btt I~w~M~a eubnn~ed/reinto/U ulicetons/lora eandtield~tmI rT .Inte in copron WI e a I NE ative xeinyse a amaf niversity "an u uron nersitv Research Report Series No. 22 March 2002 abiua xperime tatin S nriu urn a am ddEN&9mm 2001 CO i TON RESEARCH REPOR i ACKNOWLEDGMENTS This publication is a joint contribution of Auburn University, Alabama Agricultural Experiment Stations, Alabama A&M University, 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. 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 Editors, Contributors VARIETY TRIALS Cherokee County Cotton Variety Trial .................................................... ................... ............................. B lack B elt C otton Variety Trial .................................................................................................................... 1 Cotton Variety Response to the Reniform Nematode in South Alabama ............................................... 3 BIOLOGICAL CONTROLS The Effect of Red Imported Fire Ants on Cotton Aphid Outbreaks in Alabama Cotton .......................................................... 4 Evaluation of Plant Growth-Promoting Rhizobacteria for Control of Cotton Seedling Diseases in North Alabama ............... 5 Evaluation of Plant Growth-Promoting Rhizobacteria for Control of Cotton Seedling Diseases in Central Alabama ............ 6 Evaluation of Cotton Transplants Treated with Plant Growth-Promoting Rhizobacteria in North Alabama .................................. 8 Evaluation of Cotton Transplants Treated with Plant Growth-Promoting Rhizobacteria in Central Alabama................................ 9 CROP PRODUCTION Row Spacing and Skip Rows for Cotton in Central Alabama .......................................................................... 10 Sprinkler and Subsurface Drip Irrigation,Tennessee Valley Research and Extension Center ................................................ 10 Water Resource Development for Irrigation in the Tennessee Valley ................................................... 13 Evaluation of Terra Control SC 823 on Irrigated and Nonirrigated Cotton ........................................... 14 Surface-Applied Broiler Litter in Reduced Tillage Cotton ......................... ................................................................................. 15 Changes in Central Alabama Cotton Soils, 1991 and 2001 ............................................................... 16 The Old Rotation and Cullars Rotation-2001 ....................................................................... 19 GROW H REGULATORS, DEFOLIANTS, AND HERBICIDES Evaluating New Growth Regulators for Cotton .......................................................................................... ....................... 21 N ew H arvest A ides for Cotton .................................................. ................................. ........................ 21 Evaluation of a Wick Applicator for Applying Mepiquat Chloride to Cotton ..................... ........................ 22 Liberty-Link Cotton Weed Management Programs ...................................................................... 23 INSECTICIDES Tarnished Plant Bug Control in Cotton ......................................................................... 24 Evaluation of Insecticides for Control of Insect Pests in Bt Cotton and Selectivity Against Beneficial Species ................................ ........................................ 25 Thrips M anagement in Cotton ............................................... ......... .. ..................... .......................... 26 Statewide Monitoring of Bollworm/Budworm Populations with HELID ................................................. .......................... 27 Evaluation of Bollgard II and Phytogen Varieties for Control of Fall Armyworm and Bollworm Species .............................. 27 NEMATICIDES Management of the Reniform Nematode with Anhydrous Ammonia.......................................................................................... 29 Evaluation of the Soil Fumigant Vapam for Reniform Nematode Management in Cotton .......................................................... 30 Telone Fall Fumigation Versus Spring Fumigation for Reniform Nematode Management in Cotton ............................................ 30 Impact of Fall Fumigation with Telone and Post Plant Temik Applications on Cotton Production .............................................. 31 Impact of Various Crop Rotations and Winter Cover Crops on the Reniform Nematode in Cotton .............................................. 32 FUNGICIDES Evaluation of Full Season Cotton Varieties for Response to Boll Rot Disease in Alabama ....................................................... 34 Evaluation of Selected Fungicides for Control of Cotton Boll Rot Disease on DPL458BR ...................................................... 35 Evaluation of Selected In-furrow Fungicides for Control of Seedling Disease of Cotton in North Alabama ............................ 36 Evaluation of Selected In-furrow Fungicides for Control of Seedling Disease of Cotton in Central Alabama .......................... 38 Evaluation of Selected Seed Treatment Fungicides for Control of Seedling Disease of Cotton in North Alabama..................... 39 Evaluation of Selected Seed Treatment Fungicides for Control of Seedling Disease of Cotton in Central Alabama ............... 42 Evaluation of Selected Fungicides for Control of Seedling Disease in Ultra Narrow Row Cotton..................... 44 MOLECULAR STUDIES Development of Novel Transformation Systems in Cotton .......................................................... 45 Isolation of Genes Related to Cotton Performance and Quality ...................................................... 45 Developing in vitro Cotton Culture Systems for Reniform Nematode Studies .............. ................................ 46 Authors' Index ........................................................................................... 48 EDITORS Kathy S. McLean Assistant Professor Entomology and Plant Pathology Auburn University C. Dale Monks Associate Professor and Extension Specialist Agronomy and Soils Auburn University CONTRIBUTORS James R. Akridge Superintendent Brewton Experiment Field James W. Baier Assistant Professor, Biosystems Engineering Auburn University R.R. Beauchamp Extension Agent-Elmore County Alabama Cooperative Extension System W. C. Birdsong Wiregrass Research and Extension Center James Bolton Department of Plant and Soil Science Alabama A&M University Charles Burmester Extension Agronomist Tennessee Valley Research and Extension Center, Belle Mina, Alabama Linda Carter Department of Entomology & Plant Pathology Auburn University Jamey Clary Multi-County Agent Coordinator Alabama Cooperative Extension System Larry M. Curtis Professor and Extension Specialist Biosystems Engineering Auburn University Dennis P. Delaney Extension Specialist, Agronomy and Soils Auburn University Dewang Deng Department of Plant and Soil Science Alabama A&M University David Derrick County Agent, Cherokee County Alabama Cooperative Extension System Bobby Durbin Superintendent Field Crops Unit, E.V. Smith Research Center Shorter, Alabama Mickey D. Eubanks Assistant Professor Entomology and Plant Pathology Auburn University Wilson H. Faircloth Graduate Research Assistant Agronomy and Soils Auburn University Extension Entomologist Entomology and Plant Pathology Auburn University William S. Gazaway Professor and Extension Specialist, Emeritus Entomology and Plant Pathology Auburn University Kathy Glass Agricultural Program Associate II Agronomy and Soils Auburn University Nick W. Greer Entomology and Plant Pathology Auburn University Bob Goodman Associate Professor Agricultural Economics and Rural Sociology Auburn University David H. Harkins Agricultural Program Assistant Tennessee Valley Research and Extension Center, Belle Mina, Alabama Aaron Jeffries Department of Plant and Soil Science Alabama A&M University lan Kaplan Graduate Research Assistant Entomology and Plant Pathology Auburn University Joe W. Kloepper Professor Entomology and Plant Pathology Auburn University L. Kuykendall Extension Agent-Autauga County Alabama Cooperative Extension System Gary W. Lawrence Entomology and Plant Pathology Mississippi State University Kathy S. McLean Assistant Professor Entomology and Plant Pathology Auburn University Charles Mitchell Extension Agronomist Agronomy and Soils Auburn University C. Dale Monks Associate Professor and Extension Specialist Agronomy and Soils Auburn University Don P. Moore Superintendent Prattville Experiment Field Marshall M. Nelson Natural Resources Conservation Service Bobby E. Norris Superintendent Tennessee Valley Research and Extension Center, Belle Mina, Alabama Perry L. Oakes Natural Resources Conservation Service Aaron J. Palmateer Graduate Research Assistant Entomology and Plant Pathology Auburn University Michael G. Patterson Professor, Agronomy and Soils Auburn University Malcomb Pegues Gulf Coast Research and Extension Center Fairhope, Alabama M. S. Reddy Research Fellow IV Entomology and Plant Pathology Auburn University Wayne Reeves USDA-ARS Soil Scientist Auburn University Hamidou Sakhanokho Department of Plant and Soil Science Alabama A&M University Govind Sharma Department of Plant and Soil Science Alabama A&M University Edward Sikora Associate Professor Entomology and Plant Pathology Auburn University Ron H. Smith Professor and Extension Entomologist Entomology and Plant Pathology Auburn University Khairy Soliman Department of Plant and Soil Science Alabama A&M University Yonathan Tilahun Department of Plant and Soil Science Alabama A&M University Larry W: Wells Superintendent Wiregrass Research and Extension Center Headland, Alabama Zhengdao Wu Department of Plant and Soil Science Alabama A&M University Rudy Yates Extension Agent-Dallas County Alabama Cooperative Extension System Allan Zipf Department of Plant and Soil Science Alabama A&M University VARIETY TRIALS CHEROKEE COUNTY COTTON VARIETY TRIAL Charles Burmester and David Derrick Cherokee County is a large cotton growing area in northeast Alabama with unique soil types that are not represented in the state cotton variety trials. Each year an Extension cotton variety trial is conducted in the area for farmers to use as a guide in con- junction with results from the Alabama Cotton Variety Tests. In 2001, the trial was conducted on the farm of Randall and Nick McMichen on a Holston fine sandy loam soil. Cotton was planted no-till into a winter cover crop of wheat on May 7 and consisted of eight rows of each variety planted the length of the field. A total often cotton vari- eties were planted. All variet- ies were genetically modified and contained the Roundup Ready gene that allows weed control applications with Roundup Ultra until the 4t leaf stage. The cotton variety Pay- master 1218 B/RR was used as a check variety between each plot to reduce field variability. All varieties were spindle picked, and seed cotton was weighed in a boll buggy. A seed cotton sample from each variety was ginned on a tabletop gin for lint percentage and quality. Cotton growing conditions were excellent in 2001 and re- sulted in record yields (see table). Insect numbers were very low and only minimal control measures were required. All varieties tested produced more than two and one-half bales. Yields of Stoneville 4892 BR and Fibermax 989 BR led this test site in 2001. Cotton quality was also excellent with no varieties with micronaire reading below 3.5 or length reading below 1.11. YIELD AND QUALITY OF COTTON VARIETIES IN THE CHEROKEE COUNTY TRIAL Variety Seed cotton yield Lint 1 Lint Mic. 2 Length Unif. 3 Strength lbs/ac % lbs/ac Stoneville 4892 BR 3,784 0.437 1,654 4.2 1.18 86.9 34.2 Fibermax 989 BR 3,827 0.423 1,619 3.7 1.16 84.3 32.2 Deltapine 436 RR 3,338 0.414 1,381 3.9 1.14 82.9 29.6 Deltapine 451 B/RR 3,427 0.401 1,374 3.5 1.22 85.3 31.2 Stoneville 4793 RR 2,972 0.460 1,367 3.9 1.15 85.9 31.6 Sure Grow 215 RR 3,195 0.423 1,351 4.3 1.14 85.1 29.5 Sure Grow 501 BR 3,070 0.435 1,335 4.3 1.16 85.9 30.6 Paymaster 1218 B/RR 3,102 0.430 1,334 3.9 1.15 85.9 31.6 Paymaster 1199 RR 2,995 0.439 1,315 4.6 1.15 84.3 29.2 Sure Grow 521 R 2,920 0.432 1,261 3.8 1.11 81.6 27.9 1 Lint % determined on a small cotton gin without cleaners. This percentage is usually higher than normal turn-out at a cotton gin. 2 Mic.=micronaire. 3 Unif.=uniformity. BLACK BELT COTTON VARIETY TRIAL Dennis Delaney, C. Dale Monks, Rudy Yates, Jamey Clary, and Kathy Glass Cotton acreage in the Black Belt region ofAlabama has fallen from historic levels, but cotton is still important to the economy of the area and particularly important to the producers who grow it. Area cotton producers asked the Alabama Cooperative Extension System and Alabama Agricultural Experiment Station for help in obtaining up-to-date unbiased information on the unique soils on their farms. Since cotton production requires specialized equip- ment and experience not available at the area Research and Exten- sion Center, a replicated on-farm variety test using commercial equipment and farm scale plots was established on a producer's field for the second year. Afield was selected onthe Stanley Walters' farmnear Gallion, Alabama, in Hale County on a Faunsdale clay loam soil. Rows were bedded during the winter, and allowed to settle. All plots were maintained throughout the season with standard, herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Allproductionprac- tices were carried out across all varieties, regardless of technology or genetically engineered traits. Twenty-four commercially available varieties were planted on April 30,2001 with a twelve-row vacuumplanter, with approxi- mately three seed per foot of row. Six replications of each variety Vlt;lU LIIIL 2 ALABAMA AGRICULTURAL EXPERIMENT STATION were planted in a modified randomized complete block design. Each plot consisted of two 38-inch rows approximately 900 feet long of a single variety. Soil moisture was good, and an excellent stand was achieved. Rainfall was plentiful through most of the season, with only brief periods of dry weather. The plots were defoliated on Septem- ber 6, when all varieties were ready. Heavy and repeated rains leading to wet soil conditions prevented harvesting until October 26, which led to some lint and quality loss, although overall yields were good. Two replications were combined at harvest, giving three harvested replications of 0.26 acre each for analysis. A weigh- ing boll buggy was used to weigh each replication, and a grab sample was taken. One pound grab samples were ginned on a mini-gin, and analyzed with HVI equipment at the Auburn Univer- sity Textile Engineering Physical Testing Laboratory. Premature leaf discoloration and drop due to an undeter- mined cause has been a recurring problem on many area cotton fields. When similar (but less severe) symptoms occurred in this test, ratings were taken (see table) approximately two weeks be- fore maturity. The cotton industry has renewed emphasis on lint quality in recent years, and producers have asked to see value-per-acre data instead ofjust simply yield per acre. Results are presented in the following table, with varieties ranked by value in $ per acre, with lint yield, turnout, quality, and leaf ratings for each variety listed. Value per acre was determined from the USDA loan chart, assum- ing a base of $0.55 per pound of lint for SLM-41, leaf= 4, and adding or subtracting values from the loan chart for micronaire, length, and strength. No adjustments were made for seed costs or other cultural expenses to these figures. Producers can modify these numbers as needed for their particular situation. Results showed that there was a range of total value of over $230 per acre from the lowest to highest valued variety, or 373 pounds per acre of lint. There were also significant differences in quality and other measurements. Earlier varieties were likely at a relative disadvantage in the 2001 season due to increased expo- sure to weathering between maturity and harvest, compared to later varieties. Area producers can use these results to compare the perfor- mance of these varieties on Black Belt soils, with the potential for significantly higher returns from their crop. Producers should not rely on any one source, however, to guide their choices, but should also use other information such as the multi-year data from the Alabama Agricultural Experiment Station Cotton Variety Trials, and other public and private sources. BLACK BELT COTTON VARIETY TRIAL, HALE COUNTY, ALABAMA Lint Turnout Lint Lint Lint Leaf Value 2 Lint yield mic. length strength discoloration I value Name lb/ac % units in g/tex $/ac cent/Ib Deltapine DP 491 915 42 37 1.10 28.3 8.0 516.52 56.45 Deltapine DeltaPEARL 881 41 38 1.10 27.3 7.7 497.32 56.45 Deltapine DP 565 874 39 40 1.08 26.9 7.7 493.37 56.45 AgriPro HS 46 886 40 42 1.06 27.7 8.7 489.07 55.20 FiberMax FM 991 RR 815 40 39 1.08 28.5 8.7 460.07 56.45 FiberMax FM 989 792 43 38 1.09 29.5 7.3 449.46 56.75 FiberMax FM 989 BR 805 41 35 1.05 27.5 7.7 442.75 55.00 Deltapine DP 436 RR 753 39 43 1.07 25.9 5.3 414.15 55.00 Sure-Grow SG 215 BR 841 43 41 1.01 24.5 6.3 402.00 47.80 Phytogen PSC 952 757. 42 45 1.02 26.2 7.7 389.86 51.50 Paymaster PM 1560 BG 754 43 42 1.03 26.0 6.7 389.82 51.70 Deltapine DP 451 B/RR 756 40 44 1.03 24.6 8.3 381.78 50.50 Phytogen PSC GA 161 675 39 35 1.11 29.1 7.3 381.04 56.45 Deltapine DP 655 B/RR 737 40 35 1.04 26.6 8.0 379.56 51.50 FiberMax FM 989 RR 729 43 36 1.03 28.4 7.3 375.44 51.50 Sure-Grow SG 747 690 43 41 1.05 25.2 7.3 373.98 54.20 Deltapine DP 425 RR 729 40 45 1.03 25.3 6.7 368.15 50.50 Phytogen PSC 355 699 42 46 1.02 26.3 6.3 359.99 51.50 Deltapine NuCotn 33B 701 40 38 1.03 25.2 7.3 355.41 50.70 Sure-Grow SG 501 BR 666 42 44 1.03 26.5 6.0 342.99 51.50 AgriPro HS 4600 RR 680 43 46 0.99 25.1 8.7 324.36 47.70 Sure-Grow SG 521 R 591 41 39 1.02 25.9 7.3 305.55 51.70 Stoneville ST 4892 BR 594 44 40 1.00 25.0 6.7 283.93 47.80 Stoneville ST 4691 B 542 43 40 1.03 25.5 5.7 280.21 51.70 LSD (P=0.10) 71 1.7 6 0.03 1.2 1.8 SVisual rating of premature leaf discoloration approximately two weeks before defoliation; 10 = 100% defoliated. 2 Value = $0.55/Ib of lint for SLM41, If =4, + loan premiums and discounts. 3 2001 COTTON RESEARCH REPORT COTTON VARIETY RESPONSE TO THE RENIFORM NEMATODE IN SOUTH ALABAMA K. S. McLean, A. J. Palmateer, N. W. Greer, L. Carter, K. Glass, G. W. Lawrence, and J. R. Akridge Cotton varieties were examined with and without Telone II for their response to the reniform nematode (Rotylenchulus reniformis) in south Alabama. The test was conduced in a producer's field naturally infested with the reniform nematode and monocultured in cotton. The soil was a silty loam. Telone II at a rate of 3 gallons per acre was applied two weeks before planting by injecting the chemical 12 inches deep with shanks directly in the row. Di-Syston at a rate of 7 pounds per acre was applied at planting in the seed furrow with chemical granular applicators attached to the planter. Plots consisted of one row, 25 feet long with a 36-inch row spacing. All plots were arranged in a split plot design with six replications. Blocks were separated by a 20-foot alley. All plots were maintained with standard production practices recommended by the Alabama Extension System commonly used in the area. Plots were not irrigated. Population densities ofreniform nematode were determined at planting and at harvest. Ten soil cores, 1 inch in diameter and 8 RENIFORM NEMATODE FINAL POPULATION AND SEED COTTON YIELD FOR SELECTED COTTON VARIETIES -Reniform/150cc of soil- -Yield seed cotton 2 Cotton variety Treated 1 Untreated Treated Untreated Deltapine NuCotton 33B 5717 bcd 7648 abc 2407 c-j 1914 fgh Deltapine NuCotton 35B 4017 bcd 7854 abc 2504 b-h 2286 cde Deltapine DP 5415 RR/ 4661 bcd 7081 abc 2281 f-j 2165 def Deltapine DP 20B 7519 ab 4223 c 2330 e-j 1958 fgh Deltapine DP 451B/RR 10738 a 7253 abc 2233 hij 2136 d-g PhytoGen PSC 161 5605 bcd 9322 ab 2697 a-d 2132 d-g Fiber Max FM 989 4996 bcd 4790 c 2175 ij 2083 efg Sure-Grow 821 4275 bcd 6103 abc 2310 e-j 2030 efg Sure-Grow 747 5227 bcd 6309 abc 2707 abc 2571 ab Paymaster PM 1560BG/RR 5279 bcd 5717 abc 2509 b-h 2155 def Deltapine DP 436RR 5768 bcd 6257 abc 2315 e-j 1861 ghi Deltapine DP 458B/RR 4687 bcd 9364 ab 2504 b-h 2503 a-d Deltapine DP 655B/RR 5279 bcd 5390 abc 2528 b-h 1571 j PhytoGen PSC 355 4120 bcd 5450 abc 2262 h-j 2025 efg PhytoGen HS 12 4067 bcd 6566 abc 2625 a-e 2194 def Stoneville ST 4691B 4481 bcd 8163 abc 2397 c-j 2267 cde Stoneville ST 4892BR 6978 abc 6232 abc 2649 a-d 2170 def Sure-Grow 125BR 5176 bcd 5356 abc 2668 a-d 2484 abc Sure-Grow 501BR 2318 d 7931 abc 2480 b-i 2605 a Paymaster PM 1218BG/RR 6129 bcd 8025 abc 2146 jk 2286 cde DP Delta Pearl 6051 bcd 5176 abc 2692 a-d 2504 abc GARST/AgriPro 1500RR 6566 a-d 4893 bc 2320 e-j 2054 efg Fiber Max FM 966 3863 bcd 8111 abc 2426 c-j 2093 efg Sure-Grow 521R 7854 ab 4584 c 2586 b-f 2117 d-g Deltapine DP 565 3039 cd 9656 a 2393 c-j 1924 fgh Deltapine DP 491 3966 bcd 5047 bc 2562 b-g 2064 efg Germain's GC-271 4017 bcd 7768 abc 2774 ab 2301 b-e PhytoGen Phy 72 Acala 6824 abc 7056 abc 1842 k 1619 ij Stoneville ST 580 5794 bcd 5974 abc 2383 d-j 2107 efg Stoneville ST 580 7236 abc 5768 abc 2325 e-j 2146 def Deltapine DP 555 BG/RR 7819 ab 6206 abc 2929 a 2397 a-d LSD (P=0.05) 4348 4516 318 285 CV 49 42 11 12 1 Di-Syston (7 lb/ac - at planting) added in all treatments without Telone II. 2 See cotton yield in pounds per acre. Means compared using Fisher's protected least significant difference test (P=0.05). r C TII I IY A inches deep were collected from the two center rows of each plot in a systematic sam- pling pattern. Nematodes were extracted using gravity sieving and sucrose centrifugation technique. Plots were har- vested on October 18. The season was cool and dry initially