PEANUT DISEASE CONTROL FIELD TRIALS 2002 1 Entomology and Plant Pathology Departmental Series No. 6 May 2003 Alabama Agricultural Experiment Station John Jensen, Interim Director Auburn University Auburn, Alabama Peanut Disease Control Field Trials, 2002 Printed in cooperation with the Alabama Cooperative Extension System (Alabama A&M University and Auburn University) 2 ALABAMA AGRICULTURAL EXPERIMENT STATION Table of Contents Introduction .................................................................................................................................................. 3 Comparison of Moncut 70DF with Abound 2SC and Folicur 3.6F for the Control of Foliar and Soil-Borne Diseases ........................................................................................................ 5 Impact of In-Furrow and Foliar Applications of Selected Fungicides on the Occurrence of Leaf Spot Diseases and White Mold in Peanut ................................................................................ 7 Comparison of the Efficacy of Experimental and Registered Fungicides for the Control of Leaf Spot Diseases and Southern Stem Rot .................................................................................... 9 Determination of the Impact of In-Furrow Applications of Selected Fungicides on Disease Control and Peanut Yield .................................................................................................. 11 Evaluation of Echo 720 and Headline 2.09EC for the Control of Foliar and Soil-Borne Diseases of Peanut ........................................................................................................................... 13 Comparison of New Fungicides for the Control of Foliar and Soil-Borne Diseases of Peanut ...................... 15 Evaluation of Moncut 70DF for Control of Foliar and Soil-Borne Diseases of Peanut .................................. 17 Evaluation of In-Furrow and Foliar Applications of Abound 2.08SC for the Control of Foliar and Soil-Borne Diseases of Peanuts .................................................................................... 19 Control of Leaf Spot Diseases and White Mold of Peanut Using Headline 2.09EC ..................................... 21 Recommended Fungicide Programs for the Control of Diseases on Dryland Peanut ................................... 23 Recommended Fungicide Programs for the Control of Diseases on Irrigated Peanut .................................. 26 Calendar Schedule and AU-Pnut Advisory Compared in an Irrigated Peanut Production System ................ 28 Evaluation of Abound 2SC in Calendar and AU-Pnut Leaf Spot Advisory Programs ................................... 30 Impact of Temik 15G Application Rate on the Control of Peanut Root-Knot Nematode and the Yield of Selected Commercial Peanut Cultivars ..................................................................... 32 Impact of Selected Fungicide Programs on Disease Control on Commercial Peanut Lines .......................... 35 Comparison of Calendar Schedule and AU-Pnut Advisory for Disease Control in a Dryland Peanut Production System ............................................................................................. 37 Reaction of Commercial Peanut Lines to Diseases and Yield Response, 2002 PVT Test ............................ 40 Severity of Leaf Spot Diseases, Southern Stem Rot, and Tomato Spotted Wilt on Experimental Peanut Lines, UPPT 2002 ....................................................................................... 42 The information contained herein is available to all persons regardless of race, color, sex, or national origin. Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability. PEANUT DISEASE CONTROL FIELD TRIALS 2002 3 Peanut Disease Control Field Trials, 2002 A. K. Hagan, K. L. Bowen, H. L. Campbell, and M. E. Rivas-Davila1 Introduction Fungicides, cultural practices, and resistant cultivars are available for the control of damaging diseases and nematode pests that can limit peanut yield. A management program that incorporates these practices can enhance the control of diseases and nematode pests and can increase crop yield and profit potential. In order to provide timely information concerning disease management practices, Alabama Agricultural Experimental