RESEARCH REPORT NO. 19 JUNE 2001 ALABAMA ACRICULTURAL EXPERIMENT STATION LUTH ER WATERS, DIRECTOR AUBURN UNIVERSITY AU BURN, ALABAMA http://www.ag.auburn.edu/resinfo/forageandfield.html CONTENTS Contributors Acknowledgments VARIETY TRIALS Cherokee County Cotton Variety Trial .................................................................................................................................... 1 Variety Evaluation in Ultra Narrow Row Cotton at E. V. Smith ............................................................................................. 1 Cotton Variety Response to the Reniform Nematode ..................................................................................................................... 2 BIOLOGICAL CONTROLS The Effects of Red Imported Fire Ants on Insect Pests and Beneficial Arthropods in Alabama Cotton.............................4 Evaluation of Recharge TM (Azospirillum) and PGPR for Seedling Disease Control and Growth Promotion of Cotton ................................................................................................................................... 5 Evaluation of Ascend DC TM , Recharge TM , and PGPR 89B61 for Seedling Disease Control and Growth Promotion of Cotton ................................................................................................................................... 6 CROP PRODUCTION Tillage, Cover Cropping, and Poultry Litter Effects on Cotton ............................................................................................... 7 Evaluation of Subsurface Drip Irrigation in the Wiregrass ...................................................................................................... 8 Evaluation of an Ag Leader m Cotton Yield Monitor ............................................................................................................. 8 INSECTICIDE APPLICATIONS Evaluation of Insecticides for Control of Detrimental Species and Selectivity Against Beneficial Species in B t C otton ......................................................................................................................................................................... 10 Thrips Control in Cotton ................................. ..................................................................................................................... 11 Thrips Control for Ultra Narrow Row Cotton at E. V. Smith and Prattville Experiment Field ............................................. 12 NEMATICIDE APPLICATIONS Efficacy of Anhydrous Ammonia for Management of the Reniform Nematode in Cotton................................................... 13 Effect of Post-Plant Nematicides on Cotton Production in Reniform Nematode Infested Fields. .................................... 14 Fall Fumigation Versus Spring Fumigation for Reniform Nematode Control in Heavily Infested Cotton Fields ................ 16 HERBICIDE APPLICATIONS Evaluation of CGA 362622 for Weed Control in Cotton ............................................................................................................ 17 Potential for Weed Species Shifts in Roundup Ready Cotton ....................................................................................................... 17 FUNGICIDE APPLICATIONS Evaluation of Experimental Seed Treatment Fungicides for Control of Seedling Disease of Cotton ........................................ 19 Evaluation of Selected In-furrow Fungicides for Control of Seedling Disease of Cotton ........................................................... 20 Evaluation of Selected In-furrow Fungicides for Control of Natural Infestations of Seedling D isease of C otton ................................................................................................................................................. 22 Evaluation of Experimental In-furrow Fungicide Combination Treatments for Control of Seedling D isease of C otton ............................................................................................................................................. 24 Evaluation of Experimental In-furrow Fungicides for Control of Seedling Disease of Cotton ................................................ 26 Evaluation of Selected Fungicides for Control of Seedling Disease in Ultra Narrow Row Cotton...................28 GROWTH REGULATORS Dimilin and Boron Effects on Cotton at E. V. Smith ................................................................................................................ 29 G row th Regulator Effects on Cotton ............................................................................................................................................ 30 A uthors' Index .............................................................................................................................................................................. 3 1 Information contained herein is available to all persons regardless of race, color, sex, or national origin. EDITORS Kathy S. McLean Assistant Professor Entomology and Plant Pathology Auburn University CONTRIBUTORS James R. Akridge Superintendent Monroeville Research Field Jim Baier Assistant Professor, Biosystems Engineering Auburn University James Bannon Associate Director Alabama Agricultural Experiment Station William C. Birdsong Area Agronomist Wiregrass Research and Extension Center Headland, AL Charles Burmester Extension Agronomist Tennessee Valley Research and Extension Center Belle Mina, AL H. L. Campbell Research Associate II Entomology and Plant Pathology Auburn University Larry M. Curtis Professor and Extension Specialist Biosystems Engineering Auburn University J. Doyle Eco Soil Systems, Inc. San Diego, CA Dennis R Delaney Extension Associate, Agronomy and Soils Auburn University David Derrick County Agent, Cherokee County Alabama Cooperative Extension System Bobby Durbin Superintendent Field Crops Unit, E.V. Smith Research Center Shorter, AL C. Dale Monks Associate Professor and Extension Specialist Agronomy and Soils Auburn University Mickey D. Eubanks Assistant Professor Entomology and Plant Pathology Auburn University Wilson H. Faircloth Graduate Research Assistant Agronomy and Soils Auburn University Barry L. Freeman Extension Entomologist Entomology and Plant Pathology Auburn University Kathy Glass Agricultural Program Associate I Agronomy and Soils Auburn University William S. Gazaway Professor and Extension Specialist, Emeritus Entomology and Plant Pathology Auburn University J. W. Kloepper Professor, Entomology and Plant Pathology Auburn University D. A. Mays Adjunct Professor Plant and Soil Science Alabama A&M University Kathy S. McLean Assistant Professor Entomology and Plant Pathology Auburn University C. Dale Monks Associate Professor and Extension Specialist Agronomy and Soils Auburn University Don R Moore Superintendent Prattville Experiment Field S. R Nightengale Superintendent, Plant Breeding Unit E.V. Smith Research Center Tallassee, AL Bobby E. Norris Superintendent Tennessee Valley Research and Extension Center Belle Mina, AL E. Z. Nyakatawa Graduate Research Assistant Plant and Soil Science Alabama A&M University Aaron Palmateer Graduate Research Assistant Entomology and Plant Pathology Auburn University Michael G. Patterson Professor, Agronomy and Soils Auburn University Randy Raper Affiliate Associate Professor National Soil Dynamics Lab, USDA-ARS K. C. Reddy Graduate Research Associate Plant and Soil Science Alabama A&M University M. S. Reddy Research Fellow IV Entomology and Plant Pathology Auburn University Ron H. Smith Professor and Extension Entomologist Entomology and Plant Pathology Auburn University Eric Schwab Cooperating Staff National Soil Dynamics Lab, USDA-ARS Auburn, AL Larry W. Wells Superintendent Wiregrass Research and Extension Center Headland, AL 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. VARIETY TRIALS CHEROKEE COUNTY COTTON VARIETY TRIAL Charles Burmester and David Derrick Cherokee County is a large cotton growing area in north- east 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 conjunction with results from the Alabama Cotton Variety Tests. In 2000 the trial was conducted on the farm of Randall and Nick McMichen on a Holston fine sandy loam soil. Cot- ton was planted no-till into a winter cover crop of wheat on May 3 and consisted of eight rows of each variety planted the length of the field. A total of ten cotton varieties were planted. All varieties were genetically modified and contained the Roundup Ready gene that allows weed control applications with Roundup Ul- tra until the 4 leaf stage. The cotton variety Paymaster 1218 BG/RR was used as a check variety between each plot to re- duce field variability. Cotton growing conditions were very dry in 2000 but the deep soil still produced good yields (Table 1). Insect numbers were very low and only minimal control measures were re- quired. All varieties were spindled picked, and seed cotton was weighed in a boll buggy. A seed cotton sample from each va- riety was ginned on a table top gin for lint percentage. Final lint yield results are presented in the table. CHEROKEE COUNTY COTTON YIELD RESULTS Variety Paymaster 1218 BGRR SureGrow 501 Bt/RR SureGrow 521 RR Deltapine 420 RR Stoneville 4793 RR Stoneville 4892 Bt/RR Deltapine 458 Bt/RR Deltapine 436 RR Deltapine 451 Bt/RR SureGrow 125 Bt/RR Seed cotton yield lbs/ac 2620 2710 2480 2540 2250 2300 2440 2530 2420 2360 Lint 42 38 39 38 41 39 37 35 36 37 Lint lbs/ac 1095 1016 977 968 911 902 895 891 878 878 VARIETY EVALUATION IN ULTRA NARROW Row COTTON AT E.V. SMITH Dennis P. Delaney, Kathy Glass, C. Dale Monks, Bobby Durbin, and James Bannon Variety selection is one of the most important decisions a cotton producer must make, and little information is available about how different cultivars perform in an Ultra Narrow Row production system. The objective of this test was to compare the suitability of several picker type cotton varieties for use in this type of system. Twenty selected varieties were planted at the E.V. Smith Field Crops Unit on May 19 with a small plot drill. Approxi- mately 180,000 seed per acre were planted in 7-inch rows in plots 10.5 feet wide by 25 feet long. Weeds were controlled with conventional soil-applied herbicides, and insects were controlled with foliar materials. A total of 100 pounds per acre of nitrogen was applied at planting, with other fertilizers ap- plied according to soil test. A total of 6.35 inches of irrigation was applied during an extremely dry season. One application of five ounces per acre Pix? was ap- plied at the matchhead square stage. Initial defoliation was on September 14; a second boll opener and defoliant was applied on September 20, and a desiccant on September 26. The center 7 feet by 25 feet of each plot was harvested on September 29 with a broadcast header. Grab samples were ginned on a mini-gin, and lint was analyzed by HVI. Due to the dry weather, all varieties grew less than 30 inches in height (see table). Lint yields ranged from approxi- mately 850 to nearly 1400 pounds per acre; however, most varieties were not statistically different in yield, except at the I~ I~J nna\~ -~ a rA rr~ rcrln+arl h+ a rrk+ rrr ,re r\+ a~~k rr~r n~r ~l~~+a/l +ka 2 ALABAMA AGRICULTURAL EXPERIMENT STATION extremes. Lint turnout from grab samples ranged from 31 to 40%, and there were several statistical differences in lint quality. LINT YIELDS AND QUALITY DATA OF ULTRA-NARROW ROW COTTON VARIETIES Variety Lint yield Turnout Height Mic Length Uniformity Strength lbs/ac % in units in % g/tex SureGrow 747 1391 37 20 51 1.12 86 27.1 Stoneville ST 4892BR 1379 38 24 50 1.07 84 29.3 Paymaster 1218BG/RR 1375 38 22 51 1.09 86 27.9 SureGrow 501 B/R 1363 36 22 47 1.07 85 29.4 SureGrow 125B/R 1301 35 22 43 1.07 84 28.4 Stoneville ST4793R 1298 38 21 48 1.09 87 29.7 Deltapine DP20B 1278 37 18 44 1.08 83 25.7 Deltapine NuCotn 33B 1276 34 20 47 1.14 86 29.8 FiberMax 832 1253 35 23 42 1.12 82 30.5 Phytogen PSC 355 228 37 19 47 1.09 85 29.2 Stoneville ST474 1214 38 21 53 1.07 85 26.2 Paymaster 1560BG/RR 1189 37 21 46 1.08 83 28.3 FiberMax 989 1174 36 20 44 1.15 85 31.1 Deltapine DP458B/RR 1167 35 22 48 1.13 86 30.8 Stoneville BXN47 1153 39 19 48 1.10 88 29.7 FiberMax 819 1148 40 19 45 1.14 86 30.7 SureGrow 105 1112 35 19 48 1.12 86 29.6 Deltapine DP655B/RR 1046 36 19 41 1.06 82 28.9 AgriPro HS44 928 36 16 48 1.08 83 29.7 Phytogen PSC 952 849 31 17 46 1.05 81 27.9 LSD (P=.10) 268 2 4 5 0.05 4 3.7 COTTON VARIETY RESPONSE TO THE RENIFORM NEMATODE Kathy S. McLean, William S. Gazaway, Aaron Palmateer, and J. R. Akridge Twenty cotton varieties were evaluated for their response to the reniform nematode (Rotylenchulus reniformis) in Huxford, Alabama. The test was conduced in a field naturally infested with the reniform nematode and monocultured in cot- ton. The soil was a silty loam. Cotton varieties were planted in two-row plots, 25 feet long with a 36-inch row spacing. In one row of the plots, Temik 15G was applied at planting in the seed furrow with chemical granular applicators attached to the planter. In the other row, Di-Syston 8EC was applied as a directed spray in the seed furrow at 10 gallons per acre applied through 8002E flat fan nozzles. 