but adequate mois- ture through the season pro- duced a good cotton growth. Reniform nematode numbers increased in all plots regardless of variety or nematicide (see table). DP 451B/RR, PM 1218BG/RR,SG 521R, and PM 1199RR all produced signifi- cantly higher final reniform populations compared to SG 501BR. In treated plots seed cotton yield varied 1034 pounds per acre for the DP 655B/RR and SG 501BR, re- spectively, without Telone II. Cotton seed yield varied 1087 pounds per acre for the DP 555BG/RR and PhytoGen Phy 72 Acala respectively with the application of Telone II. The application of Telone II in- creased yields averaged over all varieties by 298 pounds seed cotton per acre. Three varieties-DP 458B/RR, SG 501BR, andPM 1218BG/BR- produced numerically equal or greater yields without Telone II, thus indicating possible tol- erance to the reniform nema- tode. ALABAMA AGRICULTURAL EXPERIMENT STATION BIOLOGICAL CONTROLS THE EFFECTS OF RED IMPORTED FIRE ANTS ON COTTON APHID OUTBREAKS IN ALABAMA COTTON Ian Kaplan and Micky D. Eubanks Red imported fire ants, Solenopsis invicta, are an invasive species found in high densities throughout the southeastern United States. Agricultural fields are particularly sensitive to fire ants due to their aggressive, predatory nature and the simplified insect fauna found in these systems. Fire ant presence in agricul- tural systems has been theorized to provide beneficial control of pest species. Alternatively, it has also been hypothesized that fire ants disrupt pest control through interference of natural enemies. In Southeastern cotton fields, fire ants may interfere with predators of cotton aphids, Aphis gossypii. Fire ants and cotton aphids may engage in a mutually beneficial relationship whereby fire ants protect aphids from natural enemies in exchange for hon- eydew. Aphid honeydew is a sugary solution produced by aphids that ants may use as food. In both caged greenhouse experiments and large scale field experiments, the following hypotheses were tested: (1) fire ants defend aphids from ladybird beetle larvae and green lacewing lar- vae, Chrysoperla carnea, and (2) this protection contributes to aphid outbreaks. Ladybird beetle and green lacewing larvae were chosen because they are abundant predators that consume large numbers of aphids in Alabama cotton fields. Their consumption rates may regulate aphid populations below levels that are eco- nomically damaging. Therefore, fire ant interference may release aphids from these biological control agents. The purpose of this experiment was to document the impact of aphid protection by red imported fire ants on cotton aphid survival. Caged greenhouse experiments were performed to test the hypotheses. In choice experiments, fire ants more frequently for- aged on cotton plants with aphids than on cotton plants without aphids (approximately 103 ants per plant with aphids; approxi- mately five ants per plant without aphids). These data suggest that aphids attract fire ants into the canopy of cotton plants. In other caged experiments, aphids exposed to ladybird beetle or green lacewing larvae demonstrated a significantly higher rate of survival when simultaneously exposed to fire ants. Aphid popula- tions were reduced by 45% in the presence of ladybird beetle larvae and 63% in the presence of green lacewing larvae. With the addition of fire ants to the aphid-predator treat- ments, aphid populations approximately doubled. Fire ant response to predator presence was similar between larval types; both types of predators were instantaneously attacked by multiple ants upon detection. Neither predator demonstrated an ability to endure fire ant exposure and subsequent attack; they both suffered signifi- cant mortality (approximately 96%). This strongly suggests that fire ants disrupt aphid predation by ladybird beetle and green lacewing larvae. During the 2000 growing season, aphids were sampled weekly in cotton fields at the E.V Smith Research Center. Three large fields that were planted with Stoneville BXN47 and one that was planted with Paymaster 1218 BG/RR were sampled. These fields were at least 20 hectares and separated by 1 to 2 kilometers. Two 1.2 hectare plots were established at opposite ends of each field. Plots were separated by at least 100 meters. Plots were divided into two treatments: high fire ant density or low fire ant density. Treatments were assigned randomly and established using Amdro?, a commercially available fire ant bait that decreases fire ant abundance. Amdro was applied manually (1 pound per acre) two to three times during the field season. This treatment was effective at reducing fire ant densities. In Amdro treated field plots, fire ant density was reduced by 72%. Aphid sampling consisted of visually searching the upper six leaves of a cotton plant and counting all visible aphids on the top and bottom of each leaf. Ten plants per plot were randomly selected to be visually searched. Aphids were significantly more abundant in cotton plots with high densities of fire ants than in cotton plots with experimentally suppressed densities of fire ants (Figure 1). Results from the greenhouse and field experiments suggest that fire ants promote aphid outbreaks by protecting them from predators. Aphid honeydew appears to be the stimulus for this interaction. Observational evidence and empirical data from green- house experiments indicate that fire ant presence alone does not Figure 1. Numbers of aphids in relation to density of fireants. 25 - 20 - 15 - 10 - 5 0- T Hign Low Fire Ant Fire Ant 4 2001 CorroN RESEARCH REPORT have a negative impact on aphid populations. This suggests that fire ants found in the canopy of cotton plants are involved in honeydew retrieval. Aphids, therefore, may serve as a stimulus for ant presence in the canopy of cotton plants. Our data indicates that this may be detrimental to the biological control of aphid populations. Alternatively, fire ant presence on plant foliage has the potential to stimulate the biological control of other pest spe- 5 cies through chance encounter. Pest insects in cotton, including caterpillars, stinkbugs, and tarnished plant bugs, can cause great amounts of damage. Therefore the cost of inflated aphid popula- tions needs to be weighed against the benefit of enhanced bio- logical control of alternative pest species. In future studies the effect of this fire ant-cotton aphid interaction on herbivorous in- sects will be examined. EVALUATION OF PLANT GROWTH- PROMOTING RH IIZOBACTERIA FOR CONTROL OF COTTON SEEDLING DISEASES IN NORTH ALABAMA N.W. Greer, A.J. Palmateer, K.S. McLean, M.S. Reddy, and J.W. Kloepper A cotton test was planted on April 11 at the Tennessee Valley Research and Extension Center near Belle Mina, Alabama. The field site was a Decatur silty loamn Two rows of each plot were also infested with millet seed inoculated with Pythium spp. and Rhizoctonia solani. Treatments consisted of six plant growth-promoting rhizobacteria (PGPR) treatments and a non-treated control. Among these PGPR strains, GBO3 was produced as industrially formu- lated endospores, GBO3 plus IN937a was produced similarly and formulated with a chitosan powder, and Azospirillum brasilense was in a liquid formulation supplied by Ecosoil, Inc. PGPR strains C4-7-12, OCR7-8-38, and 89B61 were produced under laboratory conditions. All PGPR treatments were mixed with tap waterto yield 1.7 x 107 cfu/ml. PGPR were applied as in-furrow sprays at the time of seeding with an 8002E nozzle mounted on the cotton planter and calibrated to deliver 6 gallons per acre at 18 pounds per square inch. The cotton variety Paymaster PM 1218BG/RR was planted in plots consisting of four rows, 25 feet long with 40-inch row spacing. Plots were arranged in a randomized complete block de- sign with six replications. A 20-foot alley separated blocks. Temik 15G (5 pounds per acre), was applied in-furrow at planting as a nematicide. Plots were maintained with standard herbicide, insec- ticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Stand health was re- corded at two, four, and seven weeks after planting (WAP) and skip index was recorded at seven WAP to determine the percent seedling loss and stand density due to cotton seedling diseases. Plots were harvested for yield on September 27. Data were ana- lyzed using ANOVA and means were compared using Fischer's protected LSD. Cotton seedling disease incidence was high in 2001 due to cold, wet conditions. Seedling emergence at two WAP ranged from 72% to 64% for the non-treated control and Camomonas acidovorans (C4-7-12), respectively (see Table 1). By seven WAP cotton stand ranged from a high of 64% to a low of 54% in the Azosporillum brasilence and C acidovorans (OCR7-8-38), respec- tively. There was no effect by any of the PGPR used, however, on healthy stand of cotton at two, four, and seven WAP compared to the non-treated control. Also, PGPR did not have any effect on TABLE 1. EFFECT OF SELECTED PGPR STRAINS ON COTTON STAND, SKIP INDEX, AND YIELD UNDER NATURAL DISEASE PRESSURE Healthy stand' Skip Seed cotton 3 Treatment/concentration plants/25ft index 2 lb/ac April 26 May 9 May 30 May 30 Sept. 27 Non-treated control 73 81 78 2 3762 Bacillus subtifils (GBO3) 1.7 x 107 cfu/ml 74 78 80 1 3498 B. subtilis (GBO3) 1.7 x 107 cfu/ml + 77 83 74 1 3654 B. amyloliquifaciens (IN937a) 1.7 x 107 cfu/ml Azosporillum brasilense 1.7 x 107 cfu/ml 63 71 73 3 3489 A. brasilense 1.7 x 10 7 cfu/ml + 54 69 67 3 3571 Pseudomonas putida (89B61) 1.7 x 107 cfu/ml Comamonas acidovorans (C4-7-12) 1.7 x 107 cfu/ml 67 80 76 2 3417 C. acidovorans (OCR7-8-38) 1.7 x 107 cfu/ml 70 83 73 2 3568 LSD (P = 0.05) 20 20 16 3 319 1 Mean from six replications with 125 seed per row. 2 Mean skip index per 25 ft of row from six replications based on the rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 3 ft gap;...25= no plants. 3 Mean seed cotton yield from six replications. WIIC ~IVUVIIVV ~1 U1V VWI~VYJ V~ VV~CVI~ Y~CUIC U VCU ~LL+LU LIIUIVLCCVU ~LV~~U IIYVUU CV VV ALABAMA AGRICULTURAL EXPERIMENT STATION skip index rated at seven WAP. No treatment effects were ob- served on yield of cotton under the conditions tested, although seed cotton yields ranged from3762.0 to 3416.6pounds per acre forthe non- treated control and C acidovorans (C4-7-12), respectively. Under high disease pressure, seedling emergence at two WAP ranged from 34% to 23% for the non-treated control and A. brasilence, respectively (see Table 2). By seven WAP cotton stand ranged froma high of 17% to a low of 10% in theAzosporillum brasilence plus Pseudomonas putida (89B61) and A. brasilense, re- spectively. There was no effect, however, by any of the PGPR used on healthy stand of cotton at two, four, and seven WAP compared to the non-treated control. PGPR also did not have any effect on skip index rated at seven WAP. No treatment effects were observed on yield of cotton under the conditions tested, although seed cotton yields ranged from2241.8 to 1837.0 pounds per acre for the non-treated control and C acidovorans (C4-7-12), respectively. TABLE 2. EFFECT OF SELECTED PGPR STRAINS ON COTTON STAND, SKIP INDEX, AND YIELD UNDER HIGH DISEASE PRESSURE Healthy stand Skip Seed cotton Treatment/concentration plants/25ft index 2 lb/ac April 26 May 9 May 30 May 30 Sept. 27 Non-treated control 42 29 22 14 2242 Bacillus subtilis (GBO3) 1.7 x 107 cfu/ml 30 19 15 16 1861 B..subtilis (GBO3) 1.7 x 107 cfu/ml + 33 23 15 15 1956 B. amyloliquifaciens (IN937a) 1.7 x 107 cfu /ml Azosporillum brasilense 1.7 x 107 cfu /ml 29 17 13 16 1929 A. brasilense 1.7 x 107 cfu /ml + 36 30 22 13 1929 Pseudomonas putida (89B61) 1.7 x 107 cfu /ml Comamonas acidovorans (C4-7-12) 1.7 x 107 cfu /ml 39 25 17 16 1837 C. acidovorans (OCR7-8-38) 1.7 x 107 cfu /ml 37 20 18 15 2141 LSD (P= 0.05) 12 13 9 5 374 1 Mean from six replications with 125 seed per row. 2 Mean skip index per 25 ft of row from six replications based on the rating scale: 1 = 1 ft gap; 2 =2 ft gap; 3 = 3 ft gap;... 25 = no plants. 3 Mean seed cotton yield from six replications. EVALUATION OF PLANT GROWTH-PROMOTING RHIZOBACTERIA FOR CONTROL OF COTTON SEEDLING DISEASES IN CENTRAL ALABAMA N.W. Greer, A.J. Palmateer, K.S. McLean, M.S. Reddy, and J.W. Kloepper A cotton test was planted on April 19 at the E.V. Smith Research Center near Shorter, Alabama. The field site was a sandy loam. Two rows of each plot were also infested with millet seed inoculated with Pythium spp. and Rhizoctonia solani. Treatments consisted of six plant growth-promoting rhizobacteria (PGPR) treatments and a nontreated control. Among these PGPR strains, GBO3 was produced as industrially formu- lated endospores, GBO3 plus IN937a was produced similarly and formulated with a chitosan powder, and Azospirillum brasilense was in a liquid formulation supplied by Ecosoil Inc. PGPR strains C4-7-12, OCR7-8-38, and 89B61 were produced under laboratory conditions. All PGPR treatments were mixed with tap water to yield 1.7 x 107 cfu/ml. PGPR treatments were applied as in-furrow sprays at time of seeding with an 8002E nozzle mounted on the cotton planter and calibrated to deliver 6 gallons per acre at 18 pounds per square inch. The cotton variety Paymaster PM 1218BG/RR was planted in plots consisting of four rows, 25 feet long with an in-row spac- ing of 40 inches. Plots were arranged in a randomized complete block design with six replications. A 20-foot alley separated blocks. Temik 15G (5 pounds per acre), was applied in-furrow at planting as a nematicide. Plots were maintained with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Healthy stand was recorded at two, four, and six weeks after planting (WAP) and a skip index was recorded at six WAP to determine the percent seed- ling loss and stand density due to cotton seedling diseases. Plots were harvested to determine yield on September 10. Data were analyzed using ANOVA and means were compared using Fisher's protected LSD. Cotton seedling disease incidence was high in 2001 due to cold, wet conditions. Seedling emergence at two WAP ranged from 72% for the non-treated control and Bacillus subtilus (GBO3) 6 2001 COTTON RESEARCH REPORT 7 plus B. amyloliquifaciens (IN937a) treatment, to 64% for the Camomonas acidovorans (C4-7-12) treatment (see Table 1). By six WAP, cotton stands ranged from a high of 64% to a low of 54% in the Azosporillum brasilence plus 89B61 and C acidovorans (OCR7-8-38) treatments, respectively. There was no effect, how- ever, by any of the PGPR treatments used on healthy stand of cotton at two, four, and six WAP compared to the non-treated control. PGPR treatments also did not have any effect on skip index rated at six WAP. No treatment was observed to have a higher yield than the non-treated control although there were dif- ferences between treatments under the conditions tested. The A. brasilense, A. brasilense plus Pseudomonas putida (89B61), and the C acidovorans (C4-7-12) treatments allhadyields significantly(P = 0.05) lower than the non-treated control. Additionally, the C acidovorans (C4-7-12) treatment had a significantly lower yield than both the B. subtilis and the C acidivorans (OCR7-8-38) treatments. Under high disease pressure, seedling emergence two WAP ranged from 71% to 55% for the A. brasilence and A. brasilence plus Pseudomonas putida (89B61) treatments, respectively (see Table 2). By six WAP cotton stand ranged from a high of 65% to a low of 46% in the Comamonas acidovorans (C4-7-12) and A. brasilense plus P putida (89B61) treatments, respectively. There was no effect, however, by any of the PGPR treatments used on healthy stand of cotton at two, four, and six WAP compared to the non-treated control. PGPR treatments also did not have any effect on skip index rated at six WAP. No treatment effects were ob- served on yield of cotton under the conditions tested, although seed cotton yields ranged from 3736 to 3326 pounds per acre for the C acidovorans (OCR7-8-38) and C acidovorans (C4-7-12), respectively. TABLE 1. EFFECT OF PGPRs ON COTTON STAND, SKIP INDEX, AND YIELD UNDER NATURAL DISEASE PRESSURE - Healthy stand' b Skip Seed cotton 3 Treatment/concentration plants/25ft index 2 lb/ac May 3 May 16 May 31 May 31 Sept. 10 Non-treated control 90 84 78 1 4070 a Bacillus subtilis (GBO3) 1.7 x 107 cfu/ml 89 77 74 2 3973 a B. subtilis (GBO3) 1.7 x 107 cfu/ml + 90 75 78 2 3590 abc B. amyloliquifaciens (IN937a) 1.7 x 107 cfu/ml Azosporillum brasilense 1.7 x 107 cfu/ml 83 79 75 2 3375 bc A. brasilense 1.7 x 107 cfu/ml + 86 82 80 1 3366 bc Pseudomonas putida (89B61) 1.7 x 107 cfu/ml Comamonas acidovorans (C4-7-12) 1.7 x 107 cfu/ml 80 77 80 1 319 c C. acidovorans (OCR7-8-38) 1.7 x 107 cfu/ml 88 78 68 3 381 ab LSD (P = 0.05) 16 15 16. 2 570 1 Mean from six replications with 125 seed per row. 2 Mean skip index per 25 ft of row from six replications based on the rating scale: I = 1 ft gap; 2 =2 ft gap; 3 3 ft gap;...25 = no plants. 3 Mean seed cotton yield from six replications. Means within columns followed by the same letter are not significantly different according to LSD (P = 0.05). TABLE 2. EFFECT OF PGPRs ON COTTON STAND, SKIP INDEX, AND YIELD UNDER HIGH DISEASE PRESSURE Healthy stand Skip Seed cotton 3 Treatment/concentration plants/25ft index 2 lb/ac May 3 May 16 May 31 May 31 Sept. 10 Non-treated control 83 72 69 2 3441 Bacillus subtilis (GBO3) 1.7 x 107 cfuml 81 69 74 1 3379 B. subtilis (GBO3) 1.7 x 10' cfu/ml + 85 77 77 1 3555 B. amyloliquifaciens (IN937a) 1.7 x 107 cfu/ml Azosporillum brasilense 1.7 x 107 cfu/ml 88 80 78 0 3687 A. brasilense 1.7 x 107' cfu/ml + 69 58 57 0 3648 Pseudomonas putida (89B61) 1.7 x 107 cfu/ml Comamonas acidovorans (C4-7-12) 1.7 x 107 cfu/ml 85 77 81 1 3326 C. acidovorans (OCR7-8-38) 1.7 x 10' cfu/ml 77 57 60 1 3736 LSD (P = 0.05) 21 28 27 1 552 SMean from six replications with 125 seed per row. 2 Mean skip index per 25 ft of row from six replications based on the rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3 ft gap;...25 = no plants. 3 Mean seed cotton yield from six replications. 8 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF COTTON TRANSPLANTS TREATED WITH PLANT GROWTH-PROMOTING RHIZOBACTERIA IN NORTH ALABAMA N.W. Greer, A.J. Palmateer, K.S. McLean, M.S. Reddy, and J.W. Kloepper A cotton test was planted on April 11 at the Tennessee Valley Research and Extension Center near Belle Mina, Alabama. The field site was a Decatur silty loam. Treatments consisted of four transplant treatments, two with a commercial preparation, BioYieldTM, which contains Paenobacillus macerans strain GBO3 and Bacillus amyloliquifaciens strain IN937a, and two without BioYieldTM. A non-treated direct seeding control and an in-furrow spray direct seeding control with BioYieldTM were also used. BioYieldTM trans- plant treatments were mixed with a soil-less medium, and cotton was planted into Styrofoam trays with an individual cavity size of 1.6 in 2 and a volume of 2.1 in 3 . Non-treated transplants were planted the same way. All transplants were grown in the greenhouse until they were three to four weeks old. They were then manually planted in the field. The BioYieldTM in-fiurrow spray was mixed with tap water to yield 1.7 x 107 cfu/ml and was applied with an 8002E nozzle mounted on the cotton planter and calibrated to deliver 6 gallons per acre at 18 pounds per square inch. Cotton was transplanted at a rate of two plants per foot and seeded at a rate of five seed per foot of row. The cotton variety Paymaster PM 1218BG/RR was planted in plots consisting of four 25-foot long rows with only one row being transplanted. There was a between row spacing of40 inches. Plots were arranged in a randomized complete block design with four replications. A 20-foot alley separated blocks. Plots were main- tained with standard herbicide, insecticide, and fertility produc- tion practices as recommended by the Alabama Cooperative Ex- tension System. Percent stand and skip index were recorded at two, four, and seven weeks after planting (WAP) to determine the percent seedling loss and stand density due to cotton seedling diseases. Plots were harvested to determine yield on September 27. Data were analyzed using ANOVA and means were compared using Fischer's protected LSD. Cotton seedling disease incidence was high in 2001 due to cold, wet conditions. Seedling survival at two WAP ranged from 100% to 46% for the four-week-old transplants without BioYield TM and the two seeded controls, respectively (see table). By seven WAP cotton stand ranged from a high of 99% to a low of 48% in the four-week-old transplants without BioYieldTM and the two seeded controls, respectively. There were differences from the control by all of the transplant treatments on healthy stand of cotton at two, four, and seven WAP. No treatment effects were observed on yield of cotton under the conditions tested, although seed cotton yields ranged from 3155 to 2752 pounds per acre for the three-week-old transplants with BioYieldTM and the three-week- old transplants without BioYieldTM, respectively. EFFECT OF BIO YIELDTM ON COTTON AS MEASURED BY PERCENT SURVIVAL AND YIELD Treatment Healthy stand Seed cotton 2 % survival lb/ac April 26 May9 May 30 Sept. 27 4-week-old transplants with BioYield T 81 b 81 b 79 b 3102 3-week-old transplants with BioYield T 94 ab 92 ab 90 ab 3155 4-week-old transplants without BioYield TM 100 a 100 a 99 a 2759 3-week-old transplants without BioYield T 98 a 97 a 95 a 2752 Non-treated control 45 c 50 c 51 c 3102 Seeding with BioYield TM 46 c 50 c 48 c 2871 LSD (P = 0.05) 15 14 14 703 1 Mean from four replications with seeding rate at 125 seed per row, and transplanting rate at 50 plants per row. 2 Mean seed cotton yield from four replications. Means within a column followed by the same letter are not significantly different according to LSD (P = 0.05). 