Station personnel conducted foliar and soil-borne disease, as well as nematode control trials at the Wiregrass Research and Extension Center (WGREC) in Headland, Alabama, and at the Gulf Coast Research Center (GCREC) in Fairhope, Alabama. This report summarizes the results of those trials. During the 2002 production season, temperatures were near normal at the WGREC and GCREC (see Figure 1). At the WGREC, monthly rainfall totals for June, July, August, and September were below historical average, and yields on the dryland peanut trials were depressed by the below-average rainfall totals, particularly by Figure 1. Daily minimum and maximum temperature (oF), April to October 2002. 1 Hagan and Bowen are Professors and Campbell and Rivas-Davila are Research Associates in the Auburn University Department of Entomology and Plant Pathology. 4 ALABAMA AGRICULTURAL EXPERIMENT STATION the dry weather in late August and early September (see Figure 2). The reduced rainfall also suppressed the development of leaf spot diseases in the dryland and to some extend in the irrigated peanuts trials. In contrast, at the GCREC rainfall totals during much of the growing season were well above the historical average for that location. As a result, late leaf spot and peanut rust pressure was exceptionally high. The heavy rains did not reduce yield of the early harvested studies but some of the later planted studies, which could not be dug or harvested on time, were lost. Figure 2. Daily precipitation (inches) April to October 2002. PEANUT DISEASE CONTROL FIELD TRIALS 2002 5 Comparison of Moncut 70DF with Abound 2SC and Folicur 3.6F for the Control of Foliar and Soil-Borne Diseases Objective: To assess the efficacy of candidate and registered fungicides applied under a 14-day spray schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 20, 2002 Experimental Design: Randomized complete block with six replications. Plot size was six 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 7, August 19, and September 7. Application of Treatments: Fungicide treatments were applied with a tractor-mounted boom sprayer with TX8 hollow cone nozzles calibrated to deliver 15 gallons per acre. Applications were made as follows: 1= June 20, 2= July 3, 3= July 17, 4= July 31, 5= August 14, 6= August 28, and 7= September 1. Disease Assessment: Early and late leaf spot were visually rated on September 18 using the Florida leaf spot scoring system. Southern stem rot incidence was assessed as the number of disease loci on October 1 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Rhizoctonia limb rot was assessed on October 1 using a 1-5 scale. Harvest: Peanut were dug on October 1 and yields were reported at 10.7% moisture. 6 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF APPLICATION OF M ONCUT 70DF WITH ABOUND 2SC AND FOLICUR 3.6F FOR THE CONTROL OF FOLIAR AND SOIL-BORNE DISEASES, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Untreated control Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb + Moncut 70DF 0.54 lb Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 0.54 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 0.89 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Headline 2.09EC 0.4 pt Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Headline 2.09EC 0.4 pt Headline 2.09EC 0.89 lb + Moncut 70DF 0.4 pt LSD (P = 0.05) 1 Application timing — 1-7 1,3,5,6,7 2,4 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2,7 3,5 4,6 1,2,4,6,7 3 5 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2,4,6,7 3,5 1,7 2,4,6 3,5 1,6,7 2,3,4,5 3,5 —————Disease ratings————— Leaf Southern Rhizoctonia spot 1 stem rot2 limb rot3 8.7 a 3.5 cd 4.0 c 3.7 c 3.8 c 5.0 b 29.8 a 14.3 b 10.7 bc 9.8 bc 14.5 b 14.5 b — Yield lbs/ac 1121 f 1.7 ab 4029 e 1.7 ab 4735 cd 1.8 a 1.8 a 1.8 a 4344 de 4312 de 4211 e 3.7 c 13.8 b 1.8 a 4360 de 3.5 cd 4.0 c 3.7 c 2.7 e 4.3 de 9.0 cd 4.7 de 4.5 de 1.7 ab 5203 bc 1.8 a 4921 bc 1.7 ab 5288 b 1.2 bc 5957 a 3.0 de 4.2 e 1.0 c 5397 b 0.7 4.7 0.5 521 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. 