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 cotton seed. All plots were maintained with standard production practices rec- ommended by the Alabama Extension System commonly used in the area. Plots were not irrigated. Cotton seedling stand was recorded at 28 days after plant- ing. Population densities of reniform nematode were deter- mined at planting and just before harvest on October 13. Ten soil cores, 1 inch in diameter and 8 inches deep, were col- lected 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 October 30. The drought severely affected cotton growth and yield. Reniform nematode populations increased from the initial 3000 per 150 cc of soil to an average of 4,577 and 3,587 per 150 cc of soil for the Temik 15G and Di-Syston treatments, respec- tively (see table). Temik 15G increased seed cotton yield in half of the varieties compared to Di-Syston. In those ten vari- eties the final reniform population was lower in the Temik 15G plots compared to the Di-Syston plots. No difference in yield was observed between plots in Delta Pine 458 B/RR, Delta Pearl, SureGrow 747, and Fiber Max 989, indicating possible tolerance to the reniform nematode. r~E rrn 2 ALABAMAAGRICULTURALExPERIMENT STATION 2000 COTTON RESEARCH REPORT 3 EFFECT OF RENIFORM NEMATODE ON YIELD OF SELECTED COTTON VARIETIES Treatment Reniform count Seed cotton yield noJ150 cc of soil lbs/ac Di-Syston Temik Di-Syston Temik Stoneville X9905 3493 7184 472 428 Stoneville 6M045 3476 3553 721 891 Stoneville 4892BR 4557 3296 692 893 Stoneville X9903 5948 4171 728 699 Stoneville 4691B 4351 3167 668 779 Stoneville BXN4 6128 2806 627 707 Delta Pine 451 B/RR 4969 4918 820 685 Delta Pine 458 B/RR 5381 2987 687 682 Delta Pine 565 3708 5201 772 641 Delta Pine X9084 3115 2394 651 726 Delta Pearl 2291 5330 900 905 SureGrow 501 B/R 4841 3013 849 731 SureGrow 747 5124 3527 1007 944 Paymaster 1560 BG/RR 4609 2214 540 409 Paymaster 1218 BG/RR 3656 1776 385 303 Stoneville 474 7184 2549 699 581 Phytopen 355 4095 3115 813 985 FiberMax 989 5227 3141 816 828 LSD (0.05) 3115 5201 193 189 ALABAMA AGRICULTURAL EXPERIMENT STATION BIOLOGICAL CONTROLS THE EFFECTS OF RED IMPORTED FIRE ANTS ON INSECT PESTS AND BENEFICIAL ARTHROPODS IN AIABAMA COTTON Micky D. Eubanks Red imported fire ants, Solenopsis invicta, are usually con- sidered serious pests. Fire ants are voracious predators and evi- dence suggests they are important natural enemies of insect pests. Fire ant workers, however, are indiscrete, generalist predators and probably attack beneficial arthropods as well as economic pests. Fire ants could indirectly cause pest outbreaks if their impact is greater on beneficial arthropods than pests. Surprisingly few studies have attempted to definitively de- termine the net effect of fire ants on agricultural pests. As a result, it is unclear whether fire ants have a net positive or net negative effect on the biological control of important cotton pests. The goal of this study was to quantify the effects of red imported fire ants on populations of insect pests and beneficial arthropods. The relationship between fire ant and arthropod abundance was esti- mated from sampling data and greenhouse and field experiments were used to quantify the effect of fire ants on the survival and population sizes of specific pests and beneficials. Four large cotton fields at E.V. Smith Research Center were sampled throughout the 2000 growing season for fire ants, insect pests, and beneficial arthropods. Three fields were planted with Stoneville BXN47 and one field was planted with Paymaster 1218 BG/RR. Densities of S. invicta workers were negatively associ- ated with all 17 species of insect herbivores sampled in cotton, including bollworms, loopers, and tarnished plant bugs. The abun- dance of fire ants, however, was also negatively correlated with the densities of 22 of 24 natural enemy species collected in cotton. Fire ants suppressed the densities of some of the most im- portant natural enemies in cotton included ladybird beetles, spi- ders, green lacewings, and big-eyed bugs. Path analysis of the sampling data suggested that the indirect effects of fire ants on pests was often complex because fire ants not only suppressed populations of beneficial natural enemies (i.e., natural enemies like ladybeetles that primarily consumed pests), but also natural enemies that interfered with biological control (i.e., predators like spiders that seemed to primarily consume beneficials instead of pests). The results of 2000 were very similar to 1999 results. The results of greenhouse experiments mirrored the field data to a large extent. Red imported fire ants reduced the survival of bollworm caterpillars by 90%, bollworm eggs by 75%, and tarnished plant bugs by 70% on caged cotton plants. These data provide further evidence that fire ants are important predators of important cotton pests and that fire ants attack multiple stages of moth pests. Unfortunately, fire ants reduced ladybird beetle sur- vival by 50% and green lacewing survival by 38% in similar green- house experiments. Surprisingly, foraging fre ant workers did not reduce the survival of spiders in greenhouse experiments sug- gesting that the negative impact of fire ants on spiders in the field may not be due to direct consumption of spiders. Sampling data and greenhouse experiments strongly sug- gest that fire ants are the most important predators in cotton and that fire ants have a huge impact on pests and natural enemies. With these data, however, it is difficult to determine the net effect of fire ants on pests. That is, does the suppression of pests by fire ants outweigh the loss of biological control as a result of fire ant predation on other natural enemies? Is overall pest suppression higher with or without fire ants? To answerthese questions, fire ant populations were reduced in cotton fields with fire ant baits and pest populations were com- pared between fields with high fire ant densities and low densities of other natural enemies and fields with low fire ant densities but high densities of other natural enemies. Baits are excellent tools for this type of experiment because they are composed of an in- ert, pregelled corn "grit" carrier and soybean oil that is very at- tractive to foraging fire ant workers but ignored by other insects. A toxicant (either a slow-acting insecticide or an insect growth regulator) is incorporated into the oil so that when foragers find the bait and carry it back to the colony the toxicant is spread throughout the mound and all members of the colony are affected. Broadcast baits, therefore, are specific to ants and do not poison other arthropods. Fire ants populations were suppressed in four cotton fields at E.V. Smith and four additional fields were untreated and used as controls. Baits were very effective at reducing fire ant popula- tions. Fire ant populations were 72% larger in untreated fields (high fire ant fields) than in treated fields (low fire ant fields). Caterpillar populations were 41% smaller in high fire ant fields than in low fire ant fields and tarnished plant bug densities were 76% lower in high fire ant fields than in low fire ant fields. This pest reduction was even more impressive given the huge impact fire ants had on other natural enemies. Big-eyed bug popu- lations were 26% smaller in cotton fields with high fire ant densi- ties than in fields with low fire ant densities, hooded beetle popu- lations were 43% smaller, ladybeetle populations were 46% smaller, spider populations were 50% smaller, lacewing popula- tions were 75% smaller, and damsel bugs populations were 82% smaller in cotton fields with high fire ant densities. These results indicate that even though fire ants decimate populations of other natural enemies, fire ants are still incredibly effective at suppressing pest populations. The net effect of fire ants on biological control in cotton, therefore, is positive. 4 2000 COTTON RESEARCH REPORT EVALUATION OF RECHARGETM (AzosPIRILLUM) AND PGPR FOR SEEDLING DISEASE CONTROL AND GROWTH PROMOTION OF COTTON M. S. Reddy, S. P. Nightengale, J. W. Kloepper, and J. Doyle This experiment was conducted at the Plant Breeding Unit of E. V. Smith Research Station, Tallassee, Alabama. The test was planted on May 25 at a seeding rate of five seeds per foot of row. The field has a history of continuous cropping to cotton. The treatments were mixed with water and applied as an in-furrow spray at planting in an open furrow at 17 fluid ounces per 25 feet of row with a CO2 backpack sprayer. Rows were manually closed immediately after application oftreatments with a Planet Juniorm planter. Plots consisted of four rows 25 feet long with a between row spacing of 3.2 feet. Plots were arranged in a randomized com- plete block design with six replications. A 20-foot alley separated blocks. All plots were maintained throughout the season with stan- dard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Stand counts were recorded two and four weeks after planting to determine the percent seedling loss due to cotton seedling dis- ease. Seedling shoot height, stem caliper (stem diameter), and shoot and root fresh weights were measured at four weeks after planting. Plots were harvested on November 6. Data were ana- lyzed using ANOVA and means were compared using Fisher's protected LSD. Significant differences in stands among treatments were observed two and four weeks after planting. Two weeks after planting, Recharge + PGPR strain S8-G6 and Recharge + PGPR strain IN-26 significantly increased stands compared to the un- treated control. Four weeks after planting, Recharge + PGPR strain 89B61 and Recharge + PGPR strain 90-166 significantly increased stands compared to the control. Four weeks after planting, the treatments containing the four PGPR strains showed significantly increased height and caliper, and strains 90-166, IN-26 and S8-G6 signifi- cantly increased root fresh weight compared to the untreated con- trol. There were no significant differences in shoot fresh weight among treatments. Recharge + PGPR strain 89B61, Recharge + PGPR strain S8-G6, and Recharge + PGPR strain IN-26 significantly increased yields compared to the untreated control. INFLUENCE OF VARIOUS BIOLOGICAL TREATMENTS ON HEALTHY STAND, GROWTH PROMOTION, AND YIELD OF COTTON Treatment (rate/ha) Stand (plants/25 ft) June 9 June 23 Seedling growth four weeks after planting Seed cotton yield Height (in) Caliper 1 (in) SFWT 2 (g) RFWTP(g) (lbs/ac) Recharge 159 fl oz 95.8 82.3 9.37 0.11 3.75 0.405 1269 Recharge 159 fI oz + 91.0 90.4 9.48 0.11 3.88 0.405 1408 PGPR 89B61 1.7 X 107 CFU 4 /ml Recharge 159 fl oz + 74.7 91.3 9.53 0.11 3.46 0.483 1408 PGPR 90-166 1.7 X 107 CFU/ml Recharge 159 fl oz + 101.7 78.2 9.69 0.12 3.87 0.444 1743 PGPR S8-G6 1.7 X 107 CFU/ml Recharge 159 fl oz + 111.5 79.7 10.16 0.12 4.11 0.539 1773 PGPR IN-26 1.7 X 107 CFU/ml Untreated control 83.7 72.3 8.85 0.10 3.69 0.381 1018 LSD (0.05) 21.6 14.3 0.63 0.009 0.66 0.065 598 LSD (0.10) 17.9 11.9 0.51 0.007 0.55 0.054 497 ' Caliper = stem diameter. 2 SFWT = shoot fresh weight. 3 RFWT = root fresh weight. 4 CFU = colony-forming units. 5 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF ASCEND DC , RECHARGETM, AND PGPR 89B61 FOR SEEDLING DISEASE CONTROL AND GROWTH PROMOTION OF COTTON M. S. Reddy, S. P. Nightengale, J. W. Kloepper, and J. Doyle This experiment was conducted at the Plant Breeding Unit of E. V. Smith Research Station, Tallassee, Alabama. The test was planted on May 24 at a seeding rate of 16 seeds per meter of row. The field had a history of cotton seedling disease and the soil type was a sandy loam. The treatments were mixed with water and applied as an in-furrow spray at planting in an open furrow at 17 fluid ounces per 25 feet of row with a CO 2 backpack sprayer. Rows were manually closed immediately after application oftreat- ments with a Planet JuniorTmplanter. Plots consisted of four rows 25 feet long with a between row spacing of 3.2 feet. Plots were arranged in a randomized com- plete block design with six replications. A 20-foot alley separated blocks. Plots were maintained throughout the season with stan- dard herbicide, insecticide, and fertility production practices as recommended by the Alabama Cooperative Extension System. Stand counts were recorded two and four weeks after planting to determine the percent seedling loss due to cotton seedling dis- ease. Seedling shoot height, stem caliper (stem diameter), and shoot and root fresh weights were measured four weeks after planting. Plots were harvested on November 6. Data were analyzed using ANOVA and means were compared using Fisher's protected LSD. Significant differences in stand among treatments were observed two and four weeks after planting. Two weeks after planting, use of Recharge, Ascend at 350 g/ha and Recharge + Ascend + PGPR resulted in significantly greater stands than the untreated control. Ascend at 84 g/ha was significant. Four weeks after planting, only the Recharge + Ascend + PGPR treatment produced a significantly better stand than the control. All treatments significantly increased seedling height ex- cept Ascend 84g. The PGPR alone or combined with Recharge and Ascend significantly increased caliper compared to the con- trol. There were no significant differences for shoot fresh weight. The high rate of Ascend and the Recharge + Ascend + PGPR significantly increased root fresh compared to the control. All treatments produced significantly greater yields com- pared to the control. Yield for the Recharge + Ascend + PGPR treatment was significantly higher than the Recharge, both rates of Ascend, or PGPR alone. INFLUENCE OF VARIOUS BIOLOGICAL TREATMENTS ON HEALTHY STAND, GROWTH PROMOTION, AND YIELD OF COTTON iii i i I iiii r r r Treatment (rate/ha) Stand (plants/25 ft) June 9 June 23 Seedling growth four weeks after planting Seed cotton yield Height (in) Caliper '(in) SFWT 2 (g) RFWTP(g) (lbs/ac) Recharge 159 fl oz 104.0 76.0 8.98 0.13 5.14 0.409 3467 Ascend DC 350 g 91.3 86.3 9.72 0.13 5.31 0.464 3552 Ascend DC 84 g 88.7 73.9 9.09 0.12 4.78 0.402 3612 PGPR strain 89B61 83.5 85.8 9.29 0.13 5.17 0.422 3654 1.7 X 107 CFU 4 /ml Recharge 159 ft oz+ Ascend 350 g + 93.2 101.3 9.21 0.13 5.24 0.459 4049 PGPR strain 89B61 1.7 X 10 07CFU/ml Untreated 75.7 82.0 8.23 0.12 4.76 0.387 3168 LSD (0.05) 15.6 17.2 0.66 0.007 0.76 0.065 264 LSD (0.10) 12.9 14.3 0.55 0.006 0.63 0.054 216 1 Caliper = stem diameter. SSFWT = shoot freshoot fresh weight. 3 RFWT = root fresh weight. 4 CFU = colony-forming units. 