2001 COTTON RESEARCH REPORT EVALUATION OF COTTON TRANSPLANTS TREATED WITH PLANT GROWrH- PROMOTING RHIZOBACTERIA IN CENTRAL ALABAMA N.W. Greer, A.J. Palmateer, K.S. McLean, M.S. Reddy, and J.W. Kloepper A cotton test was planted on April 19 at the E.V. Smith Re- search Center near Shorter, Alabama. The field site was a sandy loam. Treatments consisted of four transplant treatments, two with a commercial preparation, BioYieldTM, which contains Paenobacillus macerans strain GBO3 and Bacillus amyloliquifaciens strain IN937a, and two without BioYieldTM. A non-treated direct seeding control and an in-furrow spray direct seeding control with BioYieldTM were also used. BioYieldTM trans- plant treatments were mixed with a soil-less medium, and cotton was planted into Styrofoam trays with an individual cavity size of 1.6 square inches and a volume of 2.1cubic inches. Non-treated transplants were planted the same way. All transplants were grown in the greenhouse until they were three to four weeks old. They were then manually planted in the field. The BioYield TM in-furrow spray was mixed with tap water to yield 1.7 x 107 cfu/ml and was applied with an 8002E nozzle mounted on the cotton planter and calibrated to deliver 6 gallons per acre at 18 .pounds per square inch. The cotton variety Paymaster PM 1218BG/RR was trans- planted at a rate of two plants per foot and seeded at a rate of five seed per foot. Plots consisted of four 25-foot long rows with only one row being transplanted. There was a between row spacing of 40 inches. Plots were arranged in a randomized complete block design with six replications. A 20-foot alley separated blocks. Plots were maintained with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Coopera- tive Extension System. Percent stand and skip index were recorded at two, four, and six weeks after planting (WAP) to determine the percent seedling loss. Plots were harvested to determine yield on September 10. Data were analyzed using ANOVA and means were compared using Fisher's protected LSD. Cotton seedling disease incidence was high in 2001 due to cold, wet conditions. At two and six WAP, the four-week-old trans- plants without BioYield TM had a significantly (P = 0.05) higher stand count than the seeding with BioYieldTM control (see table). At four WAP, the four-week-old transplants without BioYieldTM had a significantly higher stand count than both seeded controls. There were no differences in yield among the transplant treat- ments, but all had significantly lower yields than the seeded con- trols. EFFECT OF BIO YIELDTM ON COTTON STAND AND YIELD Treatment Healthy stand 1- Seed cotton 2 % survival lb/ac May 3 May 16 May 31 Sept. 10 4-week-old transplants with BioYield TM 79 76 75 2728 b 3-week-old transplants with BioYield M 84 77 77 2803 b 4-week-old transplants without BioYield T 91 88 86 2807 b 3-week-old transplants without BioYield T 81 75 73 2812 b Non-treated control 81 74 77 3309 a Seeding with BioYield M 76 64 68 3441 a LSD (P = 0.05) 11 11 12 452 SMean from four replications with seeding rate at 125 seed per row, and transplanting rate at 50 plants per row. 2 Mean seed cotton yield from six replications. Means within columns followed by the same letter are not significantly different according to LSD (P = 0.05). 9 ALABAMA AGRICULTURAL EXPERIMENT STATION CROP PRODUCTION Row SPACING AND SKIP Rows FOR COTTON IN CENTRAL ALABAMA Dennis Delaney, C. Dale Monks, Bob Goodman, and Bobby Durbin An experiment was established in central Alabama to inves- tigate the potential for 30-inch row cotton compared to 40-inch rows, as well as the potential for skip row planting to reduce seed and other costs of production. Cotton was planted on May 2, 2001 at the E.V. Smith Re- search Center Field Crops Unit on a Compass silt loam soil. Sure- Grow 125 BR cotton was planted in 30- and 40-inchrows, with and without a full skip every two rows ("2 and 1"). The experimental design was a randomized complete block with four replications. Plot size was 25 feet long and eight row widths wide for the respec- tive treatment. Recommended production practices, such as fertil- ity, weed and insect control, and growth regulators were followed. Seeding rate and in-furrow insecticides and fungicides at planting were adjusted to supply equivalent rates per acre, while pre-emer- gence herbicides and fertilizers were broadcast. Cotton was harvested from the two center rows of each plot on September 17 with spindle pickers adapted for plot harvesting and their respective row spacings. Seed cotton was weighed and approximately 1-pound grab samples were taken. Samples were pro- cessed on a l0-sawmini-gin, and lint samples analyzed by the Auburn University Textile Engineering HVI Laboratory. Returns above vari- able costs were calculated using Alabama Cooperative Extension Sys- tem Cotton Budgets adjusted for expenses with each system.r Yields and returns above specified variable costs are shown in the table. Lint yield was highest with 40-inch solid cotton, fol- lowed by 30-inch solid, 30-inch skip, and then 40-inch skip. Net YIELDS AND RETURNS FOR 30- AND 40-INCH ROWS, WITH AND WITHOUT FULL SKIPS Row spacing Lint yield Net return lb/ac $/ac 30-inch solid 1285 377 30-inch skip 1222 387 40-inch solid 1391 435 40-inch skip 1031 281 LSD @ P = 0.10 150 83 '$/ac above variable costs. returns nearly followed yields with 40-inch solid > 30-inch skip > 30-inch solid > 40-inch skip. Yields and returns for 40-inch cotton were reduced by using a skip row, while those of the 30-inch rows were not statistically different @ P = 0.10. There were statistically significant interaction effects of row spacing and of net returns (P<0.05) for the treatment combinations. Lint turnout was slightly increased by solid planting (40.6% vs. 39.2% for skip). Uniformity, micronaire, length, and strength were not affected by row spacing or skip row treatments or their interactions. These data indicate that in a year with relatively good weather and high yields, the traditional 40-inch solid row spacing offered the highest lint yields and returns to producers, and that lint qual- ity was not affected by any of the treatments. SPRINKLER AND SUBSURFACE DRIP IRRIGATION, TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER Larry M. Curtis, Charles H. Burmester, David H. Harkins, B. E. Norris, and James W. Baier Three experiments involving application and use of sprin- kler and subsurface drip irrigation continued in 2001 at the Ten- nessee Valley Research and Extension Center, Belle Mina, Ala- bama. The experiments were as follows: Sprinkler irrigation water requirements and irrigation scheduling. This experiment was established in 1999 to evaluate a range of irrigation application capabilities to identify the minimum design flow rate that will produce optimum yields. Treatments included four sprinkler irrigation capabilities and a nonirrigated treatment. Irrigation was managed using soil moisture sensors and Moiscot (a spreadsheet-based scheduling method). The irri- gation capabilities were (1) 1 inch every 12.5 days, (2) 1 inch every 6.3 days, (3) 1 inch every 4.2 days, and (4) 1 inch every 3.1 days. The results for 1999, 2000, and 2001 are presented in Figure 1. Minimal yield differences were noted in 2001 while significant dif- ferences were measured in 1999 and 2000. Rainfall variability and treatment effects accounted for the wide range of yield responses for each of these years. Subsurface drip irrigation (SDI) placement and irrigation water requirements. This experiment was initiated in 1998 to evalu- ate placement of SDI relative to crop row direction and row spac- ing and to evaluate water requirements for cotton production us- 10 ~~~PTP Q~111CTP/I T~ Qllllt71~1 P/1111~IQ IPnT rQTPQ tlPr QrrP ~x~nl rp t~yppmpy, ~I I--I I III I SI II II I / L+\ I- 2001CorrN RSEARH REORT11 Figure 1. Sprinkler irrigated cotton yield results. 3.50 LII1999 U02004 3.00 2.50 2.00 0.50 Im 0.00 not irrigated. 1 "12.54 I dIays 1 16.3 days 11",M,4.2 days rrigation System Capability Figure 2. Drip plac( 3.50 3.00 02.50 CL 4I) 2.00 1.,50 0,501 u.uu ement and irrigation scheduling. L1998 111999 *2000 [12001 ....F....m. i; 71m n I ir not irrigated 30% T 60% T 90% T 30%11I 60%11 Perpendicular (T) vs Between Rows (11) 1l- 3.1 days 90%11 ii-ii- 0.11~3 2001 Co-r-rONRESEARCHREPORT 0 LIII 2001 I r:::::i::--:::i::::. ;i:;:::i:i: t ' """' ' ' r- 12 ALABM GIUTRLEPRMN TTO ing SDI. Drip tubing was buried 15 inches deep with emitters at two-foot intervals along the tubing. Tubing placement treatments were (1) between every other row-80 inch spacing between drip lines and (2) perpendicular to rows-80-inch spacing between drip lines Irrigation treatments were based on daily applications equal to 30%, 60%, and 90% of pan evaporation after full crop canopy with adjustments based on percent canopy prior to full canopy cover. Yield results for four years (1998 through 2001) are pre- sented in Figure 2. Subsurface drip irrigation (SDI) tape procdcts and fertigation. A SDI study initiated in 1998 was designed to com- pare five different drip irrigation tape products with a dgation component included. This study was installed in an a ,a where continuous crops have been produced for many years Emitters were loc ,d two feet along the tape with tape buried 15 inches betweei : ery other row. Rows 340 feet in length were used to better sinmulate field conditions. Each tape product was evaluated using a single (conventional) surface applied sidedress versus multiple sidedress applications injected through the SDI system. (see table). A tape product was also used on the surface using a conventional fertilizer treatment. In 1998 little difference between fertility treatments was ob- served. In 1998 sufficient rainfall occurred late in the growing sea- son so that fertilizer in the upper layers of the soil was more readily available. In 1999, extremely dry conditions in the upper layers of the soil profile made conventional applied fertilizer less available resulting in yield reduction compared to fertilizer applied through the irrigation system. In 2001 initiation of fertigation was inadvert- ently delayed more than two weeks. Even though the fertigation schedule was modified to insure that all scheduled fertilizer was applied, the delay reduced fertigated yields. Significant yield differences were observed each year be- tween nonirrigated plots and tape plots with fertility treatments. Figures 3 anid 4 illustrate yield results for 1998 through 2001 for conventional and fertigated treatments. To date only minimal dif- ferences have been observed between the different drip irrigation tape products. VARIOUS APPLICATIONS USED TO EVALUATE TAPE PRO UCTS I rrig ated Nonirrigated Fertigated Conventional Drip tape on surface Preplant 75#N + 60#K 75#N + 60#K 75#N + 60#K 75#N + 60#K Sidedress 60#N + 60#K 60#N + 60#K 60#N + 60#K 60#N All sidedress was applied at early to mid-square for the conventional and surface drip tape treat- ments; the sidedress treatment was divided into eight equal applications for the fertigated treatments beginning at early to mid-square. Figure 3. Conventional fertility program and tape comparison. (e C. IA09 0 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 --- 1998 11999 M 2000 L1 2001 not irrigated Surface T-Tape TTape: Raintape Product Type Netafilm Eurotape 12 ALABAMAAGRICULTURALEXPERIMENT STATION 2001 COTTON RESEARCH REPORT 1 Figure 4. Fertigated program and tape comparison. 3.50 2........ .,uuI T-Tape Raintape Neta Film Eurotape Tape Product WATER RESOURCE DEVELOPMENT FOR IRRIGATION IN THE TENNESSEE VALLEY Larry M. Curtis, Marshall M. Nelson, and Perry L. Oakes In conjunction with the Natural Resources Conservation Service (NRCS), construction requirements (including cost) for off-stream irrigation storage reservoirs were investigated. This report presents a procedure useful for estimating off-stream water storage reservoir construction costs in Alabama under various conditions. Exact costs of particular installations will vary to some extent from costs predicted by any generalized estimating proce- dure. However, the estimates produced by the procedure outlined should prove useful to anyone considering such an undertaking and wanting to determine the least cost approach suitable to their site, conditions, and needs. This estimation procedure should also be useful to funding agencies and private of governmental agen- cies interested in irrigation as a planning tool for agricultural de- velopment in Alabama. The procedures also should be applicable to other states or regions with appropriate adjustments to suit conditions. The spreadsheet program developed in this investigation allows a competent user to quickly explore various scenarios in reservoir construction and compare construction cost estimates by changing various dimensions and land contour inputs. The program will be available for use by qualified NRCS and Extension personnel assisting farmers and others interested in the possibili- ties of off-stream irrigation storage reservoirs. This program should be used only by individuals familiar with the engineering prin- ciples involved in reservoir construction. Personnel using the program should be aware of the need for a geological study of any site considered for an off-stream storage reservoir, in order to determine whether a liner might be needed. Qualified NRCS personnel or professional engineering firms can provide the best possible evaluation of a site's water- holding capacity, and recommendation as to the type of liner needed, if any. The results of this investigation are published by the Ala- bama Agricultural Experiment Station (Bulletin 647) "Estimated Cost of Off-streamIrrigation Storage Reservoirs." This publication is available on the Web at http:// w w w. ag. auburn. edu / resinfo/publications/ bull647irrigreservoircosts.pdf S2.50 2.00 Q. M 1.50 m 1.00 0.50 0.00 LU 'I IIII 1 .I I-,-_-i: ::_:aggg~%gg I f I :::::i:ii ::i::i IIIIIIl 1 i I EVALUATION OF TERRA CONTROL SC 823 ON IRRIGATED AND NONIRRIGATED COTTON Edward Sikora, Larry Wells, Bobby Durbin, Don Moore, B. E. Norris, and Malcomb Pegues The soil conditioner Terra Control SC 823 is an ecologically compatible polymer dispersion for stabilizing topsoil layers. Terra Control forms a three-dimensional matrix in the soil profile that is permeable to water and oxygen but is stable against soil erosion due to wind or rain. Terra Control retains moisture longer in the soil and protects soil and plants from drying out, allowing for economical water management. The objective of these studies was to determine if a single application of Terra Control SC 823 after planting would provide long-term water retention in the root zone that would benefit plants during extended periods of drought. A secondary objective was to determine if this long-term water retention would increase inci- dence of seedling blights. Irrigated cotton trials were established at the Wiregrass Regional Research and Extension Center, the Tennessee Valley Research and Extension Center, and the E. V. Smith Research Center. Trials were conducted using overhead center-pivot irri- gation. Nonirrigated cotton trials were established at the Wiregrass Regional Research and Extension Center, the Ten- nessee Valley Research and Extension Center, the Gulf Coast Research and Extension Center, and the Prattville Experiment Field. Each trial consisted of three treatments, replicated six times, in a randomized complete block design. Each treatment/replication consisted of a four-row plot, 30 feet long. The cotton variety Sure Grow 125 BR was used at all loca- tions. Trials were planted during the months of April and May, depending on their location in the state. Terra Control treatments were applied as a broadcast spray at planting at 7.5 or 10 gallons per acre. Fertilizer applications were determined by soil test infor- mation. Insect and weed control required applying insecticide and herbicides as needed. Stand counts were taken at 21 and 35 days post planting and a skip index was made at 35 days post planting. Seed cotton yield was determined at harvest. There were no apparent differences in stand count or skip index among treatments at any location (data not shown). There were no significant differences in yield among the three irrigated cotton treatments at any of the three locations (see table). Nor were there any significant differences in yield among the three nonirrigated cotton treatments at any of the four locations (see table). Alabama received unusually heavy rains in June (13 cm), July (10 cm), and August (24 cm), which likely diminished any positive effect the Terra Control may have had on cotton produc- tion in 2001. EFFECT OF TERRA CONTROL SC 823 UNDER IRRIGATED AND NONIRRIGATED CONDITIONS ON COTTON SEED YIELD Seed cotton yield (pounds/plot) Treatments E.V. Smith Prattville Gulf Coast Tennessee Wiregrass Valley Irrigated Control 5.7 a - - 10.8 a 9.9 a Terra Control 6.3 a - - 11.0 a 10.4 a 7.5 gal/ac Terra Control 6.1 a - - 10.6 a 9.9 a 10 gal/ac Nonirrigated Control 14.0 a 10.2 a 11.7 a 9.6 a Terra Control 14.3 a 10.1 a 11.5 a 8.6 a 7.5 gal/ac Terra Control 14.0 a 9.8 a 11.6 a 9.4 a 10 gal/ac Numbers followed by the same letter are not significantly different. 14 ALABAMAAGRICULTURALEXPERIMENT STATION 2001 COTT--ON RESEARCH REPORT 1 SURFACE-APPLIED BROILER LITTER C. C. Mitchell and W.C. Birdsong Research with broiler litter on cotton has been conducted since 1991 on a Norfolk fine sandy loam in central Alabama (E.V. Smith Research Center) and since 1999 on a Dothan sandy loam in south Alabama (Wiregrass Research and Extension Center). The objectives of both studies were to (1) determine the effect of surface-applied broiler litter as a source of nitro- gen (N) for reduced tillage cotton and (2) determine the re- sidual effects of poultry broiler litter application on N availabil- ity for cotton production. The central Alabama study was in conventionally tilled cotton from 1991 to 1994, conservation tilled corn from 1995 to 1997, and conservation tilled cotton since 1998. Both studies compared the effects of total N rates from poultry broiler litter with total N from ammonium nitrate and the residual effects of broiler litter N the year after application. At the central Ala- bama location, non-irrigated cotton yields during the 11-year study ranged from 855 pounds lint per acre in 1998 to 1520 pounds of lint per acre in 2001 (Tables 1 and 2 provide average lint yields from 1991 to 2001). At the south Alabama locations, yields ranged from 1010 pounds of lint per acre in 2000 to 1170 in 2001 (Table 3). Average total N in broiler litter used in these studies was 2.98% on a fresh weight basis (60 pounds total N per ton). These tests on Coastal Plain soils have demonstrated that broiler litter can be used as the sole N source for cotton. All broiler litter may be applied at planting and rates can be based upon the total N in broiler litter. Rates do not need adjusting when litter is surface applied and not incorporated as in conservation tillage systems. Residual N from broiler litter on cotton is small but sig- nificant ranging from 66% relative yields at broiler litter rates of 120 pounds total N per acre to 76% relative yield at 240 pounds N per acre. The "no-nilrogen" check treatment produced an average of 52% relative yield the last four years of the study in central Alabama. On fields that have not received previous applications of broiler litter, anN availability factor of one-half should be assumed for south Alabama and an N availability factor of two-thirds should be assumed for central Alabama. However, because of the re- sidual effect of N two years after application, long-term availabil- ity factors will be around 90% at recommended N rates. When broiler litter is used as a source of N, more than the recommended rates of P and K will be applied. IN REDUCED TILLAGE COTTON TABLE 1. MEAN COTTON LINT YIELDS FOR CONVEN- TIONALLY TILLED COTTON, 1991-1994, AT E.V. SMITH RESEARCH CENTER IN CENTRAL ALABAMA N source Total N rate Cotton, 1991-1994 Ib/ac lb lint/ac No N 0 550 d Am. nitrate 60 840 bc Am. nitrate 60 + Pix 840 bc Am. nitrate 120 940 abc Am. nitrate 120 + Pix 940 abc Broiler litter 120 880 abc Broiler litter 120 + Pix 850 bc Broiler litter 180 960 a Broiler litter 180 + Pix 950 ab Broiler litter 240 970 a Broiler litter 240 + Pix 940 abc Values followed by the same letter are not significantly different at P<0.05. TABLE 2. MEAN YIELDS FOR CONSERVATION TILLED CORN (1995-1997) AND CONSERVATION TILLED COTTON (1998-2001) AT E.V. SMITH RESEARCH CENTER IN CENTRAL ALABAMA N source Total N rate Corn,1995-97 Cotton,1998-01 lb/ac bu/ac lb lint/ac No N 0 46 e 540 c Am. nitrate 60 99 bc 940 a Am. nitrate 120 107 ab 1030 a Am. nitrate 180 103 abc 990 a Am. nitrate 240 98 bc 940 a Broiler litter 120 107 ab 990 a Broiler litter 180 103 abc 1020 a Broiler litter 240 117 a 1040 a Broiler litter 120 Residual 58 e 680 b Broiler litter 180 Residual 73 d 760 b Broiler litter 240 Residual 89 c 780 b Values followed by the same letter are not significantly different at P<0.05. ALABAMA AGRICULTURAL EXPERIMENT STATION TABLE 3. ANNUAL COTTON LINT YIELDS AT WIREGRASS RESEARCH AND EXTENSION CENTER, 1999-2001 Treatment Yield, pounds lint per acre Mean relative 1999 ' 2000 1 20011 Mean 1 yield (%) 2 Check 580 b 570 e 470 f 540 g 50 f Commerical fertilizer, 1080 a 1010 a 1170 ab 1080 a 100 a 120-90-90 BL x 950 a 840 cd 940 bcd 910 bc 84 bc BL 1.5x 950 a 860 bc 860 cd 890 cd 82 bcd BL2x 1130 a 980 ab 980 abc 1030 ab 95 ab BL 2.5x - 1050 a 1230 a 1140 a 104 a Residual BL x - 710 d 540 ef 630 fg 58 ef Residual BL 1.5x - 710 d 700 def 700 ef 65 ef Residual BL 2x - 830 cd 690 def 760 def 71 cde Residual BL 2.5x - - 800 cde 800 cde 68 de 1 Means different at P<0.10. 