments. STAND COUNT, SKIP INDEX, AND YIELD IN CENTRAL ALABAMA, 2007 Treatment 1. Untreated + Gaucho 2. RTU Baytan Thiram + Allegiance + Gaucho 3. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Vortex FL + Gaucho 4. RTU Baytan Thiram + Allegiance + Trilex Allegiance + Baytan 30 Gaucho 5. RTU Baytan Thiram + Allegiance + Trilex Vortex FL + Allegiance Gaucho 6. RTU Baytan Thiram + Allegiance + DynastyCST + Gaucho LSD (P≤0.10) 1 Rate 2.08 1.95 0.49 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 0.06 + 2.08 1.95 0.49 + 0.42 0.49 + 0.16 2.08 1.95 0.49 + 0.42 0.22 + 0.49 2.08 1.95 0.49 2.57 + 2.08 Rate unit ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg ml/kg —Stand/10ft row1— 21 DAP2 35 DAP 62.6 a4 68.6 b 79.0 a 83.4 ab 70.8 a 80.2 ab Skip index3 35DAP 5.6 a 3.0 b 3.0 b Seed cotton yield lb/A 3536 a 3463 a 3528 a 69.2 a 83.2 ab 2.0 b 3463 a 76.6 a 89.8 a 2.6 b 3567 a 77.8 a 14.3 94.2 a 12.8 2.2 b 1.7 3715 a 324.9 Plant stand was based on the number of plants per 10 feet of row. 2 Days after planting. 3 Skip index rating is equal to the footage of row greater than 1 foot not occupied by seedling. 4Means within columns followed by different letters are significantly different according to Fisher’s LSD (P ≤ 50 ALABAMA AGRICULTURAL EXPERIMENT STATION NEMATICIDE COMBINATION EFFECTS ON SELECTED NEMATODE SPECIES IN CENTRAL ALABAMA, 2007 N. S. Sekora, K. S. Lawrence, G. W. Lawrence, and S. Nightengale The site was infested with the nematode species Rotylenchulus reniformis and Meloidogyne incognita and was a sandy loam. The temperature was 66.9 degrees F with copious moisture at the 4-inch planting depth. Seed treatments of the cotton cultivar DP 444 BG/RR were previously applied by the manufacturer. Vydate C-LV was applied with a two-row, CO2-charged backpack sprayer as a foliar spray at the fourth true leaf plant stage. Temik 15G (15 pounds per acre) was applied at planting in the seed furrows by chemical granular applicators attached to the planter. Orthene 90S (0.12 pound per acre) was applied for thrips control in all plots. Plots were composed of two 25 foot rows spaced 40 inches apart in a randomized complete block design with five replications per treatment. Soil samples were taken at planting to determine the initial level of nematode infestation. Ten soil cores, 1 inch in diameter by 6 inches deep, were taken randomly from the two rows of each plot. Nematodes were extracted from the soil by gravity sieving and sucrose centrifugation. The average number of R. reniformis present was 66.2 nematodes per 150 cc of soil while the mean number of M. incognita present was 90.2. As prescribed by the Alabama Cooperative Extension System, normal fertility production, herbicide, and insecticide practices were observed throughout the growing season. At six weeks after planting (WAP), stand counts and vigor rating were taken to establish the impact of the nematodes on plant development. On September 18 all plot were harvested. Data means were compared with Fisher’s protected least significant difference (LSD) and all data were analyzed with the GLM procedure. Rainfall totals for April through September were 2.01, 0.47, 1.15, 6.82, 3.26, 2.2 inches, respectively. Total rainfall was 15.91 inches. Monthly average minimum temperatures for April through September were 48.9, 58.2, 67.8, 71.4, 73.7, 66.4 degrees F with an average maximum temperature of 74.7, 87.4, 94.4, 91.8, 99.6, 88.6 degrees F, respectively. At 6 WAP, R. reniformis numbers increased 25 percent to an average of 82.8 nematodes per 150 cc of soil while M. incognita numbers decreased 46 percent to 48.9 per 150 cc. The mean change of R. reniformis per plot ranged -32.6 percent to 2200 percent from the initial populations; M. incognita varied -66.7 percent to 305 percent from initial counts. Plant stands and vigor showed no significant difference (P≤0.10) between any of the treatments versus the control at 6 WAP. Seed yields ranged from 1435 to 418 pounds per acre over the control. All treatments showed a significant (P≤0.10) increase in yield over the control except the Temik 15G 5 pounds per acre side-dress treatment. The Temik 15G, Aeris + Temik 15G, and Avicta + Temik 15G treatments demonstrated the greatest increase in yield over the remaining treatments. SUMMARY OF STAND COUNTS, VIGOR, NEMATODE VUMBERS, AND YIELD BY TREATMENT Treatment 1 Control 2 Aeris 3 Avicta 4 Temik 15 G 5 Aeris Vydate CLV 6 Avicta Vydate CLV 7 Temik 15 G Vydate CLV 8 Aeris Temik 15 G 9 Avicta Temik 15 G 10 Aeris Temik 15 G 11 Avicta Temik 15 G 12 Temik 15 G LSD (P≤0.10) 1 2 Rate 48 mgai/seed 500.4 mgai.seed 5 lb/A 48 mgai/seed 16 oz/a 500.4 mgai.seed 16 oz/a 5 lb/A 16 oz/a 48 mgai/seed 5 lb/A 500.4 mgai.seed 5 lb/A 48 mgai/seed 5 lb/A side dress 500.4 mgai.seed 5 lb/A side dress 5 lb/A side dress Stand 25 ft row1 Jun 5 70.4 75.0 75.2 82.8 72.8 78.0 73.4 66.8 78.6 63.0 79.2 68.8 12.4 Vigor 1-5 sc2 Jun 5 2.8 3.2 3.0 3.3 3.3 3.3 2.9 3.2 3.7 3.7 3.2 3.2 0.8 ——Total nematodes 150 cc soil3—— R. reniformis M. incognita M. incognita Jun 5 Jun 5 Jun 5 135.5 45.2 679.8 105.4 45.2 334.8 60.2 60.2 391.4 90.3 30.1 612.9 75.3 45.2 448.1 45.2 60.2 75.3 75.3 120.4 75.3 75.3 77.0 45.2 45.2 60.2 30.1 105.4 30.1 45.2 44.7 391.4 525.3 293.6 334.8 468.7 381.1 293.6 275.3 Seed lb/A4 Sep 18 540 c 1272 ab 1377 ab 1975 a 1260 ab 1452 ab 1760 ab 1859 a 1975 a 1359 ab 1603 ab 958 bc 494.2 Counts based on number of plants/25 ft row. Vigor ratings based on scale from 1 – 5, 1 being the least vigorous and 5 being the most. 3 Counts based on number of nematodes/150 cc soil. 4 Means followed by same letter do not significantly differ (P≤0.10, Fisher’s protected least significant difference (LSD)). NEMATICIDES ON-FARM FIELD TRIALS TO TEST THE EFFECTIVENESS OF SEED NEMATICIDES FOR MANAGING RENIFORM AND ROOT-KNOT NEMATODES ON COTTON IN ALABAMA, 2007 L. Kuykendall, J.Clary, W. S. Gazaway, W. S. Birdsong, B. Dillard, W. G. Grffith, C. D. Monks, D. P. Delaney, H. Potter, and T. Reed Fields for these trials with selected farmer cooperators (Table 1) were sampled prior to planting to confirm nematode pressure. All trial fields chosen had very high populations of either reniform or root-knot nematodes. Seed from the same seed lot was used for all treatments within each trial. The cotton cultivar DP 555BG/RR was used for all trials except for Lawrence County where DP 444BG/RR was used. Gaucho Grande was included as an untreated check treatment with no nematicide claims. All test treatments were planted in three to five randomized replications per location. The severe heat and drought significantly impacted cotton yields and results from nematicide treatments (Table 2). Trials from Tuscaloosa and Macon Counties are not reported due to extremely poor yields or weighing equipment malfunctions. The trials in Elmore, Lawrence and Macon Counties with lint yields of 508 pounds per acre or less showed no differences in lint cotton yields between treatments. The two trials in Elmore County with lint cotton yields of 750 pounds and greater exhibited a significant yield increase for the seed treatments Aeris and Avicta when compared to the the untreated check and 5 pounds Temik at planting. In these two trials, the increase in lint yield over the untreated check averaged 146 pounds per acre for Aeris and 182 pounds per acre for Avicta. Dry weather at planting may have contributed to the lack of yield response of the traditional treatment of 5 pounds of Temik at planting. No significant yield differences were shown by any treatment based on stastical analysis. County 1. Barbour 2. Elmore 3. Elmore 4 .Elmore 5. Lawrence 6. Macon 7. Macon 8. Tuscaloosa Farmer-Cooperator Walt Corcoran Richard Edgar Carl and Paul Taylor Mark and Dale Taylor Mark Hamilton John T. Ingram and Sons Segrest Brothers Clyde Lavelle TABLE 1. LOCATION OF TRIALS Extension Agronomist William Birdsong/Brandon Dillard Leonard Kuykendall Leonard Kuykendall/Jeff