6 r----L~ --- ~- II CROP PRODUCTION TILLAGE, COVER CROPPING, AND POULTRY LITTER EFFECTS ON COTTON K. C. Reddy, E. Z. Nyakatawa, and D. A. Mays The development of conservation tillage systems capable of reducing soil erosion and improving soil quality while increas- ing yields and profits remains a challenge for cotton producers in the Southeast. They are hesitant to adopt conservation tillage prac- tices because of the typically inadequate and less vigorous crop stand. Since 1996, researchers have been evaluating the effects of tillage (conventional till, mulch-till, and no-till), cropping sys- tems (cotton alone or cotton in summer and rye in winter ), and nitrogen sources and rates (ammonium nitrate and poultry litter at 0, 90, 180 pounds of nitrogen per acre) on cotton germination and yield at Belle Mina, Alabama. The purpose ofthis article is to present results from that research. Cotton seedling counts under no-till were 40 to150% greater than those under conventional till at one and two days during seedling emergence. Cotton in summer and rye in winter crop- ping system had 14 to 50% greater seedling counts than cotton alone treatment during the first four days of emergence in 1998. Similarly, the poultry litter source of nitrogen increased seedling emergence by 17 to 50% in 1998 compared to the ammonium nitrate source. In all these cases, the differences progressively nar- rowed by the fourth day of seedling emergence. These seedling counts correlated significantly to cotton lint yield especially in 1998 when the season was much drier and the conservation tillage and poultry litter application treatments were able to conserve more moisture. TABLE 1. COTTON LINT YIELD AS INFLUENCED BY TILLAGE, CROPPING SYSTEM, AND SOURCE OF NITROGEN Treatment Lint yield (bs/ac) 1997 1998 Conventional vs mulch-till 980 vs 1030 (NS) 1205 vs 1270 (NS) Conventional vs no-till 980 vs 1215 * 1205 vs 1285 * Cotton alone vs cotton-rye 1090 vs 1100 (NS) 1210 vs 1270 (NS) Ammonium nitrate vs poultry litter 1170 vs 1035 (NS) 1355 vs 1205 (NS) NS = Treatment differences are non-significant; * = Treatment differences are significant. TABLE 2. VOLUMETRIC SOIL WATER CONTENT (M 3 M- 3 ) IN THE To 7 CM OF THE SOIL IN CoTToN PLOTS Days of seedling emergence 1 - 2 3 4 CT 1 NT CT NT CT NT CT NT 1997 0.21 0.275* 0.185 0.245* 0.175 0.205* 0.165 0.205* 1998 0.215 0.255* 0.165 0.205* 0.13 0.175* 0.11 0.155* *= Treatment differences are significant SCT = conventional till; NT = no till. Cotton lint yields under no-till were greater by 7 to 24% than that under conventional till and mulch-till systems. Poultry litter source ofnitrogen produced similar cotton lint yield as ammonium nitrate (Table 1). The combination of (1) no-till, (2) cotton-in-summer- and-rye-in-winter cropping system, and (3) surface appli- cation of 180 pounds of nitro- gen per acre through poultry litter conserved soil moisture in the top 7centimeters of the soil (Table 2). This resulted in early seedling emergence, high seed- ling vigor, good plant growth, and high lint yields of cotton. These treatments would be ap- propriate for use in the South- east where soil erosion is a problem and plenty of poultry litter is available each year from the poultry industry. 2000COTTONRESEARCHREPORT 7 ALABAMA AGRICULTURAL EXPERIMENT STATION EVALUATION OF SUBSURFACE DRIP IRRIGATION IN THE WIREGRASS Larry M. Curtis, William C. Birdsong, and Jim Baier Subsurface drip irrigation was evaluated for the second year at the Wiregrass Regional Research and Extension Center. The center received record low rainfall during the 2000 growing sea- son, resulting in tremendous difficulties in germination. The re- search plot area was irri- gated with an overhead sprinkler system to initiate germination. No-till plots 1400.00 had less germination, result- ing in reduced yields com- pared to conventional till. Future plans called for 0.00 evaluating the potential for germination (if needed) us- ing subsurface drip irriga- o tion rather than sprinkler ir- rigation. 6 .0 The subsurface drip irrigation tape was installed 40o0o in 1999 between every other row, 15 inches deep oo and with emitters located every 2 feet along the tape. Treatments included the LOFow FERTIGATED following: no-till and conventional till, fertigation through the sys- tem and conventional fertilizer, high flow and low flow tape, and nonirrigated plots. The 2000 yield results for these treatments are indicated in the chart below. SDI COTTON PLOTS HEADLAND 2000 LOW FLOW -NON HIGH FLOW- HIGHFLOW-NON NOT IRRIGATED FERTIGATED FERTIGATED :FERTIGATED EVALUATION OF AN AG LEADERTM COTTON YIELD Charles H. Burmester, Randy Raper, and Eric Schwab An Ag LeaderT m PF 3000 cotton yield monitor was evalu- ated in normal cotton field situations and in harvesting large re- search plots at the Tennessee Valley Research and Extension Center at Belle Mina, Alabama, in 2000. The yield monitor was installed on a John Deere model 9920 two-row cotton picker. This picker has four cotton chutes that deliver cotton to the basket. Cotton flow sensors were installed on all four chutes. Other sensors installed were a fan speed sensor and a header height sensor. Ground speed was determined through a Trimble T m GPS system installed on the picker. The objectives of this study were to determine (1) picker modification and user knowledge needed to operate the Ag Leader cotton yield moni- tor, (2) accuracy of the Ag Leader monitor in farm cotton field conditions, and (3) feasibility of the Ag Leader monitor in cotton research plot areas. MONITOR Installation of the yield monitor was fairly straightforward. The most difficult task was cutting each side of the cotton chutes for installation of the flow sensors. This picker had two curved chutes, which made alignment more difficult. Technical support in installation and trouble shooting problems was excellent. Early season evaluations were done in large fields located on the Research and Extension Center. Yield predictions by the Ag Leader system were compared to weights measured by dump- ing into a boll buggy equipped with scales. In most cases, early season yield predictions by the Ag Leader system were 1 to 6% greater than actual weights measured. This variance increased as more baskets were picked. The problem was due to cotton string- ers developing over the flow sensors in the curved chute. Very little cotton stringer development was found in the straight chutes. A quick brushing of the sensors in the curved chutes after each 8 " It 11 t ga~aeea~gpsRI~ 'BIWI~Bl~OsBPIII~I~I~sop~n~ WB~B~a~8g~B~a~l~i~i$I 2000 CorroN RESEARCH REPORT TABLE 1. SEED COTTON YIELD PREDICTIONS USING THE AG LEADERTM YIELD MONITOR IN A LARGE FIELD Actual weight lbs 1915 1786 1651 2689 2680 2636 2570 Monitor prediction lbs 1930 1854 1627 2630 2846 2723 2654 Variation +0.8 +3.8 -3.8 -2.2 +6.2 +3.3 +3.2 TABLE 2. SEED COTTON YIELD PREDICTION USING THE AG LEADERTM YIELD MONITOR IN A SMALL PLOT AREA Actual weight Monitor prediction Variation lbs lbs % 1366 1398 +2.3 1324 1333 +0.6 1353 1385 +2.4 1322 1340 +1.4 1398 1409 +0.8 1346 1383 +2.7 1365 1407 +3.1 1367 1371 +0.2 592 586 -1.0 1212 1268 +4.1 9 dumping eliminated the problem. After this, predicted yields measured by the Ag Leader system became more consistent and were generally within 5% of measured yield (Table 1). The yield monitor was also evaluated in a drip irrigation test area with plots that measured two rows wide and 340 feet long. Each plot was picked, and the weight of the cotton was measured in a boll buggy. This weight was compared to that predicted by the yield monitor. Measured weights ranged from 77 to 208 pounds per plot. In this test, the Ag Leader system very accurately pre- dicted yields. Measured yield and Ag Leader predicted yields varied only from -1.0 to +4.1 percent (Table 2). Overall evaluations of the Ag Leader PF 3000 cotton yield monitor were very favorable. With only limited knowledge of the system, we were able to install and operate the system with mini- mal difficulties. Yield prediction by the Ag Leader system were generally within 5% both in field and large plot situations. _ ALABAMA AGRICULTURAL EXPERIMENT STATION INSECTICIDE APPLICATIONS EVALUATION OF INSECTICIDES FOR CONTROL OF DETRIMENTAL SPECIES AND SELECTIVITY AGAINST BENEFICIAL SPECIES IN BT COTTON Ron Smith Approximately 65% of Alabama's cotton acreage has been planted to Bollgard' M Bt varieties during the past five seasons. This trend is expected to continue. Insects that are occurring most often at damaging levels in Bollgard fields are the plant bug com- plex, escape bollworms, fall armyworms, and stink bugs. Beneficial insects may be used to a greater degree in Bollgard cotton where no boll weevils are present. However, when beneficials are maintained further into the season, economic dam- age from subthresholds of one, or combinations of, damaging insects often occur. Insecticides that can selectively remove damag- ing insects without suppressing beneficials would be highly desirable. Tests were conducted in 2000 to determine the efficacy and selectivity of several insecticides on the plant bug complex, stink bugs, and beneficials. Field trials were held at the Wiregrass Research and Exten- sion Center and Prattville Experiment Field. Cotton was planted using customary production practices and monitored at regular intervals. Tests were initiated when uniform natural threshold populations were detected. Plots were of various sizes, but were generally eight or more rows wide by several hundred feet in length. (Larger plots must used for mobile pests such as plant bugs and stink bugs.) Multiple samples were taken within each treated area by either sweep net or drop cloth. Treatments were made by traditional hiboy application techniques with standard nozzles, volumes, and pressure. Evaluations were made one, three to five, and seven days post treatment. The first test at Prattville Experiment Field was targeted to- wards a primarily nymphal population of tarnished plant bugs on June 26. At one day post treatment all chemicals gave some sup- pression when compared to the untreated check. However, a wide range of control was found between the different treatments. Cen- tric at 0.062 pound active ingredient (a.i.) per acre, Assail at 0.05 pound a.i. per acre, and Lorsban at 0.2 pound a.i. per acre gave the best control after 24 hours. At 10 days post treatment Centric at 0.047 and 0.062 pound a.i. per acre, Orthene at 0.2 pound a.i. per acre, Assail at 0.05 pound a.i. per acre, and Bidrin at 0.2 pound a.i. per acre gave the best plant bug suppression. Lorsban at 0.2 pound a.i. per acre was the most selective. Centric, Orthene, As- sail, and Ammo showed little selectivity against the minute pirate bug and lady beetles. The second test at Prattville Experiment Field was also tar- geted towards a nymphal plant bug population on July 10. Bidrin at 0.2 pound a.i. per acre, Asana at 0.032 pound a.i. per acre, Centric at 0.047 pound a.i. per acre, Steward at 0.09 pound a.i. per acre, and Assail at 0.05 pound a.i. per acre gave superior plant bug suppression at three days post treatment. Steward, Assail, and Baythroid gave the greatest selectivity towards big eyed bugs while Leverage, Bidrin, and Centric were the least selective. Stew- ard was distinctly the most selective on minute pirate bugs while Centric, Bidrin, and Assail were the least selective. All treatments gave excellent control of the cotton fleahopper species. The test at the Wiregrass Research and Extension Center was conducted under an extremely heavy nymphal stink bug popu- lation (3 x threshold). At 24 hours post treatment Ammo at 0.06 pound a.i. per acre, Bidrin at 0.33 and 0.5 pound a.i. per acre, Baythroid at 0.03 pound a.i. per acre, Decis at 0.02 pound a.i. per acre, Vydate at 0.25 and 0.5 pound a.i. per acre, Centric at 0.047 and 0.62 pound a.i. per acre, Capture at 0.05 pound a.i. per acre, Leverage at 0.038 + 0.026 pound a.i. per acre, and Orthene at 0.8 pound a.i. per acre, all gave good control of the nymphal stage of the southern green stink bug. Steward at 0.11 pound a.i. per acre and Dibrome at 0.94 pound a.i. per acre gave approximately 50% suppression. Due to the maturity of cotton (bolls beginning to open) and late date (September 26) few beneficials were present. 