2 Means different at P<0.05 CHANGES IN CENTRAL ALABAMA COTTON SOILS, 1991 AND 2001 C. C. Mitchell, L. Kuykendall, and R.R. Beauchamp In 1991, Autauga and Elmore Counties in Central Alabama participated in a statewide cotton survey. These counties planted 29,200 acres of cotton with an average yield of711 pounds lint per acre in 1991. In 2001, cotton was still the major agricultural crop in this region although rural development, urban sprawl, and a weak agricultural economy had reduced the total planted cotton acre- age in 2001 to 22,300 acres. Average yield in 1999 was 550 pounds lint per acre due primarily to an extended drought in 1998 to 2000. However, during this same period, planted cotton acreage increased 46% statewide. All cotton planted in Autauga and Elmore Counties is on Upper Coastal Plain soils or on related alluvial soils of river ter- races. The 1991 survey identified several soil-related concerns in cotton fields in the Upper Coastal Plain region of Central Alabama. Sixty-two percent of the fields surveyed in 1991 had pronounced traffic pans (hard pans) within 10 inches of the soil surface. This compared to 41% statewide. In 1991, tillage practices were not noted because all fields were conventionally tilled. This included use of a chisel or moldboard plow, disking, and harrowing fol- lowed by mechanical cultivation for weed control. Very few prac- ticed any form of deep tillage such as subsoiling. Tillage practices were responsible for extensive traffic pans identified in cotton fields. The major plant nutrition concern identified in 1991 was a potential for potassium (K) deficiency. Sixty-eight percent of cot- ton leaf samples taken at early bloom were below the sufficiency level of 1.5% K. On the other hand, soil test K levels in the plow layer were all "medium" or higher. However, 90% of the subsoil samples were "medium" or "low" in extractable K. Low subsoil levels were probably influencing K in cotton leaves. The objective of this study was to revisit the same fields that were surveyed in 1991 in order to assess any changes in land use patterns, tillage systems, and soil fertility status of cotton soils in Central Alabama. The 2001 survey was limited to Autauga and Elmore Counties. The 1991 survey involved 36 randomly chosen fields in Autauga and Elmore Counties. These same fields were revis- ited during the winter of 2001. An additional 32 fields that were not part of the 1991 survey were included in the 2001 survey. In 1991, the survey was conducted during the summer and fall and included cotton leaf samples. The 2001 survey included soil samples at depths of 0 to 2 inches, 2 to 8 inches, and 12+ 16 2001 COlToN RESEARCH REPORT 17 inches (subsoil sample). The reason for sampling at different depths was to assess the impact of tillage practices on soil nutrient stratification. Random sub-samples were taken within a 1-acre area repre- sentative of the entire field. The entire field was not sampled. Detailed maps were made in 1991 so each site could be revisited. In 2001, GPS was used to identify each site for future surveys. The area sampled was the same area sampled in 1991. Each soil sample consisted of 15 to 20 sub-samples, which were combined by depth. The samples were dried and analyzed by the Auburn University Soil Testing Laboratory for pH, estimated cation exchange capac- ity (soil group), and Mehlich-l extractable P, K, Mg, and Ca. Some of the samples were tested for Mehlich-1 extractable micronutri- ents and metals. Some of the surface samples (0 to 2 inch) were also tested for total organic matter. Tillage practices, previous crop, cover crop, depthto an argillic horizon (clay layer), and presence and depth of a traffic pan were recorded for each field. Land use. Both Autauga and Elmore counties are experienc- ing population increases and urban sprawl associated with the cities of Montgomery, Prattville, and Wetumpka, Alabama. How- ever, of the 36 cotton fields surveyed in 1991, all but four were still being planted in cotton. One field had been converted to a subdi- vision, one was planted in pine trees, and two were planted in crops other than cotton. Soil type. Where cotton is planted in Autauga and Elmore Counties, soils are very typical of Coastal Plain soils throughout Central and South Alabama. Halfofthe fields surveyed were in the Lucedale series, which is described as a deep, well-drained, mod- erately permeable soil of the Southern Coastal Plain Major Land Resource Area. Local farmers refer to Lucedale soils as "red land" because of the red surface color of these soils. Lucedale soils may be found on slopes of 0 to 15% but cotton is planted mainly on the more level sites. Surface soil textures of the soils in this survey were mostly fine sandy loams. Depth to argillic horizon is referred to as "depth to clay" by most fannrmers in this region. However the argillic horizon texture is usually sandy clay, sandy clay loam, loam, or silty clay loam rather than "clay." This depth is a reflection of the major soil series present (Table 1) but may also influence the formation and depth of traffic pans. Traffic pans. Traffic pans or hard pans were found in 63% of the fields surveyed in 2001 (62% in 1991). This was a surprise considering that 51% of the farmers practiced some form of con- servation tillage with subsoiling, usually paratilling or paraplowing. Traffic pans were identified using a soil penetrometer within the rows of cut cotton stalks. Since the survey was during the winter of 2001, soil moisture at the time of the survey was high. Many of the fields where traffic pans were found had no in-row subsoiling or paraplowing the previous season. However, some that had deep tillage prior to planting had recreated traffic pans within the row. Traffic pans are a known impediment to deep rooting and may be a major yield-limiting factor in drought years. The situation has not improved since 1991. Tillage practices. The most dramatic change in the 10 years since 1991 has been in tillage practices. In 1991, all fields surveyed were conventionally tilled. In 2001, 56% of the fields surveyed had some form of conservation tillage, usually strip tillage. However, only 15% of the fields had a winter cover crop planted, usually wheat or rye. This is reflected in the very low value for mean soil organic matter of 0.6% in the surface 2 inches of soil. Seventy-five percent of the fields surveyed had soil organic matter less than 0.8% in the surface 2 inches (Table 2). Based on soil organic matter data published from Alabama's Old Rotation experiment, this low level of soil organic matter results in poor soil quality and a very low cotton yield potential. Soil pH. Central Alabama cotton farmers appear to be doing a very good job of maintaining an optimum soil pH (5.8 to 6.9) in the rooting zone. One of the thoughts behind taking a 0- to 2-inch sample and a 2- to 8-inch sample was to identify any stratification that may be developing as a result of the dramatic increase in conservation tillage practices over the past 10 years. Overall, there does not appear to be a dramatic pH stratification effect beyond what would be expected in these naturally acid, Coastal Plain soils. No differences due to tillage practice could be identified in this survey. However, there does appear to be a trend toward higher pH values in the surface soils due to liming. This tendency may become more pronounced as producers lime surface soils under conservation tillage practices. Phosphorus. The 1991 survey found no evidence that phos- phorus was a yield-limiting concern in Upper Coastal Plain cotton fields. The 2001 survey confirms this conclusion with 92% of the TABLE 1. SOIL AND CROPPING CHARACTERISTICS OF 68 CENTRAL ALABAMA COTTON FIELDS Soil or cropping characteristic Percent of fields surveyed Soil classification (Ex. of series) Rhodic Paleudults (Lucedale fsl) 50 Typic Paleudults (Bama fsl) 3 Plinthic Paleudults (Bowie sl) 6 Arenic Paleudults (Lucy Is) 4 Typic Kandiudults (Norfolk sl) 13 Typic Hapludults (Wickham fsl) 22 Others (Roanoke fsl) 2 Depth to argillic horizon (subsoil "clay") 0-6 inches 13 7-12 inches 78 >12 inches 5 Not applicable 4 Depth to traffic pan (hardpan) 0-6 inches 36 7-12 inches 27 >12 inches 0 No traffic pan present 37 Tillage practices Conventional tillage 44 Conservation tillage with subsoiling 51 Conservation tillage without subsoiling 5 Cover crops planted Yes 15 No 85 2001COTTONRESEARCHREPORT 17 ALABAMA AGRICULTURAL EXPERIMENT STATION surface soils testing high or very high in extractable P. There does appear to be a trend toward stratification of P in the surface 2 inches of soil as would be expected with increasing conservation tillage and surface P application. Potassium. Potassium also appears to be accumulating in surface soils with decreasing extractable K with depth. Soils tested high or very high in K in 86% of the surface 2 inches, 67% of the 2- to 8-inch layer, and 31% of the subsoil. As noted in the 1991 survey, low K in the subsoil could aggravate a K deficiency during a drought if roots are unable to get adequate K from the subsoil. However, research in 1997 and 1999 in Alabama concluded that broadcast K applications and high plow layer K are more efficient than trying to increase subsoil K for cotton production. Recent research from long-term potassium studies confirms that extract- able plow-layer K is well correlated with cotton yield. Magnesium and calcium. Regardless of sampling depth, 97 to 98% of the fields had "high" levels of extractable soil Mg for TABLE 2. SOIL TEST VALUE DISTRIBUTION IN COTTON FIELDS IN AUTAUGA AND ELMORE COUNTIES, 2001 Analysis and rating -Sample depth (inches)- 0-2 2-8 12+1 Soil organic matter (n=44) 0 to 0.4% 55 - - 0.4 to 0.8% 20 - - 0.8 to 1.2% 9 - - >1.2% 16 - Cation exchange capacity (n = 68) <4.6 cmol/kg 15 18 8 4.6-9.0 cmol/kg 81 78 85 >9.0 cmol/kg 4 4 7 Soil pH, (n=49) .<5.0 2 0 3 5.0-5.7 13 21 34 5.8-6.9 81 75 63 7.0+ 4 4 0 Extractable P (n=68) Very low/low (<12 mg/kg) 4 13 69 Medium (13-25 mg/kg) 4 21 21 High (26-50 mg/kg) 37 50 6 Very high (>50 mg/kg) 55 16 4 Extractable K (n=68) Very low/low (<45 mg/kg) 1 3 23 Medium (46-90 mg/kg) 13 30 46 High (91-180 mg/kg) 62 63 31 Very high (>180 mg/kg) 24 4 0 Extractable Mg (n=68) Low (<25 mg/kg) 3 2 2 High (25+ mg/kg) 97 98 98 Extractable Ca (n=68) <250 mg/kg 5 4 6 250-500 mg/kg 38 47 61 501-750 mg/kg 38 38 30 750-1,000 mg/kg 16 9 3 >1,000 mg/kg 3 2 0 112 + inhces = subsoil. 2 n = number of samples analyzed. cotton. Calcium is not rated for cotton in Alabama because main- taining an optimum soil pH through liming generally assures suf- ficient Ca for most Alabama cotton soils. This survey indicated that 95% of the fields had extractable Ca levels above 250 mg Ca per kg (500 pounds Ca per acre). Soiltestvalues above 150 mg Caper kg (300 pounds per acre) would be considered "high" for peanuts, one of the most calcium-sensitive crops grown in Alabama. Micronutrients and metals. Mehlich-1 (dilute double acid) is not the best extractant for estimating plant availability of micronutrients. In fact, there are few studies that show signifi- cant correlation between M1 extractable micronutrients and plant response to micronutrients over a range of soils. The same would be true of M1 extractable metals in soils. However, because of the convenience of analytical technology, the mi- cronutrients and metals listed in Table 3 were analyzed using inductively coupled argon plasma (ICAP) spectroscopy on the soil extracts. The values serve as a broad benchmark. Very TABLE 3. MEHLICH-1 EXTRACTABLE SOIL MICRONUTRIENTS AND METALS FROM AUTAUGA AND ELMORE COUNTIES Analysis Mean Std. Dev. Minimum Maximum mg/kg 0-2 inch depth Cu 0.5 0.4 0.0 1.6 Mn 30.5 19.3 4.0 72.1 Zn 2.6 1.7 0.7 6.4 B 0.4 0.3 0.1 1.5 Ba 2.5 0.9 0.2 3.9 Co 0.2 0.1 0.1 0.5 Cr 0.6 0.5 0.2 2.3 Pb 0.8 0.3 0.5 1.5 Na 7.8 8.0 0.0 28.0 2-8 inch depth Cu 0.6 0.7 0.0 2.4 Mn 26.5 16.4 4.6 59.1 Zn 1.9 1.2 0.2 5.3 B 0.5 0.3 0.0 1.2 Ba 2.8 1.2 0.2 5.7 Co 0.2 0.1 0.1 0.5 Cr 0.7 0.5 0.2 2.4 Pb 0.9 0.3 0.5 1.6 Na 8.3 8.3 0.0 31.0 12+ inch depth (subsoil) Cu 0.6 0.6 0.0 1.9 Mn 18.7 11.1 1.4 42.1 Zn 1.4 1.7 0.2 6.5 B 0.4 0.2 0.0 0.8 Ba 2.6 0.7 0.0 3.5 Co 0.2 0.1 0.0 0.5 Cr 0.6 0.4 0.3 2.4 Pb 0.9 0.3 0.5 1.5 Na 11.2 9.9 0.0 34.9 18 2001 COTTON RESEARCH REPORT 1 large and very low values for a particular micronutrient or metal may be reason for concern. The only micronutrient routinely recommended for cotton is boron (B). In general, hot water extractable B values above 0.1 mg/ kg are sufficient for cotton. This is near the detection limit for ICAP analyses using the Ml extract. Zinc values above 0.6 mg/kg are generally considered sufficient for most crops. Values above 10 mg Zn/kg may be toxic to sensitive crops such as peanuts. The mean values and ranges for extractable micronutrients and metals in these soils do not present any evidence that producers should be overly concerned about micronutrient or metal deficiencies or toxicities in cotton or any other crop. In spite of a dramatic shift toward conservation tillage in the past decade, traffic pans remain a potential yield-limiting factor in cotton fields of Central Alabama. Increased use of paratilling and in-row subsoiling has not eliminated the pres- ence of traffic pans within the surface 12 inches of soil. This situation is aggravated by poor overall soil quality as indicated by very low soil organic matter (mean=0.6%). The situation could be improved by using winter cover crops more extensively and al- lowing more biomass to accumulate on the soil surface. In general, soil fertility does not appear to be a limiting factor in cotton production. Most fields sampled had optimum soil pH and high P and K in the surface 8 inches of soil. While the extractant used for micronutrients and metals is not ideally correlated with plant availability, it does provide some indica- tion that micronutrient availability and metal contamination of cotton fields is not a major concern at this time. THE OLD ROTATION AND CULLARS ROTATION - 2001 Charles Mitchell, Wayne Reeves, and Dennis Delaney The Old Rotation Experiment (circa 1896) and the Cullars Rotation Experiment (circa 1911) on the campus of Auburn Uni- versity are the two oldest, continuous experiments in the world in which cotton in grown. The Old Rotation was placed on the U.S. National Register of Historical Places in 1988 and the Cullars Rota- tion will be nominated for this prestigious honor in 2002. The Old Rotation is primarily a crop rotation study with and without winter legumes as a source of nitrogen. It is on a Pacolet fine sandy loam, a transition soil from the Piedmont to the Coastal Plain. The Cullars Rotation is a much larger study with 14 soil fertility variables (N, P, K, S, lime, and micronutrients) replicated three times on a Marvyn loamy sand Coastal Plain soil. The three replications are rotated each year to (1) cotton followed by (2) corn followed by winter wheat that is harvested for grain and is double-cropped with (3) soybean. Since 1996, both experiments have been in conservation tillage with either in-row subsoiling or paratilling prior to planting. Before then, they were planted using conventional tillage and mechanical cultivation. Both experiments are non-irrigated. The 2001 growing season produced the highest wheat yields on record for the Old Rotation and the all-time record cotton yield. Dry weather late in the growing season reduced the yield potential of soybeans. Interestingly, since 1996 when the two tests were switched to conservation tillage, record yields have been pro- duced by all crops grown in these tests. Record yields have been attributed to better soil quality (higher soil organic matter and better structure), greater rainfall infiltration, less pesticide use, boll- weevil eradication, Bollgard? and Roundup Ready? or Liberty- Link? varieties, less weed pressure, less insect pressure and dis- eases, and good growing conditions (except for a drought in 2000). Highest crop yields are shown in Table 1. Treatments and crop yields from the 2001 growing season are presented in Table 2 (The Old Rotation) and Table 3 (The Cullars Rotation). Plans for the 2002 growing season include es- tablishing an irrigation system on half of all plots on the Old Rota- tion. TABLE 1. RECORD YIELDS ON THE OLD ROTATION AND CULLARS ROTATION EXPERIMENTS AT AUBURN UNIVERSITY Crop Rank Year Yield Cotton 1 2001 1600 Ib lint/acre 2 1994 1490 3 1993 1270 Corn 1 1999 236 bu/acre 2 2001 193 3 1997 148 Wheat (1961-present) 1 2001 94 bu/acre 2 2000 81 3 1999 79 Oat (beforel 960) 1 1958 109 bu/acre 2 1937 97 3 1956 87 Rye (1978-present) 1 1981 55 2 1988 48 3 1979 40 Soybean(1957-present) 1 1996 67 bu/acre 2 1992 61 3 1983 55 m~'117~1 \151 I I It-~~ ~1~C1 7-~1?90%) COTTON DEFOLIATION, BOLL OPENING, AND REGROWTI LEAFLESS APPLICATIONS defoliation at 14 DAT. LeafLess tion at 14 DAT. Both Aimand L H FOLLOWING AIM AND -14 days after treatment- 21 days Treatment Rate/ac Defoliation Open bolls regrowth Aim + COC 0.7 oz + 1 pt 82 83 28 Aim + Harvade + COC 0.5 oz + 0.5 pt + 1 pt 93 80 18 Aim + Finish + COC 0.7 oz + 1 pt + 1 pt 84 92 29 Aim + Dropp + COC 0.7 oz + 0.2 lb. + 1 pt 88 84 15 LeafLess + COC 10 fl. oz + 1 pt 84 85 20 LeafLess + Finish + COC 10 fl. oz + 1 pt + 1 pt 92 92 30 Def + Dropp 1 pt + 0.15 lb. 79 84 18 Untreated 43 75 22 LSD (P=0.05) 9 8 NS 1 COC = crop oil concentrate. s plus COC provided 84% defolia- eafLess treatments provided defo- liation equal to Defplus Dropp at 14 DAT. Aimplus Finish plus COC and LeafLess plus Finish plus COC bothprovided excel- lent boll opening at 14 DAT. Cotton dessication was less than 4% with all treatments at 14 DAT (data not shown). Ter- minalregrowthwas30% orlower withalltreatntsat21 DAT. Aim plus Harvade plus COC was evaluated for weed dessication in other field trials and provided good to excellent dessication of annual momingglory, sicklepod, and pigweed (data not shown). EVALUATION OF A WICK APPLICATOR FOR APPLYING MEPIQUAT CHLORIDE TO COTTON Charles H. Burmester This study was conducted to determine the feasibility of using a wick applicator to apply mepiquat chloride to cotton. A replicated field experiment was conducted on the Tennessee Val- ley Research and Extension Center, Belle Mina, Alabama, on a Decatur silt loam. All plots consisted of eight rows, 40 feet long. Half the area was supplemented with irrigation to provide two moisture regimes. Mepiquat chloride treatments included the fol- lowing: none, standard rate broadcast sprayed at early bloom as determined by plant monitoring, and one-half and two-thirds of the standard rate applied using a wick applicator. Irrigated treat- ments received an additional 5.7 inches of water in five applica- tions during the season. All cotton received one treatment of 8 ounces of mepiquat chloride at early bloom while the irrigated cotton received an additional 8-ounce application at mid-bloom. A four-row wick applicator was obtained from Dixie Wick Company of Grifton, North Carolina. This applicator consisted of perforated plastic pipe covered with a cotton canvas over each row. A metering air orifice was used to control the flow rate. Differ- ences between the wick applicator and a broadcast sprayer were determined by height and nodes above white flower (NAWF) measurements and by final yields. The 2001 growing season was excellent for cotton produc- tion in northern Alabama. This is reflected in the excellent rain-fed cotton yields of between 3,270 and 3,710 pounds of seed-cotton per acre. Although mepiquat chloride treatment did slightly re- duce heights, nonirrigated cotton yields were not effected by FIELD COMPARISON OF MEPIQUAT CHLORIDE TREAT- MENTS BROADCAST SPRAYED OR APPLIED WITH A WICK APPLICATOR, BELLE MINA, ALABAMA Mepiquat chloride Height Seed cotton First Aug. 15 yield picking in lb/ac % Nonirrigated Check 49 3,460 88 8 oz. broadcast 45 3,710 87 5.3 oz. Wick 47 3,270 93 4.0 oz. Wick 45 3,500 90 Irrigated Check 64 3,270 75 8 oz. + 8 oz. broadcast 51 3,680 80 5.3 oz. + 5.3 oz. Wick 52 3,570 80 4.0 oz. + 4.0 oz. Wick 52 3,780 80 mepiquat chloride treatments (either sprayed or applied with the wick applicator). Irrigated cotton grew much taller and mepiquat chloride treat- ments greatly reduced height (see table). Little difference in height or yield was found between mepiquat chloride treatments applied either as a spray or through the wick applicator. Although irri- gated cotton without mepiquat chloride had slightly lower yields 22 nlm -e Cinl~h -C I:( ~~ r I) / n7 ~ 1 nt $- 1 nt Ka 2001 COrrTON RESEARCH REPORT than irrigated cotton treated with mepiquat chloride, irrigated cot- ton yields were comparable to the nonirrigated treatments. Irriga- tion in this high rainfall year caused rank growth and delayed maturity without mepiquat chloride treatment and resulted in lower yields. 