Clary Leonard Kuykendall/Jeff Clary Tim Reed/Heath Potter Leonard Kuykendall/Jeff Clary Leonard Kuykendall/Jeff Clary Warren Griffith Farmer County Richard Edgar Elmore County Mark and Dale Taylor Elmore County Carl and Paul Taylor Elmore County Mark Hamilton Lawrence County TABLE 2. POUNDS LINT COTTON/ACRE: CHANGE FROM UTC (UNTREATED CHECK) No repetitions 4 3 3 3 5 Nematode Species Reniform Reniform Reniform Reniform Rootknot Gaucho Grande UTC 508 848 757 464 407 Aeris + 25 + 106 + 186 -1 -9 + 61 Avicta 0 + 145 + 218 -9 -2 + 70 Temik 5 lbs -2 +6 + 13 +13 +6 +7 C.V. % LSD (P≤0.10) 14.3 12.6 2.2 7.9 NS NS NS NS John T. Ingram and Sons Macon County Average 52 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF AVICTA FORMULATION VARIANTS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 K.S. Lawrence, S. R. Moore, C. H. Burmester, and B. E. Norris Avicta seed treatment and experimental variants were evaluated for the management of reniform nematodes in a naturally infested producer’s field near the Tennessee Valley Research and Education Center in Belle Mina, Alabama. The field had a history of reniform nematode infestation, and the soil type was a Decatur silty loam. Avicta and the variants were applied to DP 444 BG/RR seed by the manufacturer. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 15 feet wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at 29, 59, 89 and 150 days after planting (DAP). Ten soil cores, 1 inch in diameter and 6 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 1. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007 with a total rainfall accumulation of only 6.15inches from planting through harvest. Thus reniform nematode pressure was secondary to the drought conditions. Reniform nematode numbers at planting averaged 2438 vermiform life stages per 150 cm3 of soil at planting. Reniform numbers had not increased by 29 and 59 DAP most probably due to the drought (see table). By 89 DAP, reniform populations had increased in all seed treatments although no differences in population numbers were observed between any treatments. At harvest 150 DAP, nematode populations in all seed treatments declined to below at-plant populations. Seed cotton yields varied by 265 pounds per acre at harvest with an average of 1858 pounds per acre of seed cotton produced over all seed treatments. None of the nematicide seed treatments increased yields as compared to the Cruiser control under these drought conditions in north Alabama. The lack of rainfall probably attributed to the lack of response from the nematicide treatments. EVALUATION OF AVICTA FORMULATION VARIANTS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 Treatment 1. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5FS 2. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 3. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + 14905A 4. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + A14905B 5. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + A15953 6. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + STP15273 + STP 17217 LSD (P ≤ 0.05) 1 Rate ai 7.5+2.5+21g/100kg + 0.34+0.03mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.38 + 0.38mg/seed Rotylenchulus reniformis/ —————150 cm3 soil———— May 30 Jun 29 Jul 29 Oct 1 402 a 1 108 2086 788 371 a 556 a 139 a 294 a 433 a 576 170 77 139 77 92 107 1576 1483 1205 1854 1638 956 494 618 618 417 587 327 Seed cotton lb/A 1873 1751 2016 1865 1824 1819 321 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.05). 2007 COTTON RESEARCH REPORT 53 EVALUATION OF AVICTA VARIANTS ALONE AND IN COMBINATIONS WITH VYDATE C-LV OR TEMIK 15G FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 K.S. Lawrence, C. H. Burmester, G. W. Lawrence, and B. E. Norris Avicta variants, alone and in combination with Vydate CLV or Temik 15G, were evaluated for the management of reniform nematodes in a naturally infested producer’s field near the Tennessee Valley Research and Education Center in Belle Mina, Alabama. The field had a history of reniform nematode infestation, and the soil type was a Decatur silty loam. Avicta was applied to the seed, DP 444 BG/RR, by the manufacturer. Temik 15G (5 pounds per acre) was applied at planting on May 1 in the seed furrow with chemical granular applicators attached to the planter. Vydate C-LV was applied as a foliar spray at the fourth true leaf plant growth stage with a two-row, CO2-charged backpack sprayer. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at 29, 59, 89 and 150 days after planting (DAP). Ten soil cores, 1 inch in diameter and 6 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 1. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007; thus, reniform nematode pressure was low to moderate under these conditions. Rainfall was limited to 6.14 inches for the entire growing season. Reniform nematode numbers at planting averaged 608 vermiform life stages per 150 cm3 of soil. Cotton seedling stand was similar among all treatments (data not shown). By 29 and 59 DAP, reniform numbers had not increased due to the drought, and no differences (P ≤ 0.10) in population numbers were observed between any treatments (see table). Rainfall in July stimulated reniform populations and all seed treatments had lower nematode numbers (P ≤ 0.10) as compared to Centric 40WG (11), Temik at plant with a side dress application (10), the STP15273 + STP17217 experimental combination (8), and A14905A (7). At harvest 150 DAP, A14905A (7) continued to support greater populations (P ≤ 0.10) than all of the remaining 12 nematicide combinations. Seed cotton yields varied by 573 pounds per acre between the numerically highest yielding treatment, Apron XL + Maxim 4FS + Systane 40WP + Temik 15G + Temik 15G (sidedress), and the lowest yielding treatment, Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Centric 40WG. An average of 3488 pounds per acre was produced over all nematicides. Yields averaged 3609 pounds per acre over the seed treatments plus Temik 15G followed by 3360 pounds per acre in the Avicta 4.17 FS seed treatments and 3441 pounds per acre in the Avicta experimental treatments. None of the nematicide treatments increase yields (P ≤ 0.10) as compared to the Cruiser control. EFFECT OF SEED TREATMENTS ON NEMATODE NUMBERS AND SEED COTTON YIELD Treatment 1. Apron XL + Maxim 4FS + Systane 40WP + Cruiser 5FS 2. Apron XL + Maxim 4FS + Systane 40WP + Temik 15G 3. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Temik 15G 4. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS 5. Apron XL + Maxim 4FS + Systane 40WP + A14905A 6. Apron XL + Maxim 4FS + Systane 40WP + A14905B 7. Apron XL + Maxim 4FS + Systane 40WP + A15953 8. Apron XL + Maxim 4FS + Systane 40WP + STP 15273 + STP 17217 9. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Temik 15G 10. Apron XL + Maxim 4FS + Systane 40WP + Temik 15G + Temik 15G (SD2) 11. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Centric 40WG 12. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Vydate CLV Rate ai 7.5+2.5+21g/100kg + 0.03mg/seed 7.5+2.5+21g/100kg + 5 lb/A 7.5+2.5+21g/100kg + 0.34+ 5 lb/A/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.38+ 0.38mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 5 lb/A 7.5+2.5+21g/100kg + 5 lb/A + 5 lb/A 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 56g/ha 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 17 oz/A Rotylenchulus reniformis/ Seed ————150 cm3 soil———— cotton May 30 Jun 29 Jul 29 Oct 1 lb/A 93 93 2395 b 1 1298 a 3382 77 93 77 77 77 77 124 108 108 77 93 77 124 124 155 93 77 93 124 155 139 155 2549 b 2039 b 2627 b 1375 b 5160 a 2596 b 3708 a 2178 b 3507 a 6983 a 1391 b 973 b 572 b 896 b 664 b 633 b 3028 a 1545 b 942 b 865 b 633 b 850 b 3585 3854 3391 3494 3466 3466 3344 3547 3862 3289 3369 continued 54 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF SEED TREATMENTS ON NEMATODE NUMBERS AND SEED COTTON YIELD (CONT) Treatment 13. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Temik 15G + Vydate CLV LSD (P ≤ 0.10) 1 Rate ai 7.5+2.5+21g/100kg + 0.34+0.03mg/seed+ 5 lb/A + 17 oz/A Rotylenchulus reniformis/ —————150 cm3 soil————— May 30 Jun 29 Jul 29 Oct 1 108 216 1792 b 742 b 576 107 956 327 Seed cotton lb/A 3395 708 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.10). 2SD = sidederess application applied at pinhead square. EVALUATION OF THE EXPERIMENTAL AGST06012 ALONE AND IN COMBINATION WITH AVICTA CP, INHIBIT OR TEMIK 15G FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 K.S. Lawrence, C. H. Burmester, and B. E. Norris The experimental seed treatment AGST06012 was evaluated alone and in combination with Avicta, InHibit, or Temik 15G for the management of reniform nematodes in a naturally infested producer’s field near the Tennessee Valley Research and Education Center in Belle Mina, Alabama. The field had a history of reniform nematode infestation, and the soil type was a Decatur silty loam. Dynasty CST, Cruiser, Avicta 4.17 FS, AGST06012, and Origin Ascend were applied to DP 444 BG/RR seed by the manufacturers. InHibit (0.3 mg per seed) was added as a slurry to the seed immediately before planting. On May 1, Temik 15G (5.0 pounds per acre) was applied at planting in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at 29, 59, 89, and 150 days after planting (DAP). Ten soil cores, 1 inch in diameter and 6 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 1. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007 with total rainfall equaling only 6.15 inches; thus, reniform nematode pressure was low to moderate under these conditions. Reniform nematode numbers at planting averaged 3260 vermiform life stages per 150 cm3 of soil at planting. Cotton seedling stand was similar among all treatments (data not shown). By 29 and 59 DAP, reniform numbers had not increased due to the drought, and no differences (P ≤ 0.10) in population numbers were observed between any treatments (see table). Rainfall in July stimulated reniform populations and the AGST06012 + OriginAscend seed treatment alone and in combination with In-Hibit CST andAGST06012 + Temik 15G had lower nematode numbers as compared to the Dynasty CST + Cruiser + Avicta 4.17 FS treatment. At harvest 150 DAP, reniform populations had declined in all treatments. Seed cotton yields varied by 473 pounds per acre at harvest with an average of 1932 pounds per acre of seed cotton produced over all nematicides. Although no nematicide treatment was greater (P ≤ 0.10) than the control, the AGST06012 + Temik 15G combination increased (P ≤ 0.10) yields over the AGST06012 +InHibit CST seed treatment. EVALUATION OF AVICTA FORMULATION VARIANTS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 Treatment 1. Untreated Check 2. Dynasty CST + Cruiser + Avicta 4.17 FS 3. AGST06012 + Cruiser + Avicta 4.17 FS 4. AGST06012 + InHibit CST 5. AGST06012 + OriginAscend+InHibit CST... 6. AGST06012 + OriginAscend 7. AGST06012 + Temik 15G LSD (P ≤ 0.10) 1 Rate ai 0.34+0.03+0.15mg/seed 0.30+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.30 + 0.15 mg/seed 0.30+0.35+0.26mg/seed 0.30+0.35+0.26mg/seed 0.30mg/seed + 5 lb/A Rotylenchulus reniformis/ —————150 cm3 soil————— May 30 Jun 29 Jul 29 Oct 1 256 93 4511 ab1 726 316 124 7122 a 278 270 93 5207 ab 324 196 124 4110 ab 572 196 286 105 261 108 170 93 105 3399 b 3538 b 4172 b 2878 401 494 185 617 Seed cotton lb/A 1769 ab 1961 ab 2035 ab 1539 b 1859 ab 1955 ab 2242 a 370 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.05). 2007 COTTON RESEARCH REPORT 55 AVICTA, AERIS, TEMIK 15G, AND VYDATE C-LV MANAGEMENT OPTIONS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN NORTH ALABAMA, 2007 K.S. Lawrence, C. H. Burmester, G. W. Lawrence, and B. E. Norris Avicta and Aeris seed treatments, Temik 15G, and Vydate C-LV were evaluated for the management of reniform nematodes in a naturally infested producer’s field near the Tennessee Valley Research and Education Center in Belle Mina, Alabama. The field had a history of reniform nematode infestation, and the soil type was a Decatur silty loam. Avicta and Aeris were applied to the seed by the manufacturer. Temik 15G (5.0 pounds per acre) was applied at planting on May 1, in the seed furrow with chemical granular applicators attached to the planter. Vydate C-LV was applied at 17 ounces per acre as a foliar spray at the fourth true leaf plant growth stage with a two-row, CO2charged backpack sprayer. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at 29, 59, 89, and 150 days after planting (DAP). Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 1. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). Rainfall was the limiting factor in the 2007 season; thus, reniform nematode pressure was low to moderate under these conditions. Only 15.3 inches of rain was recorded for the entire growing season. Reniform nematode numbers at planting averaged 1186 vermiform life stages per 150 cm3 of soil. At 29 DAP, reniform numbers had not increased due to the drought; however, by 89 DAP, reniform populations had increased in all the Temik 15G treatment combinations as compared to the control, Aeris, and Avicta alone or in combination with Vydate. At harvest 150 DAP, nematode populations in all treatments declined and six nematicide treatments supported fewer nematodes than the control treatment. An average of 1630 pounds per acre of seed cotton was produced over all nematicide treatments. Avicta and Aeris combined with Temik 15G at planting increased seed cotton yields (P ≤ 0.10) by an average of 258 pounds per acre as compared to the Cruiser control. Yields averaged 1349 pounds per acre over all Avicta treatments followed by 1683 pounds per acre in the Aeris treatments. Temik 15G yields with or without the seed treatments averaged 1545 pounds per acre. The addition of Vydate produced an average yield of 1421 pounds per acre. EFFECT OF AVICTA, AERIS, TEMIK, AND VYDATE ON RENIFORM NUMBERS AND SEED COTTON YIELDS Treatment 1. Control 2. Aeris 3. Avicta 500.4 mgai seed 4. Temik 15G 5. Aeris + Vydate CLV 6. Avicta + Vydate CLV 7. Temik 15G + Vydate CLV 8. Aeris + Temik 15G 9. Avicta + Temik 15G 10. Aeris + Temik 15G SD 2 11. Avicta + Temik 15G SD 12. Temik 15G + Temik 15G SD LSD (P ≤ 0.10) 1 2 Rate ai 48 mgai/seed 500.4 mgai/seed 840gm/ha 48 mgai/seed+561g/ha 500.4 mgai/seed +561g/ha 561g/ha + 840gm/ha 48 mgai/seed+840gm/ha 500.4 mgai/seed + 840 gm/ha 48 mgai/seed+840gm/ha 500.4 mgai/seed + 840 gm/ha 840 gm/ha Rotylenchulus reniformis/ ——————150 cm3 soil—————— May 30 Jun 29 Jul 29 Oct 1 29 DAP 59 DAP 89 DAP 150 DAP 278 ab 1 278 b 2024 b 1669 a 108 b 124 b 2256 b 587 b 232 ab 139 b 1221 b 1004 ab 433 a 108 b 3044 a 927 ab 108 b 124 b 2148 b 1020 ab 155 b 510 a 2070 b 757 b 247 ab 124 b 3414 a 541 b 232 ab 93 b 4125 a 757 b 278 ab 170 b 3229 a 1530 a 108 b 201 b 2503 ab 556 b 108 b 185 b 2719 ab 1190 a 170 b 139 b 3167 a 263 b 259 152 1671 777 Seed cotton lb/A 1322 b 1628 a 1211 b 1539 a 1587 a 1324 b 1352 b 1805 a 1355 b 1713 a 1507 ab 1486 ab 322 Numbers in columns followed by the same letter are not significantly different by Fisher’s LSD at P ≤ 0.10. SD is the side dress application of Temik 15G at pin head square. 56 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF AVICTA FORMULATION VARIANTS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 K.S. Lawrence, S. R. Moore, and J. R. Akridge Avicta seed treatment and experimental variants were evaluated for the management of reniform nematodes in a naturally infested producer’s field near Huxford, Alabama. The field had a long history of reniform nematode infestation, and the soil type was classified as a loam. Avicta and the variants were applied to DP 555 BG/RR seed by the manufacturer. Temik 15G (5.0 pounds per acre) was applied at planting on May 1 in the seed furrow with chemical granular applicators attached to the planter. Vydate C-LV was applied at 16 ounces per acre as a foliar spray at the fourth true leaf plant growth stage with a two-row, CO2-charged backpack sprayer. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 36-inch row spacing and were arranged in a randomized complete block design with six replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007 with a total of 15.3 inches of rainfall recorded at this location. Thus, reniform nematode pressure was secondary to the drought conditions. Reniform nematode numbers at planting averaged 377 vermiform life stages per 150 cm3 of soil at planting. Cotton stand was uniform across all seed treatments with at least nine plants per 10 feet of row (see table). Reniform numbers had not increased at 34 DAP as observed in previous years most probably due to the drought. By 67 DAP, reniform populations had increased in all seed treatments although no differences (P ≤ 0.10) in population numbers were observed between any nematicide treatment. At harvest, 161 DAP, nematode populations in all seed treatments had increased an average of 42 percent as compared to the midseason sample, but no differences between seed treatments were observed. Seed cotton yields varied by 175 pounds per acre at harvest with an average of 1309 pounds per acre of seed cotton produced over all nematicide seed treatments. None of the nematicide seed treatments increased yields (P ≤ 0.10) as compared to the Cruiser control under these drought conditions in south Alabama. The lack of rainfall probably attributed to the lack of response from the nematicide treatments. Stand 10 ft row Jun 13 351 31 40 35 35 35 10 Rotylenchulus reniformis/ Seed ——150 cm3 soil—— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 618 2348 3214 1408 448 711 340 166 355 535 2438 1791 1249 1565 1746 1583 3770 2642 3059 2472 2827 2530 1291 1324 1348 1360 1227 293 EVALUATION OF AVICTA FORMULATION VARIANTS FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 Treatment 1. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5FS 2. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 3. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + 14905A 4. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + A14905B 5. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + A15953 6. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + STP15273 + STP 17217 LSD (P ≤ 0.10) Rate ai 7.5+2.5+21g/100kg + 0.34+0.03mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.38 + 0.38mg/seed 2007 COTTON RESEARCH REPORT 57 EVALUATION OF AVICTA VARIANTS ALONE AND IN COMBINATIONS WITH VYDATE C-LV OR TEMIK 15G FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 K.S. Lawrence, S. R. Moore, and J. R. Akridge Avicta seed treatment and experimental variants were evaluated for the management of reniform nematodes in a naturally infested producer’s field near Huxford, Alabama. The field had a long history of reniform nematode infestation, and the soil type was classified as a loam. Avicta and the variants were applied to the seed by the manufacturer. Temik 15G (5 pounds per acre) was applied at planting on May 1 in the seed furrow with chemical granular applicators attached to the planter. Vydate C-LV was applied as a foliar spray at the fourth true leaf plant growth stage with a two-row, CO2-charged backpack sprayer. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with six replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007; thus, reniform nematode pressure was low under these conditions. Rainfall was limited to 15.3 inches for the entire growing season. Reniform nematode numbers at planting averaged 371 vermiform life stages per 150 cm3 of soil. Cotton seedling stand was similar among all seed treatments; however, treatments combined with Temik 15G produced lower stands (see table). By 34 and 67 DAP, reniform numbers had increased from the initial population levels but no differences (P ≤ 0.10) in numbers were observed between any treatments. At harvest, 161 DAP, no seed treatment nematicide combination reduced nematode populations as compared to the Cruiser control. The seed treatment combinations with A15953 (7) and STP 15273 + STP 17217(8) supported greater reniform numbers than the cruiser control (1). Seed cotton yields varied by 493 pounds per acre at harvest with an average of 1642 pounds per acre of seed cotton produced over all nematicides. Yields averaged 1854 pounds per acre over the seed treatments plus Temik 15G followed by 1371 pounds per acre in the Avicta 4.17 FS experimental seed treatments. The addition of Vydate to Temik 15G or Avicta 4.17FS produced an average yield of 1463 pounds per acre. The Avicta 4.17 FS seed treatment with or without Vydate CLV increased yields (P ≤ 0.10) as compared to the non-treated Cruiser 5FS control under these drought conditions in south Alabama. EFFECT OF SELECTED NEMATICIDES ON COTTON STAND, NEMATODE NUMBERS AND SEED COTTON YIELD Treatment 1. Apron XL + Maxim 4FS + Systane 40WP + Cruiser 5FS 2. Apron XL + Maxim 4FS + Systane 40WP + Temik 15G 3. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Temik 15G 4. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS 5. Apron XL + Maxim 4FS + Systane 40WP + A14905A 6. Apron XL + Maxim 4FS + Systane 40WP + A14905B 7. Apron XL + Maxim 4FS + Systane 40WP + A15953 8. Apron XL + Maxim 4FS + Systane 40WP + STP 15273 + STP 17217 9. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Temik 15G 10. Apron XL + Maxim 4FS + Systane 40WP + Temik 15G + Temik 15G (SD2) 11. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Centric 40WG 12. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Avicta 4.17FS + Vydate CLV Rate ai 7.5+2.5+21g/100kg + 0.03mg/seed 7.5+2.5+21g/100kg + 5 lb/A 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.15mg/seed 7.5+2.5+21g/100kg + 0.38+ 0.38mg/seed 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 840gm/ha 7.5+2.5+21g/100kg + 5 lb/A + 5 lb/A 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 56g/ha 7.5+2.5+21g/100kg + 0.34+0.03+0.15mg/seed + 561g/ha Stand 10 ft row Jun 13 23.8 ab1 15.2 bcd 9.5 d 21.2 abc 17.3 a-d 24.7 ab 19.7 abc 26.3 a 13.2 cd 17.7 a-d 24.7 ab 22.7 abc Rotylenchulus reniformis/ Seed ———150 cm3 soil——— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 618 1519 2060 b 1317 b 348 657 773 670 489 296 682 682 605 592 811 1597 811 708 1223 759 1171 2498 708 1442 914 1467 2163 b 2433 ab 2871 ab 3218 a 2987 ab 3592 a 3798 a 1622 b 2034 b 3128 ab 2523 ab 1449 ab 1384 ab 1643 a 1327 b 1553 a 1386 ab 1314 b 1209 b 1383a 1438 ab 1702 a continued 58 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF SELECTED NEMATICIDES ON COTTON STAND, NEMATODE NUMBERS AND SEED COTTON YIELD (CONT) Treatment 13. Apron XL + Maxim 4FS + Systane 40WP + Dynasty CST + Cruiser 5 FS + Temik 15G + Vydate CLV LSD (P ≤ 0.10) 1 Rate ai 7.5+2.5+21g/100kg + 0.34+0.03mg/seed+ 5 lb/A 17 oz/A Stand 10 ft row Jun 13 13.0 cd 5.8 Rotylenchulus reniformis/ Seed ———150 cm3 soil——— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 528 978 2098 b 1557 335 1183 1568 343 2 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.10). sidederess application applied at pinhead square. SD = EVALUATION OF AVICTA CP, INHIBIT, OR TEMIK 15G WITH THE EXPERIMENTAL AGST06012 FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 K.S. Lawrence, S. R. Moore, and J. R. Akridge AGST06012, alone and in combination with Avicta, InHibit, or Temik 15G, was evaluated for the management of reniform nematodes in a naturally infested producer’s field near Huxford, Alabama. The field had a long history of reniform nematode infestation, and the soil type was classified as a loam. Dynasty CST, Cruiser, Avicta 4.17 FS, AGST06012, and Origin Ascend were applied to DP 555 BG/RR seed by the manufacturer. InHibit was added as a slurry to the seed immediately before planting. Temik 15G (5.0 pound per acre) was applied at planting on May 9 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with six replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were har- vested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007; thus, reniform nematode pressure was low to moderate under these conditions. Rainfall was limited to 15.3 inches for the entire growing season. Reniform nematode numbers at planting averaged 400 vermiform life stages per 150 cm3 of soil at planting. Cotton seedling stand was similar among all treatments with stands averaging nine plants per 10 feet of row (see table). By 34 DAP on June 13, reniform numbers increased an average of six fold; however, no differences (P ≤ 0.10) in population numbers were observed between any treatments and the untreated control. At mid-season, 67 DAP, reniform populations declined probably due to the severe drought. At harvest, 161 DAP, reniform populations had increased in all treatments without any differences (P ≤ 0.10) in population numbers between the treatments. Seed cotton yields varied by 499 pounds per acre at harvest with an average of 1260 pounds per acre of seed cotton produced over all nematicides. AGST06012 combined with Cruiser + Avicta 4.17 FS (3) or Temik 15G (7) increased (P ≤ 0.10) seed cotton yields over the untreated control and AGST06012 +InHibit CST. EVALUATION OF AVICTA CP, INHIBIT OR TEMIK 15G WITH THE EXPERIMENTAL AGST06012 FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 Treatment 1. Untreated Check 2. Dynasty CST + Cruiser + Avicta 4.17 FS 3. AGST06012 + Cruiser + Avicta 4.17 FS 4. AGST06012 +InHibit CST 5. AGST06012+OriginAscend+InHibit CST 6. AGST06012+OriginAscend 7. AGST06012 + Temik 15G LSD (P ≤ 0.10) 1 Rate ai 0.34+0.03+0.15mg/seed 0.30+0.03+0.15mg/seed 0.30+0.26mg/seed 0.30+0.35+0.26mg/seed 0.30+0.35+0.26mg/seed 0.30mg/seed + 5 lb/A Stand 10 ft row Jun 13 28.2 22.7 26.3 24.8 26.8 24.5 27.7 5.2 Rotylenchulus reniformis / Seed ———150 cm3 soil——— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 2974 1030 4262 999 c1 2008 1017 3773 1376 ab 2318 953 4146 1353 ab 2948 592 5626 1030 c 2253 747 2846 1127 bc 2163 592 3901 1177 bc 2009 476 4210 1498 a 1725 420 1386 176 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.05). 2007 COTTON RESEARCH REPORT 59 EFFICACY OF AERIS SEED TREATMENT IN COMBINATION WITH BIOLOGICAL GB 126 FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 K.S. Lawrence, S. R. Moore, G. W. Lawrence, and J. R. Akridge Aeris seed treatment and the biological strains GB 126 were evaluated for the management of reniform nematodes in a naturally infested producer’s field near Huxford, Alabama. The field had a long history of reniform nematode infestation, and the soil type was classified as a loam. All seed treatments were applied to DP 555 BG/RR seed by the manufacturer. Plots consisted of four rows, 25 feet long, with a 36-inch row spacing and were arranged in a randomized complete block design with six replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at monthly intervals. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). Rainfall was the limiting factor in the 2007 season; thus, reniform nematode pressure was low to moderate under these conditions. Only 15.3 inches of rain was recorded for the entire growing season. Reniform nematode numbers at planting averaged 109 vermiform life stages per 150 cm3 of soil. Seed cotton stand was uniform between treatments (see table). Reniform numbers began to increase at 34 DAP, and the RTU Baytan Thiram + Allegiance FL standard seed treatment combined with either Gaucho 600 FS, Aeris, or Aeris + GB 126le7 reduced (P ≤ 0.10) populations as compared to the standard control (1). At mid-season, 67 DAP, the Aeris + GB 126le7 or GB 126le6 reduced (P ≤ 0.10) nematode populations as compared to Aeris alone. By harvest, reniform populations were equivalent across all treatments. Seed cotton yields varied by 328 pounds per acre at harvest with an average of 1463 pounds per acre of seed cotton produced over all nematicide treatments. Gaucho 600 FS, Aeris, and Aeris + GB 126le7 (treatments 2, 3, and 4) increased seed cotton yields (P ≤ 0.10) by an average of 329 pounds per acre as compared to the standard seed treatment control. EFFICACY OF GB 126 ON ROTYLENCHULUS RENIFORMIS Treatment 1. RTU Baytan Thiram + Allegiance FL 2. RTU Baytan Thiram + Allegiance FL + Gaucho 600 FS 3. RTU Baytan Thiram + Allegiance FL + Aeris 4. RTU Baytan Thiram + Allegiance FL + Aeris + GB126le7 5. RTU Baytan Thiram + Allegiance FL + Aeris + GB126le6 LSD (P ≤ 0.05) 1 AND Rate ai 195 + 49 ml/100kg 195 + 49 ml/100kg + 0.375 mg ai/seed 195 + 49 ml/100kg + 0.750 mg ai/seed 195 + 49 ml/100kg + 0.750 + 0.750 mg ai/seed 195 + 49 ml/100kg + 0.750 + 0.750 mg ai/seed Stand 10 ft row Jun 13 21.3 19.3 20.7 17.7 16.7 5.8 SEED COTTON YIELD Rotylenchulus reniformis / Seed ———150 cm3 soil——— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 837 a1 1133 ab 3824 1171 b 425 b 1275 ab 3348 1565 a 296 b 373 b 669 ab 434 1622 a 592 b 386 b 991 2961 1880 1435 a 1499 a 3927 1352 ab 2306 186 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.05). 60 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF THE BIOLOGICAL MUSCODOR FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 K.S. Lawrence, S. Moore, and J. R. Akridge The biological Muscodor was evaluated for the management of reniform nematodes in a naturally infested producer’s field near Huxford, Alabama. The field had a long history of reniform nematode infestation, and the soil type was classified as a loam. Muscodor was applied with the cotton seed and placed in the seed furrow. Temik 15G (5.0 pounds per acre) was applied at planting on May 9 in the seed furrow with chemical granular applicators attached to the planter. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Plots consisted of two rows, 25 feet long, with a 36-inch row spacing and were arranged in a randomized complete block design with six replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the reniform nematode were determined at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). The drought was severe in 2007; thus, reniform nematode pressure was low to moderate under these conditions. Rainfall was limited to 15.3 inches for the entire growing season. Reniform nematode numbers at planting averaged 363 vermiform life stages per 150 cm3 of soil at planting. Cotton seedling stand was similar among all treatments with eight to nine seed per 10 feet of row (see table). By 34 DAP on June 13, no differences (P ≤ 0.10) in nematode population numbers were observed between any treatments and the untreated control. The mid-season sample on July 16 at 67 DAP found reniform populations were lower in the Temik 15G plots as compared to Muscodor 300 at 1.9 gm. At harvest, 161 DAP, populations of reniform were lower in the Muscodor treatment applied at the low rate (P ≤ 0.10) as compared to the untreated control. Seed cotton yields varied by 196 pounds per acre at harvest with an average of 1395 pounds per acre of seed cotton produced over all nematicides. No treatment increased yields over the untreated control. The lack of yield response was probably due to the intense drought. EVALUATION OF THE BIOLOGICAL MUSCODOR FOR RENIFORM NEMATODE MANAGEMENT IN COTTON IN SOUTH ALABAMA, 2007 Treatment 1. Untreated Check 2. Muscodor 300 3. Muscodor 300 4. Temik 15G LSD (P ≤ 0.10) 1 Rate ai 1.9 gm liter soil 0.95 gm liter soil 5 lb/A Stand 10 ft row Jun 13 26.6 21.2 21.6 22.6 11.7 Rotylenchulus reniformis / Seed ———150 cm3 soil——— cotton Jun 13 Jul 16 Oct 31 lb/A 34 DAP 67 DAP 161 DAP 494 1422 ab1 5778 a 1473 602 2457 a 4172 ab 1306 525 1961 ab 2487 b 1387 417 1004 b 4573 ab 1492 324 1208 1669 303 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.10). 