10 THRIPS CONTROL IN COTTON Barry L. Freeman This trial compares Adage, a promising seed treatment, to Temik, a standard in-furrow granular insecticide, for control of thrips on seedling cotton. Cotton (SG 125RR) was planted on the Tennessee Valley Research and Extension Center in Belle Mina, Alabama, on April 26, 2000. Plots were four rows by 25 feet and were replicated four times. The test area was under irrigation. Although nema- todes are not known to be a problem on this test site, a high rate of Temik treatment was added because this rate is commonly used for management of reniform nematodes. Thrips were sampled by rinsing five random plants per plot in 75% ethyl alcohol, filtering the contents, and counting both adult and larval thrips using a stereoscope. Samples were taken on May 15, May 22, and May 30. A visual rating ofthrips injury was also made for each plot on these same dates. Plots were rated from 0-5 with 0 indicating no thrips injury and 5 representing extreme injury. Plant populations were estimated on June 20 by counting all living plants in the center two rows of each plot. Cotton yields were determined by mechanically harvesting the center two rows of each plot on September 12. Thrips populations were very high, averaging more than 30 thrips per plant in some treatments (Table 1). The tobacco thrips, Frankliniella fusca, was the predominant species on the first sample date and remained common on the last two sample dates. The flower thrips, F.tritici, became common on the second sample date and was the most common species on the last sample date. The Western flower thrips, F. occidentalis, was present in fair numbers on the last two sampling dates, but was overshadowed by the two previously mentioned species. An occasional soybean thrips, Neohydatothrips variabilis, was observed throughout the test period. No difference in species composition was noted among treatments. The control plots revealed very high numbers of thrips throughout the test period, and there was a corresponding amount of damage (Table 1 and 2). The Adage treatment averaged around two larval thrips per plant on the first sample date and a little more than 13 larvae per plant on the second date. By the third sample date, the thrips population exceeded that of the control treatment (Table 1). The Adage treatment thrips populations ran somewhat contrary to the damage ratings. There was a moderate increase in damage to the Adage-treated plots over the course of the sample period (Table 2), but in no way did the amount of damage reflect the numbers ofthrips sampled. The damage to the Adage plots reflected in Table 2 was primarily crinkled leaves, but overall, the plants were growing vigorously. The Temik treatments contained the fewest numbers of thrips, and the higher rate had considerably fewer thrips than did the standard Temik treatment (Table 1). Considerable thrips re- production was revealed on the last two sample dates in the stan- dard Temik treatment (Table 1). Damage ratings of the Temik treatments were low (Table 2). All treatments lost fewer plants than the control (Table 2). Among the treatments, the highest plant population was found in the Adage treatment, followed by the standard rate of Temik, which was slightly better than the nematicidal rate of Temik (Table 2). All yields in the treated plots were much better than those ofthe control treatment, with increases ranging from 36 to 46% (Table 2). TABLE 1. NUMBERS OFTHRIPS PER FIVE PLANTS -May 15- -May 22- -May 30- -Seasonal average- Treatment A' L A L A L A L T Temik 7 lbs. a.i./ac. 1.50 1.50 15.50 10.75 6.50 9.00 7.83 7.08 14.92 Temik 5 lbs. a.i./ac. 1.75 4.25 21.75 28.25 29.75 112.25 17.75 48.25 66.00 Adage 0.3 lbs./cwt 6.50 9.00 35.00 68.25 50.25 324.25 30.58 133.83 164.42 Control 11.50 107.50 38.00 162.50 34.00 133.00 27.83 134.33 162.17 1 A=adult, L=larva, T=total. TABLE 2. THRIPS DAMAGE RATINGS, PLANT POPULATION, AND YIELD Treatment Temik 7 Ibs. a.i./ac. Temik 5 lbs. a.i./ac. Adage 0.3 lbs. a.i./cwt Control Damage ratings May 15 May 22 May 30 Average 1.00 1.00 1.00 1.00 1.00 1.00 1.75 1.25 1.00 2.00 2.75 1.92 3.25 4.25 4.75 4.08 Plants Seed cotton no/row ft lbs/ac 2.80 3512 3.04 3597 3.24 3773 2.56 2581 1 ~~U11I~~ l ~~~ ~~~ ~~--I ~~ --~~-C---r----b ------7 2000COTTONRESEARCHREPORT 11 THRIPS CONTROL FOR ULTRA NARROW Row COTTON Dennis P. Delaney, C. Dale Monks, Bobby Durbin, and Don P. Moore Ultra Narrow Row (UNR) cotton acreage has become widely adopted in the last few years in Alabama. Many man- agement practices may need to be modified to suit the needs of this system, including early season thrips control. Growers of wide row cotton often use in-furrow insecti- cides at planting, but the labeled rates per foot of row would be prohibitively expensive, because of the increased number of rows with UNR. Systemic seed treatment can also be very expensive, due the large number of seed planted, while foliar applications have the potential to kill beneficial insects and increase other pest populations. The objective of this research was to determine the optimum method of controlling early season insects in UNR cotton. The experimental design was a randomized complete block with four replications with plots 10.5 feet wide by 30 feet long. Deltapine 458 BR seed was planted on April 11 at the E.V. Smith Field Crops Unit and April 17 at Prattville Ex- periment Field. A cone type plot drill was used to plant 180,000 seed per acre in 7-inch rows. Gaucho was applied to seed as a treatment before counting, while Temik 15G was weighed for the respective rates and placed in envelopes with the seed to drop in-furrow. Orthene was foliar applied as soon as thrips or damage was noted, and then applied weekly as long as the infes- tation persisted (three appli- cations). Damage ratings were taken at the 3-leaf stage, and then weekly until the rating no longer changed. Cotyle- don-to-terminal heights were taken at the matchhead square stage, and open and closed boll counts were made at maturity. Yield was harvested from the center 7- by 25-foot section of each plot with a broad- cast header. Thrips pressure was extremely heavy in 2000 on these tests, particularly at Prattville. The untreated plots had a sil- very tint from thrips damage, and many of these plants died. In plots with severe damage, the remaining plants branched out, which would cause problems to producers while harvest- ing and contribute to bark discounts. The low rate of Temik (three pounds per acre) reduced damage surprisingly well, given the small amount per foot of row. The low rate of Temik also had the numerically highest yield at both locations, although this was not significantly dif- ferent from most other treatments (see Tables 1 and 2). Higher rates of Temik (six to nine pounds per acre) were needed to suppress damage throughout the early growing season, and to contribute to earliness. Orthene foliar sprays controlled dam- age at E. V. Smith, but cotton at Prattville was damaged very early, with control increasing through the season. Gaucho seed treatment allowed more thrips damage, but this was not re- flected in the final lint yield at either location. TABLE 1. TEMIK AND THRIPS CONTROL FOR ULTRA NARROW Row CorroN, E. V. SMITH FIELD CROPS UNIT, 2000 Treatment Leaf injury' Height Open boIls Lint cm % lbs/ac May 10 May 18 May 26 June 2 Aug. 9 Sept. 18 Untreated check 7.5 9.0 8.0 10.3 25 648 Temik, 3 Ibs/ac 5.0 5.0 3.3 15.7 25 907 Temik, 6 Ibs/ac 3.0 3.5 2.5 16.8 38 785 Temik, 9 lbs/ac 3.5 2.8 2.3 15.8 42 776 Temik, 12 Ibs/ac 2.0 3.0 2.0 15.9 38 770 Gaucho 8 oz/cwt 5.5 6.0 5.5 14.7 33 775 Orthene,0.25 lb/ac 3.0 3.0 2.3 15.4 29 712 LSD (0.10) 1.0 0.9 0.9 2.3 19 157 Injury scale: 0= no injury; 10 = dead. TABLE 2. TEMIK AND THRIPS CONTROL FOR ULTRA NARROW Row COTTON, PRATTVILLE EXPERIMENT FIELD, 2000 Treatment Leaf injury' Height Open bolls Lint cm % lbs/ac May 10 May 18 May 26 June 2 Aug. 9 Sept. 18 Untreated check 7.8 8.8 9.5 3.3 8 484 Temik, 3 Ibs/ac 4.3 6.0 6.5 14.8 34 779 Temik, 6 Ibs/ac 3.3 4.5 4.8 15.3 45 647 Temik, 9 Ibs/ac 2.8 4.0 4.5 16.7 60 752 Temik, 12 Ibs/ac 2.0 5.0 4.8 14.3 44 768 Gaucho 8 oz/cwt 5.0 6.3 7.5 10.4 30 742 Orthene, 0.25 Ib/ac 5.3 4.3 3.5 15.3 44 682 LSD (010) 1.1 1.1 0.8 2.9 20 1 09 1 Injury scale: 0 = no injury; 10 = dead. 12 ALABAMAAGRICULTURALExPERIMENT STATION NEMATICIDE APPLICATIONS EFFICACY OF ANHYDROUS AMMONIA FOR MANAGEMENT OF THE RENIFORM NEMATODE IN COTTON Kathy S. McLean, William S. Gazaway, Aaron Palmateer, and James R. Akridge The objective of this research was to determine the effi- cacy and economics of anhydrous ammonia for the manage- ment of reniform nematodes and its effect on cotton growth, development, and yield. The test was conducted in a field natu- rally infested with the reniform nematode and continuously cultured with cotton in Escambia County, Alabama. Anhydrous ammonia was compared to the fertilizer standard ammonium nitrate and to the nematicide standards Temik 15G and Telone II. Anhydrous ammonia was injected with a modified rip- per bedder. Anhydrous ammonia gas was propelled through flow regulators mounted on stainless steel delivery tubes at- tached to the trailing edge of the forward-swept chisels. The gas was injected 8 inches deep with one chisel per row. Rows were immediately hipped and bedded to seal and prevent rapid loss of the gas. All remaining rows were sub-soiled, hipped and bedded without applying the anhydrous ammonia. Ammonium nitrate was applied over the row using a hand held granular applicator. Temik 15G, the standard recom- EFFECT OF ANHYDROUS AMMONIA ON RENIFORM NE AND SEED COTTON YIELD, ESCAMBIA COUNT menced nematicide, was applied at planting using granular chemical applicators attached to the planter. Telone II was applied using the same methods as the anhydrous ammonia. Di-Syston was included for early season insect control in the fertilizer treatments. The experimental design was a randomized complete block with five replications. Plots consisted of four rows 25 feet long with a 40 inch row spacing. Replications were sepa- rated by a 20-foot border. All plots were maintained with stan- dard production practices recommended by the Alabama Co- operative Extension System commonly used in the area. Nematode population development was determined at monthly intervals throughout the season. Ten soil cores, 1- inch in diameter and 8 inches deep were collected from the two center rows of each plot in a randomized, systematic sam- pling pattern. Nematodes were extracted using a combination of gravity screening and sucrose centrifugation. Plots were rated at 28 days after planting to determine seedling emer- gence, stand uniformity, and plant vigor. Cotton was harvested utilizing a one-row cotton picker to determine the ef- IATODE POPULATIONS fects of the treatments on cot- Y, ALABAMA ton yields. Treatment and rate Reniform/150 cc of soil Yield June 2 July 5 Aug. 2 Sept. 6 Oct. 3 Ave lbs/ac Anhydrous ammonia* 196.8 71.5 142.2 51.3 70.5 106.46 1283 120 units/ac - preplant Anhydrous ammonia* 135.3 66.0 60.2 59.5 145.2 93.24 1401 90 units/ac - preplant Ammonium nitrate* 228.5 101.7 115.7 102.3 166.5 142.94 1150 90 units/ac - at plant Temik 15G 7 Ib/ac - at plant + 226.0 82.8 107.3 83.5 139.8 127.88 1012 Ammonium nitrate 90 units/ac - at plant Telone I1* 3 gaVac - at plant + 132.8 45.8 70.3 79.3 196.2 104.88 1779 Ammonium nitrate 90 units/ac - at plant Deny* 1 pt/ac at plant + 207.5 98.2 161.8 68.2 264.2 159.98 1084 Ammonium nitrate 90 units/ac - at plant LSD (0.05) 116.05 65.10 75.35 60.70 90.8 240 Note: planting rate at 10 pounds per acre (five seed per foot of row); four rows 25 feet long with a 40 inch row spacing. *Disyston (7 pounds per acre at planting) added in all treatments except the treatment consisting of Temik 15G 7 lb/ac - at plant + Ammonium nitrate 90 units/ac - at plant. Severe drought im- pacted cotton growth and de- velopment during the 2000 season. Reniform nematode numbers were low through- out the season due to the se- verely dry condition of the soil. However, the average nematode population over the entire season was numeri- cally lower in the anhydrous ammonia and Telone II plots compared to the ammonium nitrate and Temik 15G (see table). Yields followed the same trend with the highest yield produced in the Telone II treatment followed by an- hydrous ammonia at 90 and 120 units respectively. 2000COTTONRESEARCHREPORT 13 EFFECT OF POST-PLANT NEMATICIDES ON COTTON PRODUCTION IN RENIFORM NEMATODE INFESTED FIELDS William S. Gazaway, James R. Akridge, and Don P. Moore Previous studies in north Alabama showed significant cot- ton yield improvement in fields infested with reniform nematodes when post-plant nematicides were applied to plots that had been treated with a nematicide at planting. Both Temik 15G and Vydate increased yields significantly when applied to cotton at pinhead square. The purpose of these tests is to determine if post-plant applications of Temik 15G will produce similar results in central and south Alabama when applied to plots treated with either Temik 15G applied at planting or with Telone II (pre-plant fumigation). Tests were conducted in two fields. A cotton field near Huxford, Escambia County, belonging to the Ward Brothers was selected in south Alabama. Cotton yields in this field have been drastically reduced as a result of heavy reniform nematode dam- age. A second field with a similar history of reniform nematode damage was selected in central Alabama on the Avant farm near Prattville. Henceforth, the south Alabama field will be referred to as the Wardfield and the central Alabama field as the Avantfield. In the Avant field, plots were 25 feet long 36 inches wide and consisted of four rows, separated on each end by five-foot alleys. Plots were arranged in a randomized complete block de- sign with six replications. Treatments are summarized in Table 1. All plots were ripped and bedded up prior to fumigation. Telone was injected via a subsoil shank 18 inches deep to desig- nated plots on April 27, 2000. On May 27, the cotton variety SureGrow 125 BG/RR was planted at a rate of five seed per foot. Specified rates of Temik 15G were applied in the seed furrow to designated plots at planting. Temik side dress applications were applied using a coulter to designated plots at pinhead square on June 27. Soil samples for nematode analyses were taken just prior to fumigation and approximately six weeks after seedling emer- gence. Appropriate insecticides were applied as needed for early season insect control. All other cultural practices were followed according to Auburn University recommendations. In the Ward field, plots were 70 feet long and 36 inches wide and consisted of four rows, separated by five-foot alleys. Plots were arranged in a randomized complete block design with three replications. Treatments were like those in the Avant field except for treatment 3 (Temik 15G at 3.5 pounds per acre was applied instead of Telone II at five gallons per acre) and treat- ment 7 (Di-Syston 15G was applied in the furrow at planting in- stead of using the seed treatment Adage for early season insect control). Treatments are summarized in Table 2. Plots were ripped and bedded up on April 18. Telone II was applied to designated plots on the same day. On May 31, the cot- ton variety DPL-655 BG/RR was planted at a rate of five seed per foot. Plots not receiving Temik 15G at planting were treated in the seed furrow with Di-Syston 15G at a rate of seven pounds per acre for early season insect control. Nematode soil samples were taken just prior to fumigation, approximately six weeks after seed- ling emergence, and at harvest. Results for the Avant field test are summarized in Table 3. All nematicide treatments significantly increased cotton yields. However, there appeared to be no additional yield benefits from the side dress application of Temik 15G to either Temik at-plant treated plots or to Telone fumigated plots. Failure of the post- plant application of Temik to elicit a yield response could be due its inability to activate under extremely dry soil conditions that persisted at the time of and following application. The extremely low cotton yields in the test must be attributed to the exceedingly dry conditions that prevailed during most of the growing season. There appeared to be no correlation between yield response and nematode numbers. Results for south Alabama (Ward Brothers farm) are sum- marized in Table 4. The higher rate of Temik 15G (seven pounds TABLE 1. SUMMARY OF TREATMENTS IN THE AVANT FIELD Treatment 1. Telone II 2. Telone II + Temik 15G 3. Telone II 4. Temik 15G 5. Temik 15G + Temik 15G 6. Temik 15G 7. Adage Rate 3 gal/ acre 3 galV acre 7 Ib/ acre 5 galV acre 5 Ib/ acre 5 Ib/ acre 7 Ib/ acre 7 Ib/ acre Time of application pre-plant fumigation pre-plant fumigation plus side dress at pin head square pre-plant fumigation at planting at planting plus side dress at pin head square at planting seed treatment TABLE 2. SUMMARY OF TREATMENTS IN THE WARD FIELD Treatment Rate Time of application 1. Telone I 3 gal/ acre pre-plant fumigation 2. Telone II + 3 gal/ acre pre-plant fumigation plus Temik 15G 7 Ib/ acre side dress at pin head square 3. Temik 15G 3.5 Ib/ acre at planting 4. Temik 15G 5 lb/ acre at planting 5. Temik 15G + 5 lb/ acre at planting plus Temik 15G 7 lb/ acre side dress at pin head square 6. Temik 15G 7 Ib/ acre at planting 7. DiSyston 15G 7 Ib/acre at planting . 