3 Rhizoctonia limb rot was assessed on a 1-5 scale (1= 0-10% damage of a given row length, 2= 11-25%, 3= 2650%, 4= 51-75%, and 5= >75%). PEANUT DISEASE CONTROL FIELD TRIALS 2002 7 Impact of In-Furrow and Foliar Applications of Selected Fungicides on the Occurrence of Leaf Spot Diseases and White Mold in Peanut Objective: To assess the efficacy of candidate and registered fungicides in furrow and under 14-day schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 20, 2002 Experimental Design: Randomized complete block with six replications. Plot size was four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 7, August 19, and September 7. Application of Treatments: In-furrow applications were made at planting at 5 gallons per acre using a tractormounted CO2 sprayer with 8001 nozzles. Foliar fungicide were applied as a full canopy spray at a calibrated volume of 15 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made at two-week intervals: 1= June 20, 2= July 3, 3= July 17, 4= July 31, 5= August 14, 6= August 28, and 7= September 11. Disease Assessment: Early and late leaf spot were visually rated on September 18 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 1 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots were harvested on October 7 and yields were reported at 10.7% moisture. 8 ALABAMA AGRICULTURAL EXPERIMENT STATION ON THE EFFECT OF IN-FURROW AND FOLIAR APPLICATIONS OF SELECTED FUNGICIDES OCCURRENCE OF LEAF SPOT DISEASES AND SOUTHERN STEM ROT MOLD IN PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Application timing — 1-7 1,2,4 3,5,6,7 1,2,4 3,5 6,7 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 1,6,7 2,3,4,5 1,2,4,6,7 3,5 in-furrow 1,2,4,6,7 3,5 in-furrow 1,2,4,6,7 3,5 ——Disease ratings—— Leaf Southern spot 1 stem rot2 8.7 a 4.5 bc 3.2 d 3.3 d 29.3 a 17.3 bc 18.0 b 11.5 de Yield lbs/ac 1383 g 3037 f 3138 ef 3610 cd Treatment and rate per acre Untreated control Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz + Ridomil Gold 4EC 2 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz Tilt 3.6EC 2.0 fl oz+ Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Abound 2SC 6.0 fl oz + Ridomil Gold 4EC 2.0 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Bravo 720 1.5 pt Folicur 3.6F 7.2 fl oz Bravo 720 1.5 pt Bravo 720 1.5 pt + Moncut 70DF 1.1 lb Moncut 70DF 7.1 oz Bravo 720 1.5 pt Bravo 720 1.5 pt + Moncut 70DF 1.1 lb Botran 75W 12 oz Bravo 720 1.5 pt Bravo 720 1.5 pt + Moncut 70DF 1.1 lb LSD (P = 0.05) 1 3.3 d 12.3 c-e 3791 bc 3.0 d 11.8 de 3759 b-d 3.2 d 11.3 de 4066 ab 3.5 d 12.0 de 3578 c-e 3.5 d 8.7 ef 3771 b-d 5.0 b 4.2 c 4.5 bc 15.5 b-d 5.2 fg 3.3 g 3336 d-f 4106 ab 4122 ab 4.5 bc 4.0 fg 4255 a 0.6 5.1 445 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. 3 Rhizoctonia limb rot was assessed on a 1-5 scale (1= 0-10% damage of a given row length, 2= 11-25%, 3= 26-50%, 4= 51-75%, and 5= >75%). PEANUT DISEASE CONTROL FIELD TRIALS 2002 9 Comparison of the Efficacy of Experimental and Registered Fungicides for the Control of Leaf Spot Diseases and Southern Stem Rot Objective: To assess the efficacy of candidate and registered fungicides applied under a 14-day spray schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 23, 2002 Experimental Design: Randomized complete block with six replications. Plot size was six 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Prowl 3 pints + Strongarm 0.45 ounce per acre (May 7). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 10, August 24, and September 12. Application of Treatments: Foliar fungicide applications were made at two-week intervals: 1= June 24, 2= July 8, 3= July 22, 4= August 5, 5= August 19, 6= September 3, and 7= September 17 and were applied as a full canopy spray at a calibrated volume of 15 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Disease Assessment: Early and late leaf spot were visually rated on September 11 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 4 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Peanut were dug on October 4 and yields were reported at 10.4% moisture. 