2007 COTTON RESEARCH REPORT 61 EFFICACY OF AERIS SEED TREATMENT IN COMBINATION WITH BIOLOGICAL GB 126 FOR ROOT-KNOT NEMATODE MANAGEMENT IN COTTON IN ALABAMA, 2007 K.S. Lawrence, G. W. Lawrence, and S. Nightingale Aeris seed treatment and the biological strains GB 126 were evaluated for the management of the root-knot nematode at the Plant Breeding Unit in Tallassee, Alabama. The field had a long history of root-knot nematode infestation, and the soil type was classified as a sandy loam. Soil was 19.5 degrees C at a 4-inch depth at 10 a.m. with adequate moisture at planting on April 27. All seed treatments were applied to DP 444 BG/RR seed by the manufacturer. Plots consisted of two rows, 25 feet long, with a 40-inch row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 15-foot wide alley. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Population densities of the root-knot nematode were determined at monthly intervals. Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Ten soil cores, 1 inch in diameter and 8 inches deep, were collected from the two rows of each plot in a systematic sampling pattern. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on September 18. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P ≤ 0.10). Rainfall and abnormally high temperatures were the limiting factors in the 2007 season; thus, root-knot nematode pressure was moderate under these severe environmental conditions. Root-knot nematode numbers at planting averaged 32 J2 life stages per 150 cm3 of soil. Seeding cotton stand varied between treatments; however, no treatment was different (P ≤ 0.10) from the control (see table). Plant vigor was visibly improved in all nematicide seed treatments over the fungicide control. Root-knot numbers began to increase at 39 DAP with the Gaucho 600 FS, Aeris, or Aeris + GB 126le7 reducing (P ≤ 0.10) populations as compared to the RTU Baytan Thiram + Allegiance FL standard fungicide control. By harvest, root-knot populations were equivalent across all treatments. Seed cotton yields varied by 842 kg/ha at harvest with an average of 2126 kg/ha of seed cotton produced over all nematicide treatments. Gaucho 600 FS, Aeris alone, Aeris + GB 126le7, and Aeris + GB 126le6 increased seed cotton yields (P ≤ 0.10) by an average of 784 pounds per acre as compared to the standard seed treatment control, RTU Baytan Thiram + Allegiance FL. The addition of GB 126 to RTU Baytan Thiram + Allegiance FL + Aeris + numerically increased seed cotton yields over the Aeris alone by 204 pounds per acre. EFFICACY OF AERIS SEED TREATMENT IN COMBINATION WITH BIOLOGICAL GB 126 FOR ROOT-KNOT NEMATODE MANAGEMENT IN COTTON IN ALABAMA, 2007 Treatment 1. RTU Baytan Thiram + Allegiance FL 2. RTU Baytan Thiram + Allegiance FL + Gaucho 600 FS 3. RTU Baytan Thiram + Allegiance FL + Aeris 4. RTU Baytan Thiram + Allegiance FL + Aeris + GB126le7 5. RTU Baytan Thiram + Allegiance FL + Aeris + GB126le6 LSD (P ≤ 0.10) 1 Rate ai 195 + 49 ml/100kg 195 + 49 ml/100kg + 0.375 mg ai/seed 195 + 49 ml/100kg + 0.750 mg ai/seed 195 + 49 ml/100kg + 0.750 + 0.750 mg ai/seed 195 + 49 ml/100kg + 0.750 + 0.750 mg ai/seed Stand 3 m row Jun 5 21.3 19.3 20.7 17.7 16.7 5.8 Plant vigor1 Jun 5 2.3 d2 3.5 c 3.7 bc 3.9 ab 4.1 a 0.3 M. incognita/ Seed 150 cm3 soil— cotton Jun 5 Sep 18 lb/A 837 a 911 1342 b 425 b 731 2126 a — 296 b 373 b 669 ab 434 561 581 628 387 1917 a 2184 a 2056 a 511 Plant vigor based on a 1-5 scale with 5 representing the healthiest and 1 the weakest seedlings. 2 Column means followed by the same letter are not significantly different according to Fishers least significant difference test (P ≤ 0.10). 62 ALABAMA AGRICULTURAL EXPERIMENT STATION NEMOUT SEED TREATMENT FOR RENIFORM NEMATODE MANAGEMENT S. R. Moore and K. S. Lawrence The nematicide NemOut® (Paecilomyces lilacinus 251) was tested in the field, alone, and in combination with other nematicides. The soil was a Ruston very fine sandy loam with a history of reniform nematode infestation. Soil temperature was 81 degrees F at a 4-inch depth on the day of planting with adequate soil moisture. Seed treatments were applied to the seed by the manufacturers and all other treatments were applied at planting, or 34 days after planting (DAP). Orthene 90S at 0.12 pound per acre was applied to all plots as needed for thrips control. Temik 15G (5 pounds per acre) was applied at planting on May 8 in the seed furrow with chemical granular applicators attached to the planter. Vydate C-LV was applied as a foliar spray at the fourth true leaf plant growth stage with a two-row, CO2charged backpack sprayer. Plots consisted of four rows, each 25 feet long with a 40-inch row spacing, and were arranged in a randomized complete block design with six replications. Adjacent blocks were separated by 15-foot wide alleys. Standard herbicides, insecticides, and fertility production practices, as recommended by the Alabama Cooperative Extension System, were used throughout the season. Population densities of the reniform nematode were determined at 0, 34, 67, and 161 DAP. Plant vigor and seedling stand per row were determined at 34 DAP. Nematodes were extracted using the gravity sieving and sucrose centrifugation technique. Plots were harvested on October 31. Data were statistically analyzed by GLM and means compared using Fisher’s protected least significant difference test (P≤ 0.10). Reniform nematode numbers at planting averaged 388.7 vermiform life stages per 150 cm3. At 34 DAP, Temik 15G nematode numbers (P≤ 0.10) decreased compared with the untreated control. Seedling stand was reduced by the Temik + NemOut treatment. All treatments increased plant vigor as compared to the untreated control (P≤ 0.10) with the exceptions of the Temik + NemOut (treatment 6) and the NemOut alone (treatment 3). At 67 DAP, the Temik + NemOut (treatment 5) and the Aeris + NemOut (treatment 9) had lower nematode numbers as compared to the untreated control (P≤ 0.10). At 161 DAP, no differences were observed in nematode numbers compared to the untreated control (P≤ 0.10), which averaged 2952.4 vermiform life stages per 150 cm3 per treatment. All treatments yielded as well as the untreated control (P≤ 0.10) with an average of 1380.8 pounds per acre of seed cotton produced over all treatments. Treatment and Rate AI 1 Temik 15G 5.6 kg/ha 2 Avicta CP 500.4 mg/seed 3 NemOut SP 0.17 kg/ha 4 Avicta CP 500.4 mg/seed Vydate CL-V 620.7 ml/ha 5 Temik 15G 5.6 kg/ha NemOut SP 0.17 kg/ha 6 Temik 15G 5.6 kg/ha NemOut SP 0.17 kg/ha 7 Avicta CP 500.4 mg/seed NemOut SP 0.17 kg/ha 8 Aeris 48.0 mg/seed 9 Aeris 48.0 mg/seed NemOut SP 0.17 kg/ha 10 Untreated LSD (P≤0.10) 1 NEMOUT SEED TREATMENT FOR RENIFORM NEMATODE MANAGEMENT Application date1 DAP 0 0 0 0 34 0 34 0 34 0 34 0 0 34 N/A N/A Reniform 150cc 34 DAP 399.1 b4 Stand 10 ft row2 34 DAP 16.5 ab 16.7 ab 17.5 ab 18.7 ab 8.8 bc 6.8 c 18.3 ab 19.8 a 14.2 abc 17.0 ab 5.9 Vigor3 34 DAP 3.0 ab 3.3 a 2.2 c 3.0 ab 2.7 abc 2.3 bc 3.0 ab 3.0 ab 3.0 ab 2.2 c 0.5 Reniform 150cc 67 DAP 1377.7 ab Reniform 150cc 161 DAP 3309.2 a 2510.8 a 3244.5 a 3012.8 a 2395.0 a 2034.5 a 2549.2 a 4673.8 a 2523.7 a 3270.5 a 1649.2 Stand cotton lb/A 1347.2 a 1307.9 a 1405.8 a 1672.6 a 1272.8 a 1330.2 a 1453.6 a 1270.4 a 1456.6 a 1290.9 a 277.8 772.5 ab 862.7 ab 1197.4 a 656.6 ab 772.5 ab 1042.9 a 862.6 ab 939.9 a 1030.0 a 534.6 1660.9 ab 1390.5 ab 2072.9 a 733.9 b 862.7 a 1068.7 ab 1274.7 ab 798.3 b 1776.8 a 960.0 Application date of chemical measured in days after planting.2 Plant stand based on the number of seedlings/3m row.3 Plant vigor rated over the plot on a 1-5 scale.4 Numbers in columns followed by the same letter are not significantly different by Fisher’s LSD at P ≤ 0.10. 