23 Rain-fed cotton produced an earlier crop with nearly 90% of the cotton open at the first picking. The irrigated cotton was 80% open at first picking when mepiquat chloride was applied and only 75% open when mepiquat chloride was not applied. LIBERTY-LINK COTTON WEED MANAGEMENT PROGRAMS Michael G. Patterson, Wilson H. Faircloth, and C. Dale Monks Liberty-Link cotton is genetically modified for tolerance to the herbicide Liberty(glufosinate). Liberty herbicide is similar to glyphosate (Roundup, Touchdown, etc.) in that it has activity only on emerged weeds and grasses with little or no soil activity. A field study was conducted during 2001 atthe E.V. Smith Research Center Field Crops Unit to evaluate several cotton weed management programs using Liberty-Link technology. Cotton was planted in mid May. Some pro- grams received Treflan and/or Cotoran preplant incorporated (PPI) followed by two or more applications of Liberty postemergence (see table). These were compared to an untreated check and to a program using Liberty only without soil-residual herbicides. All treatments of Treflan at 0.5 pound (1 pint) per acre followed by two or more applications of Liberty at 0.32 pound active per acre provided excellent late-season control of pigweed, goosegrass and large crabgrass, sicklepod, and coffee senna. Cotoran preemergence followed by two applications of Liberty applied at the 6 leaf and 10 leaf cotton stage provided lower pigweed and grass control than treat- ments containing Treflan. The Liberty only program provided lower sicklepod and coffee senna control than programs containing Treflan or Cotoran. No visual crop injury was found with any of the programs. Liberty-Link technology is anticipated to be commercially available for the 2003 growing season on a limited basis. WEED AND LIBERTY-LINK COTTON RESPONSE TO LIBERTY-BASED PROGRAMS July 11,2001 Treatment Rate/ac Growth CIl PW GR SP CS stage % Untreated - - 0 0 0 0 0 Liberty 1.5 pt 6 leaf 0 92 94 88 88 Liberty 1.5 pt 10 leaf Treflan 1.0 pt PPI 0 98 99 99 99 Liberty 1.5 pt 6 leaf Liberty 1.5 pt 10 leaf Treflan 1.0 pt PPI 0 97 99 97 99 Liberty 1.5 pt 3 leaf Liberty 1.5 pt 6 leaf Liberty 1.5 pt 14 leaf Cotoran 2.5 pt PPI 0 87 88 98 98 Liberty 1.5 pt 6 leaf Liberty 1.5 pt 10 leaf 1 CI= crop injury, PW = pigweed, GR = annual grass (50% goosegrass, 50% large crabgrass), SP= sicklepod, CS = coffee senna. Note: ammonium sulfate (AMS) was added to Liberty treatments at the rate of 3 pounds per acre for 10 and 14 leaf applications. -~ LL J - ----V -~L- ~VII~~-IIYII ~V U1I ~~VI ~~k~t 1VY UVI~~~VII~U LLl~hL L V1 I~~V VV~L V~~ VIJVI~ 24 ALABAMA AGRICULTURAL EXPERIMENT STATION INSECTICIDES TARNISHED PLANT BUG CONTROL IN COTTON Barry L. Freeman This trial compared insecticide treatments for tarnished plant bug control in cotton. The trial was conducted on the Tennessee Valley Extension and Research Center in Limestone County, Ala- bama. Cotton, Stoneville 474, was planted on April 10, 2001 and was under irrigation. Plots were eight rows by 100 feet and unreplicated. Treatments were applied on June 15. To estimate plant bug populations and damage, post treatment samples were taken on June 21, June 25, and June 29 and consisted of 10, 6-foot drop cloth samples and the examination of 100 pinhead squares per plot. Whole field examina- tions three days prior to in- secticide applications re- vealed an average pinhead square retention of 88%, a high degree of adult plant bug activity, and a low number of plant bug nymphs. All treatments reduced plant bug numbers as com- pared to the control plot (Table 1). The Karate, Capture, Leverage, and high rate of Centric treatments lowered average plant bug populations by more than 90%. Over the same period the low rate of Centric and Assail provided an 83% reduction in bug numbers. Other treatments pro- vided less than 60% control. Pinhead square retention was improved by most insecti- cide treatments with the highest levels being found in the Ca- lypso, Karate, Capture, Asana, and low rate of Assail treat- ments (Table 2). TABLE 1. NUMBERS OF PLANT BUGS PER 100 FEET OF Row Treatment Plant bugs % change lbs a.i./ac June 21 June 25 June 29 Average from control Karate 0.0348 3 0 3 2 -98 Capture 0.05 3 3 6 4 -96 Leverage 0.0625 0 3 13 5 -95 Centric 0.0625 3 3 10 5 -95 Centric 0.0473 7 7 33 16 -83 Assail 0.075 3 20 26 16 -83 Calypso 0.09 3 30 60 31 -67 Calypso 0.047 10 33 53 32 -66 Assail 0.1 3 43 57 34 -64 Orthene 0.33 13 63 47 41 -57 Vydate 0.33 3 40 97 47 -51 Steward 0.11 13 136 60 70 -26 Asana 0.04 17 133 100 73 -23 Control - 43 120 123 95 - TABLE 2. PERCENT PINHEAD SQUARE RETENTION Treatment Pinhead square retention % change Ibs a.i./ac June 21 June 25 June 29 Average from control Calypso 0.09 96 92 88 92 +18 Karate 0.0348 86 90 94 90 +15 Capture 0.05 90 88 90 89 +14 Calypso 0.047 84 90 92 89 +14 Assail 0.075 86 90 86 87 +12 Asana 0.04 82 88 90 87 +12 Assail 0.1 84 86 86 85 +9 Leverage 0.0625 76 90 80 82 +5 Centric 0.0473 74 84 84 81 +4 Centric 0.0625 72 78 88 79 0 Control - 76 78 80 78 - Orthene 0.33 68 84 80 77 -1 24 ALABAMAAGRICULTURALExPERIMENT STATION 2001 COTTON RESEARCH REPORT EVALUATION OF INSECTICIDES FOR CONTROL OF INSECT PESTS IN BT COTTON AND SELECTIVITY AGAINST BENEFICIAL SPECIES Ron H. Smith Foliar sprays of insecticides to cotton in Alabama are greatly reduced fiom historical acreages. Most fields go weeks at a time with no insect control necessary. In this low-spray environment, tarnished plant bugs and fleahoppers may build to damaging lev- els at any point in the season. In mid- to late-season, stink bugs show the same trends. Most growers are greatly concerned about the preservation of beneficial insects and are, therefore, hesitant to apply insecti- cides to control plant bugs and or stink bugs. Several new insec- ticides will be available in the near future for bug control. The following tests were undertaken to determine how effective these new chemicals are on the plant bug-stink bug complex and how selective they are on beneficial species. Three plant bug tests were implemented on the Segrest farm in Macon County, Alabama, and the Prattville Experimental Field, Prattville, Alabama. A stink bug test was conducted at the Wiregrass Regional Research Farm, Headland, Alabama. The first test on the Segrest farm was initiated on June 25 in blooming stage cotton to a dominantly adult plant bug popula- tion. Adjacent eight-row strips were treated through a 20-acre field. Treatments were not replicated; however, four replicate counts were taken in the center four rows along the entire 500-foot treated area. Application was made with a conventional tractor-mounted boom at 10 gallons per acre and 30 pounds per square inch pres- sure. Samples were made with traditional sweep net technique on June 26, June 28, and July 2. The second test was conducted at the Prattville Experiment Field on July 17 against a marginal plant bug population that was primarily in the nymphal stage. Treatments were applied to eight rows by 60 feet with two replicates. Application was by hiboy atl0 gallons per acre and 60 pounds per square inch pressure. Evalua- tion was done by drop cloth on July 14 and July 23 from the center four rows of each plot. The stink bug test was conducted at the Wiregrass Research and Extension Center on September 13. Treatments were made to eight row adjacent strips 400 feet in length by Spray Coupe at 10 gallons per acre and 45 pounds per square inch pressure. Five replicate samples were taken from the center four rows of each plot by drop cloth on September 17, four days post treatment. All treatments suppressed adult plant bugs when compared to the untreated control in test number one on the Segrest farm. The pyrethroid Karate gave the greatest level of control followed by the experimental pyrethroid XR-225. Bidrin, Decis, Steward, and Calypso gave similar levels of control, with Assail and Centric being slightly less effective. The addition ofDibrom to Bidrin and Orthene appeared to reduce their effectiveness against adult plant bugs. In general, the pyrethroids (Decis and Karate) showed the least selectivity against big eyed bugs. The most selective insec- ticides against big eyed bugs in this test were Centric, Assail, and Bidrin plus Dibrom. Against the pirate bug, Karate was again the least selective followed by Bidrin plus Dibrom, Bidrin, XR-225, and Assail. Treatments that had as many or more pirate bugs than the untreated were Centric, Decis, Calypso, Orthene plus Dibrom, and Steward. In the plant bug test at the Prattville location, all treatments gave excellent control of plant bugs except Steward. All treat- ments suppressed lady beetles by 50% or more except Orthene and Bidrin, which were applied as a tank mixture with Dibrom. The pyrethroids Karate, XR-225, Bidrin, Orthene, and Decis were the least selective treatments against lady beetles. The third test was conducted at the Wiregrass Research farm against stink bugs. All treatments gave good control of stink bugs in this test except the two rates of Calypso. Other treatments that had low levels of stink bugs in the post treatment count were Novaluron, Assail, Orthene (at 0.75 pound per acre), Provado, and Asana. 25 26 ALABAMA AGRICULTURAL EXPERIMENT STATION THRIPS MANAGEMENT IN COTTON Barry L. Freeman This test compared insecticide treatments for thrips manage- ment in cotton. The test was located on the Tennessee Valley Research and Extension Center in Limestone County, Alabama, and was planted on April 26, 2001. Plots were four rows by 25 feet and were replicated four times each. Foliar applications (Karate and Orthene) were applied at the first true leaf stage, but due to poor growing conditions this was not until May 23. Thrips were sampled on May 21, June 2, and June 11, or 25, 37, and 46 days after planting. The samples were collected by rinsing five plants from each plot in 70% ethyl alcohol, filtering the contents, and counting the resulting larval and adult thrips. Cot- ton plants were rated visually for thrips injury on May 25, June 4, and June 11. Plant populations were determined on June 6 by counting all living plants in the center two rows of each plot. Yields were determined by mechanically harvesting the center two rows of each plot on October 22.Weather problems delayed stand emergence, seriously impacted stands and aggravated sampling. All treatments, except the control, kept thrips numbers be- low one per plant on May 21 (Table 1). By June 2 thrips popula- tions had increased, but reproduction was not high in any of the insecticide treatments. On June 11 the Adage treatments and the Gaucho 480 treatment had fewer thrips than other treatments. Thrips damage ratings showed all treatments to be better than the control (Table 2). After Orthene and Karate were applied to Adage treatments, those plots had the least amount of thrips injury. The Adage treatment had the lowest plant population and the Temik 0.75 treatment had the highest stand density, but there was less than a 15% difference among all treatments (Table 2). A poor stand existed in all plots and the poor growing conditions very likely outweighed any effects on stand that the treatments may have had. Seed cotton yields are presented in Table 2. Both Adage treatments, which received an additional foliar insecticide ap- plication, outyielded other treatments. Yields from other treat- ments were very similar. Some treatment effects on yield were undoubtedly masked by the poor stands and poor growing conditions. TABLE 1. NUMBERS OF THRIPS PER FIVE PLANTS -May 21- -June 2- -June 11- - Seasonal average- Treatments Adult Larva Adult Larva Adult Larva Adult Larva Total Adage 0.3 lbs. a.i./cwt 2 0 4 1 3 4 2.67 1.50 4.17 Adage 0.3 lbs. a.i./cwt + 2 0 2 1 2 8 2.00 3.08 5.08 Karate 0.016 Ibs. a.i./ac. Adage 0.3 Ibs. a.i./cwt + 1 0 6 1 4 6 3.25 2.33 5.58 Orthene 0.2 lbs. a.i./cwt. Gaucho 480 0.25 Ibs. a.i./cwt. 2 0 9 6 2 12 4.33 5.77 10.10 Temik 0.5 lbs. a.i./ac. 2 0 8 3 3 25 4.17 9.25 13.42 Temik 0.75 lbs. a.i./ac. 1 0 9 4 2 25 3.67 9.77 13.44 Gaucho 600 0.25 Ibs. a.i./cwt. 3 0 9 2 4 23 3.67 9.77 13.44 Control 6 5 10 17 4 53 6.25 25.12 31.37 TABLE 2. THRIPS DAMAGE RATINGS, PLANT POPULATION, AND YIELD Damage ratings 1 Plants/ Seed cotton Treatment May 25 June 4 June 11 Average row ft. lbs/ac Adage 0.3 Ibs. a.i./cwt + 1.25 2.00 2.00 1.75 1.73 2610 Karate 0.016 Ibs. a.i./ac. Adage 0.3 Ibs. a.i./cwt + 1.50 2.00 2.00 1.83 1.54 2604 Orthene 0.2 Ibs. a.i./cwt. Temik 0.75 lbs. a.i./ac. 1.00 3.00 2.25 2.08 1.74 2202 Gaucho 480 0.25 lbs. a.i./cwt. 1.25 3.00 2.25 2.17 1.53 2195 Adage 0.3 Ibs. a.i./cwt. 1.50 2.50 2.75 2.25 1.52 2055 Gaucho 600 0.25 lbs. a.i./cwt. 1.75 2.75 2.75 2.42 1.54 2189 Temik 0.5 lbs. a.i./ac. 1.25 3.00 3.00 2.42 1.56 2228 Control 3.25 4.75 4.75 4.25 1.68 2205 10 = no injury, 5 = extreme injury. 26 ALABAMAAGRICULTURALEXPERIMENT STATION 2001 COTTON RESEARCH REPORT STATEWIDE MONITORING OF BOLLWORM/BUDWORM POPULATIONS WITH HELID Ron H. Smith HELID kits were available to monitor egg populations during the 2001 cotton-growing season. (HELID is a test to identify eggs of bollworm, Helicoverpa zea [Boddie] and bud- worm, Heliothis virescens [F.])Technical help was employed from May 14 to August 17 to assist withthis project. In addi- tion, this project was coordinated with the FMC Corporation, which cooperated in this statewide effort. Private consultants from all regions of the state also cooperated in this project. The 2001 year was the third consecutive season of overall light bollworm/budwormpressure in Alabama. However, economi- cal levels of each species did occur at several different times of the season in all regions of the state. Therefore, growers in all areas utilized the results from the HELID tests in selecting the appropriate type chemistry for the species mix in their fields. Since pyrethroids are not effective on budworms, and the newer chem- istry is more effective, growers can reduce damage to bollworm/ budworm populations and make more efficient use of their inputs by utilizing information from the HELID results. More than 100 key cooperators (extension agents, con- sultants, agricultural distributors, and growers) were identi- fied to receive fax messages within a few hours after comple- tion of a HELID sample. This same information was placed on a toll free 800 line available to all interested parties within the state and region. Since Alabama growers made a significant shift back to conventional varieties in 2001 (approximately 50% Bollgard), this information assisted in selecting the appropri- ate chemistry on approximately 300,000 acres of conventional RESULTS OF HELID TESTS IN ALABAMA, 2001 Date Location BW 1 TBW Other June 4 Covington Co. 5 53 42 June 5 Macon Co. 0 50 50 June 5 Elmore Co. 13 62 25 July 1 Talladega Co. 25 75 0 July 18 Houston Co. 57 31 12 July 27 Macon Co. 50 50 0 August 3 Limestone Co. 45 55 0 August 9 Tallapoosa Co. 60 40 0 August 9 Limestone Co. 28 62 9 August 9 Macon Co. 38 62 0 1 BW = bollworm, TBW = budworm, Other = cutworms, true army- worms, or yellow striped armyworms. cotton. The price differential between pyrethroids ($3.50-5.00) and newer chemistry ($9.00-$14.00/acre application) was greater than in previous years. Results presented in the table indicate the species mix varied by time (date). In general, the "worm" population was predomi- nantly budworm during the early fruiting season (June 1-July 10), bollworm during a two- to three-week July window, and a mix of both species in August, with majority of the population budworm. Numerous eggs showed up as "unknown" in early season and were likely other non-economic species. EVALUATION OF BOLLGARD II AND PHYTOGEN VARIETIES FOR CONTROL OF FALL ARMYWORM AND BOLLWORM SPECIES Ron H. Smith Plans are under development to market cotton varieties with two Bt genes in the near future. It is anticipated that this second Bt strain will be more actie on a broader range of Lepidoterous pests. This project attempted to evaluate varieties with two stacked Bt (Bollgard II) genes against fall armyworm, soybean loopers, and other Lepidopterous species. Cotton was planted in 2000 and 2001 in replicated plots on Prattville Experiment Field, Prattville, Gulf Coast Research and Extension Center, Fairhope, and Wiregrass Research and Exten- sion Center, Headland, in anticipation of a natural population of fall annrmywonrms occurring. Three varieties were planted (conven- tional, Bollgard, and Bollgard II). These farm locations were in central, southeast, and southwest Alabama where fall annrmyworms have historically occurred. Plots were monitored weekly for fall armyworms. In 2000, at the central Alabama location, lab-reared fall armyworms were re- leased into the test plots with only limited success. However, low natural populations did occur at two sites, while soybean loopers occurred at the third location. In 2001, neither species occurred at either location, so comparisons were made on bollworm and to- bacco budworm effectiveness. Bollgard II plots incurred much less boll bract etching from fall armyworm larvae (FAW) in the 2000 season at two test loca- tions than did the Bollgard or conventional plots (Table 1). Bollgard 27 ~Ftrrr Ice mArd d++P~+l~rb ~Y~~~IPI CI ~~H rdrll 1~6 ~~mr\RP f~ kl\ll ~~~rYI11 28 ALABAMA AGRICULTURAL EXPERIMENT STATION and conventional plots showed similar levels of damage at Prattville but Bollgard had less FAW damage than the conventional plots at Headland. Bollgard II plots at Fairhope had no soybean looper larvae or defoliation while both the Bollgard and conventional plots had up to 30 larvae per six row feet and 10% foliage loss. Based on these results, Bollgard II appears to have broader Lepi- dopterous pest activity than does Bollgard. TABLE 1. BOLLGARD II EVALUATIONS 2000 SEASON Variety DP50 DP50B DP5011 Date % of bolls with fall armyworm etching Prattville August 7 2.0 0.0 0.0 August 21 20.0 9.0 0.0 August 29 28.0 23.0 2.0 Headland August 15 0.0 0.0 0.0 August 23 0.0 0.0 0.0 September 4 26.0 5.0 0.0 Date Numbers of soybean loopers/6 row feet Fairhope August 22 12.0 12.8 0.0 August 27 24.8 32.3 0.0 Date % defoliation Fairhope September 5 10.0 10.0 0.0 During the 2001 season all caterpillar pressure was light. No damage or larvae were found in the Bollgard II plots at any of the three locations. Under this low level of pressure, Bollgard plots only had low levels ofbollworm/budworm damage on one date at each of two locations (Table 2). Therefore, pressure was likely not adequate to demonstrate the improved effectiveness of Bollgard II over Bollgard against bollworms or budworms. TABLE 2. BOLLGARD EVALUATIONS 2001 SEASON Variety DP5415 NuCotn 33B Bollgard II Date % damaged fruit Prattville July 16 38.0 1.2 0.0 August 1 8.0 0.0 0.0 August 8 28.0 0.0 0.0 August 14 13.0 0.0 0.0 Fairhope July 3 1.3 0.0 0.0 July 10 2.6 0.0 0.0 July 17 10.6 0.0 0.0 August 7 2.6 0.0 0.0 Headland July 10 16.0 0.0 0.0 July 16 36.0 2.6 0.0 July 23 2.6 0.0 0.0 July 30 2.6 0.0 0.0 August 13 2.6 0.0 0.0 1 Damaged caused by either the bollworm or tobacco budworm. 28 ALABAMAAGRICULTURALEXPERIMENT STATION 2001 CorroN RESEARCH REPORT NEMATIC[DES MANAGEMENT OF THE RENIFORM NEMATODE WITH ANHYDROUS AMMONIA K. S. McLean, W. S. Gazaway, A. J. Palmateer, N. W. Greer, and J. R. Akridge The efficacy of anhydrous ammonia for the management of the reniform nematode (Rotylenchulus reniformis) was evaluated in Huxford, Alabama. The test was conduced in a field naturally infested with the reniform nematode and monocultured in cotton. The soil was a silty loam. Anhydrous ammonia was applied either in the fall or six weeks before planting by injecting the chemicals 12 inches deep with shanks. Temik 15G and Di-Syston were ap- plied at planting in the seed furrow with chemical granular applica- tors attached to the planter. PGPR consisted of Bacillus subtilis strain (GBO3) plus B. amyloliquifaciens strain (IN937a), which was applied as a directed spray in the seed furrow at 10 gallons per acre applied through 8002E flat fan nozzles. Plots consisted of four rows, 25 feet long with a 36-inch row spacing. All plots were arranged in a randomized complete block design with six replications. Blocks were separated by a 20-foot alley. Eachrow was planted with 125 Suregrow 125 BR cotton seed on May 2. All plots were maintained with standard production practices recommended by the Alabama Cooperative Extension System commonly used in the area. Plots were not irrigated. Population densities of reniform nematode were deter- mined throughout the season at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep were collected from the two center rows of each plot in a systematic sampling pat- tern. Nematodes were extracted using gravity sieving and su- crose centrifugation technique. Plots were harvested on Octo- ber 17. The season was warm and moist and was ideal for producing a good cotton growth and reniform reproduction. Thirty days after planting reniform nematode populations were significantly lower in the Temik 15G treatment compared to all other treatments (see table). No significant differences in renifor populations were observed in any of the treatments at 84 days after planting. By defoliation at 115 days after planting, the anhydrous ammonia at 200 and 120 units and the Temik 15G treatments produced signifi- cantly lower reniformpopulations than the ammoniun nitrate treat- ment. Cotton seed yield varied 501 pounds per acre for the anhy- drous ammonia 200 units and the ammonium nitrate treatments respectively. The anhydrous ammonia treatments at 200 and 90 units produced a significantly greater yield than the ammonium nitrate and the PGPR treatment. The anhydrous ammonia treat- ments increased yield over the ammonium nitrate treatments by 204 pounds per acre. EFFECT OF ANHYDROUS AMMONIA ON RENIFORM POPULATION ACROSS THE SEASON AND COTTON SEED YIELD Treatment * Rate Reniform/150 cc of soil Seed cotton formulated product May 24 June 21 Aug. 15 Sept.25 Ib/ac Anhydrous ammonia 200 units/ac - fall app. 3043 b 4944 ab 5266 a 4458 b 3093 a Anhydrous ammonia 120 units/ac - preplant 3365 b 4742 ab 6463 a 4120 b 2650 bc Anhydrous ammonia 90 units/ac - preplant 5197 a 5579 a 7223 a 5631ab 2887 ab Ammonium nitrate 90 units/ac - at plant 4326 ab 6043 a 7146 a 6875 a 2592 c Temik 15G+Ammonium nitrate 7 Ib/ac + 90 units/ac - at plant 4390 ab 3305 b 8588 a 4172 b 2831 abc PGPR +Ammonium nitrate 1 pt/ac+ 90 units/ac - at plant 4236 ab 4867 ab 7081 a 5995 ab 2592 c LSD (P=0.05) 1563 1726 3361 2332 274 SDi-Syston (7 lb/ac - at planting) added in all treatments except the Temik treatment. PGPR consisted of Bacillus subtilis strain (GBO3) + B. amyloliquifaciens strain (IN937a). 