10 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF CANDIDATE AND REGISTERED FUNGICIDES FOR THE CONTROL OF LEAF SPOT DISEASES AND SOUTHERN STEM ROT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Untreated control Bravo 720 1.5 pt Bravo 720 1.5 pt AMS21619A 480SC 5.0 fl oz Bravo 720 1.5 pt AMS21619A 480SC 5.7 fl oz Bravo 720 1.5 pt Folicur 3.6F 7.2 fl oz USF2010 3.5 fl oz USF2010 3.5 fl oz Folicur 3.6F 7.2 fl oz Bravo 720 1.5 pt Stratego 7.0 fl oz Bravo 720 1.5 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Bravo 720 1.5 pt + Moncut 70DF 1.1 lb Bravo 720 1.5 pt Folicur 3.6F 7.2 fl oz Headline 2.09EC 12.0 fl oz Bravo 720 1.5 pt Stratego 7.0 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Bravo 720 1.5 pt LSD (P = 0.05) 1 Application timing — 1-7 1,2,7 3,4,5,6 1,2,7 3,4,5,6 1,2,7 3,4,5,6 1-7 1,2 3,4,5,6 7 1-7 1,2,4,6,7 3,5 1,2,4,6,7 3,5 1,7 2,4,6 3,5 1,2,7 3,4,5,6 1,2,4 3,5,6,7 ——Disease ratings—— Leaf Southern spot 1 stem rot2 7.0 a 3.2 e-g 3.0 f-h 2.7 gh 5.0 b 3.8 cd 3.3 d-f 32.2 a 13.2 bc 12.2 bc 9.5 b-d 12.2 bc 15.5 b 13.0 bc Yield lbs/ac 1303 c 3997 ab 4050 ab 4106 ab 3904 ab 3804 ab 4061 ab 3.3 d-f 3.5 c-f 4.0 c 2.5 h 12.0 bc 10.3 bc 4.2 d 9.3 cd 3930 ab 4384 a 4525 a 4375 a 3.0 f-h 3.7 c-e 0.5 9.7 b-d 12.5 bc 6.1 3533 b 3876 ab 750 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 11 Determination of the Impact of In-Furrow Applications of Selected Fungicides on Disease Control and Peanut Yield Objective: To assess the efficacy of candidate and registered fungicides in-furrow and under 14-day schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 16, 2002 Experimental Design: Randomized complete block with six replications. Plot size was four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart per acre (May 16). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on July 11, August 12, and August 25. Application of Treatments: In-furrow applications were made at planting at 5 gallons per acre using a tractormounted CO2 sprayer with 8001 nozzles. Foliar fungicide were applied as a full canopy spray at a calibrated volume of 15 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made at two-week intervals: 1= June 20, 2= July 3, 3= July 17, 4= July 31, 5= August 14, 6= August 28, and 7= September 11. Disease Assessment: Early and late leaf spot were visually rated on September 11 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 7 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots were harvested on October 7 and yields were reported at 10.7% moisture. 12 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF IN-FURROW APPLICATIONS OF SELECTED FUNGICIDES ON DISEASE CONTROL AND PEANUT YIELD,WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Untreated control Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb AMS21619A 480SC 5.7 fl oz AMS21619A 480SC 5.7 fl oz Bravo Ultrex 1.4 lb AMS21619A 480SC 5.7 fl oz Bravo Ultrex 1.4 lb AMS21619A 480SC 5.7 fl oz Terraclor 2E 48 fl oz Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz Terraclor 2E 48 fl oz Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Terraclor 2E 96 fl oz Bravo Ultrex 1.4 lb Terraclor 4F 48 fl oz Bravo Ultrex 1.4 lb Procure 4 oz Bravo Ultrex 1.4 lb Procure 4 oz Abound 2SC 6 fl oz Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz LSD (P = 0.05) 1 Application timing — 1-7 1,2,7 3,4,5,6 1,2,7 3,4,5,6 in-furrow 1-7 in-furrow 1,2,7 3,4,5,6 in-furrow 1,2,4,6,7 3,5 in-furrow 1,2,7 3,4,5,6 in-furrow 1-7 in-furrow 1-7 in-furrow 1,2,4,6,7 3,5 in-furrow 1,2,4,6,7 3,5 ——Disease ratings—— Leaf Southern spot 1 stem rot2 6.5 a 3.7 bc 3.7 bc 2.5 ef 3.2 cd 2.0 f 10.5 a 7.0 a-c 6.8 a-c 6.7 a-c 4.2 bc 3.7 c Yield lbs/ac 1533 e 1686 de 2053 b-e 2444 ab 2678 a 2481 ab 3.0 de 6.5 a-c 2202 a-d 3.5 b-d 6.7 a-c 2037 b-e 3.5 b-d 3.8 b 3.5 b-d 6.0 bc 8.2 ab 7.0 a-c 2267 a-c 1807 c-e 2005 b-e 3.7 bc 4.5 bc 2497 ab 0.6 4.1 523 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 13 Evaluation of Echo 720 and Headline 2.09EC for the Control of Foliar and Soil-Borne Diseases of Peanut Objective: To assess the efficacy of candidate and registered fungicides under 14-day schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 23, 2002 Experimental Design: Randomized complete block with six replications. Plot size was six 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Prowl 3 pints per acre + Strongarm 0.45 ounce per acre (May 7). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 10, August 24, and September 12. Application of Treatments: Fungicides were applied as a full canopy spray at a calibrated volume of 15 gallons per acre using a six-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made at two-week intervals: 1= June 24, 2= July 1, 3= July 22, 4= August 5, 5= August 19, 6= September 3, and 7=September 17. Disease Assessment: Early and late leaf spot were visually rated on September 23 using the Florida leaf spot scoring system. Southern stem rot loci incidence was assessed as the number of disease loci per 60 feet of row on October 4 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots were harvested on October 9 and yields were reported at 10% moisture. 