2007 COTTON RESEARCH REPORT 63 NEMATICIDE COMBINATION EFFECTS ON SELECTED NEMATODE SPECIES IN CENTRAL ALABAMA, 2007 N. S. Sekora, K. S. Lawrence, G. W. Lawrence, and S. Nightengale A nematicide seed treatment test was extablished at the Plant Breeding Unit of the E. V. Smith Research and Education Center. The manufacturer applied all fungicidal seed treatments to Gossypinum hirsutum cultivar DP 444 BG/RR. Temik 15G (15 pounds per acre) was applied in the seed furrows at planting by chemical granular applicators attached to the planter. Vydate C-LV was applied as a foliar spray with a two-row, CO2-charged backpack sprayer at the fourth true leaf plant stage. Thrips insect control was established by spraying each plot with Orthene 90S (0.12 pound per acre). Plots consisted of two 25 foot rows spaced 40 inches apart arranged in a complete randomized block design. Nematode samples were taken by randomly collecting ten soil cores, 1 inch diameter by 6 inch deep, from the two rows of each plot. Nematodes were extracted from the soil samples by gravity sieving and sucrose centrifugation. The initial counts of Meloidogyne incognita at planting on April 27 ranged from 26 to 344 nematodes per 150 cc of soil with a mean number of 64.5. All other regulatory management of herbicide, fertility production, and insecticides was carried out as per the Alabama Cooperative Extension System. Test plots were picked on September 18. GLM was used to analyze the data and Fisher’s protected least significant difference (LSD) was used for comparisons. Monthly average maximum temperatures for April through September were 74.7, 87.4, 94.4, 91.8, 99.6, and 88.6 degrees F with an average minimum temperature of 48.9, 58.2, 67.8, 71.4, 73.7, and 66.4 degrees F, respectively. Rainfall totals for each month April through September, respectively, were 2.01, 0.47, 1.15, 6.82, 3.26, and 2.2 inches. Total rainfall over the growing season was 15.91 inches. Six weeks after planting (WAP) stand counts ranged from 89 to 46 percent of emergence with an average vigor rating of 3.8. Six WAP M. incognita counts increased 32 percent to a mean of 85.1 per 150 cc of soil. At 12 WAP stand counts decreased to a mean value of 69.7 percent among all plots. A maximum number of nine plants with Fusarium wilt signs were recorded from the test plots with a mean number of 2.6 plants per plot demonstrating symptoms. The ratio of M. incognita eggs per gram of root tissue had a mean value of 718 and ranged from 17 to 1775 eggs per gram. Mean plot yields ranged from 1742 to 2312 pounds per acre with a mean value of 1915 pounds per acre. No significant differences (P≤0.10) was indicated among any of the treatments for M. incognita eggs/gram of root tissue, plants with Fusarium symptoms, plant stand, or yield. FUSARIUM WILT COMPLEX AVERAGES LISTED BY TREATMENT Stand 8 m row1 Jul 23 60.2 69.4 FW plants2 Jul 23 2.4 2.2 Galling3 Jul 23 4.8 4.6 Treatment 1 Cruiser 5 FS 2 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS 3 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil 4 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Dividend 0.15 FS 5 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Dividend 0.15 FS Rate 0.342 mg ai/seed 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 8 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 16 g ai/100 kg Total nematodes/150 cc soil5 M. M. Seed cotton Eggs/gram4 incognita incognita lb/A Jul 23 Jun 5 Sep 13 Sep 18 622.2 60.0 798.3 1841 700.0 122.8 648.9 1812 68.0 3.6 4.4 760.1 45.0 767.4 1742 69.8 3.8 4.4 485.2 121.4 963.1 1835 74.2 2.0 4.6 934.8 60.0 1194.8 2021 continued 64 ALABAMA AGRICULTURAL EXPERIMENT STATION FUSARIUM WILT COMPLEX AVERAGES LISTED BY TREATMENT (CONT) Stand 8 m row1 Jul 23 74.2 FW plants2 Jul 23 3.6 Galling3 Jul 23 4.8 Treatment 6 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Bion 50 WG 7 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Bion 50 WG 8 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Thiabendazole 9 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Cruiser 5 FS Avicta 4.17 FS Mycobutanil Thiabendazole 10 Apron XL 3 LS Maxim 4 FS Systhane 40 WP A13012 Temik 15G LSD (P≤0.10) 1 Rate 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 0.6 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 1 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 8 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 0.342 mg ai/seed 0.15 mg ai/seed 21 g ai/100 kg 16 g ai/100 kg 7.5 g ai/100 kg 2.5 g ai/100 kg 21 g ai/100 kg 0.03 mg ai/seed 5 lb/A Total nematodes/150 cc soil5 M. M. Seed cotton Eggs/gram4 incognita incognita lb/A Jul 23 Jun 5 Sep 13 Sep 18 1005.9 75.0 700.4 1893 72.8 2.0 4.4 733.3 91.4 757.1 1795 67.0 1.6 4.4 995.6 45.0 715.9 2074 71.2 2.8 4.8 717.0 122.8 664.4 1830 70.2 1.8 3.2 226.9 107.8 582.0 2312 7.5 2.4 1.0 512.3 104.7 628.1 456.22 Counts based on number of plants/25 ft row. 2 Counts based on the number of plants showing symptoms/row. 3 Root galling ratings based on a scale from 0 – 10, 0 with no galling and 10 being severe galling. 4 Measurement of the number of M. incognita eggs/gram of fresh root tissue. 5 Counts based on number of nematodes/150 cc soil. MOLECULAR FACILITATING BREEDING COTTON FOR RENIFORM NEMATODE RESISTANCE R. D. Locy, D. B. Weaver, N. K. Singh, and K. S. Lawrence We have selected germplasm that shows significant resistance to reniform nematodes and developed F2 populations of crosses of these lines with commercial varieties. We now have developed F3 lines derived from F2 individuals that will be tested for reniform nematode resistance as a means of assessing the resistance of the F2 individuals from which they were derived. Such a lengthy measure is required because of difficulties in reliably evaluating F2 individual plants and the destructive nature of evaluation. In order to facilitate this screening at the whole plant level, we are developing genomic and/or proteomic markers to facilitate the evaluation of this material for nematode resistance. Our efforts focus on obtaining gene expression profiles or proteomic profiles during various stages of nematode infection. These will then be utilized to identify uniquely up- or down-regulated genes and proteins in resistant versus non-resistant genotypes. We have produced root-viewing chambers that allow us to observe cotton plant roots during nematode application and infection and are establishing exactly when we should look at samples to determine whether plants are expressing resistance determinants. We are interested in establishing whether young roots express the critical genes prior to, or early on, in the infection process, or whether the necessary proteins are only expressed later in the development of a plant. We have found root tissues of older plants to be a more refractive tissue with which to work than are younger roots. However, it is not clear whether meaningful dif- ferences can be determined using the young root tissue (plants less than 21 days of age) or whether we will require older tissue for analysis following extensive root colonization. Proteomic analysis of gene expression during nematode infection to examine the changes in protein expression during the development of a reniform nematode infection (or lack thereof) in resistant and susceptible materials is underway. Initially, our efforts focused on developing protein extraction techniques that are effective in quantitatively extracting proteins and total RNA from cotton root tissue across the period during which we will be examining reniform nematode resistance. We have utilized three techniques for protein extraction from cotton roots (Carpentier et al., 2005; Giavalisco et al., 2003; Wang et al., 2003). Despite the fact that these techniques are considered useful for “recalcitrant” plant tissues, we have been unable to obtain consistent results using these techniques. Sample-to-sample variation is greater than treatment variations in protein patterns on two-dimensional gels. We have attempted to modify these procedures, to work better for cotton, and have improved the consistency of results, but this has delayed the analysis of our breeding lines. Using the hot-borate RNA extraction technique, we are able to obtain high-quality RNA from cotton roots at all stages of development, and we are presently looking at using massively parallel signature sequencing to