1___ 1_ rr____lL_ ~--_ ALABAMAAGRICULTURALExPERIMENT STATION14 2000 COTTON RESEARCH REPORT 15 TABLE 3. RENIFORM POPULATION AND YIELD RE- SPONSE TO SIDE DRESS NEMATICIDE TREATMENTS IN CENTRAL ALABAMA 1 Treatment, rate and Reniform per Seed time of application 100 cc soil cotton April 27 July 10 lbs/ac Telone 3 gaVac, pre-plant 1227a 1971a 686a Telone + Temik* 2429a 1368a 653a 3 gal+7 lb/ac Telone 5 galVac, pre-plant 1766a 1523a 657a Temik 5 Ib/ac, at plant 1665a 2513a 597ab Temik + Temik* 2239a 1530a 698a 5 Ib+ 7 lb/ac Temik 7 Ib/ac, at plant 2128a 1832a 682a Adage seed treatment 1747a 2510a 484b 'Avant Farm, Prattville, AL. Means followed by the same letter do not significantly differ. per acre) at planting and Telone treatments provided the highest cotton yields. Temik 15G side dress applications at pinhead square did not appear to improve cotton yield. Lack of activity from post- plant Temik applications could be due to the extremely dry weather conditions that prevailed throughout the season. All nematicide treatments produced greater yields than the untreated control. Dry weather had more of an impact on cotton production than reniform nematode damage. Although some differences could be detected among nematicide treatments, these differ- ences were slight when compared to the impact of dry weather on cotton production. More tests need to be conducted under better growing conditions to assess the real value of post-plant nematicide applications in cotton. TABLE 4. RENIFORM POPULATION AND YIELD RESPONSE TO SIDE DRESS NEMATICIDE TREATMENTS IN SOUTH ALABAMA' Treatment, rate and -Reniform per 100 cc soil- Seed cotton time of application April 18 July 25 Nov. 7 lbs/ac Telone 3 gal/ac, pre-plant 1443a 469b 1154a 1347a Telone + Temik* 3 gal+7 Ib/ac 1324a 228b 1203a 1293a Temik 3.5 lb/ac, at plant 1206a 778ab 1038a 1241ab Temik 5 Ib/ac, at plant 975a 823ab 1333a 1075ab Temik + Temik* 5 lb+ 7 lb/ac 1617a 1320a 1285a 1199ab Temik 7 Ib/ac, at plant 1059a 1353a 1292a 1319a Di-Syston 7 lb/ac, at plant 1061a 1251a 2595a 1008b 'Ward Brothers Field- Huxford, AL. Means followed by the same letter do not significantly differ. 2000COTTONRESEARCHREPORT 15 FALL FUMIGATION VERSUS SPRING FUMIGATION FOR RENIFORM NEMATODE CONTROL IN HEAVILY INFESTED COTTON FIELDS William S. Gazaway Telone II has been shown to be an effective nematicide when applied under proper soil conditions. Unlike previous fumigants, Telone II is most effective when applied to drier soil at warmer temperatures. It does not perform adequately when applied to overly wet and cooler soils-conditions that are often present in the spring when much of the cotton planting is done. The purpose of this experiment is to compare an application of Telone II made in the fall when the conditions are more favorable for the fumi- gant to (1) a Telone application and (2) the conventional Temik application in the spring. Plots contained four rows and were 50 feet long. Treat- ments were arranged in a randomized complete block design and replicated five times. The entire test area of the field was disked and subsoiled on November 16, 1998. At the same time two rates of Telone II (three and five gallons per acre, respectively) were injected in assigned plots. The following spring, Telone was ap- plied on May 111999. Temik was applied in-furrow when cotton (DPL 655BG/RR) was planted on May 22. Nematode samples were pulled on November 1 1998, February 10 1999, May 11, July 22, and October 21. The two center rows of each plot were harvested on October 21. The same test was repeated in the fall 1999-2000 growing season. The Telone fall application rates were applied on No- vember 16 1999 and the spring rate was applied April 4 2000. Temik 15G and Di-Syston 15G were not applied until May 29 during planting due to very dry soils.Nematode soil samples were taken on October 5 1999, April 18 2000, July 25, and November 7. Plots were harvested on November 7. In 1999, all nematicides outproduced the untreated plots (Table 1). The Telone fall and spring applications outperformed Temik by a slight margin. This could be due to the fact that Temik was applied to a rather dry soil on May 21, 1999 and may not have been activated properly. The field remained dry until June 2. In addition, the untreated plots yielded reasonably well, indi- cating that growing conditions for cotton for the remainder of the season were rather good. Without stress on the cotton, reniform damage was most likely kept at a minimum. In the 2000 season, yields were reduced in all treatments due to extremely dry conditions throughout the growing season. Temik did not activate due to extremely dry conditions at plant- ing. Telone II fall and spring applications produced the higher yields (Table 1). TABLE 1. FALL AND SPRING FUMIGATION IMPACT ON COTTON YIELD IN RENIFORM INFESTED FIELDS (1999 AND 2000) Nematicide Rate/ac Time of Seed cotton yield --- lbs/ao- application 1999 2000 Telone II 3 gal. Fall 2312a 1711a Telone II 5 gal. Fall 2313a 1666a Telone II 3 gal. Spring 2193a 1663a Temik 15G 7 lb. At-planting 2095ab 1110b Di-Syston 15G 7 lb. At-planting 1961b 1077b LSD(0.05) 205 344 Means followed by the same letter do not significantly differ. 16 ALABAMAAGRICULTUFIALExPERIMENT STATION 2000 COTTON RESEARCH REPORT 17 HERBICIDE APPLICATIONS EVALUATION OF CGA 362622 FOR Michael G. Patterson and Wilson H. Faircloth A new herbicide (CGA 362622) developed by Syngenta (formerly Novartis) is being tested for postemergence weed con- trol in cotton around the country. This product is a new genera- tion herbicide and active use rates are about 100 times lower than EFFICACY OF CGA 362622 FOR WEED CONTROL IN ROUNDUP READY COTTON, TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER, BELLE MINA, ALABAMA, 2000 Treatment Rate Velvet- Entireleaf Sickle- lbs ai/ac leaf morningglory pod Untreated - 0 0 0 CGA 362 0.0045 48 46 47 CGA 362 0.0067 37 40 62 Staple 0.063 65 46 8 Roundup Ultra 0.75 56 52 80 WEED CONTROL IN COTTON older herbicides developed in the 1960s and 1970s. The proposed common name is trifloxysulfuron, and its mode of action is simi- lar to other sulfonylurea herbicides like Staple and Classic. The product controls primarily broadleafweeds; however, 362622 has activity on nutsedge as well. This product was evaluated for weed control in cotton at several sites in Alabama in 1999 and 2000. Data obtained in most trials included visual crop injury and weed control ratings. The activity of 362622 at two rates was compared to Staple and Roundup Ultra on weeds approximately 4 to 5 inches tall in Roundup Ready cotton (see table). Crop injury was minimal and transient in all trials. The labeled use rate for CGA 362622 has not been deter- mined, but would likely fall in the range shown in the table. Smaller weeds are controlled to a higher degree than indicated in the table. CGA 362622 may fit in a tank mix with either Staple or Roundup to increase weed efficacy in certain situations. One advantage of this product is that it could be used on all cotton varieties. POTENTIAL FOR WEED SPECIES SHIFTS IN ROUNDUP READY COTTON Michael G. Patterson and Wilson H. Faircloth Field trials partially supportedby cotton checkofffunds were conducted at the Tennessee Valley Research and Extension Cen- ter (TVREC) and the E. V. Smith Research Center (EVSRC) to evaluate a series of treatments for their potential to increase weed tolerance to glyphosate herbicide. The dominate weed species at TVREC was pitted morningglory while the dominate species at EVSRC was sicklepod. At both TVREC and EVSRC, plot size was four rows by 25 feet. Initial morningglory populations in the test area at TVREC exceeded 100 plants per plot while initial sicklepod populations at EVSRC exceeded 200 plants per plot. Data ob- tained were visual weed control and counts, following herbi- cide applications, and seed cotton yield. SureGrow 125 B/R was planted at TVREC, and SureGrow 501 B/R cotton was planted at EVSRC. Following soil-applied herbicide treatments at planting, foliar applications were applied either at cotton growth stages of 1st leaf, 4th leaf, 8th leaf, 12th leaf, or combinations thereof. Her- bicides were applied over the top at 1st leaf and 4th leaf timings and post directed at 8th leaf and 12th leaf timings. A hand hoed weedfree tree treatment was also included for comparison. Data from TVREC shows Roundup-only treatments at ei- ther one pint or two pints per application provided late-season momrningglory control and seed cotton yields equal to the hand- hoed control or treatments containing herbicides with different modes of action (see Table 1). First year data indicate that Roundup-only systems are performing as well as systems con- taining other herbicides. Although not shown, higher weed counts following initial applications at the low Roundup rate were sub- sequently decreased with followup applications. Initial sicklepod populations at EVSRC were approximately twice the level of momingglory populations observed at TVREC (see Table 2). Both Roundup-only systems resulted in higher weed counts at late season than the systems that included alternative herbicides. However, sicklepod plants remaining in the plots at this time were not large enough to cause yield loss. They will, however, provide more seed for next year's study. ,, .. ,,,,, 2000 CorrONRESEARCHREPORT 17 ALABAMA AGRICULTURAL EXPERIMENT STATION In summary, sicklepod appears to be the most difficult of these two species to manage with a Roundup-only system. Sub- TABLE 1. MORNINGGLORY CONTROL, WEED COUNTS, AND SEED COTTON YIELDS, TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER, BELLE MINA, ALABAMA' Treatment Control Weeds Yield % no/plot lbs/plot Roundup 1.0pt 94 6 1638 at 1 If, 41f, and 121f Roundup 2.0pt 96 4 1630 at 1 f, 41f, and 12 If Roundup 1pt + 99 1 1546 Staple 0.8oz at 1 If Roundup 1.5pt at If Roundup 1 pt at 121f Meturon 3 pt pre 94 4 1660 Roundup 1 pt + Staple 0.8oz at 4If Roundup 1pt at 121f Hand hoed 96 4 1682 'Data were collected on August 4, 2000. sequent years results may provide insight into the effect of un- controlled weeds on seed buildup. TABLE 2. MORNINGGLORY CONTROL, WEED COUNTS, AND SEED COTTON YIELDS, E .V. SMITH RESEARCH CENTER, SHORTER, ALABAMA' Treatment Control Weeds Yield % no/plot lbs/plot Roundup 1.0pt 86 25 1802 at 1If, 41f, and 121f Roundup 2.0pt 88 21 1910 at 1If, 41f, and 12 If Roundup Ipt + 94 10 1788 Staple 0.8oz at 1If Roundup 1.5pt at If Roundup 1 pt at 121f Meturon 3 pt pre 97 4 1560 Roundup 1 pt + Staple 0.8oz at 4If Roundup 1pt at 121f Hand hoed 88 21 1423 'Data were collected on August 15, 2000. 18 FUNGICIDE APPLICATIONS EVALUATION OF EXPERIMENTAL SEED TREATMENTS FOR CONTROL OF SEEDLING DISEASE OF COTTON Kathy S. McLean, H. L. Campbell, Aaron Palmateer, and Bobby E. Norris The objective of this research was to evaluate experimental seed treatment fungicides for control of seedling disease of cot- ton. Two tests were planted April 20 at the Tennessee Valley Research and Extension Center, Belle Mina, Alabama. The field had a history of cotton seedling disease and the soil type was a Decatur silty loam. All fungicides were applied to the seed as seed treatments before planting. Test one was infested with mil- let seed colonized with Pythium spp. and Rhizoctonia solani and test two was left naturally infested. In both tests, 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 six replications. Blocks were sepa- rated by a 20-foot alley. The nematicide Temik 15G (at five pounds per acre) was applied in-furrow at planting. All plots were main- tained throughout the season with standard herbicide, insecticide, and fertility production practices as recommended by the Ala- bama Cooperative Extension System. Stand counts, skip index, and vigor ratings were recorded at two, four, and six weeks after planting to determine the percent seedling loss, stand density, and seedling vigor due to cotton seedling disease. The number of open bolls were counted August 30 to indicate plant maturity. Plots were harvested September 19. Cotton seedling disease pressure was moderate in the Pythium spp. and R. solani infested test. Significant differences in seedling stand were observed only at four weeks after planting (Table 1). At four weeks after planting, Delta Coat Ad + Nu- Flow M + PGE 143 + PGE 146 and Apron TL + Nu-Flow T + Nu-Flow M produced significantly greater stands than the Apron TABLE 1. EFFICACY OF EXPERIMENTAL SEED TREATMENT FUNGICIDES ON COTTON SEEDLING DISEASE ENHANCED WITH PYTHUM SPP. AND RHIZCTONIA SoLAN, TEN- NESSEE VALLEY RESEARCH AND EXTENSION CENTER, BELLE MINA, ALABAMA Rate form- Skip Seed Treatment' ulated product index 3 cotton fl oz/cwt - Stand 2 - lbs/ac May 2 May 17 May 31 May 31 Sept. 19 Untreated control -44 80 78 2.5 3790 RTU Baytan-Thiram + Apron FL 3.0 + 0.75 45 84 81 2.3 3659 Delta Coat AD + NU-Flow M 11.75 + 1.25 41 88 86 0.7 3738 Delta Coat AD + Nu-Flow M 11.75 + 1.25 46 83 80 1.8 3581 + PGE 143 + PGE 144 +0.035 +0.035 Delta Coat AD + Nu-Flow M 11.75+ 1.25 39 90 84 1.7 3738 + PGE 143 + PGE 146 +0.035+0.035 Apron TL + Nu-Flow T 2.0 + 2.25 44 90 85 1.5 3581 + Nu-Flow M + 1.25 Apron TL + Nu-Flow T 2.0 + 2.25 43 83 80 1.7 3836 + Nu-Flow M + PGE 143 +1.25+0.035 + PGE 144 +0.035 Apron TL + Nu-Flow T 2.0 + 2.25 37 79 77 2.8 3526 + Nu-Flow M + PGE 143 +1.25+0.035 + PGE 146 + 0.035 LSD (0.05) 15 10 9 2.3 225 1 All treatments were applied to seeds. Number of live seedlings per 25 feet of row; all rows received 125 seed of 'DPL 33B'. 