14 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF ECHO 720 AND HEADLINE 2.09EC FOR THE CONTROL OF FOLIAR AND SOIL-BORNE DISEASES OF PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Untreated control Echo 720 1.5 pts Echo 720 1.0 pt + PropiMax EC 2 fl oz Echo 720 1.0 pt + Propimax EC 2 fl oz Echo 720 1.0 pt + PropiMax EC 2 fl oz Abound 2SC 18.5 fl oz Echo 720 1.5 pt Echo 720 1.5 pt Folicur 3.6F 7.2 fl oz Echo 720 1.5 pt Echo 720 1.5 pt + Moncut 70DF 1.1 lb Headline 6 fl oz Folicur 3.6F 7.2 fl oz Echo 720 1.5 pt Headline 9 fl oz Folicur 3.6F 7.2 fl oz Headline 12 fl oz Echo 720 1.5 pt Headline 9 fl oz Headline 12 fl oz Folicur 3.6F 7.2 fl oz Echo 720 1.5 pt Headline 9 fl oz Folicur 3.6F 7.2 fl oz Headline 12 fl oz Echo 720 1.5 pt Headline 6 fl oz Echo 720 1.5 pt Abound 2SC 18.5 fl oz LSD (P = 0.05) 1 Application timing Leaf spot1 8.5 a Southern stem rot2 34.4 a 14.0 b-d 16.7 b 11.0 c-f 13.0 b-e Yield lbs/ac 1297 d 3872 c 3908 c 4239 a-c 4392 a-c 1-7 1-7 AU Pnut advisory 1,2,4 3,5 6,7 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2 3,4,5,6 7 Week betw.1st two sprays 3,5,6 4 7 Week betw.1st two sprays 3 4,5,6 7 Week betw.1st two sprays 3,4,5 6 1,2,4,6,7 3,5 1,2,4,6,7 3,5 5.2 b 4.2 d-f 4.2 d-f 3.7 fg 4.5 d-f 4.8 bc 3.3 g 13.8 b-d 6.5 f 14.5 bc 4191 bc 4574 ab 4146 bc 4.5 cd 8.5 ef 4521 a-c 3.3 g 7.5 f 4880 a 5.3 b 9.3 d-f 4191 bc 3.8 e-g 4.3 c-e 0.6 9.8 c-f 11.3 c-f 5.2 4179 bc 4638 ab 653 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 15 Comparison of New Fungicides for the Control of Foliar and Soil-Borne Diseases of Peanut Objective: To assess the efficacy of candidate and registered fungicides applied under a 14-day spray schedule for the control of foliar and soil-borne diseases in peanut. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 23, 2002 Experimental Design: Randomized complete block with six replications. Plot size was six 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Prowl 3 pints + Strongarm 0.45 ounce per acre (May 7). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 10, August 24, and September 12. Application of Treatments: Foliar fungicide were applied as a full canopy spray at a calibrated volume of 15 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made at two-week intervals: 1= June 24, 2=July 8, 3= July 22, 4= August 5, 5= August 19, 6= September 3, and 7= September 17. Disease Assessment: Early and late leaf spot were rated simultaneously on September 23 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 4 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots were harvested on October 9 and yields were reported at 10.4% moisture. 16 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF NEW FUNGICIDES FOR THE CONTROL OF FOLIAR AND SOIL-BORNE DISEASES OF PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Untreated control Serenade 4 lb Serenade 8 lb Serenade 2 lb + Kocide 2000 2 lb Serenade 2 lb + Kocide DF 2 lb Folicur 3.6F 0.45 pt Equus 720 1.5 pt Artisan 3.6SE 32 fl oz Equus 720 1.5 pt NAI-301 45 fl oz Equus 720 1.5 pt NAI-008 32 fl oz Equus 720 1.5 pt Folicur 3.6F 7.2 fl oz Equus 720 1.5 pt Abound 2SC 18.5 fl oz Equus 720 1.5 pt Equus 720 1.5 pt + Moncut 70DF 1.1 lb Equus 720 1.5 pt LSD (P = 0.05) 1 Application timing — 1-7 1-7 1-7 1,3,5,7 2,4,6 1,3,5,6,7 2,4 1,5,6,7 2,3,4 1,3,5,6,7 2,4 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2,4,6,7 3,5 1-7 ——Disease ratings—— Leaf Southern spot 1 stem rot2 8.7 a 6.7 b 6.8 b 5.2 c 4.2 de 3.5 ef 4.2 de 3.2 f 4.2 de 4.0 de 4.3 d 4.3 d 0.7 26.5 a 17.8 bc 23.5 ab 16.3 cd 11.0 d-f 3.3 g 4.7 g 6.3 fg 13.0 c-e 9.2 e-g 5.2 fg 9.2 e-g 6.0 Yield lbs/ac 1457 f 2073 e 1751 ef 2759 d 3332 c 4441 a 3985 ab 4166 a 3537 bc 4316 a 3969 ab 4199 a 513 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 17 Evaluation of Moncut 70DF for Control of Foliar and Soil-Borne Diseases of Peanut Objective: To assess the efficacy of candidate and registered fungicides applied under a 14-day spray schedule for the control