29 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF THE SOIL FUMIGANT VAPAM FOR RENIFORM NEMATODE MANAGEMENT IN COTTON K. S. McLean, A. J. Palmateer, N. W. Greer, G. W. Lawrence, and J. R. Akridge The efficacy of Vapam for the management of the reniform nematode (Rotylenchulus reniformis) was evaluated near Huxford, Alabama. The test was conduced in a field naturally infested with the reniform nematode and monocultured in cotton. The soil was a silty loam. Vapam ammonia was applied two weeks before plant- ing by injecting the chemicals 12 inches deep with shanks. Temik 15G treatments were applied at planting on May 25 in the seed furrow with chemical granular applicators attached to the planter. Di-Syston was applied similarly to the control. Plots consisted of four rows, 25 feet long with a 36-inch row spacing. All plots were arranged in a randomized complete block design with six replications. Blocks were separated by a 20-foot alley. Each row was planted with 125 Suregrow 125 BR cotton seed. All plots were maintained with standard production prac- tices recommended by the Alabama Cooperative Extension Sys- tem. Plots were not irrigated. Population densities of reniform nema- tode were determined through out the season at monthly intervals. Ten soil cores, 1 inch in diameter and 8 inches deep were collected from the two center rows of each plot in a systematic sampling pattern. Nematodes were extracted using gravity siev- ing and sucrose centrifugation technique. Plots were harvested on November 12. The season was dry in the spring; thus, planting was de- layed. Pre-plant populations ofreniform nematodes averaged 3614 reniform per 150 cubic cm of soil. Thirty days after planting, reni- form nematode populations were significantly lower in all the ne- maticide treatments as compared to the control (see table). The Vapam treatments reduced reniform populations 91% compared to the control. By 90 days after planting only the Vapam at the 8- gallons-per-acre rate significantly reduced the reniform popula- tions compared to the control. No significant differences in reni- form populations were observed between any treatment at 125 days after planting. Cotton seed yield varied 280 pounds per acre for the Temik 15 G 3.5 pounds per acre and the untreated control treatments respectively. The Vapam treatments increased yield over the con- trol by an average of 153 pounds per acre; however, no treatment increased yields significantly over the control. EFFECT OF VAPAM ON RENIFORM NEMATODE POPULATIONS AND SEED COTTON YIELD Treatment 1 Rate Timings Reniform/150 cc of soil Seed cotton formulated product May 2 2 June 21 Aug. 15 Sept. 25 lb/ac Control - - 3403 a 7278 a 11163 a 4532 a 2372a Vapam HL 5 GPA 14 DBP 3433 a 678 c 6927 ab 5523 a 2596 a Vapam HL 8 GPA 14 DBP 2772 a 519 c 5317 b 6257 a 2455 a Temik 15 G 3.5 Ib/ac at plant 4064 a 2480 b 9030 ab 4296 a 2652 a Temik 15 G 5.0 lb/ac at plant 4399 a 1592 bc 9219 ab 4764 a 2473 a LSD (P=0.05) 1747 1250 4305 2149 302 SDi-Syston (7 lb/ac - at planting) added in all treatments except the Temik treatments. 2 May 2 = 23 days before planting. Means compared using Fisher's proteted least significant difference test (P=0.05). TELONE FALL FUMIGATION VERSUS SPRING FUMIGATION FOR RENIFORM NEMATODE MANAGEMENT IN COTTON William S. Gazaway, J.R. Akridge, and Kathy McLean Telone II and Temik 15G are the two commonly used nematicides for controlling reniform nematodes in cotton. Telone II, a fumigant, is injected approximately 18 inches deep in raised soil beds in the spring at least one week prior to cotton planting to avoid injury to emerging cotton seedlings. Telone is a very effec- tive nematicide when applied to a soil that is well-pulverized, free of clods, and relatively warm and dry. However, if applied to cold, wet soils--conditions that often occur early in the spring in Ala- bama-the fumigant will not control nematodes effectively and may injure or even kill cotton seedlings. It appears that cotton producers could obtain better results from fumigation in the fall when the soil is warmer and drier. The purpose of this test is to compare the effectiveness of fall fumigation versus spring fumiga- tion for controlling reniform nematodes in cotton. 30 2001 COTTON RESEARCH REPORT 31 Plots consisted of four 36-inch rows thirty feet long and were arranged in a complete randomized block with five replica- tions. Nematode soil samples and yield data were taken from the center two rows. Treatments are listed in Table 1. Nematode samples were taken three times: (1) in the fall on November 4, 2000, (2) in the spring on May 5, 2001, and (3) on June 2001. Telone was injected 18 inches deep using a subsoil shank to designated plots on De- cember 4, 2000 and April 11, 2001. Other plots not receiving Telone were also subsoiled. Cotton, DPL 458 B/RR variety, was planted on May 2, 2001. All plots received cultural, weed, and insect con- trol practices according to Auburn University recommendations. All Telone II fumigated treatments significantly outproduced Temik 15G (7 pounds per acre) and the Di-Syston 15G treatments (Table 2). No significant yield differences between the fall applica- tion rates of Telone (3 gallons per acre and 5 gallons per acre, respectively) and the spring application of Telone 3-gallons-per- acre rate. This could be due to the ideal soil temperature and mois- ture conditions at the time of the Telone spring fumigation in April. The failure of Temik 15G to produce a yield response is puzzling, since soil moisture and temperature in early May was ideal for the activation ofTemik. TABLE 1. TREATMENTS APPLIED IN THE FALL/SPRING TELONE AND TEMIK TEST Treatment Rate/acre Time of application 1 Telone 11 3 gal injected in the fall 2 Telone II 5 gal injected in the fall 3 Telone II 3 gal injected in the spring 4 Temik 15G 7 Ib in seed furrow at planting 5 Di-Syston 15G 7 Ib in seed furrow at planting TABLE 2. COTTON YIELD RESPONSE TO TELONE 1 AND TO TEMIK 15G Treatment Rate/acre Application Seed cotton/acre 1 Telone II 3 gal fall 2948 a 2 Telone II 5 gal fall 3035 a 3 Telone II 3 gal spring 3010 a 4 Temik 15G 7 Ib at planting 2423 b 5 Di-Syston 15G 7 Ib at planting 2317 b LSD (P=.01) 395 IMPACT OF FALL FUMIGATION WITH TELONE AND POST PLANT TEMIK APPLICATIONS ON COTTON PRODUCTION William S. Gazaway, Kathy McLean, and Don Moore Reniform nematodes continue to be a major impediment to successful cotton production in Alabama. Losses in cotton fields heavily infested with reniform nematodes (Rotylenchulus reniformis) can range from 20% to as high as 75% depending on growing conditions. In past years, nematicides, Telone II and Temik 15 G, have been used to moderate these losses and allow growers to successfully produce a profit in these fields. Currently cotton producers who use Telone II inject it ap- proximately 18 inches deep in well-pulverized, raised soil beds seven days prior to planting. Soil conditions at this time (particu- larly in the early spring) are often too wet and too cold for the fumigant to be effective. Under these conditions, not only does Telone not control nematodes but it can remain in the soil and harm developing cotton seedlings. For this reason, Telone ap- plied the previous fall when soil conditions are drier and warmer might be more effective. Temik 15G applied at 5 to 7 pounds per acre in the seed furrow is the most frequently used nematicide to control reniform nematodes. Past trials have shown that this nematicide can be quite effective against reniformnematodes when applied at plant- ing. Moreover, trials in north Alabama have shown a substantial yield increase with an application ofTemik 15G (7 pounds per acre) or Vydate (2 pints per acre) at pinhead square. A trial was set up, therefore, to determine if similar results could be obtained with post applications of Temik in central Alabama. The Avant cotton field near Prattville, Alabama, was selected because it had suffered substantial production losses due to reni- form nematodes. The field, a sandy loam (66% sand, 29% silt, and 5% clay) was disced thoroughly in January 2001 and bedded up. Treatments were arranged in a complete randomized block design with six replicates (Table 1). Plots consisted of four 36 inch rows, 25 feet long. Data were taken from the center two rows. Telone II TABLE 1. SUMMARY OF TREATMENTS FOR AVANT TEST Treatment Rate/acre Time of application Telone II 3 gal fall fumigation. Injected 18 inches deep. Telone II 5 gal fall fumigation Telone 11 3 gal spring fumigation Temik 15G 7 lb in seed furrow at planting Temik 15 G + 7 Ib + in seed furrow at planting, fol- Temik 15G 7 Ib lowed by side dress appli- cation at pin head square. Temik 15G 5 lb in seed furrow at planting Adage - seed treatment for early sea- son insect control I / 2001CO-TTONRESEARCHREPORT 31 ALABAMA AGRICULTURAL EXPERIMENT STATION was injected 18 inches beneath the top of the raised bed surface at 3 gallons per acre and at 5 gallons per acre to designated plots. All plots not receiving Telone were sub-soiled at the same 18 inch depth. The fall Telone fumigation which normally would be ap- plied in November or December, 2000 was not made until January 29, 2001 due to wet soil conditions. Soil temperature at the time of fall fumigation was 54 0 F. On March 28, 2001, Telone II at3 gallons per acre was injected into the designated spring fumigation plots. Soil temperature was 51OF at time of fumigation. Again all other plots received the same subsoil treatment as the spring fumigated plots. On May 21, 2001, all plots were planted with Sure Grow 125 BR seed treated with the insecticide Adage. Temik 15 G was ap- plied in the seed furrow at 5 pounds per acre or 7 pounds per acre to designated plots. Temik 15G was later applied as a side dress treatment on July 6, 2001 to designated plots. Nematode samples were taken the previous fall (on Novem- ber 30, 2000), on April 10, 2001, on August 01, 2001, and at harvest (on October 1,2001). Plots that received Telone II applied in the fall at 5 gallons per acre produced significantly higher yields than plots receiving no nematicide (i.e. Adage treated) or plots treated with Temik 15G at 7 pounds per acre (Table 2). Plots receiving Temik 15G at plant- ing (7 pounds per acre) and a side dress treatment (7 pounds per acre) at pin head square produced the second highest yields in the test but were not significantly greater than other Telone plots or Temik (5 pounds per acre) plots. Plots treated with Temik 15G (5 pounds per acre) at planting and the untreated plots produced slightly better yields than Temik (7 pounds per acre). TABLE 2. COTTON YIELD RESPONSE TO TELONE AND TO TEMIK APPLICATIONS Treatment Rate/acre Application Seed cotton/acre Telone II 5 gal fall fumigation 2948 a Temik 15G + 7 Ib + at planting 2791 ab Temik 15G 7 lb pinhead square Telone II 3 gal spring fumigation 2682 ab Telone 11 3 gal fall fumigation 2638 ab Temik 15G 5 Ib at planting 2561 ab Adage treated seed 2400 b Temik 15 7 lb at planting 2279 b LSD (P=0.05) 505 IMPACT OF VARIOUS CROP ROTATIONS AND WINTER COVER CROPS ON THE RENIFORM NEMATODE IN COTTON W.S. Gazaway, J.R. Akridge, and K.S. McLean Previous research in Alabama revealed that certain non- host crops reduced reniform nematode populations to manage- able levels within one cropping year. Cotton alternated with sum- mer non-host crops on alternate years produced significantly more cotton than continuous cotton with or without a nematicide. How- ever, reniform populations returned to potentially damaging lev- els after one growing season back in cotton. Some cotton produc- ers also believe that certain winter cover crops have a beneficial effect on cotton production in reniform infested fields. The pur- pose of this test is to reaffirm non-host crops' ability to reduce reniformpopulations and to determine if certain winter cover crops or fallow will reduce reniformpopulations to safe levels. The test was conducted on the Ward Brothers' farm near Huxford, Alabama, in a loam field (49% sand, 34% silt, and 17% clay). This field has had a high infestation of reniform nematodes for more than 12 years and, as a result, experienced substantial cotton yield losses over that period. The experimental design was a split plot, randomized design with five replications. Plots con- sisted of four 36-inch rows, 25 feet long. Main plots were the winter cover crops that include common vetch (Cahaba White), rye (Wren's Abruzzi), and fallow. Subplots were summer crops that include cotton (DPL 458 B/RR), corn (DeKalb 683), soybean (AgriPro 5588-RR), and peanut (Southern Runner). (In 2000, soy- bean 'AgriPro 5588-RR' cultivar replaced 'Centennial' because 'Centennial' seeds were no longer available.) The crop rotation scheme consisted of a 1-year rotation of a non-host summer crop with cotton. That is, peanut, corn, and soybean were planted dur- ing even years and cotton was planted in odd years. Two treat- ments (i.e., continuous cotton) were planted to cotton every year. One continuous cotton treatment received a nematicide/ insecti- cide (Temik 15G) and the other continuous cotton treatment (no nematicide) received only an insecticide, Di-Syston 15G. This rotation study was begun with winter cover crops and a fallow treatment following cotton in the fall of 1997. Non- host crops and cotton for the continuous cotton plots were planted to designated plots in the spring of 1998. Cotton was planted to all plots in the spring of 1999, followed by non-host crops again in 2000. Cotton was planted to all plots again in the spring of 2001. Cotton (DPL-458 B/RR) was planted to all plots May 2001. Di-Syston 15G was applied at 7 pounds per acre in the seed furrow at planting for early season insect control to all treatments except the continuous cotton plus nematicide treatment. Temik 15G was applied at 7 pounds per acre in the seed furrow at planting to the continuous cotton plus nematicide treatment plots. Soil samples were pulled for nematode analyses from the two inner rows of each plot on May 2, 2001 and October 21, 2001. Cotton was har- vested from the two inner rows of each plot on October 21,2001. 32 1 1 _ _1 _1 I~IVII~ II 2001 COTTON RESEARCH REPORT 33 All other cultural practices, weed control, and insect control were implemented according to Auburn University recommendations. All treatments including continuous cotton produced rela- tively good yields due to ideal growing conditions throughout the 2001 growing season (Table 1). The cotton following peanut rotation produced the highest cotton yield (Tables 1 and 3). The corn/cotton rotation and the soybean/cotton rotation produced the next highest yields although they were not significantly greater than continuous cotton with or without a nematicide (Table 3). Although the peanut/cotton rotation increased yields significantly, no such increases occurred with either the corn/cotton rotation or the soybean/cotton rotation in 2001. Although there appears to be no significant difference between winter cover crops and fal- low (Table 2), the fallow/peanut rotation produced significantly higher cotton yields than the rest (Table 1). Cotton yields follow- ing the winter cover rye in 2001 were significantly improved over cotton yields following rye in 1999. This improvement may be attributed to leaving rye stubble standing in the field rather than incorporating it in the soil prior to planting the summer crop as it had been done in years previous to 2000. Since then, no nitrogen deficiency symptoms have been observed in cotton or in the other summer non-host crops. TABLE 1. CROP ROTATIONS RANKED IN ASCENDING ORDER ACCORDING TO COTTON YIELD, HUXFORD, ALABAMA, 2001 Rotation scheme Seed cotton yield lb/ac Fallow/peanut/cotton 3704 a Vetch/peanut/cotton 3107 ab Rye/peanut/cotton 2964 b Rye/com/cotton 2929 b Fallow/corn/cotton 2857 b Vetch/soybean/cotton 2771 b Fallow/cotton/cotton 2765 b Vetch/corn/cotton 2741 b Fallow/soybean/cotton 2719 b Rye/soybean/cotton 2696 b Vetch/cotton/cotton 2617 b Rye/cotton+Temik/cotton+Temik 2601 b Fallow/cotton + Temik/cotton + Temik 2531 b Rye/cotton/cotton 2520 b Vetch/cotton + Temik/cotton + Temik 2470 b LSD (P=0.05) 676 TABLE 2. EFFECT OF WINTER COVER CROPS AND WINTER FALLOW ON 1999 AND 2001 COTTON PRODUCTION Winter cover crop -Seed cotton (lb/ac)- 1999 2001 Fallow 2615 b 2916 a Vetch 2849 a 2741 a Rye 2085 c 2742 a LSD (P=0.05) 233 406 Reniform nematode population response reflected a similar pattern as the yield response between summer crop rotations and continuous cotton (Table 4). Reniform populations declined sig- nificantly following one year of corn, soybean, or peanut while populations remained high in both nematicide-treated and un- treated continuous cotton plots (see Nov. 9, 00 column, Table 4). After one crop of cotton, reniform nematode populations had re- bounded to damaging levels by the end of the growing season in all treatments (see Oct. 17, 01 column, Table 4). Winter cover crops did not appear affect reniform populations (Table 5). One year corn/cotton, soybean/cotton, and peanut/cotton rotations were more effective than the nematicide Temik in reduc- ing reniform nematodes to manageable levels. The rapid buildup ofreniform nematodes after one season of cotton in 1999 and 2001 confirms that rotation, like a nematicide treatment, is good for only one growing season. TABLE 3. IMPACT OF CROP ROTATION WITH NON-HOST SUMMER CROPS ON COTTON PRODUCTION IN 1999 AND 2001 1998 and 2000 -Seed cotton (lb/ac)- summer crops 1999 2001 Corn 2808 a 2842 b Peanut 2739 a 3259 a Soybean 2720 a 2729 b Cotton 2175 b 2634 b Cotton + Temik 2139 b 2534 b LSD (P=0.05) 219 283 SSoybean cultivar changed from Centennial in 1998 to AgroPro- 5588-RR in 2000. TABLE 4. IMPACT OF ONE YEAR OF COTTON (2001) ON RENIFORM POPULATIONS FOLLOWING NON-HOST SUMMER CROPS THE PREVIOUS YEAR (2000) Growing seasons -Reniform per 100 CC soil- 2000/2001 Nov. 9,00 May 2,01 Oct. 17,01 Cotton/cotton 2394 663 4050 Cotton/cotton + Temik 1336 520 3130 Corn/cotton 529 74 2470 Soybean/cotton 596 159 2787 Peanut/cotton 489 247 2856 LSD (P=0.05) 449 236 855 TABLE 5. IMPACT OF WINTER COVER CROPS ON RENIFORM POPULATIONS DURING AND AFTER COTTON PRODUCTION Winter cover crop -Reniform per 100 CC soil- Nov. 9,00 May 2,01 Oct. 17,01 Fallow 1076 328 3413 Vetch 990 236 2741 Rye 1140 433 3107 LSD (P=0.05) 778 408 750 2001 Co-r-rONRESEARCHREPORT 33 ALABAMA AGRICULTURAL EXPERIMENT STATION FUNGICIDES EVALUATION OF FULL SEASON COTTON VARIETIES FOR RESPONSE TO BOLL ROT DISEASE IN ALABAMA A. J. Palmateer, K. S. McLean, K. Glass, and M. D. Pegues A cotton variety trial was pla Research and Extension Center i cluded 27 early season and 25 ft soil type was a sandy loam. Plots long with a 40-inch wide row sl randomized complete block desig were separated by a 20-foot alley. pounds per acre) was applied in-fu maintained throughout the season ticide, and fertility production pr Alabama Cooperative Extension S ated by recording the number of from a thousandth of an acre section within each plot. Rat- ings of boll rot were conducted on September 25 at 148 days after planting. Percent diseased bolls (number of diseased bolls divided by total number counted) was calculated for each variety. Plots were har- vested on November on 14. Cotton boll rot disease incidence was high for early- planted cotton in 2001 due to wet conditions. Disease in- dexes for the early season cot- ton varieties ranged from a high of 32.5 % diseased bolls to a low of 18.1% diseased bolls for Germain's GC-377 and Deltapine DP451B/RR, respec- tively (Table 1). Deltapine DP451B/RR, Sure-Grow215B, nted on May I at the Gulf Coast in Fairhope, Alabama, and in- ll season cotton varieties. The consisted of two rows, 25 feet pacing and were arranged in a n with four replications. Blocks The nematicide Temik 15G (5 rrow at planting. All plots were with standard herbicide, insec- actices as recommended by the ystem. Cotton boll rot was evalu- healthy bolls and diseased bolls TABLE 1. VARIETY RE REGULAR EARLY SEASOI and PhytoGen PSC 355 had the lowest disease indexes ofthe early variety cotton; however, 12 varieties produced significantly less boll rot than Germain's GC-377. Disease indexes for the full season cotton varieties ranged from a high of 28.5% disease bolls to a low of 11.4 % diseased bolls for Sure-Grow 821 and Deltapine DP655BRR, respectively (Table 2). DeltapineDP655BRR, Deltapine DP 5690,4600 RR, and Deltapine NuCotton 35B had the lowest boll rot disease indexes; however, 18 varieties produced signifi- cantly less boll rot than Sure-Grow 821. In 2001, the early and full season varieties overall averaged 24.87% and 23.91% boll rot dis- ease indexes; thus, there are no generalizations that can be made between early and full season varieties. SPONSE TO COTTON BOLL ROT AND YIELD OF SELECTED N COTTON VARIETIES AT THE GULF COAST RESEARCH AND EXTENSION CENTER Diseased Disease Yield Variety 1 Bolls bolls index 2 seed cotton no/plot no/plot % lb/ac Deltapine NuCotton 33B 82 abc 31 a-d 27 a-d 1006 abc Deltapine DP 20B 81 abc 31 a-d 27 a-d 802 c-e Deltapine DP 422B/RR 93 a 32 a-d 26 a-e 912 a-e Deltapine DP 451B/RR 88 ab 19 e 18 e 889 a-f Stoneville BXN 47 83 abc 29 a-e 26 a-e 1046 a Sure-Grow 747 94 a 29 a-e 23 b-e 841 a-f Sure-Grow 105 83 abc 34 ab 29 ab 854 a-f Paymater PM1560BG 81 abc 30 a-d 27 a-e 876 a-f Deltapine DP 428B 85 ab 24 b-e 22 b-e 958 a-d Deltapine DP 425RR 96 a 32 a-d 25 a-e 959 a-d Deltapine DP 436RR 93 a 37 a 28 abc 844 a-f PhytoGen PSC 355 81 abc 22 de 21 cde 980 a-d Stoneville ST 4691B 90 a 28 a-e 24 b-e 1028 a Stoneville ST 4892BR 87 ab 30 a-e 26 a-d 815 b-f Sure-Grow 125BR 87 ab 24 b-e 21 b-e 700 f Sure-Grow 501BR 88 ab 29 a-e 25 a-e 955 a-d Paymaster PM 1218BG/RR 84 ab 23 cde 22 b-e 961 a-d 1500 RR 65 c 27 a-e 29 abc 908 a-f Fiber Max FM 966 84 abc 27 a-e 23 b-e 994 a-d Sure-Grow 521R 81 abc 24 b-e 22 b-e 916a-e Sure-Grow 215B 83 abc 22 de 20 de 1026 ab Deltapine DP 491 80 abc 26 b-e 24 b-e 975 a-d Germain's GC-271 81 abc 29 a-e 27 a-d 873 a-f Germain's GC-377 70 bc 33 abc 32 a 914 a-e PM 1199 RR 89 ab 34 abc 28 a-d 736 ef AMX 4207 84 abc 30 a-e 26 a-d 787 def Stoneville ST 4793R 83 abc 25 b-e 24 b-e 921 a-e LSD (P=0.05) 19 11 8 211 1 Planted May 1, 2001. 2 Disease index= (no. of disease boils/no, of healthy boils + disease bolls) X 100. 