3 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). TL + Nu-Flow T + Nu-Flow M + PGE 143 + PGE 146 seed treatment. No seed treatment produced a significantly lower skip index, indicating a more evenly spaced seedling stand than the control at six weeks after planting. No significant differences were observed in the number of open bolls on five plants per plot. Seed cot- ton yields varied 310 pounds per acre in the Apron TL+Nu- Flow T + Nu-Flow M + PGE 143 +PGE 144 andthe Apron TL + Nu-Flow T + Nu-Flow M+PGE 143 +PGE 146 seed treatments, respectively. The average yield of seed cotton from the fungicide-treated plots was not greater than the yield of the untreated control. Cotton seedling disease incidence was light in the natu- rally infested test. Significant differences in seedling stand were observed at two, four, and six weeks after planting (Table 2). At two weeks after planting, Apron TL + Nu- Flow T + Nu-Flow M + PGE 2000COTTONRESEARCHREPORT 19 ALABAMA AGRICULTURAL EXPERIMENT STATION 143 + PGE 144 produced sig- nificantly greater stands than the untreated control. How- ever, by four and six weeks after planting, Delta Coat AD + Nu-Flow M + PGE 143 + PGE 146 produced greater stands than Delta Coat AD + Nu-Flow M and Delta Coat + AD + Nu-Flow M+ PGE 144. No seed treatment produced a significantly lower skip index, indicating a more evenly spaced seedling stand than the control at six weeks after plant- ing. No significant differences were observed in the number of open bolls on five plants per plot. Seed cotton yields varied 209 pounds per acre for the Apron TL + Nu-Flow T + Nu- Flow M seed treatment and the Apron TL + Nu-Flow T +Nu- Flow M + PGE 143 +PGE 144 seed treatment, respectively. The average yield of seed cot- ton from the fungicide-treated plots was not greater than the yield of the untreated control. TABLE 2. EFFICACY OF EXPERIMENTAL SEED TREATMENT FUNGICIDES ON COTTON SEEDLING DISEASE, TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER, BELLE MINA, ALABAMA Rate form- Skip Seed Treatment' ulated product index 3 cotton fl oz/cwt ------ Standlbs/ac May 2 May 17 May 31 May 31 Sept. 19 Untreated control 57 94 95 0.6 3581 RTU Baytan-Thiram + Apron FL 3.0 + 0.75 60 98 100 0.3 3555 Delta Coat AD + NU-Flow M 11.75 + 1.25 53 91 92 0.7 3476 Delta Coat AD + Nu-Flow M 11.75 + 1.25 51 89 92 0.2 3528 + PGE 143 + PGE 144 +0.035 +0.035 Delta Coat AD + Nu-Flow M 11.75 + 1.25 59 100 102 0.3 3424 + PGE 143 + PGE 146 +0.035 +0.035 Apron TL + Nu-Flow T 2.0 + 2.25 61 95 97 0.3 3633 + Nu-Flow M + 1.25 Apron TL + Nu-Flow T 2.0 + 2.25 72 97 98 0.0 3424 + Nu-Flow M + PGE 143 +1.25+0.035 + PGE 144 + 0.035 Apron TL + Nu-Flow T 2.0 + 2.25 60 93 93 0.3 3502 + Nu-Flow M + PGE 143 +1.25+0.035 + PGE 146 +0.035 LSD (0.05) 14 10 11 0.7 348 'All treatments were applied to seeds. 2 Number of live seedlings per 25 feet of row; all rows received 125 seed of DPL 33B. 3 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fishers protected least significant difference test (P=0.05). EVALUATION OF SELECTED IN-FURROW FUNGICIDES FOR CONTROL OF SEEDLING DISEASE OF COTTON K. S. McLean, H. L . Campbell, Aaron Palmateer, Bobby E. Norris, Larry W. Wells, and Don P. Moore The objective of this research was to evaluate in-furrow fungicides for control of seedling disease of cotton. This cotton fungicide test was planted at three locations including the Ten- nessee Valley Research and Extension Center in Belle Mina, the Prattville Experiment Field in Prattville, and the Wiregrass Re- search and Extension Center in Headland. These fields have a history of cotton seedling disease. Fungicides were applied as a seed treatment or as an in-furrow or spray or granular application at planting. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles calibrated to deliver 20 gallons per acre at 30 pounds per square inch. In-furrow granular applications were applied with chemical granular applicators attached to the planter. 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 six replications. Each plot was infested with millet seed inoculated with Pythium spp. and Rhizoctoniasolani. Blocks were separated by a 20-foot alley. The nematicide Temik 15G (five 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 recommended by the Alabama Cooperative Extension System. Stand counts, skip index, and vigor ratings were recorded at two, four, and six weeks after planting to determine the percent seedling loss, stand density, and seedling vigor due to cotton seedling disease. Plots were harvested and data recorded.a 20 1 -I 2000 CorroN RESEARCH REPORT 21 At the Tennessee Valley Research and Extension Center, cotton seedling disease incidence was moderate. Significant dif- ferences in seedling stand were observed at two, four, and six weeks after planting (Table 1). At two weeks after planting, Terraclor 4F and Ridomil Gold PC produced significantly greater stands than Rovral 4CF. By four weeks after planting, Ridomil Gold PC, Terraclor 15G, Terraclor Super X 18.8G, Terraclor 4 F, and Terraclor 15G all produced greater stands than the control. By six weeks after planting, Ridomil Gold PC, Terraclor 15G, Terraclor Super X 18.8G, Terraclor 4F, Terraclor 15G, and Terraclor EC all produced greater stands than the control. At six TABLE 1. EFFICACY OF SELECTED IN-FURROW FUNGICIDES COTTON SEEDLING DISEASE AT TENNESSEE VALLEY RE CENTER IN NORTH ALABAMA Treatment and rate Application formulated product treatment Stand'- May 2 May 17 Untreated control 25 55 Terraclor Super X 18.8G 5.5 Ib/ac In furrow 27 75 Terraclor Super X EC 48 fl oz/ac In furrow 25 66 Terraclor 2E 48 fl oz/ac In furrow 24 66 Terraclor 15G 5 lb/ac In furrow 28 80 Terraclor 4F 24 fl oz/ac In furrow 33 72 Rovral 4CF 5.2 fl oz/ac In furrow 22 54 Rovral 4CF 6 fl oz/ac In furrow 27 51 Ridomil Gold 11 PC 7 lb/ac In furrow 33 83 Quadris 2SC 5.56 fl oz/ac In furrow 26 57 Delta Coat AD 11.75 fl oz/ac Seed 31 63 Ridomil Gold 0.075 fl oz/1000 ft In furrow 29 62 LSD (0.05) 9 10 'Number of live seedlings per 25 feet of row; all rows received 125 2 Skip index ratings based on 25 feet of row. Ratings correspond t example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plant Means compared using Fisher's protected least significant differen TABLE 2. EFFICACY OF SELECTED IN-FURROW FUNGICIDES COTTON SEEDLING DISEASE AT PRATTVILLEY EXPERIMEN BAMA Treatment and rate Application formulated product treatment Stand'- April 25 May 10 Untreated control 55 46 TSX 18.8G 5.5 Ib/ac In furrow 57 53 TSX EC 48 fl oz/ac In furrow 59 59 Terraclor 2E 48 fl oz/ac In furrow 63 57 Terraclor 15G5 Ib/ac In furrow 59 56 Terraclor 4F 24 fl oz/ac In furrow 69 67 Rovral 4CF 5.2 fl oz/ca In furrow 68 62 Rovral 4CF 6 fl oz/ac In furrow 63 59 Ridomil Gold PC 11G 7 Ib/ac In furrow 61 58 Quadris 2SC 5.56 fl oz/ac In furrow 76 73 Delta Coat AD 11.75 fI oz/cwt Seed 66 64 Ridomil Gold 4EC 0.075 fl oz/1000 ft In furrow 53 49 LSD (0.05) 12 11 'Number of live seedlings per 30 feet of row; all rows received 150 2 Skip index ratings based on 25 feet of row. Ratings correspond example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plant Means compared using Fishers protected least significant differer weeks after planting, these fungicides also produced a signifi- cantly lower skip index, indicating a more evenly spaced seed- ling stand than the control. Seed cotton yields varied over 588 pounds per acre for the Terraclor Super X 18.8G and the Rovral 4CF, respectively. Terraclor Super X 18.8G, Terraclor 4F, Ridomil Gold, Quadris, and Ridomil Gold PC all produced significantly greater yields than the control. The average yield of seed cotton from the fungicide-treated plots was 196 pounds greater than the yield of the untreated control. At the Prattville Experiment Field cotton seedling disease incidence and severity were moderate and severe drought affected yields. Significant differ- ences in seedling stand were ON SUREGROW 125B/RR observed at two and four SEARCH AND EXTENSION weeks after planting (Table 2). At two weeks after plant- ing, Quardis 2SC,Terraclor Skip Seed cotton 4F, Rovral 4CF, and Delta _ index 2 lbs/ac Coat AD treatments pro- May31 May 31 Sept.19 May 31 May 31 Sept. 19 duced significantly greater 53 14.8 3055 6 14.7 305 stands than the untreated con- 76 4.7 3523 65 5.3 3194 trol. At four and six weeks 68 3.8 3113 after planting, Quardis 2SC, 78 2.8 3181 Rovral 4CF, Terraclor 4F, 70 5.7 3474 Terraclor 2E, Terraclor Super 54 12.2 2993 X 2EC, RidomilPC 1 G, and 54 14.7 2935 Delta Coat AD treatments 81 2.7 33278153 13.7 332748 significantly improved stands 60 9.0 3314 compared to the untreated 51 12.5 3379 control. These treatments 8 4.9 311 produced a significantly SureGrow 125 B/RR seed. lower skip index, indicating to distance of skipped plants; for a more evenly spaced seed- s. ling stand compared to the ce test (P=0.05). control at six weeks after planting. Seed cotton yields ON SUREGROw 125BIRR varied 242 pounds per acre IT FIELD IN CENTRAL ALA- in the Delta Coat AD and the Rovral 4F (5.2 fluid ounces per acre) treatments, respec- Skip Seed cotton tively. The average yield of - index 2 lbs/ac seed cotton from the eleven May 24 May 24 Aug.30 fungicide-treated plots was not 47 20.7 1404 than the d ofthe un- 54 16.0 1295 greaterthantheyieldoftheun- 63 11.7 1399 treated control. 58 13.0 1307 At the Wiregrass Re- 53 16.7 1258 search and Extension Center, 67 10.3 1375 cotton seedling disease inci- 65 11.0 1203 dence was moderate and a 60 12.0 1314 severe drought affected 59 14.7 1234 72 7.3 1379 yields. Significant differ- 64 9.3 1445 ences in seedling stand were 49 19.3 1300 observed at two and four 10 7.7 169 weeks after planting (Table SureGrow 125 RP seed. 3). At two weeks after plant- to distance of skipped plants; for ing, Quardis 2SC and both ts. ice test (P=0.05). 2000 CarrONRESEARCHREPORT 21 22 ALABAMA AGRICULTURAL EXPERIMENT STATION rates of Rovral 4CF produced significantly greater stands than the untreated control. At four weeks after planting, Quardis 2SC, Rovral 4CF( 5.2 fluid ounces per acre), and Terraclor 2E treatments significantly im- proved stands compared to the untreated control. However, no treatment produced a signifi- cantly lower skip index, indicat- ing a more evenly spaced seed- ling stand compared to the con- trol at six weeks after planting. Seed cotton yields varied 889 pounds per acre in the Rovral 4CF and the Quadris 2SC treat- ments, respectively. The average yield ofseed cotton fromthe ten fungicide-treated plots was 382 pounds greater than the yield of the untreated control. TABLE 3. EFFICACY OF SELECTED IN-FURROW FUNGICIDES ON STONEVILLE 474 CoTTON SEEDLING DISEASE AT WIREGRASS RESEARCH AND EXTENSION CENTER IN SOUTHEAST ALABAMA Treatment and rate Application Skip Seed cotton formulated product treatment Stand' index 2 lbs/ac May 5 May 19 June 2 June 2 Oct. 23 Untreated control 65 72 70 3.7 1295 Terraclor Super X 18.8G 5.5 Ib/ac In furrow 62 68 68 5.2 1759 Terraclor Super X EC 48 fl oz/ac In furrow 72 77 74 3.5 1953 Terraclor 2E 48 fl oz/ac In furrow 65 80 76 2.0 1643 Terraclor 15G Ib/ac In furrow 65 73 69 2.7 1875 Terraclor 4F 24 fl oz/ac In furrow 70 77 74 3.8 1972 Rovral 4 CF 5.2 fl oz/ac In furrow 75 81 80 2.5 2068 Rovral 4 CF 6 fl oz/ac In furrow 73 76 75 4.0 1469 Ridomil Gold 7 Ib/ac In furrow 65 72 69 6.3 1469 Quadris 2 SC 5.56 fl oz/ac In furrow 77 83 79 2.5 1179 Ridomil Gold PC 0.075 fl oz/1000 ft In furrow 73 78 75 5.0 1392 LSD (0.05) 11 11 14 4.0 404 1 Number of live seedlings per 25 feet of row; all rows received 125 seed. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fishers protected least significant difference test (P=0.05). EVALUATION OF SELECTED IN-FURROW FUNGICIDES FOR CONTROL OF NATUmRAL INFSmIONS OF SEEDULING DISES OF CnON Kathy S. McLean, H. L . Campbell, Aaron Palmateer, Bobby E. Norris, Don P. Moore, and Larry W. Wells The objective of this research was to evaluate in-furrow fungicides for control of natural infestations of seedling disease of cotton. This cotton fungicide test was planted at three loca- tions including the Tennessee Valley Research and Extension Center in Belle Mina, the Prattville Experiment Field in Prattville, and the Wiregrass Research and Extension Center in Headland. These fields have a history of cotton seedling disease. Fungicides were applied as a seed treatment or as an in-furrow or spray or granular application at planting. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles calibrated to deliver 20 gallons per acre at 30 pounds per square inch. In-furrow granular applications were applied with chemical granular applicators at- tached to the planter. Plots consisted of two rows, 25 or 30 feet long with a 36- or 40-inch wide row spacing. The plots were arranged in a random- ized complete block design with six replications. Blocks were separated by a 20-foot alley. The nematicide Temik 15G (five 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, skip in- dex, and vigor ratings were recorded at two, four, and six weeks after planting to determine the percent seedling loss, stand den- sity, and seedling vigor due to cotton seedling disease. Plots were harvested and data recorded. Cotton seedling disease incidence and severity was light to moderate at the Tennessee Valley Research and Extension Cen- ter in Belle Mina. Significant differences in seedling stand were observed at two, four, and six weeks after planting (Table 1). At two weeks after planting, Quardis 2SC produced significantly greater stand than the untreated control. Comparedto theuntreated control, stands were significantly improved at four weeks after planting by seven of the fungicides and at six weeks after plant- ing by nine of the herbicides. However, no treatment produced a significantly lower skip index, indicating a more evenly spaced seedling stand compared to the control at six weeks after plant- ing. Seed cotton yields ranged from 3,920.40 pounds per acre to 3,444.70 pounds per acre for the Quadris 2 SC and the Ridomil Gold PC treatments, respectively. The average yield of seed cot- ton from the eleven fungicide-treated plots was not greater than the yield of the untreated control. Cotton seedling disease incidence and severity was light and a severe drought affected yields at the Prattville Experiment Field in Prattville. Significant differences in seedling stand were not observed at two, four, or six weeks after planting (Table 2). At six weeks after planting, stands ranged from 2.7 to 2.46 plants per urr~ 3uuru ~vrrly~urnr rv ur~ MN11' novral 4 ~r ~.~ rr ouac In rurrow 22 ALABAMAAGRICULTURALEXPERIMENT STATION 2000 ,- COTTON ,. RESARC RPOR 2 I COTTON SEEDLING DISEASE AT PRATTVILLE EXPERIMENT FIELD Significantdifferencesinseed- ling stand were not observed Treatment and rate Application Skip Seed cotton at two and six weeks after formulated product treatment Stand' index 2 lbs/ac April 25 May 10 May 24 May 24 Aug. 30 planting (Table 3). At four Untreated control 93 79 67 5.7 1597 weeks after planting Terraclor TSX 18.8G 5.5 lb/ac In furrow 85 75 74 3.3 1568 Super X 18.8G, Ridomi Gold TSX EC48 fl oz/ac In furrow 89 85 80 3.3 1408 PC, and Quadris 2SC pro- Terraclor 2E 48 fl oz/ac In furrow 92 86 74 3.3 1421 duced significantly greater Terraclor 15G 5 lb/ac In furrow 86 75 74 5.0 1525 stands than Terraclor Super X Terraclor 4F 24 fl oz/ac In furrow 90 76 80 4.7 1525 2EC. Plant stands ranged from Rovral 4CF 5.2 fl oz/ac In furrow 86 83 78 4.0 1411 a high of2.54 to a low of 2.12 Rovral 4CF 6 fl oz/ac In furrow 83 78 81 2.7 1602 a hg o 25 to a loo2 Ridomil PC 11G 7 Ib/ac In furrow 88 75 81 2.7 1435 at six weeks afterplanting. No Quadris 2SC 5.56 fl oz/ac In furrow 95 85 79 3.7 1556 fungicide treatment produced Delta Coat AD 11.75 fl oz/cwt Seed 89 75 74 3.3 1517 a significantly lower skip in- Ridomil Gold 4EC 1.0 fl oz/ac In furrow 85 74 75 5.3 1520 dex, indicating a more evenly LSD (0.05) 15 15 13 2.7 167 spaced seedling stand com- SNumber of live seedlings per 30 feet of row; all rows received 150 seed of SureGrow 125 RR pared to the control at six 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for weeks after planting. Seed cot- example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using ton yields varied 851 pounds Fishers protected least significant difference test (P=0.05). per acre for the Terraclor 15G and the Ridomil Gold treat- ments, respectively. The aver- age yield of seed cotton from the ten fungicide-treated plots was 390 pounds per acre greater than the yield ofthe un- treated control. foot of row with the control TABLE 1. EFFICACY OF SELECTED IN-FURROW FUNGICIDES ON SUREGROW 125B/RR measuring 2.57 plants. Rovral COTTON SEEDLING DISEASE AT TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER 4CF and Ridomil Gold PC Treatment and rate Application Skip Seed cotton 1IG produced a significantly formulated product treatment - Stand - - index 2 lbs/ac lower skip index, indicating a May 2 May 17 May 31 May 31 Sept. 19 more evenly spaced seedling Untreated control - 43 78 84 4.3 3855 stand compared to the control Terraclor Super X 18.8G 5.5 Ib/ac In furrow 50 79 84 5.0 3547 at six weeks after planting. Terraclor Super X EC 48 fl oz/ac in furrow 44 77 86 4.7 3667 Seed cotton yields varied 194 Terraclor 2E 48 fl oz/ac In furrow 37 77 92 3.7 3693 Terraclor 15G 5 Ib/ac In furrow 43 84 93 4.0 3607 pounds per acre in the Rovral Terraclor 4F 24 fl oz/ac In furrow 49 88 93 5.0 3468 4F six fluid ounces per acre Rovral 4CF 5.2 fl oz/ac In furrow 46 84 94 3.7 3871 and the Terraclor Super X EC Rovral 4CF 6 fl oz/ac In furrow 49 82 91 5.0 3547 treatments, respectively. The Ridomil Gold PC 7 Ib/ac In furrow 42 82 89 4.0 3445 average yield of seed cotton Quadris 2SC 5.56 fl oz/ac In furrow 59 90 100 3.0 3920 from the eleven fungicide- Delta Coat AD 11.75 oz/cwt Seed 39 70 75 5.3 3484 treated plots was not greater Ridomil Gold 4EC 1 .Ofl oz/ac In furrow 45 85 100 3.5 3724 tatedota nreate LSD (0.05) 16 11 10 2.8 274 than the yield of the untreated Number of live seedlings per 25 feet of row; all rows received 125 seed of SureGrow 125 B/RR. control. 2Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for Cotton seedling disease example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using incidence was light and a se- Fishers protected least significant difference test (P=0.05). vere drought affected yields at the Wiregrass Research and TABLE 2. EFFICACY OF SELECTED IN-FURROW FUNGICIDES ON SUREGROW 125BIRR Extension Center in Headland. 2000COTTONRESEARCHREPORT 23 TABLE 3. EFFICACY OF SELECTED IN-FURROW FUNGICIDES ON SUREGROW 125B/RR CorrON SEEDLING DISEASE AT WIREGRASS RESEARCH AND EXTENSION CENTER Treatment and rate Application Skip Seed cotton formulated product treatment Stand' index 2 lbs/ac May 5 May 19 June 2 June 2 Oct. 23 Untreated control 66 65 62 7.8 1199 Terraclor Super X18.8G 5.5 lb/ac In-furrow 64 67 63 7.7 1431 Terraclor Super X2EC 48 fl oz/ac In-furrow 56 53 53 13.3 1701 Terraclor 2E 48 fl oz/ac In-furrow 57 57 54 9.3 1759 Terraclor 15G 5 lb/ac In-furrow 55 60 56 8.8 2030 Terraclor 4F 24 fl oz/ac In-furrow 57 57 55 11.5 1469 Rovral 4 CF 5.2 fl oz/ac In-furrow 60 62 59 7.8 1489 Rovral 4 CF 6 fl oz/ac In-furrow 58 60 57 9.2 1411 Ridomil Gold 7 Ib/ac In-furrow 63 65 63 6.3 1914 Quadris 2 SC 5.56 fl oz/ac In-furrow 62 66 64 8.3 1179 Ridomil Gold 4 EC 1.0 fl oz/ac In-furrow 64 62 57 11.0 1295 LSD (0.05) 11 12 12 7.9 429 INumber of live seedlings per 25 feet of row; all rows received 125 seed of SureGrow 125 B/RR. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fishers protected least significant difference test (P=0.05). EVALUATION OF EXPERIMENTAL IN-FURROW FUNGICIDE COMBINATION TREATMENTS FOR CONTROL OF SEEDLING DISEASE OF COTTON Kathy S. McLean, H. L. Campbell, Aaron Palmateer, Bobby E. Norris, and Don P. Moore The objective of this research was to evaluate in-furrow fungicide combination treatments for control of seedling disease of cotton. This cotton fungicide test was planted at three loca- tions including the Tennessee Valley Research and Extension Center in Belle Mina and the Prattville Experiment Field in Prattville. These fields have a history of cotton seedling disease. Fungicides were applied as a seed treatment or as an in- furrow or spray or granular application at planting. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles cali- brated to deliver 20 gallons per acer at 30 pounds per square inch. In-furrow granular applications were applied with chemical granu- lar applicators attached to the planter. 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 six replications Blocks were separated by a 20- foot alley. The nematicide Temik 15G (five pounds per acre) was applied in-furrow at planting All plots were maintained through- out the season with standard herbicide, insecticide, and fertility production practices as recommended by the Alabama Coopera- tive Extension System. Stand counts, skip index, and vigor rat- ings were recorded at two, four, and six weeks after planting to determine the percent seedling loss, stand density, and seedling vigor due to cotton seedling disease. Plots were harvested and data recorded. Seedling disease incidence and severity were moderate at the Tennessee Valley Research and Extension Center in north Alabama. Significant differences in seedling stand were observed at four and six weeks after planting (Table 1). At four weeks after planting, the stand in the Ridomil G + CGA-279202 (0.04 + 0.125 pound active ingredient per acre) treatment was significantly greater than the Delta Coat AD and Quadris 2SC at the high rate. By six weeks after planting, Ridomil G + Rovral 4F, Ridomil G + PCNB, and Ridomil Gold + Terraclor 4 F produced better stands than Delta Coat AD. However, there were no significant differ- ences in the skip index. No significant differences were observed in the number of open bolls on five plants per plot. Seed cotton yields varied 392 pounds per acre for the Ridomil G + CGA- 279202 (0.04 + 0.156 pound active ingredient per acre) and the Delta Coat AD treatments, respectively. The average yield of seed cotton from the fungicide-treated plots was not greater than the yield of the untreated control. Cotton seedling disease incidence was moderate and a se- vere drought reduced yields at the Prattville Experiment Field in central Alabama. Significant differences in seedling stand were observed at four and six weeks after planting (Table 2). At four weeks after planting, eight of the fungicide treatments produced significantly greater stand than the untreated control. However, no treatment produced a significantly lower skip index compared 24 ALABAMAAGRICULTURALExPERIMENT STATION 2000 CoUoN RESEARCH REPORT 25 AT TENNESSEE VALLEY RESEARCH AND EXTENSION CENTI Treatment and rate formulated product Application treatment Untreated Control Terraclor Super X In furrow 1.85 oz ai/1000 ft row Quadris 2SC 8.35 fl oz/ac In furrow Quadris 2SC 5.56 fl oz/ac In furrow Ridomil Gold + Terraclor 4F In furrow 0.075 fl + 7.4 fl oz/1000f row Ridomil Gold 0.075 fl oz/1000 ft row In furrow Delta Coat AD 11.75 oz/cwt Seed Ridomil G + PCNB In furrow 0.040 Ib av/ac + 1.0 Ib ail/ac Ridomil G + CGA-279202 In furrow 0.040 lb aVac + 0.125 Ib ail/ac Ridomil G + CGA-279202 In furrow 0.040 Ib ail/ac + 0.156 Ib ail/ac Ridomil G + Rovral 4F In furrow 0.040 Ib aV/ac + 0.156 Ib ail/ac - n -Stand' May2 May17 May 31 58 99 101 56 99 105 65 93 102 59 94 101 58 104 108 59 99 102 55 89 94 60 106 110 66 106 107 58 97 104 58 99 108 to the control, indicating a 3INATIONS ON more evenly spaced seedling stand at six weeks after plant- ER ing. Seed cotton yields varied Skip Seed cotton 166 pounds per acre in the index 2 lbs/ac Quadris 2SC 8.35 fluid ounces May 31 Sept. 19 per acre and the Ridomil G + 0.2 3894 CGA 0.156 pound active in- 0.5 3868 gredient per acre treatments, respectively. The average yield 0.3 3816 of seed cotton from the ten 0.2 3711 fungicide-treated plots was not 0.5 4025 greater than the yield ofthe un- treated control. 0.3 3711 0.0 3685 0.3 3868 0.0 3868 0.2 4077 0.3 3868 LSD (0.05) 16 12 13 0.6 279 i Number of live seedlings per 25 feet of row; all rows received 125 seed of SureGrow 125 B/RR. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 -= 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants.Means compared using Fisher's protected least significant difference test (P=O.05). TABLE 2. EFFICACY OF EXPERIMENTAL IN-FURROW FUNGICIDE COMBINATIONS ON DPL NUCOTN 35B COTToN SEEDLING DISEASE AT PRATTVILLE EXPERIMENT FIELD Treatment and rate formulated product Application Skip Seed cotton treatment Stand 1 index 2 lbs/ac April 25 May 10 May 24 May 24 Aug. 31 Untreated control - 110 91 96 Terraclor Super X EC In furrow 118 106 107 1.85 oz a/V1000 ft Quadris 2SC 8.35 fl oz/ac In furrow 108 92 100 Quadris 2SC 5.56 fl oz/ac In furrow 112 96 96 Ridomil Gold + In furrow 113 100 95 0.075 fl oz/1000 ft row + Terraclor 2E 7.4 f oz1 000 ft row Ridomil Gold 0.075 fl oz/1 000 ft In furrow 115 95 96 Delta Coat AD 11.75 oz/cwt. Seed 106 95 93 Ridomil Gold .040 Ib ail/ac In furrow 117 98 100 + PCNB 1.0 Ib avac Ridomil Gold 0.040 Ib aV/ac In furrow 105 94 100 + CGA-279202 0.125 Ib aV/ac Ridomil Gold 0.040 lb a/ac In furrow 109 95 92 + CGA-279202 0.156 lb ail/ac Ridomil Gold 0.040 Ib ail/ac In furrow 114 91 94 + Rovral 0.156 Ib ail/ac LSD (0.05) 20 13 12 2.8 1629 1.5 1544 2.7 2.0 2.3 1662 1549 1568 2.0 1556 2.7 1573 2.3 1573 2.0 1585 2.3 1496 2.7 1625 1.5 196 Number of live seedlings per 30 feet of row; all rows received 150 seed of DPL NuCotn 35B. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants.Means compared using Fisher's protected least significant difference test (P=0.05). 