of foliar and soil-borne diseases in peanut. Location: Gulf Coast Research and Extension Center, Fairhope, AL Soil Type: Malbis fine sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 6, 2002 Experimental Design: Randomized complete block with six replications. Plot size was four 30-foot rows spaced 38 inches apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton-cotton rotation. Cultural Practices: Herbicides: Prowl 2 pints per acre (May 6), Gramoxone Max 6 ounces + Storm 1 pint per acre + Activate 1 pint per 50 gallons (May 23), Select 13 ounces + Prime Oil 1 pint per acre (June 7), Storm 1.5 pt + Butyrac175 1 pint per acre + Activate 1 pint per 50 gallons (June 12), and Cadre 1 ounce + Butyrac 175 12 ounces per acre + Windcheck 2 quarts per100 gallons (July 1). Fungicides: See table. Insecticides: Temik 5-6 pounds per acre (May 6). Nematicides: None. Irrigation: None. Application of Treatments: Fungicides were applied as a full canopy spray at a calibrated volume of 20 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made as follows: 1= June 19, 2= July 1, 3= July 15, 4= July 29, 5= August 12, 6= August 27, and 7= September 11. Disease Assessment: Early and leaf spot and rust were visually rated on September 20 using the Florida leaf spot scoring system and the ICRISAT rust rating scale, respectively. Counts of southern stem rot loci were made on September 20 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Peanut were dug September 20 and harvested until October 8 due environmental conditions. Yields were reported at 10% moisture. 18 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF MONCUT 70DF FOR THE CONTROL OF FOLIAR AND SOIL-BORNE DISEASES OF PEANUT, GULF COAST RESEARCH AND EXTENSION CENTER, FAIRHOPE, AL, 2002 Treatment and rate per acre Untreated control Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb + Moncut 70DF 0.54 lb Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 0.54 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 0.89 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Headline 2.09EC 0.4 pt Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb Bravo Ultrex 1.4 lb Headline 2.09EC 0.4 pt Headline 2.09EC 0.89 lb + Moncut 70DF 0.4 pt LSD (P = 0.05) 1 Application timing — 1-7 1-7 2,4 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2,7 3,5 4,6 1,2,4,6,7 3 5 1,2,7 3,4,5,6 1,2,4,6,7 3,5 1,2,4,6,7 3,5 1,7 2,4,6 3,5 1,6,7 2,4 3,5 —————Disease ratings————— Leaf Southern spot 1 Rust2 stem rot3 4.2 a 2.8 bc 3.0 b 3.0 b 2.8 bc 2.8 bc 6.7 a 4.3 b 3.5 b-d 2.8 d 4.3 b 3.0 cd 12.3 a Yield lbs/ac 2111 d 10.0 ab 3464 a-c 4.2 d 9.0 bc 3020 c 3686 a-c 6.8 b-d 3173 bc 4.5 d 4347 a 2.7 bc 3.8 b-d 7.2 b-d 3732 a-c 2.5 bc 2.3 c 2.5 bc 3.0 b 3.8 b-d 3.0 cd 3.0 cd 3.3 b-d 4.2 d 5.7 d 4.8 d 5.8 cd 3751 a-c 3804 a-c 3778 a-c 4011 ab 2.7 bc 4.0 bc 6.7 cd 3449 bc 0.6 1.1 3.3 898 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Rust rated using the ICRISAT 1-9 rating scale ( 1= no disease,... 9 = 80 100% of leaves diseased or wilted). 3 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 19 Evaluation of In-Furrow and Foliar Applications of Abound 2.08SC for the Control of Foliar and Soil-Borne Diseases of Peanuts Objective: To assess the efficacy of candidate and registered fungicides in-furrow and under 14-day schedule for the control of foliar and soil-borne diseases in peanut. Location: Gulf Coast Research and Extension Center, Fairhope, AL Soil Type: Malbis fine sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: April 25, 2002 Experimental Design: Randomized complete block with six replications. Plot size was four 30-foot rows spaced 38 inches apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton-cotton rotation. Cultural Practices: Herbicides: Prowl 3 pints per acre (April 25), Gramoxone Max 6 ounces + Storm 1 pint per acre + Activate1 pint per 50 gallons (May 6 and May 23), Select 13 ounces + Prime Oil 1 pint per acre (June 7), Storm 1.5 pint + Butyrac 175 1 pint per acre + Activate 1 pint per 50 gallons (June 12), and Cadre 1 ounce +Butyrac 175 12 ounces per acre + Windcheck 2 quarts per 100 gallons (July 1). Fungicides: See table. Insecticides: Temik 5-6 pounds per acre (April 25). Nematicides: None. Irrigation: None. Application of Treatments: In furrow applications were made at planting using