analyze samples. This approach appears at this point to be more straight-forward than the proteomic approach we were planning. BREEDING NEW VARIETIES OF COTTON FOR HEAT AND DROUGHT TOLERANCE: ELITE GERMPLASM DEVELOPMENT USING MOLECULAR MARKERS R. D. Locy, D. B. Weaver, and N. K. Singh Using a chlorophyll fluorescence screening procedure we developed, we have screened 1782 accessions of the cotton (Gossypium hirsutum) germplasm collection (US National Cotton Germplasm Collection, College Station, Texas). Twenty-two of these accessions demonstrated photosynthesis that was dramatically more heat stress stabile than existing commercial varieties. These accessions were evaluated for whole plant heat stress stability in growth chambers, and their performance compared to that of DP 90, a variety considered to be among the most heat and drought tolerant available. While all 22 of the accessions performed better than DP 90, seven of the elite 22 were clearly superior in performance during heat stress to DP 90 and the other accessions. We have attempted to make crosses between these seven elite accessions and commercial varieties to generate F1 hybrids and subsequent F2 populations for breeding. However we have had great difficulty obtaining flowers to use for crossing. This is because these materials are highly photoperiodic land races that do not flower readily in the Auburn, Alabama, environment. Consequently, we have sent all accessions to the Cotton, Inc. winter nursery to obtain crosses. However, only one cross yielded F1 seeds. These F1 plants were grown in the field in summer 2007. The plants flowered and were self manually pollinated. However, due to the severe summer drought conditions, all flowers aborted and did not yield any F2 seed. In the meantime, we have had plants of each of the seven elite accessions growing in the greenhouse in pots for 2.5 years. These plants are now prolifically flowering, and we have now made a significant number of crosses to DP 90 with all seven elite accessions. We expect to have a significant number of F1 plants to take to the field in summer 2008 with which to make F2 populations. 66 ALABAMA AGRICULTURAL EXPERIMENT STATION At the same time we are developing a set of molecular markers that we expect to utilize as markers in breeding to move the genes for heat tolerance into commercial germplasm. We have completed the differential display analysis of gene expression during 2- and 20-hour heat stress in DP 90 and have identified approximately 100 cDNA sequences that are differentially displayed during heat stress in DP 90. We are presently analyzing these sequences in more detail and are preparing to examine cDNA sequences from the other seven elite genotypes. Additionally, we have initiated a proteomic analysis of differentially expressed proteins during heat stress in DP 90 and the seven elite accessions. We have obtained preliminary data to demonstrate the workability and cost effective application of the technique in a breeding situation where multiple samples must be screened. We have demonstrated that there are proteins that are differentially expressed in response to heat stress that vary between the accessions examined to date, but we have not been successful in reducing sampling variation to obtain good quality samples for analysis from all accessions of interest. It appears that in species without a complete genomic sequence (such as cotton), there may be additional difficulties in using this technique for gene identification although the emergence of a larger cotton Unigene set and the BLAST utility we have developed (discussed above) may make this less of a concern. PRODUCTION AND CHARACTERIZATION OF BT RESISTANCE IN COTTON BOLLWORM, HELICOVERPA ZEA W. J. Moar Since 2004, we have selected for Bt resistance in cotton bollworm (CBW), Helicoverpa zea, the last major cotton caterpillar pest in which there is no Bt resistant colony, and the more difficult of the two major caterpillar pests to control in Bt and non-Bt cotton. We currently have a population of CBW with greater than 100-fold resistance to Cry1Ac (the Bt in Bollgard and Widestrike). For 2007 we proposed to: (1) Continue laboratory selection with our Cry1Ac toxin resistant strain of CBW (2) Determine the characteristics in MVPII that negatively impact the resistant strain (3) Once 100-fold resistance is achieved, the following experiments will be conducted: a) Evaluate fitness costs b) Determine level of resistance needed to survive on Bollgard cotton c) Select for resistance using Cry1Ac protoxin (4) Select for Cry2a resistance Laboratory selection with the Cry1Ac toxin resistant strain of CBW continued throughout 2007. Although selection pressure remained the same (500 ppm Cry1Ac toxin), resistance did increase to 150 to 200 fold. Cry1Ac-resistant CBW had negligible cross resistance to protoxin (Cry1Ac form found in MVPII). There were no binding differences for both Cry1Ac, Cry1Aa, and GalNac, further suggesting that the primary mechanism of resistance to Cry1Ac toxin is not an alteration in binding which is typically observed for protoxin selection and resistance, and a mechanism of resistance in pink bollworm and tobacco bud worm. Crossing studies confirm previous reports that resistance is inherited as a co-dominant trait There appears to be significant fitness costs associated with Cry1Ac resistance in CBW such as significantly increased pupal mortality, a male-biased sex ratio, lower mating success, significantly higher larval mortality, lower larval weight, longer larval developmental period, lower pupal weight, longer pupal duration, and produced significantly higher number of morphologically abnormal adults over three generations. Although several attempts were made to select for Cry2A resistance, the significant fitness costs observed with adults resulted in only one to two generations of survivors before the colony crashed. Cry1Ac-resistant CBW was also tested on field-grown Bt (DP 555BG/RR) and non Bt-cotton (DP 491). The Bt resistance colony (AR) had significantly higher larval survivorship, number of larval instar reached, and duration of larval survival after feeding on Bt cotton squares. However, AR could still not complete larval development on Bt cotton. These results support the difficulty of maintaining Cry1Ac resistant populations of H. zea in the laboratory, and may help explain why field-evolved resistance has yet to be observed in this major pest of Bt cotton. CONTRIBUTORS INDEX Author J. R. Akridge F. J. Arriaga K. S. Balkcom J. Bergtold W. C. Birdsong C. Brodbeck Pages 29-30,32,56,57-58,58,59,60 23-25,39-40 21-22,23-25,31-32,34-35,39-40 23-25 51 11-12,26-27,27-28 S. Nightengale B. E. Norris S. H. Norwood Author C. C. Mitchell W. J. Moar C. D. Monks S. R. Moore Pages 23-25,34-35,36-38,39-40 66 7-8,8-9,10-11,13-15,15-16,21-22,29-30,51 32,42,43-44,44-45,46,46-48,49,52,56, 57-58,58,59,60,62 50,61,63-64 7-8,8-9,10-11,41,52,53-54,54,55 11-12,27-28 C. H. Burmester 7-8,8-9,10-11,11-12,20-21,27-28,52, 53-54,54,55 J. Clary L. M. Curtis D. P. Delaney B. Dillard C. Dillard 51 7-8,8-9,10-11,11-12 23-25,34-35,36-38,51 51 27-28 M. G. Patterson 13-15,15-16 H. Potter A. J. Price R. Raper T. Reed D. Schrimsher N.S. Sekora J. N. Shaw N. K Singh R. H. Smith D. Sullivan D. B. Weaver A. Winstead R. P. Yates 51 13-15 11-12 51 41 50,63-64 11-12,26-27,27-28 65,65-66 17-18,18-19 26-27 33,65,65-66 11-12 36-38 M. P. Dougherty 7-8,8-9,10-11,11-12,26-27 F. Ducamp B. Durbin B. Durham J. P. Fulton W. S. Gazaway K. Glass 39-40.. 31-32 7-8,11-12 7-8,8-9,10-11,11-12,26-27,27-28 29-30,31,51 31 R. W. Goodman 27-28 W. G. Griffith M. H. Hall D. H. Harkins J. Holliman G. Huluka L. Kuykendall 51 27-28 7-8,8-9,10-11,11-12 36-38 36-38 51 G. W. Lawrence 32,50,53-54,55,59,61,63-64 K. S. Lawrence 29-30,31-32,32,41,42,43-44,44-45,46, 46-48,49,50,52,53-54,54,55,56,57-58 58,59,60,61,62,63-64,65 65,65-66 27-28 R. D. Locy P. L. Mask