2000 CorrONRESEARCHREPORT 25 IIi EVALUATION OF EXPERIMENTAL IN-FURROW FUNGICIDES FOR CONTROL OF SEEDLING DISEASE OF COTTON Kathy S. McLean, H. L . Campbell, Aaron Palmateer, Bobby E. Norris, and Don P. Moore The objective of this research was to evaluate experimental in-furrow fungicide combinations for control of seedling disease of cotton. This cotton fungicide test was planted at Tennessee Valley Research and Extension Center in Belle Mina and Prattville Experiment Field in Prattville. These fields have a history of cot- ton seedling disease. Fungicides were applied as a seed treatment or as an in-furrow spray or granular application at planting. All in-furrow fungicide sprays were applied with flat tip 8002E nozzles calibrated to deliver 20 GPA at 30 PSI. In-furrow granular appli- cations were applied with chemical granular applicators attached to the planter. Plots were infested with millet seed inoculated with Pythium spp. and Rhizoctoniasolani. Plots consisted of two rows, 25 to 30 feet long with 36 inch wide row spacing. Plots were arranged in a randomized complete block design with six 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 throughout the season with standard herbicide, insec- ticide, and fertility production practices as recommended by the Alabama Cooperative Ex- tension System. Stand counts, skip index, and vigor ratings were recorded at two, four, and six weeks after planting to de- termine the percent seedling loss, stand density, and seed- ling vigor due to cotton seed- ling disease. Plots were har- vested and data recorded. Cotton seedling disease incidence was moderate Ten- nessee Valley Research and Extension Center. Significant differences in seedling stand were observed at two, four, and six weeks after planting (Table 1). Ridomil G + CGA-279202 produced the greatest stand at two weeks after planting. At four and six weeks Ridomil Gold + Terraclor 4 F, Ridomil G + PCNB, and Ridomil G + CGA-279202 produced sig- nificantly greater stands than the untreated control. Ridomil G + PCNB and Ridomil G + CGA-279202 also produced a significantly lower skip index, indicating a more evenly spaced seedling stand than the control at six weeks after planting. However, four weeks after planting only Vitavax-PCNB + Alle- giance FL (6.0 +0.75 fluid ounces per hundred weight) produced a significantly lower skip index. No significant differences were observed in the number of open bolls on five plants per plot. Seed cotton yields varied 496 pounds per acre for the Ridomil Gold + Terraclor 4 F and the untreated control, respectively. Ridomil Gold + Terraclor 4 F and Ridomil G + PCNB significantly increased the yields over the control. The average yield of seed cotton from the fungicide-treated plots was 241.8 pounds greater than the yield of the untreated control. Cotton seedling disease incidence and severity was moder- ate and a severe drought affected yields at the Prattville Experi- ment Field. Significant differences in seedling stand were observed at four and six weeks after planting (Table 2). At four weeks after planting, Terraclor Super X 2EC and Quardis 2SC treatments produced significantly greater stands than the untreated control. At six weeks after planting, eight of the ten fungicide treatments TABLE 1. EFFICACY OF EXPERIMENTAL IN-FURROW FUNGICIDE COMBINATIONS ON SUREGROW 125B/RR CorroN SEEDLING DISEASE AT TENNESSEE VALLEY RESEARCH AND EXTENSION CENTER Treatment and rate Application Skip Seed cotton formulated product treatment Stand 1 ' . index 2 lbs/ac May2 May17 May 31 May 31 Sept. 19 Untreated control - 29 52 50 7.2 3084 Terraclor Super X In furrow 33 63 60 6.1 3398 1.85 oz ai/1000 ft row Quadris 2SC 8.35 fl oz/ac In furrow 30 60 56 5.8 3136 Quadris2SC 5.56 fl oz/ac In furrow 28 57 53 6.4 3215 Ridomil Gold + Terraclor In furrow 29 69 66 4.8 3581 0.075 fl + 7.4 fl oz/1000 ft row Ridomil Gold EC In furrow 31 65 59 6.0 3267 0.075 fl oz/1000 ft row Delta Coat AD 11.75 oz/cwt Seed 31 69 66 3.4 3398 Ridomil G + PCNB In furrow 36 78 75 2.3 3555 0.040 Ib ailac + 1.0 Ib ai/ac Ridomil G + CGA-279202 In furrow 31 60 59 4.5 3319 0.040 Ib ai/ac + 0.125 Ib ai/ac Ridomil G + CGA-279202 In furrow 38 69 67 3.3 3372 0.040 Ib ai/ac + 0.156 Ib ai/ac Ridomil G + Rovral In furrow 23 56 53 7.6 3110 0.040 Ib ai/ac + 0.156 Ib ai/ac LSD (0.05) 10 13 12 2.9 382 Number of live seedlings per 25 feet of row; all rows received 125 seed of SureGrow 125 B/RR. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25= no plants. Means compared using Fisher's protected least significant difference test (P=0.05). 26 ALABAMAAGRICULTURALEXPERIMENT STATION 2000 CorrTToN RESEARCH REPORT 27 TABLE 2. EFFICACY OF EXPERIMENTAL IN-FURROW FUNGICIDE COMBINATIONS ON SUREGROW 125 B/RR CorrON SEEDLING DISEASE AT PRATTVILLE EXPERIMENT FIELD Treatment and rate Application Skip Seed cotton formulated product treatment Stand' index 2 lbs/ac April 25 May 10 May 24 May 24 Aug.31 Untreated control - 72 68 67 7.5 1428 Terraclor Super X In furrow 81 86 87 3.3 1440 1.85 oz ai/1000 ft row Quadris 2SC 8.35 fl oz/ac In furrow 83 81 87 3.5 1492 Quadris2SC 5.56 fl oz/ac In furrow 81 81 81 5.5 1392 Ridomil Gold + Terraclor In furrow 79 76 77 5.7 1476 1.0 fl + 7.4 fl oz/1000 ft row Ridomil Gold EC In furrow 77 75 76 6.3 1412 0.075 fl oz/1000 ft row Delta Coat AD 11.75 oz/cwt Seed 81 79 80 3.5 1568 Ridomil G + PCNB In furrow 74 72 73 5.2 1488 0.040 Ib aivac + 1.0 Ib ai/ac Ridomil G + CGA-279202 In furrow 72 66 57 9.3 1533 0.040 Ib aiVac + 0.125 Ib aiVac Ridomil G + CGA-279202 In furrow 77 72 72 8.0 1295 0.040 Ib ai/ac + 0.156 Ib aiVac Ridomil G + Rovral In furrow 74 69 69 7.2 1335 0.040 Ib aVac + 0.156 Ib aiVac LSD (0.05) 15 14 12 4.3 213 'Number of live seedlings per 30 feet of row; all rows received 150 seed of DPL NuCotn 35B. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fishers protected least significant difference test (P=0.05). significantly improved stands compared to the untreated con- trol. However, no treatment produced a significantly lower skip index, indicating a more evenly spaced seedling stand compared to the control at six weeks after planting. Seed cot- ton yields varied 274 pounds per acre in the Delta Coat AD and the Ridomil Gold + PCNB treatments, respectively.The average yield of seed cotton from the ten fungicide-treated plots was 151 pounds greater than the yield of the untreated control. EVALUATION OF SELECTED FUNGICIDES FOR CONTROL OF SEEDLING DISEASE IN ULTRA NARROW Row COTTON Kathy S. McLean, H. L. Campbell, Aaron Palmateer, C. Dale Monks, and Dennis P. Delaney The objective of this research was to evaluate in-furrow fungicides for control of seedling disease of cotton in an Ultra Narrow Row management scheme. A cotton fungicide test was planted April 20 at the Auburn University, E. V. Smith Research Center, in Shorter, Alabama. Fungicides were applied either as seed treatments, in-fur- row granules, or as a broadcast spray. Fungicides applied as a broadcast spray were applied immediately before planting utiliz- ing a backpack CO,-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 complete block design with six replications. Blocks were separated by a 20-foot alley. All plots were maintained throughout the season with stan- dard herbicide, insecticide, and fertility production 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 planting to determine the per- cent seedling loss, stand density, and seedling vigor due to cotton seedling disease. The number of open and closed bolls were counted on August 30 to indicate relative plant maturity. The center 7 feet of each plot was harvested on September 19 with a finger stripper. Cotton seedling disease incidence was moderate. Signifi- cant differences in seedling stand were observed. At two and four weeks after planting, all fungicide treatments increased stand over the control except Ridomil Gold 7 pounds per acre. TSX EC, Rovral 4 F, Ridomil Gold, and Quadris 2SC produced signifi- cantly more uniform stands than the control at six weeks after planting. No significant differences were observed in the percent of open bolls. Seed cotton yields varied 214 pounds per acre for the Delta Coat AD and the TSX EC treatments, respectively, with no significant differences between any treatments. When the seed cotton yields ofthe fungicide treatments were averaged they were not greater than the untreated control. EFFICACY OF EXPERIMENTAL IN-FURROW FUNGICIDE ON DP 458BIRR SEEDLING DISEASE IN ULTRA NARROW Row COTTON Treatment and rate Application Skip Open Seed formulated product treatment Stand index 2 bolls cotton % lbs/ac April 25 May 10 May 23 May 23 Aug. 9 Aug. 24 Untreated control 34 36 42 17.2 45 2020 TSX 18.8G 5.5 lb/ac In-furrow 45 45 43 16.7 55 1906 TSX EC Broadcast 43 42 41 14.8 46 2089 48 fl oz/ac Rovral 4CF 5.2 fl oz/ac Broadcast 43 46 43 12.2 50 2016 Ridomil Gold 7 Ib/ac in-furrow 34 36 42 16.0 49 2090 Ridomil Gold Broadcast 46 46 43 14.7 46 1917 0.1 fl oz/1000 row ft Quadris 2.08 SC Broadcast 43 44 42 15.8 47 2035 6.0 fl oz/ac Delta Coat AD Seed 45 44 41 17.2 55 1875 11.75 fl oz/cwt LSD (0.05) 7 8 6 4.2 16 286 SNumber of live seedlings per 25 feet of row; all rows received 150 seed of DP 458B/RR. 2 Skip index ratings based on 25 feet of row. Ratings correspond to distance of skipped plants; for example: 1 = 1-foot gap; 2 = 2-foot gap; and so on to 25 = no plants. Means compared using Fisher's protected least significant difference test (P=0.05). ALABAMAAGRICULTURALExPERIMENT STATION28 GROWTH REGULATORS DIMILIN AND BORON EFFECTS ON COTTON AT E. V. SMITH Dennis P. Delaney, C. Dale Monks, and Bobby Durbin For a number of years, Dimilin? and boron foliar sprays have been recommended in some states to control insects and promote fruit set in soybeans. This study is intended to investi- gate whether these treatments may also be of value to cotton pro- ducers. Several timings and combinations of Dimilin and boron (Solubor) sprays were applied to Deltapine NuCotn 33B at the E. V. Smith Research Center, Field Crops Unit. BORON AND DIMILIN AS GROWTH REGULATORS FOR BT CoTToN Lint yield Height Nodes Treatment lbs/ac cm total Dimilin 1189 63 24.9 2 oz*4 times, PHS Dimilin 1091 60 23.8 4 oz*4 times, PHS Dimilin 1182 59 24.4 4 oz*2 times, FB Dimilin + Solubor 1150 60 24.1 (4 oz + 1.25 Ib)*2 times, FB Solubor 1136 57 23.7 FB Untreated 1130 61 25.2 LSD (0.10) 70 5 1.4 PHS=Pinhead square; FB=Full bloom. Means followed by same letter do not significantly differ (P=.10, LSD) The experimental design was a randomized complete block with six replications. Plots consisted of four bedded 40 inch rows, 30 feet long. Treatments were Dimilin at 2 or 4 fluid ounces per acre applied starting at pinhead square and repeated four times on a two week schedule; or sprays starting at full bloom and repeated in 14 days of 4 ounces per acre Dimilin, 1.25 pounds per acre Solubor, or 4 ounces per acre Dimilin + 1.25 pounds per acre Solubor. All four rows of each treatment were sprayed with a small plot tractor at 21 gallons per acre or a backpack CO 2 sprayer at 15 gallons per acre. A total of 7.45 inches of irrigation was applied. One broadcast application of Pix at 8 ounces per acre was made at the early bloom stage. Measurements were made of total plant height, plant map- ping for retention and nodes, and percent open bolls. The center two rows of each plot were harvested with a spindle picker, weighed, and a composite sample ginned for lint yields. Several measurements were slightly affected by application of Dimilin and/or boron. Lint yield was slightly increased by 4 ounces per acre of Dimilin applied twice starting at full bloom, vs four applications starting at Pinhead square, while total nodes were decreased compared to the untreated check. Height was slightly decreased by Solubor alone vs Dimilin at 2 ounces per acre four times. Most of these differences were barely above the LSD, and cannot be easily explained. 2000COTTONRESEARCHREPORT 29 ALABAMA AGRICULTURAL EXPERIMENT STATION GROWTH REGULATOR EFFECTS ON COTTON Dennis P. Delaney, C. Dale Monks, Bobby Durbin, and James Bannon Growth regulators are often used in cotton to control veg- etative growth and encourage early fruit set. Each year, trials are conducted to compare established products with new products that are, or soon will be, available to producers. A study was con- ducted at the E. V. Smith Research Center, Field Crops Unit, to compare Pix?, Pix Plus?, and Pix Ultra? to an untreated check treatment. Deltapine NuCotn 33B was planted on 23 May, 2000 in bedded, 40-inch rows. Recommended fertility, weed control, and insect control measures were followed. Plots were irrigated with lateral move system for a total of 7.45 inches during an extremely dry season. The experimental design was a randomized complete block with six replications. Plots were four rows wide and 30 feet long. Treatments were applied using a small plot tractor (21 gallons per acre) or backpack sprayer (15 gallons per acre) at 30 pounds per square inch to all four rows. The first application was at the pin- head square stage with the second applied 14 days later. All treat- ments were applied at 8 fluid ounces per acre of formulated prod- uct, with Activate Plus? added to each treatment. Data were taken on height from cotyledon to terminal and position 1 fruit retention. The center two rows were harvested with a spindle picker and weighed, and a composite sample ginned for lint yield calculations. Due to the extremely dry weather and heat stress this sea- son, few differences were noted (see table.) GROWTH REGULATOR EFFECTS ON COTTON Height Fruit retention' Open bolls Lint yield Treatment Aug. 29 Aug. 29 Oct. 2 Nov. 6 cm % % lbs/ac Untreated check 67 76 76 1026 Pix Plus 49 80 61 957 Pix Ultra 57 81 58 1056 Pix 49 86 64 1015 LSD (0.10) 4 7 10 NS 1 Indicates first position fruit retention. 2 Means followed by same letter do not significantly differ (P=.10, LSD) 30 2000 COTTON RESEARCH REPORT 31 AUTHORS' INDEX Author Page James R. Akridge Jim Baier James Bannon William C. Birdsong Charles Burmester H. L. Campbell Larry M. Curtis J. Doyle Dennis R Delaney David Derrick Bobby Durbin Mickey D. Eubanks Wilson H. Faircloth Barry L. Freeman Kathy Glass William S. Gazaway J. W. Kloepper D. A. Mays Kathy S. McLean C. Dale Monks Don P. Moore S. P. Nightengale Bobby E. Norris E. Z. Nyakatawa Aaron Palmateer Michael G. Patterson Randy Raper K. C. Reddy M. S. Reddy Ron Smith Eric Schwab Larry W. Wells 2-3,13,14-15 8 1-2,30 8 1, 8-9 19-20,20-22,22-24,24-25, 26-27,28 8 5,6 1-2,12,28,29,30 1 1-2, 12,29,30 4 17,17-18 11 1-2 2-3, 13,14-15,16 5,6 7 2-3,13, 19-20,20-22,22-24, 24-25,26-27,28 1-2,12,28,29,30 12,14-15,20-22,22-24, 24-25,26-27 5,6 19-20,20-22,22-24,24-25, 26-27 7 2-3,13,19-20,20-22,22-24, 24-25,26-27,28 17,17-18 8-9 7 5,6 10 8-9 20-22,22-24 2000COTTONRESEARCHREPORT 31