a tractor-mounted CO2 sprayer with 8001 nozzles. Foliar fungicides were applied as a full canopy spray at a calibrated volume of 20 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made as follows: 1= June 12, 2= Ju1 1, 3= July 9, 4= July 22, 5= August 8, 6= August 19, and 7= September 3. Disease Assessment: Early and late leaf spot and rust were visually rated on September 11 using the Florida leaf spot scoring system and the ICRISAT rust rating scale, respectively. Counts of southern stem rot loci were made on September 12 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots were harvested on September 19. Yields were reported at 10% moisture. 20 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF IN-FURROW AND FOLIAR APPLICATIONS OF ABOUND 2.08SC ON FOLIAR AND SOIL-BORNE DISEASES OF PEANUT, GULF COAST RESEARCH AND EXTENSION CENTER, FAIRHOPE, AL, 2002 Treatment and rate per acre Untreated control Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz + Ridomil Gold 4EC 2 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 18.5 fl oz Bravo 720 1.5 pt Abound 2SC 6 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Abound 2SC 6.0 fl oz + Ridomil Gold 4EC 2.0 fl oz Tilt 3.6EC 2.0 fl oz + Bravo 720 1.0 pt Abound 2SC 12.3 fl oz Bravo 720 1.5 pt Bravo 720 1.5 pt Folicur 3.6F 7.2 fl oz Bravo 720 1.5 pt Bravo 720 1.5 pt + Moncut 70DF 1.1 lb LSD (P = 0.05) 1 ——————Disease ratings—————— Application Leaf Soouthern timing spot 1 Rust2 stem rot3 4.8 a 1-7 1,2,4 3,5,6,7 1,2,4 3,5 6,7 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 in-furrow 1,2,4 3,5 6,7 1,6,7 2,3,4,5 1,2,4,6,7 3,5 2.5 d 2.8 bcd 2.8 bcd 6.7 a 3.2 b 3.2 b 2.8 b 9.2 a 4.8 bc 7.2 ab 4.5 bc Yield lbs/ac 4161 b 5036 a 5013 a 5111 a 2.7 cd 3.2 b 7.7 ab 4848 a 3.2 b 3.0 b 5.8 abc 5298 a 3.0 bc 2.5 b 6.3 abc 5138 a 3.0 bc 2.7 b 4.7 bc 4973 a 2.8 bcd 2.8 b 5.5 abc 5159 a 3.0 bc 2.7 cd 0.5 2.8 b 2.8 b 0.8 6.0 abc 4720 ab 3.0 c 3.8 5181 a 801.6 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Rust rated using the ICRISAT 1-9 rating scale ( 1= no disease,... 9 = 80 100% of leaves diseased or wilted). 3 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 21 Control of Leaf Spot Diseases and White Mold of Peanut Using Headline 2.09EC Objective: To assess the efficacy of Headline 2.09EC applied under different spray schedules and rates for the control of foliar and soil-borne diseases in peanut. Location: Gulf Coast Research and Extension Center, Fairhope, AL Soil Type: Malbis fine sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 6, 2002 Experimental Design: Randomized complete block with six replications. Plot size was four 30-foot rows spaced 38 inches apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton-cotton rotation. Cultural Practices: Herbicides: Prowl 2 pints per acre (May 6), Gramoxone Max 6 ounces + Storm 1 pint per acre + Activate 1 pint per 50 gallons (May 23 and June 7), and Cadre 1 oz + Butyrac 175 12 ounces per acre + Windcheck 2 quarts per 100 gallons (July 1). Fungicides: See table. Insecticides: Temik 5-6 pounds per acre (May 6). Nematicides: None. Irrigation: None. Application of Treatments: Foliar fungicides were applied as a full canopy spray at a calibrated volume of 20 gallons per acre using a four-row tractor-mounted boom sprayer with TX8 nozzles. Applications were made at two-week intervals: 1= June 19, 2= July 1, 3= July 15, 4= July 31, 5= August 12, 6= August 27, and 7= September 11. Disease Assessment: Early and late leaf spot were rated simultaneously using the Florida leaf spot scoring system. Peanut rust was assessed using the ICRISAT rust rating scale. Evaluation of leaf spot and rust were made on September 12. Counts of southern stem rot loci were made on September 20 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Peanuts were dug on September 20 and harvested until on October 8 due environmental conditions. Yields were reported at 10% moisture. 