34 2001 CO-TTON RESEARCH REPORT TABLE 2. VARIETY RESPONSE TO COTTON BOLL ROT AND YIELD OF SELECTED REGULAR FULL SEASON COTTON VARIETIES AT THE GULF COAST RESEARCH AND EXTENSION CENTER Diseased Disease Yieldseed Variety Bolls bolls index 2 cotton no/plot no/plot % lb/a c Deltapine Acala 90 98 abc 18 a-d 15 bc 767 ef Deltapine DP 5690 92 abc 16 cd 13 bc 741 f Deltapine DP 5415 91 abc 18 a-d 17 bc 933 a-e Deltapine NuCotton 33B 102 ab 28 abc 21 abc 964 abc Deltapine NuCotton 35B 94 abc 16 cd 15 bc 1078 a Deltapine DP 5415 RR 92 abc 19 a-d 17 bc 779 def Deltapine DP 5690RR 103 ab 25 a-d 19 abc 861 b-f Deltapine DP 448B 109 a 32 a 23 ab 867 b-f PytoGen PSC 161 91 abc 19 a-d 18 bc 957 a-d Fiber Max FM 989RR 80 bc 24 a-d 24 ab 860 b-f Fiber Max FM 832 73 c 16 cd 18 bc 768 ef Sure-Grow 821 74 c 29 abc 28 a 905 a-f Sure-Grow 747 106 ab 26 a-d 21 abc 939 a-e Paymaster PM 1560BG/RR 87 abc 24 a-d 22 ab 908 a-f Deltapine DP 458BRR 104 ab 21 a-d 16 bc 974 b-f Deltapine DP655BRR 96 abc 12 d 11 c 799 c-f PhytoGen HS 12 89 abc 31 ab 23 ab 969 abc Stoneville ST 4892BR 93 abc 22 a-d 19 abc 1036 ab DP Delta Pearl 98 abc 22 a-d 19 abc 1068 a 4600 RR 107 a 19 a-d 14 bc 1030 ab Deltapine DP 565 93 abc 26 abc 23 ab 1029 ab Deltapine DP 491 86 abc 19 a-d 18 bc 997 ab PytoGen Phy 72 Acala 87 abc 25 a-d 22 ab 778 def Stoneville ST 580 92 abc 22 a-s 18 abc 875 b-f Stoneville STX 9905 92 abc 18 bcd 17 bc 1006 ab LSD (P=0.05) 27 14 10 184.72 ' Planted May 1, 2001. 2 Disease index= (no. of disease bolls/no, of healthy bolls + disease bolls) X 100. EVALUATION OF SELECTED FUNGICIDES FOR CONTROL OF COTTON BOLL ROT DISEASE ON DPL458BR A. J. Palmateer, K. S. McLean, and M. D. Pegues A cotton fungicide test was planted on June 7 at the Gulf Coast Research and Extension Center in Fairhope, Alabama. The test site was a sandy loam soil. All fungicides were applied as a foliar spray using TX-12 cone nozzles, mounted on ground slides spraying upward with two nozzles per row calibrated to deliver 26 gallons per acre at 75 pounds per square inch. Plots consisted of two rows, 40 feet long, with a 38-inch wide row spacing and were arranged in a randomized complete block design with five replications. A10-foot alley was cut prior to defoliation to facilitate harvest. The nematicide Temik 15G (5 pounds per acre) was applied in-furrow at planting. All plots were maintained throughout the season with standard herbi- cide, insecticide, and fertility production practices as recom- mended by the Alabama Cooperative Extension System. Plots were sprayed at full bloom and two weeks later. The number of healthy and rotted bolls were recorded on October 10. Plots were harvested on November 26. The incidence of boll rot was moderate due to the late planting. Seed cotton yields varied by 737 pounds per acre for the Folicur 4 ounces active ingredient per acre at full bloom plus 14 days and Messenger 2.25 grams active ingredient per acre at full bloom plus 14 days applications (see table). One application at full bloom for Terraclor 4F, Rovral 4F, and Mes- senger showed numerically higher yields in comparison to each 35 36 ALABAMA AGRICULTURAL EXPERIMENT STATION treatment applied again 14 days later whereas applications at 2SC, Benlate 50WP, and Folicur treatments, respectively. No treat- full bloom plus 14 days later increased cotton yield for Quadris ments produced a significantly greater yield than the control. EFFECT OF SELECTED FUNGICIDES ON COTTON BOLL ROT DISEASE INCIDENCE AND SEED COTTON YIELD Treatment Rate Spray schedule Healthy boills Diseased bolls' Disease index 2 Yield seed ai/ac Oct. 24, 01 Oct. 24,01 % cotton(/b/ac) Quadris 2SC 6 oz Full bloom 78 ab 6 a 7 a 5239 a Quadris 2SC 6 oz Full bloom + 14 days 91 a 4 a 4 a 5285 a Benlate 50WP 0.5 lb Full bloom 81 ab 7 a 8 a 5012 a Benlate 50WP 0.5 Ib Full bloom + 14 days 76 ab 8 a 10 a 5367 a Folicur 4 oz Full bloom 82 ab 8 a 9 a 4890 a Folicur 4 oz Full bloom + 14 days 87 ab 7 a 7 a 5465 a Terraclor 4F 16 oz Full bloom 75 ab 7 a 9 a 5340 a Terraclor 4F 16 oz Full bloom + 14 days 76 ab 6 a 8 a 5070 a Rovral 4F 4 oz Full bloom 76 ab 9 a 11 a 5221 a Rovral 4F 4 oz Full bloom + 14 days 81 ab 6 a 7 a 4914 a Messenger 2.25 gm Full bloom 84 ab 10 a 10 a 5082 a Messenger 2.25 gm Full bloom + 14 days 85 ab 5 a 5 a 4728 a Control 70 b 8 a 11 a 4989 a LSD (P=0.05) 18 6 7 962 1 Number of diseased bolls per 50 ft of row. 2 Disease index = (no. of disease bolls/no, of healthy bolls + disease bolls) X 100. Means compared using Fisher's protected least significant difference test (P=0.05). EVALUATION OF SELECTED IN-FURROW FUNGICIDES FOR CONTROL OF SEEDLING DISEASE OF COTTON IN NORTH ALABAMA K. S. McLean, A. J. Palmateer, N. W. Greer, and B. E. Norris This cotton fungicide test was planted on April 11 at the Tennessee Valley Research and Extension Center, Belle Mina, Ala- bama. The field had a history of cotton seedling disease and the soil type was a Decatur silty loam. Fungicides were applied as a seed treatment or as an in-furrow spray or granular applications at planting. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles calibrated to deliver 6 gallons per acre at 18 pounds per square inch. In-furrow granular applications were applied with chemical granular applicators attached to the planter. Plots consisted oftwo rows, 25 feet long with a 40-inch wide row spacing and were arranged in a randomized complete block design with five replications. Two rows of each plot were infested with millet seed inoculated with Pythium spp. and Rhizoctonia solani and the remaining two row were left in a natural state. Blocks were separated by a 20-foot alley. The nematicide Temik 15G (5 pounds per acre) was applied in-furrow at planting. All plots were maintained throughout the season with standard herbicide, insec- ticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Stand counts and skip index ratings were recorded at two, four, and six weeks after plant- ing to determine the percent seedling loss and stand density due to cotton seedling disease. Plots were harvested on September 19. Significant differences in seedling stand were observed in the inoculated plots at two, four, and six weeks after planting (Table 1). At two weeks after planting, Ridomil Gold PC, Terraclor Super X 18.8G, Quadris SC, and Ridomil Gold PC plus Quadris SC pro- duced significantly greater stands than the untreated control. Ridomil Gold PC, Terraclor Super X 18.8G, Quadris SC, Ridomil Gold PC plus Quadris SC, Terrazole 4E plus Quadris SC, and Rovral 4E increased stand over the control at four and six weeks after planting. A significantly lower skip index, indicating a more evenly spaced seedling stand, was observed two weeks after planting only in the Ridomil Gold PC treatment. However, by four and six weeks after planting Ridomil Gold PC, Terraclor Super X 18.8G, Quadris SC, Ridomil Gold PC plus Quadris SC, Terrazole 4E plus Quadris SC, and Rovral 4E all produced a significantly lower skip index than the control. Seed cotton yields varied more than 988 pounds per acre for the Quadris SC and the Ridomil Gold EC treat- ments. Ridomil Gold PC, Terraclor Super X 18.8G, Terraclor Super XEC, Quadris SC, andRidomil Gold PC plus Quadris SC, Terrazole 4E plus Quadris SC, and Rovral 4E all produced significantly greater yields than the control. The average yield of seed cotton from all fungicide-treated plots was 424 pounds per acre greater than the untreated control. Significant differences in seedling stand were not observed spaced seedling stand, was observed six weeks after planting in in the naturally infested plots at two and four weeks after planting six of the nine fungicide treatments when compared to the control. (Table 2). However, at six weeks after planting, Ridomil Gold PC, Seed cotton yields varied 365.9 pounds per acre for the Terrazole Terraclor Super X 18.8G, Quadris SC, and Quadris SC plus Ridomil 4E plus Rovral 4E and the Terraclor Super X EC treatments respec- Gold PC produced significantly greater stands than the untreated tively. The average yield of seed cotton from the fungicide-treated control. A significantly lower skip index, indicating a more evenly plots was not greater than the yield of the untreated control. TABLE 1. EFFECT OF SELECTED FUNGICIDES ON COTTON STAND, SKIP INDEX, AND YIELD UNDER HIGH DISEASE PRESSURE Treatment Ratel Timings - Stand 2 Skip index 3 Seed cotton April 26 May 14 June 11 April 26 May 14 June11 lb/ac Untreated control - - 35 de 25 c 29 d 11 b 13 a 14 a 2203 c Terrazole 4E + Quadris 7.0 + 5.0 oz/ac In furrow 50 bcd 47 b 50 c 12 ab 6 bc 4 bc 2844 a Terrazole 4E + Rovral 4E 7.0 +4.0 ozlac In furrow 35 de 31 c 29 d 10 b 13 a 13 a 2180 c TSX 18.8 G 5.5 lbs In furrow 62 ab 72 a 71 ab 8 bc 2 c 4 bc 2770 ab TSX EC 48 oz/ac In furrow 27 e 31 c 24 d 15 a 13 a 13 a 2491 b Rovral 4E 6.0 oz/ac In furrow 46 cd 47 b 48 c 10 b 7 b 7 b 2540 b Ridomil Gold PC 7 lb/ac In furrow 68 a 74 a 79 a 4 c 3 c 3 c 2752.ab Ridomil Gold EC 1.0 fl oz/ac In furrow 28 e 25 c 20 d 12 ab 13 a 15 a 2044 c Quadris SC 6.0 oz/ac In furrow 60 abc 57 b 60 bc 8 bc 8 b 6 bc 3032 a Quadris SC+ Ridomil Gold 6.0 +1.0 oz/ac In furrow 52 bc 57 b 56 bc 8 bc 5 bc 6 bc 2993 a LSD (P=0.05) 15 12 17 5 4 4 286 Rate of formulated product. 2 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 3 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). TABLE 2. EFFECT OF SELECTED FUNGICIDES ON COTTON STAND, SKIP INDEX, AND YIELD UNDER Low DISEASE PRESSURE Treatment Rate' Timings Stand 2 - Skip index 3 Seed cotton April 26 May 14 June 11 April 26 May 14 June 11 lb/ac Untreated control - - 73 a 76 a 50 c 5 abc 3 ab 6 a 3573 abc Terrazole 4E + Quadris 7.0 + 5.0 oz/ac In furrow 61 a 75 a 64 bc 8 a 3 ab 2 b 3361 bcd Terrazole 4E + Rovral 4E 7.0 + 4.0 oz/ac In furrow 58 a 84 a 52 c 4 abc 2 ab 2 b 3670 a TSX 18.8 G 5.5 Ilbs In furrow 67 a 79 a 77 ab 6 abc 2 b 2 b 3325cd TSX EC 48 ozlac In furrow 56 a 71 a 51 c 8 a 5 a 4 ab 3304 d Rovral 4E 6.0 oz/ac In furrow 63 a 73 a 62 bc 8 ab 3 ab 3 ab 3366 bcd Ridomil Gold PC 7 Ib/ac In furrow 67 a 79 a 84 a 4 bc 1 b 2 b 3429 abcd Ridomil Gold EC 1.0 fl ozlac In furrow 74 a 88 a 54 c 4 c 1 b 1 b 3589 ab Quadris SC 6.0 ozlac In furrow 71 a 79 a 72 ab 5 abc 3 ab 3 ab 3432 abcd Quadris SC + Ridomil Gold 6.0 + 1.0 oz/ac In furrow 73 a 75 a 71 ab 6 abc 4 ab 2 b 3474 abcd LSD (P=0.05) 18 18 22 4 4 3 257 1 Rate of formulated product. 2 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 3 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 2001COTTONRESEARCHREPORT 37 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF SELECTED IN-FURROW FUNGICIDES FOR CONTROL OF SEEDLING DISEASE OF COTTON IN CENTRAL ALABAMA K. S. McLean, A. J. Palmateer, N. W. Greer, and D. Moore This cotton fungicide test was planted on April 13 at the Prattville Experiment Field in Prattville, Alabama. The field had a history of cotton seedling disease and the soil type was a Decatur silty loam. Fungicides were applied as a seed treat- ment or as an in-furrow or spray or granular application at plant- ing. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles calibrated to deliver 6 gallons per acre at 18 pounds per square inch. In-furrow granular applications were applied with chemical granular applicators attached to the planter. Plots consisted of two rows, 30 feet long with a 36-inch wide row spacing and were arranged in a randomized complete block design with five replications. Two rows of each plot were infested with millet seed inoculated with Pythium spp. and Rhizoctonia solani and the remaining two rows were left in the natural state. Blocks were separated by a 20-foot alley. The nematicide Temik 15G (5 pounds per acre) was applied in-furrow at planting. All plots were maintained throughout the season with standard her- bicide, insecticide, and fertility production practices as recom- mended by the Alabama Cooperative Extension System. Stand counts and skip index ratings were recorded at two, four, and six weeks after planting to determine the percent seedling loss and stand density due to cotton seedling disease. Plots were harvested on September 19. Significant differences in seedling stand were observed in the inoculated plots at two, four, and six weeks after planting (Table 1). At two weeks after planting, the seedling emergence of Delta Coat AD at 11.75 ounces per cwt and Rovral 4E was 39% and 13% of the total seed planted, respectively, compared to 27% in the control. This trend continued with the percent stand decreas- ing at four and six weeks after planting. A significantly lower skip index, indicating a more evenly spaced seedling stand, was not observed as compared to the control. Seed cotton yields varied over 399 pounds per acre for the Terraclor Super X 18.8G and the Messenger treatments respectively. The average yield of seed cotton from the fungicide-treated plots was not greater than the yield of the untreated control. Significant differences in seedling stand were not observed in the naturally infested plots at two, four, and six weeks after planting. However, when the stand was averaged over all treat- ments, only 48% of the seed emerged and survived by six weeks after planting. A significantly lower skip index indicating a more evenly spaced seedling stand was observed at six weeks after planting with the Ridomil Gold PC treatment as compared to the control. Seed cotton yields varied over 347 pounds per acre for the Quadris SC and the Terraclor Super X 18.8G treatments respec- tively. The average yield of seed cotton fromthe fungicide-treated plots was not greated than the yield of the untreated control. TABLE 1. EFFECT OF SELECTED FUNGICIDES ON COTTON STAND, SKIP INDEX, AND YIELD UNDER HIGH DISEASE PRESSURE Treatment Rate' Timings Stand 2 Skip index 3. Seed cotton April 26 May 14 June 11 April 26 May 14 June 11 lb/ac Untreated control - t 35 a-d 34 a-d 30 a-d 15 abc 14 bcd 13 abc 1932 Terrazole 4E + Quadris 7.0 + 5.0 oz/ac In furrow 33 a-d 29 bcd 27 bcd 14 abc 16 a-d 15 ab 1843 Terrazole 4E + Rovral 4E 7.0 + 4.0 ozlac In furrow 34 a-d 33 a-d 31 a-d 17 abc 16 a-d 14 abc 2013 TSX 18.8 G 5.5 Ibs In furrow 23 cd 22 cd 26 bcd 19 ab 18 ab 15 ab 2121 TSXEC 48 oz/ac In furrow 38 abc 39 a-d 34 abc 14 bc 12 d 11 bc 1940 Rovral 4E 6.0 oz/ac In furrow 17 d 21 d 17d 19 a 18 ab 18 a 1726 Ridomil Gold 7 Ib/ac In furrow 32 a-d 36 a-d 33 a-d 17 abc 13 bcd 11 bc 2065 Ridomil Gold 1.0 fl ozlac In furrow 37 abc 33 a-d 32 a-d 16 abc 12 cd 11 ab 1798 Quadris 6.0 oz/ac In furrow 26 bcd 25 bcd 29 cd 18 ab 19a 15 ab 1932 Quadris + Ridomil Gold 6.0 + 1.0 oz/ac In furrow 28 bcd 28 bcd 24 bcd 18 ab 16 a-d 14 ab 1927 Delta Coat AD 11.75floz/cwt Seed trt 50 a 50 a 46 a 14 abc 12 d 8c 2036 Delta Coat AD 9.0 fl oz/cwt Seed trt 41 abc 42 abc 38 abc 17 abc 13 bcd 12 abc 2101 Messenger 2.25 oz/ac In furrow 46 ab 44 ab 42 ab 12 c 12 cd 11 bc 1948 Messenger 1.125 oz/ac In furrow 25 cd 22 d 21 cd 18 ab 17 abc 16 ab 1722 LSD (P=0.05) 19 20 18 5 5 6 403 Rate of formulated product. 2 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 3 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 38 2001 COTTON RESEARCH REPORT TABLE 2. EFFECT OF SELECTED FUNGICIDES ON COTTON STAND, SKIP INDEX, AND YIELD UNDER Low DISEASE PRESSURE Treatment Rate' Timings - Stand 2-------Skip index Seed cotton April 26 May 14 June 11 April 26 May 14 June 11 b/ac Untreated control - - 56 a 61 a 55 a 9 abc 9 ab 9 ab 3053 Terrazole 4E + Quadris 7.0 + 5.0 oz/ac In furrow 63 a 65 a 55 a 11 abc 10 ab 8 abc 3073 Terrazole 4E + Rovral 4E 7.0 + 4.0 oz/ac In furrow 67 a 57 a 55 a 12 a 10 a 8 abc 3037 TSX 18.8 G 5.5 Ibs in furrow 64 a 67 a 49 a 12 ab 9 ab 9 a 2867 TSX EC 48 oz/ac In furrow 76 a 73 a 69 a 7 abc 6 ab 5 abc 2908 Rovral 4E 6.0 ozlac In furrow 56 a 63 a 58 a 9 abc 8 ab 8 abc 3089 Ridomil Gold 7 Ib/ac In furrow 63 a 55 a 54 a 8 abc 8 ab 7 abc 2960 Ridomil Gold 1.0 fl ozlac In furrow 76 a 69 a 66 a 6 c 5 b 4 c 3194 Quadris 6.0 oz/ac In furrow 59 a 66 a 62 a 9 abc 6 b 6 abc 3214 Quadris + Ridomil Gold 6.0 + 1.0 oz/ac In furrow 80 a 74 a 63 a 10 abc 7 ab 7 abc 3146 Delta Coat AD 11.75 fl oz/cwt Seed trt 68 a 64 a 59 a 9 abc 6 ab 5 abc 2871 Delta Coat AD 9.0 fl oz/cwt Seed trt 71 a 68 a 63 a 10 abc 5 b 6 abc 3190 Messenger 2.25 ozlac In furrow 69 a 71 a 63 a 7 bc 6 ab 5 bc 3012 Messenger 1.125oz/ac In furrow 60 a 53 a 51 a 9 abc 9 ab 7 abc 3008 LSD (P=0.05) 27 26 23 5 5 4 367.0 SRate of formulated product. 2 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 3 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). EVALUATION OF SELECTED SEED TREATMENT FUNGICIDES FOR CONTROL OF SEEDLING DISEASE K. S. McLean, A. J. Palmateer, N. W. Greer, and B. E. Norris This cotton fungicide test was planted on April 20 at the Tennessee Valley Research and Extension Center in Belle Mina, Alabama. The field had a history of cotton seedling disease and the soil type was a Decatur silty loam. All seed treatments were applied to the seed by the manufacturer. Plots consisted of two rows, 25 feet long with a 40-inch wide row spacing and were ar- ranged in a randomized complete block design with five replica- tions. Two rows of each plot were infested with millet seed inocu- lated with Pythium spp. and Rhizoctonia solani and the remain- ing two rows were left naturally infested. Blocks were separated by a 20-foot alley. The nematicide Temik 15G (5 pounds per acre) was applied in-furrow at planting. All plots were maintained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Stand counts and skip index rat- ings were recorded at two, four, and six weeks after planting to determine the percent seedling loss and stand density due to cotton seedling disease. Plots were harvested on October 9. Significant differences in seedling stand were observed in the inoculated plots at two and four weeks after planting (Table 1). At two and four weeks after planting, Maxim 4 FS plus Azoxystrobin plus Apron XL 3 LS and Azoxystobin plus Apron XL 3 LS plus Maxim4 FS plus Systhane 40 WSP produced signifi- OF COTTON IN NORTH ALABAMA cantly greater stands than all other seed treatments. All seed treat- ments except Apron XL 3 LS plus Maxim4 FS produced a signifi- cantly greater stand than the control. A significantly lower skip index, indicating a more evenly spaced seedling stand, was ob- served at four weeks after planting in all the seed treatments as compared to the control. Seed cotton yields varied over 1,657 pounds per acre for the Azoxystobin plus Apron XL 3 LS plus Maxim 4 FS plus Systhane 40 WSP and the untreated control treatments. All seed treatments significantly increased seed cot- ton yields over the untreated control. The average yield from the fungicide-treated plots was 1,090 pounds per acre greater than the yield of the untreated control. Significant differences in seedling stand were observed in the naturally infested plots at two and four weeks after planting (Table 2). At two and four weeks after planting, the untreated control and Apron XL 3 LS plus Maxim 4 FS plus Systhane 40 WSP produced greater stands than ten of the other seed treat- ments. Skip indexes were very low in this test; thus, the seedling stand was uniform. Seed cotton yields varied over 753 pounds per acre for the untreated control and the Maxim 4 FS plus Azoxystobin plus Apron XL 3LS treatments. The average yield from the fungicide-treated plots was not greater than the yield of the untreated control. 39 40 ALABAMAARCLUA XPRMN TTO TABLE 1. EFFECT OF SELECTED SEED TREATMENTS ON COTTON STAND, SKIP INDEX, AND SEED COTTON YIELD UNDER HIGH DISEASE PRESSURE Treatment Rate/I 00kg seed Application -Stand 25 ft rowI - -Skip index 2- Seed cotton 14 DAP 28 DAP 14 DAP 28 DAP Ilac Untreated control Apron XL 3 LS + Maxim4FS+ Systhane 4OWSP Apron XL 3 LS + Maxim 4 FS Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS + Maxim 4 FS Azoxystrobin + Apron XL 3 LS + Maxim 4 FS Azoxystrobin + Apron XL 3 LS + Maxim 4 ES Azoxystrobin + Maxim 4 ES + Apron XL 3 ES Maxim 4 ES + Azoxystrobin + Apron XL 3LS Apron XL 3 LS + Maxim 4 ES Azoxystobin + Apron XL 3 LS Maxim 4 ES + Systhane 40 WSP Azoxystrobin + Apron XL 3LS + Maxim 4 ES + Systhane 40 WSP Azoxystrobin + Baytan 30 + Allegiance-El LSD (P=0.05) ~4 17f 10 :;h 1 5l719h 7.5+ 2.5+ 21 7.5+ 2.5 8.0+ 7.5 10.0+ 7.5 15.0+ 7.5 8.0 + 7.5 + 1.25 8.0 + 7.5 + 2.5 10.0+ 7.5+ 1.25 10.0 + 2.5 + 7.5 1.25 + 15.0 + 7.5 7.5+ 1.25 8.0+ 75+ 2.5+ 21.0 10.0 +7.5 + 2.5+ 21.0 4.0 + 10.0 + 15.0 Seed trt 68 bc 56 de 3 def 5 cde 2924 a-e Seed trt Seed trt Seed trt Seed trt Seed trt 45 de 55 cd 62 bcd 68 bc 53 cd 30 f 57 de 66 cd 61 cde 48 e 8 bc 4 de 3 def 3 def 5 de Seed trt 58 bcd 56 de 3 def Seed trt 63 bcd 57 de 2 def Seed trt 61 bcd 61 cde 5def Seedtrt 90a 9Oab 2ef Seed trt 65 bc 55 de 4 de Seedtrt 92a 104a If Seed trt 76 ab 87 b 2 def Seedtrt 68bc 77bc 4def 19 17 2 12 b 4 c-f 5 cd 4 c-f 6 c 2085 f-h 2726 cde 2739 cde 2906 a-e 2987 a-d 3 c-g 2456 e-g 4 c-g 2699 cde 4 c-g 3023 abc 1Ig 3272 ab 6 c 2 fg 2522 def 3376 a 3 d-g 2807 b-e 2 efg 2807 b-e 480 SNumber of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 2 Skip index ratings on 25 ft of row. Rating scale: I = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 40 ALABAMAAGRICULTURAL EXPERIMENT STATION 2001 COTTON RESEARCH REPORT 4 TABLE 2. EFFECT OF SELECTED SEED TREATMENTS ON COTTON STAND, SKIP INDEX, AND SEED COTTON YIELD UNDER Low DISEASE PRESSURE Treatment Rate/I 00kg seed Application -Stand 25 ft row- -Skip index 2 - Seed cotton 14 DAP 28 DAP 14 DAP 28 DAP lac Untreated control Apron XL 3 LS + Maxim4FS+ Systhane 4OWSP Apron XL 3 LS + Maxim 4 ES Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS Azoxystrobin + Apron XL 3 LS + Maxim 4 FS Azoxystrobin + Apron XL 3 LS + Maxim 4 FS Azoxystrobin + Apron XL 3 LS + Maxim 4 ES Azoxystrobin + Maxim 4 ES + Apron XL 3 ES Maxim 4 ES + Azoxystrobin + Apron XL 3 LS Apron XL 3 LS + Maxim 4 ES Azoxystobin + Apron XL 3 LS Maxim 4 ES + Systhane 40 WSP Azoxystrobin + Apron XL 3 LS + Maxim 4 ES + Systhane 40 WSP Azoxystrobin +, Baytan 30 + Allegiance-El LSD = (P=0.05) 7.5+ 2.5+ 21 7.5+ 2.5 8.0+ 7.5 10.0+ 7.5 15.0+ 7.5 8.0 + 7.5 + 1.25 8.0 + 7.5 + 2.5 10.0 + 7.5 + 1.25 10.0 + 2.5 + 7.5 1.25 + 15.0+ 7.5 7.5+ 1.25 8.0+ 75+ 2.5+ 21.0 10.0 +7.5 + 2.5 +'21.0 4.0 + 10.0 + 15.0 125 a 133a 0c Seed trt 126a l31lab 0Oc Seed trt Seed trt Seed trt Seed trt Seed trt 98 b-e 94 cde 98 b-e 78 e 84 e 111 a-e 100 efg 104 d-g 82 g 91 efg Seed trt 85Sde 87 fg I bc 4 a I bc 2 bc 2 bc l b 0b l b l b l b l b 3 a 3727 a 3408 a-d 3186 cde 3261 b-e 3233 b-e 3052 de 3199 cde 1Ibc lb 3214 b-e Seed trt 92 cde 101 d-g I bc I b 3316 a-e Seed trt 95 cde 106c-f I bc lb 3029de Seed trt 91lcde 101ld-g 2 ab l b 2974 e Seed trt I11abc 128abc Oc lb Seed trt 110 a-d 128 abc I bc I b 3063 de 3491 abc Seed trt llOa-d 124 a-d 0 c 0 b 3248 b-e Seed trt 91 cde 110 b-f 2 bc 1 b 3050 de 25 24 2 418 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 2 Skip index ratings on 25 ft of row. Rating scale: I = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fishers protected least significant difference test (P=0.05). 412001COTTONRESEARCHREPORT ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF SELECTED SEED TREATMENT FUNGICIDES FOR CONTROL OF SEEDLING DISEASE K. S. McLean, A. J. Palmateer, N. W. Greer, and D. Moore This cotton fungicide test was planted on April 20 at the Prattville Experiment Field in Prattville, Alabama. The field had a history of cotton seedling disease and the soil type was a sandy loam. All seed treatments were applied to the seed by the manufacturer. Two rows of each plot were infested with millet seed inoculated with Pythium spp. and Rhizoctonia solani and the remaining two rows were left naturally infested. Plots consisted of two rows, 25 feet long with a 40-inch wide row spacing and were arranged in a randomized complete block design with five replications. Blocks were separated by a 20- foot alley. The nematicide Temik 15G (5 pounds per acre) was applied in-furrow at planting. All plots were maintained through- out the season with standard herbicide, insecticide, and fertil- ity production practices as recommended by the Alabama Co- operative Extension System. Stand counts and skip index rat- ings were recorded at two, four, and six weeks after planting to determine the percent seedling loss and stand density due to cotton seedling disease. Plots were harvested on October 9. OF COTTON IN CENTRAL ALABAMA Significant differences in seedling stand were observed in the inoculated plots at two and four weeks after planting (Table 1). At two and four weeks after planting, Maxim 4 FS plus Azoxystrobin plus Apron XL 3 LS and Azoxystobin plus Apron XL 3 LS plus Maxim 4 FS plus Systhane 40 WSP at the high rates produced significantly greater stands than the untreated control. Eleven seed treatments produced a significantly greater stand than the control at four weeks after planting. A significantly lower skip index, indicating a more evenly spaced seedling stand, was ob- served at two weeks after planting in the Azoxystrobin plus Maxim 4 FS plus Apron XL 3, and the Azoxystrobin plus Baytan 30 plus Allegiance FL seed treatments as compared to the untreated con- trol. Seed cotton yields varied over 1253 pounds per acre for the Azoxystobin plus Apron XL 3 LS plus Maxim 4 FS plus Systhane 40 WSP and the untreated control treatments. Twelve of the seed treatments significantly increased seed cotton yields over the untreated control. The average yield of seed cotton from the fun- gicide-treated plots was 793 pounds per acre greater than the yield of the untreated control. TABLE 1. EFFECT OF SELECTED SEED TREATMENTS ON COTTON STAND, SKIP INDEX, AND SEED COTTON YIELD UNDER HIGH DISEASE PRESSURE Treatment Rate/1 00kg seed Application -Stand 25 ft row -Skip index 2 - Seed cotton May 11 May 24 May 11 May 24 lb/ac Untreated control - 8 b-e 6 d 22 a-d 19 abc 1389 h Apron XL 3 LS + Maxim 4 FS + 7.5+ 2.5+ 21 Seed trt 12 a-d 18 ab 19 d-g 16 bc 1926 ef Systhane 40WSP Apron XL 3 LS + Maxim 4 FS 7.5 + 2.5 Seed trt 6 cde 8 cd 22 abc 20 ab 1648 gh Azoxystrobin + Apron XL 3 LS 8.0 + 7.5 Seed trt 9cde 11 bcd 21 a-e 19 abc 1975 efg Azoxystrobin + Apron XL 3 LS 10.0 + 7.5 Seed trt 5 de 13 a-d 23 ab 16 bc 2134 c-f Azoxystrobin + Apron XL 3 LS 15.0 + 7.5 Seed trt 11 a-d 15 abc 20 b-g 17 bc 2231 a-f Azoxystrobin + ApronXL 3 LS + 8.0 + 7.5 + 1.25 Seed trt 10 bcd 11 bcd 19 c-g 20 ab 2091 def Maxim 4 FS Azoxystrobin + Apron XL 3 LS + 8.0 + 7.5 + 2.5 Seed trt 11 a-d 18 ab 21 b-f 18 bc 2338 a-e Maxim 4 FS Azoxystrobin + Apron XL 3 LS + 10.0 + 7.5 + 1.25 Seed trt 12 abc 20 a 19 d-g 17 bc 2497 abc Maxim 4 FS Azoxystrobin + Maxim 4 FS + 10.0 + 2.5 + 7.5 Seed trt 11 a-d 15 abc 18 fg 16 c 2159 b-f Apron XL 3 FS Maxim 4 FS + Azoxystrobin + 1.25 + 15.0 + 7.5 Seed trt 17 a 20 a 17 g 17bc 2338 a-e Apron XL 3 LS Apron XL 3 LS + Maxim 4 FS 7.5 + 1.25 Seed trt 11 a-d 14 a-d 20 b-d 18 abc 1626 gh Azoxystobin + Apron XL 3 LS 8.0 + 75 + Seed trt 8 b-e 20 a-d 22 a-d 18 abc 2642 a Maxim 4 FS + Systhane 40 WSP 2.5 + 21.0 Azoxystrobin + Apron XL 3 LS + 10.0 + 7.5+ Seed trt 17 a 17 ab 18 efg 17 bc 2430 a-d Maxim 4 FS + Systhane 40 WSP 2.5 + 21.0 Azoxystrobin + Baytan 30 + 4.0 + 10.0 + 15.0 Seed trt 13 ab 16 abc 18 efg 17 bc 2531 ab Allegiance-FI LSD (P=0.05) 7 8 3 4 394 1 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 2 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 42 2001 CorroN RESEARCH REPORT 43 Significant differences in seedling stand were not ob- served in the naturally infested plots at two and four weeks after planting (Table 2). At four weeks after planting, only 21% of the seed survived due to dry conditions. A significantly lower skip index, indicating a more evenly spaced seedling stand, was observed at four weeks after planting in the Azoxystrobin plus Maxim 4 FS plus Apron XL 3, the Maxim 4 FS plus Azoxystrobin plus Apron XL 3 LS, the Apron XL 3 LS plus Maxim 4 FS and the Azoxystobin plus Apron XL 3 LS plus Maxim 4 FS plus Systhane 40 WSP low rate seed treatments compared to the untreated control. Seed cotton yields varied over 1056 pounds per acre for the Azoxystobin plus Baytan 30 plus Allegiance FL and the Azoxystobin plus Apron XL 3 LS seed treatments. The average yield of seed cotton from the fungicide-treated plots was not greater than the yield of the untreated control. TABLE 2. EFFECT OF SELECTED SEED TREATMENTS ON COTTON STAND, SKIP INDEX, AND SEED COTTON YIELD UNDER Low DISEASE PRESSURE Treatment Rate/1 00kg seed Application -Stand 25 ft row 1- -Skip index 2 Seed cotton May 11 May 24 May 11 May 24 lb/ac Untreated control - 25 a 24 a 16 abc 16 a 3470a Apron XL 3 LS + Maxim 4 FS + 7.5 + 2.5 + 21 Seed trt 26 a 25 a 14 bc 15 ab 3393a Systhane 40WSP Apron XL 3 LS + Maxim 4 FS 7.5 + 2.5 Seed trt 26 a 27 a 13 bc 13 abc 3369a Azoxystrobin + Apron XL 3 LS 8.0 + 7.5 Seed trt 21 a 22 a 17 abc 14 abc 3340a Azoxystrobin + Apron XL 3 LS 10.0 + 7.5 Seed trt 18 a 21 a 20 a 15 ab 2425 c Azoxystrobin + Apron XL 3 LS 15.0 + 7.5 Seed trt 25 a 26 a 15 bc 16 ab 3199 a Azoxystrobin + Apron XL 3 LS + 8.0 + 7.5 + 1.25 Seed trt 30 a 26 a 15 bc 13 abc 3127 ab Maxim 4 FS Azoxystrobin + Apron XL 3 LS + 8.0 + 7.5 + 2.5 Seed trt 21 a 25 a 16 bc 15 abc 2957 abc Maxim 4 FS Azoxystrobin + Apron XL 3 LS + 10.0 + 7.5 + 1.25 Seed trt 20 a 24 a 17 ab 14 abc 2502 bc Maxim 4 FS Azoxystrobin + Maxim 4 FS + 10.0 + 2.5 + 7.5 Seed trt 21 a 24 a 15 bc 11 c 2986 abc Apron XL 3 FS Maxim 4 FS + Azoxystrobin + 1.25 + 15.0 + 7.5 Seed trt 30 a 31 a 14 bc 14 bc 3199 a Apron XL 3 LS Apron XL 3 LS + Maxim 4 FS 7.5+ 1.25 Seed trt 30 a 28 a 15 bc 11 bc 3107 ab Azoxystobin + Apron XL 3 LS 8.0+ 75+ Seed trt 29 a 29 a 13 c 11 bc 3078 abc Maxim 4 FS + Systhane 40 WSP 2.5+ 21.0 Azoxystrobin + Apron XL 3 LS + 10.0 + 7.5 + Seed trt 27 a 21 a 17 ab 13 abc 3132 ab Maxim 4 FS + Systhane 40 WSP 2.5+ 21.0 Azoxystrobin + Baytan 30 + 4.0 + 10.0 + 15.0 Seed trt 32 a 31 a 13 c 12 abc 3480 a Allegiance-FI LSD (P=0.05) 14 11 5 4 667 1 Number of live seedling per 25 ft of row; all rows received 125 Suregrow 125 BR seed. 2 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2 = 2 ft gap; 3 = 3ft gap;... 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 2001CO-FFONRESEARCHREPORT 43 44 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF SELECTED FUNGICIDES FOR CONTROL OF SEEDLING DISEASE IN ULTRA NARROW Row COTTON K. S. McLean, D. P. Delaney, C. D. Monks, A. J. Palmateer, N. W. Greer, and L. Carter, A cotton fungicide test was planted on April 12 at the E. V. Smith Research Center in Shorter, Alabama. Fungicides were ap- plied either as seed treatments, in-furrow granules, or as a broad- cast spray. Fungicides applied as a broadcast spray were applied immediately before planting utilizing a backpack CO 2 charged six- foot boom with flat fan tip 8002E nozzles calibrated to deliver 10 gallons per acre at 30 pounds per square inch. In-furrow granular treatments were applied with the seed at planting. DP 458 B/RR was planted in all plots at a rate of 180,000 seed per acre with a cone type drill. Plots consisted of 18 rows, 25 feet long with a 7- inch wide row spacing and were arranged in a randomized com- plete block design with six replications. Blocks were separated by a 20-foot alley. All plots were maintained throughout the sea- son with standard herbicide, in- secticide, and fertility produc- tion practices as recommended by the Alabama Cooperative Extension System. Stand counts, skip index, and vigor ratings were recorded at two, four, and six weeks after plant- ing to determine the percent seedling loss, stand density, and seedling vigor due to cot- ton seedling disease. The num- ber of open and closed bolls were counted on August 9 to indicate relative plant maturity. The center 7 feet of each plot was harvested on September 6 with a finger stripper. Cotton seedling disease incidence was moderate in 2001 due to dry conditions. Significant differences in seedling stand were observed. At two and six weeks after planting, all fungicide treat- ment stands were equivalent to the control except Terraclor Super X 18.8G. No differences in the skip index were observed. Seed cotton yields varied 427 pounds per acre for the Quadris 2SC and the Terraclor Super X EC at 48 ounces per acre treatments, respec- tively, with no significant differences between any treatments. The average yield of seed cotton from the fungicide-treated plots was not greater than the yield of the untreated control. EFFECT OF SELECTED FUNGICIDES ON COTTON STAND, SKIP INDEX, AND SEED COTTON YIELD PER ACRE Skip Seed cotton Treatment Rate Stand per 25 foot of row I index 2 lb/ac April 24 May 11 May 23 May 23 Sept. 6 Untreated control - 47 ab 46 ab 43 a 7.8 5007 TSX 18.8 G 5.5 lb/ac 33 c 37 b 30 b 12.0 4911 TSX2EC 48fl oz/ac 45 ab 42 ab 43 a 8.3 4733 TSX2EC 96 fl ozlac 40 bc 41 ab 42 a 10.7 5085 Rovral 4CF 5.2 fl oz/ac 47 ab 46 ab 40 a 9.0 5042 Ridomil Gold PC 7 Ib/ac 39 bc 43 ab 36 ab 10.1 4775 Ridomil Gold PC 3.0 fl ozlac 49 a 42 ab 36 ab 10.3 4768 Quadris 2.08 SC 6.0 fl oz/ac 45 ab 50 a 38 ab 8.7 5160 Delta Coat AD 11.75 fl oz/cwt 44 ab 44 ab 37 ab 9.6 4735 LSD (P=0.05) 9 10 10 4.7 475 1 Number of live seedling per 25 ft of row. 2 Skip index ratings on 25 ft of row. Rating scale: 1 = 1 ft gap; 2= 2 ft gap; 3 = 3ft gap;... 25= no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 44 ALABAMAAGRICULTURALEXPERIMENT STATION 2001 CO-rON RESEARCH REPORT MOLECULAR STUDIES DEVELOPMENT OF NOVEL TRANSFORMATION SYSTEMS IN COTTON Allan Zipf, Hamidou Sakhanokho, Govind Sharma, and Khairy Soliman The current project concerning novel transformation sys- tems in cotton ultimately aims to provide Alabama farmers with new cotton lines that have improved fiber qualities. This project has the long-term goal of providing a farmer-driven source for transgenic plants alongside the offerings of corporations, such as Monsanto, Dow, and Pioneer. The objectives of this project were to (1) develop reliable tissue culture systems for producing diploid plants, and (2) discover new regenerable germplasms for use in transforma- tion for both cotton improvement and for study of gene func- tion. Current achievements include developing reliable somatic embryogenesis culture system for producing diploid plants, and evaluating somaclonal variation from tissue culture proce- dure. Developing reliable somatic embryogenesis culture sys- tem for producing diploid plants. The importance ofboth car- bohydrate and nitrogen source in the development of highly embryogenic callus among diploid cottons has been elucidated. A new generation of Gossypium arboreum somatic embryos has been produced and several methods for improving somatic embryo maturation, somatic embryo germination, and seedling acclimation are currently being evaluated. Though plants have been obtained, the recovery rate is still abysmal and needs to be improved before successful transformation can be initiated. Evaluating somaclonal variation from tissue culture pro- cedure. DNA was successfully extracted from several regener- ated tetraploid plants for further, in-depth evaluation of somaclonal variation, if any, from the process. Purity was checked by both UV spectrophotometer and by agarose gel electrophoresis. An AFLP kit was purchased and the DNA will be evaluated after researchers receive appropriate training on a recently purchased ABI 3100 capillary electrophoresis system. Other polymorphic PCR-based markers, such as SSR, will also be used to provide further information. A set of cotton SSR marker primers has been purchased from Research Genetics (Invitrogen) and a series has also been obtained from a col- laborator, Dr. Sukumar Saha, USDA/ARS/CSRL, MS. ISOLATION OF GENES RELATED TO COTTON PERFORMANCE AND QUALITY Khairy Soliman, Allan Zipf, Govind Sharma, Zhengdao Wu, Aaron Jeffries, and James Bolton An important objective of cotton research at Alabama A&M University is to reveal genes that may have roles in either cotton growth or fiber quality. A number of projects trying to find genes associated with various aspects of cotton culture are being con- ducted through a diverse set of active collaborators. Three of these projects will be discussed in this article. Identification of members of the cellulose synthase (GhCesA) gene family in cultivated cottons. Because cotton equals fiber equals cellulose, it is extremely important to understand the dy- namics of cotton fiber development, starting with the number and kinds ofgenes involved and including fiber initiation to fiber elon- gation to fiber maturation. In an ongoing pilot project with Dr. Debby Delmer, UC-Davis, researchers are studying the evolutionary diversity of cellulose synthase (CesA) in Gossypium (see Figure 1). Primers were de- signed from regions conserved in both Gossypium and Arabidopsis that successfully amplify fragments from both diploid and tetrap- loid members of the genus. Preliminary results indicate that the regions spanned are highly conserved, with little rearrangement. Figure 1. Graphical alignment results of a BLAST search of the sequence for CesA PCR 1A + 2A fragment clone 1. color Key for ati8nentL cores ) 10) 150 200 250 300 350 400 ... . .. . . . .. -- - -- - -- - 45 -- ALABAMA AGRICULTURAL EXPERIMENT STATION Indications are that at least three members of the CesA gene family exist in tetraploid cottons. Identification of genes related to cotton fiber development using unique mutants. In a separate USDA Capacity Building project, with a USDA collaborator, Dr. Sukumar Saha, fiber cells are being studied to characterize the Li-1 mutant fiber develop- ment. Short fiber and distorted stems and leaves characterize this mutant that is inherited as a Mendelian dominant (see Figure 2). This mutation represents a change in a very important fiber gene and researchers hope to find a marker linked to the mutation, if not the mutated gene itself, by developing a linkage map based on inheritance in an F 2 population. Figure 2. Morphology of the Li-1 mutant. Leaves taken from Upland (left) and Li-1 mutant (right). Note distorted morphology of the mutant leaf. Identification of fiber-related genes by differential screen- ing. Another Capacity Building project aims to identify cotton genes associated with fiber quality. Messenger RNAs were iso- lated from the fiber layers of high yielding Upland cotton, TM-1, and high fiber quality Pima cotton, 3-79, respectively. A cDNA library was constructed from the high fiber-quality line, 3-79, and screened differentially with the cDNA probes obtained from mRNAs of TM-1 and 3-79, respectively. Thirteen cDNA clones were selected for sequencing and subjected to northern hybrid- ization analysis. Five of the thirteen cDNAs showed high expres- sion in the twenty day-post-anthesis (DPA) fiber tissue of 3-79 cotton. Northern blotting suggests that these genes are not unique to Pima cotton but definitely are expressed in higher amounts. Sequence analysis indicated the presence of a cotton lipid trans- fer protein, a mitogen-activated protein kinase and a novel gene with no homologous sequences in the Genbank database. The remaining two separate cDNAs showed high identity in nucle- otide sequence to 6 DPA G. arboreum and 7 to 10 DPA G. hirsutum fiber cDNAs, respectively, but of unknown functions. The cDNA clones differentially expressed in the 3-79 cotton fiber were pre- sumed to be associated with cotton fiber quality, but their specific contribution has not been determined (see Figure 3). These se- quences represent one of the few reports to study fiber-associ- ated gene expression in Pima cotton (G. barbadense). The rela- tionship of these highly expressed genes to fiber quality remains for the next round of studies. Figure 3. Differential expression of clones PFbland PFb2 in 3-79 cotton fiber. PFbl 379 TM-1 18S rRNA PFb2 3-79 TM-1 18S rRNA DEVELOPING IN VITRO COTTON CULTURE SYSTEMS FOR RENIFORM NEMATODE STUDIES Dewang Deng, Allan Zipf, Govind Sharma, and Yonathan Tilahun Reniform nematodes, Rotylenchulus reniformis, are becom- ing an increasingly serious threat to cotton producers with their continued spread into uninfected cotton production areas. How- ever, studies on the infection by and resistance to reniform nema- 46 C;VLIUII IIUt=l. ..... 2001 COTTON RESEARCH REPORT todes are difficult to perform in the field or even in the greenhouse. As an alternative, in vitro root cultures could be used as a model to study plant tolerance and susceptibility to the nematode. Cotton ex- cised root cultures have not been studied successfully in earlier inves- tigations, hence the critical need for the present study. The objectives of this study were to (1) develop long-term (at least 30 day) cotton root cultures, (2) sterilize viable reniform nematodes, and (3) establish continuous reniform infections in the root cultures. For the first time, continuous culture in liquid medium of excised roots of Gossypium hirsutum has been achieved, with healthy roots being maintained for at least four weeks. Cultures 47 were incubated in Cotton Root Culture Medium [CRCM] (1/2 MS basal liquid mediumplus 50 mg myo-inositol, 0.5 mg nicotinic acid, 0.5 mg pyridoxine-HC1, 0.5 mg thiamine-HC1, and 15 g/L glucose) under a minimal rocking condition in the dark at room temperature. The elongation of roots was genotype-specific and was more ef- fective in liquid than on agar medium. However, the pattern of elongation was similar: there was an initial surge of root elonga- tion and then a dramatic slowdown after the second week, con- tinuing without death up to 10 weeks or more (see figure). This sigmoid pattern of elongation was also seen in uncut, soil-grown plants. It is hoped this method has potential use for the research of nematode infections. Timecourse of root elongation for different culture treatment. A. Change in weekly root length for different treatments. B. Relative change in weekly root elongation for different treatments. ANOVA analysis showed there was significance (P<0.01) between the two treatments. Root Elongation 25 20 E 0) -J C) 0) A 10. 5 0- 1 week 2 week 3 week 4 week S1st week *2nd week [" 3rd week 0 4th week DPL 5415 Root Culture DPL 5415 Natural Growth 0% Root Elongation 25% 50% 75% 100% Relative Growth LV ni B 48 ALABAMA AGRICULTURAL EXIERIMENT STATION AUTHORS' INDEX Author Page Author Page James R. Akridge James W. Baier R.R. Beauchamp W.C. Birdsong James Bolton Charles Burmester L. Carter Jamey Clary Larry M. Curtis Dennis P. Delaney Dewang Deng David Derrick Bobby Durbin Mickey D. Eubanks Wilson H. Faircloth Barry L. Freeman William S. Gazaway Kathy Glass N. W. Greer Bob Goodman David H. Harkins Aaron Jeifries Ian Kaplan J. W. Kloepper L. Kuykendall G. W. Lawrence Kathy S. McLean Charles Mitchell C. Dale Monks Don P. Moore Marshall M. Nelson Bobby E. Norris Perry L. Oakes Aaron Palmateer 3,29,30,30-31,32-33 10-13 16-19 15-16 45-46 1,10-13,22-23 3,44 1-2 10-13, 13 1-2,10,19-20,21,44 46-47 I 10,14 4-5 21-22,23 24,26 29,30-31,31-32,32-33 1-2,3,34-35 3,5-6,6-78,9,29,30136-371 38-39,39-41,42-43,44 10 10-13 45-46 4-5 5-6,6-718.,9 16-19 3y,30 315-6,6-7,8,9,29130.130-311 31-32,32-33.,34-35,35-36.9 36-37,38-39,39-41,42-43.,44 15-16,16-19,19-20 1-2, 10,21,21-22,23144 14,21,31-32,38-39,42-43 13 10-13,14,36-37,39-41 13 3,5-616- 78,9,29,30.134-35, 35-36,36-37938-39,39-41, 42-43,44 Michael G. Patterson Malcomb Pegues M. S. Reddy Wayne Reeves Hamidou Sakhanokho Govind Sharma Edward Sikora Ron H. Smith Khairy Soliman Yonathan Tilahun Larry W. Wells Zhengdao Wu Rudy Yates Allan Zipf 21-22,23 1434-35,35-36 5-6,6-7,819 19-20 45 45,45-46,46-47 14 25,27,27-28 45,45-46 46-47 14 45-46 1-2 45,45-46,46-47 48 ALABAMAAGRICULTURAL 'EXkRIMENT STATION Alabama's Agricultural Experiment Station System AUBURN UNIVERSITY Main Agricultural Experiment Station, Auburn. IMESTONE MADISON JACKSON * Alabama A&M University * E. V. Smith Research Center, Shorter. TMRA MARSHAL L DE KALB E2 1. Tennessee Valley Research and HCHEROKEExtension Center, Belle Mina 2. Sand Mountain Research and Extension Center, Crossville JEFFO S3. North Alabama Horticulture Station, TALLEDEGA CLEBURNE Cullman HELY4. Upper Coastal Plains Station, Winfield 5. Chilton Area Horticulture Station, COOSA TALLAP4 CHAMBER Clanton C566. Piedmont Research Station, Camp Hill 7. Prattville Experiment Field, Prattville !UG 8. Black Belt Research and Extension Center, Marion Junction B9. Lower Coastal Plain Research Station, Camden 10. Monroeville Experiment Field, Monroeville C CHENRY 11. Wiregrass Research and Extension CRENSH VCOFFEEDALECenter, Headland 12. Brewton Experiment Field, Brewton 2 GENEVA13. Ornamental Horticulture Station, .1 DSpring Hill 14. Gulf Coast Research and Extension Center, Fairhope