22 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF HEADLINE 2.09EC ON THE CONTROL OF LEAF SPOT DISEASES AND WHITE MOLD OF PEANUT, GULF COAST RESEARCH AND EXTENSION CENTER, FAIRHOPE, AL, 2002 Treatment and rate per acre Untreated control Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 7.2 fl oz Headline 2.09EC 6 fl oz Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb Headline 2.09EC 9 fl oz Folicur 3.6F 7.2 fl oz Headline 2.09EC 12 fl oz Bravo Ultrex 1.4 lb Headline 2.09EC 9 fl oz Headline 2.09EC 12 fl oz Folicur 3.6F 7.2 fl oz Bravo Ultrex 1.4 lb Headline 2.09EC 9 fl oz Folicur 3.6F 7.2 fl oz Headline 2.09EC 12 fl oz Bravo Ultrex 1.4 lb Headline 2.09EC 6 fl oz Bravo Ultrex 1.4 lb Abound 2SC 18.5 fl oz ——————Disease ratings—————— Application Leaf Southern timing spot 1 Rust2 stem rot3 — 1-7 1,2,7 3,4,5,6 1,2 3,4,5,6 7 Week betw.1st two sprays 3,5,6 4 7 4.7 a 2.3 b 2.7 b 2.8 b 6.5 a 3.2 bc 2.8 c 3.3 bc 11.8 a 5.7 bc 4.0 bc 3.5 c Yield lbs/ac 2710 d 3781 a-c 4542 a 3579 bc 2.7 b 3.2 bc 5.2 c 4137 ab Week betw. 1st two sprays 2.7 b 3 4,5,6 7 Week betw. 1st two sprays 2.7 b 3,4,5 6 1,2,4,6,7 3,5 1,2,4,6,7 3,5 2.5 b 2.7 b 2.8 b 3.0 b 0.7 3.0 bc 3.8 c 3881 a-c 2.8 c 4.0 c 4416 ab 3.0 bc 2.8 bc 3.8 b 3.3 bc 0.9 8.0 b 4.2 c 4.7 c 6.2 bc 2.7 4003 a-c 3728 a-c 4003 a-c 3269 cd 849 Bravo Ultrex 1.4 lb 1,2,4,6,7 Bravo Ultrex 1.4 lb + Moncut 70DF 1.1 lb 3,5 Bravo Ultrex 1.4 lb Stratego 14.0 fl oz LSD (P = 0.05) 1 1,2,5,6,7 3,4 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Rust rated using the ICRISAT 1-9 rating scale ( 1= no disease,... 9 = 80 100% of leaves diseased or wilted). 3 Southern stem rot lesions taken at plot inversion are expressed as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 23 Recommended Fungicide Programs for the Control of Diseases on Dryland Peanut Objective: To compare the effectiveness of recommended fungicides programs for the control of leaf spot diseases and southern stem rot on selected cultivars of peanut in a dryland production system. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: C-99R, Georgia Green, and Virugard Planting: Date: May 22, 2002 Experimental Design: Split plot on a randomized complete block design with four replications. Peanuts line were whole plots and fungicide programs were subplots. Subplots consisted of four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Site was cropped to switch grass for the previous three years. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (May 7). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: None. Application of Treatments: Fungicides were applied with a tractor-mounted boom sprayer with three TX-8 hollow cone nozzles per row calibrated to deliver approximately 15 gallons per acre of spray volume. Applications were made as follows: 1= June 25, 2= July 9, 3= July 23, 4= August 6, 5= August 21, 6= September 3, and 7= September 17 Disease Assessment: Early and late leaf spot were rated together using the Florida peanut leaf spot scoring system on September 18 on Virugard, September 30 on Georgia Green, and October 17 on C-99R. Counts of southern stem rot loci were made on September 24 on Virugard, October 4 on Georgia Green, and October 17 on C-99R immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots planted with Virugard were dug on September 24; Georgia Green, October 4; and C-99R, October 17. Plots were harvested on September 30, October 8, and October 23, respectively. Yields were reported at 10.2% moisture. 24 ALABAMA AGRICULTURAL EXPERIMENT STATION ON TABLE 1. EFFECT OF RECOMMENDED FUNGICIDE PROGRAMS FOR THE CONTROL OF DISEASES DRYLAND PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.5 pt Folicur 3.6F 0.45pt Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 1.4 lb Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 0.4 lb Bravo Ultrex 1.4 pt Bravo Ultrex 1.4 pt Abound 2SC 1.2 pt Bravo Ultrex 1.5 pt Abound 2SC 0.75 pt Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Headline 6.4 fl oz Application timing 1,2,7 3-6 1,2,4-7 3 1,2,7 3-6 1-7 1,2,4,6,7 3,5 1,2,6,7 3,4 5 1,2,6,7 3,4,5 1,2,7 3-6 1,2,4-7 3 1,2,7 3-6 1-7 1,2,4,6,7 3,5 1,2,6,7 3,4 5 1,2,6,7 3,4,5 1,2,7 3-6 1,2,4-7 3 1,2,7 3-6 Leaf spot rating1 1 d 1.5 b-d 1.25 cd 1.25 cd 1.75 bc 1.25 cd Cultivar Virugard 1.25 cd 1.75 bc 2.75 a 2.75 a 2.75 a 1.75 bc 2 b C-99R Bravo Ultrex 1.5 pt Folicur 3.6F 0.45pt Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 1.4 lb Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 0.4 lb Bravo Ultrex 1.4 pt Bravo Ultrex 1.4 pt Abound 2SC 1.2 pt Bravo Ultrex 1.5 pt Abound 2SC 0.75 pt Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Headline 6.4 fl oz 1.25 cd 2.75 a 2 b 2.75 a continued Georgia Green Bravo Ultrex 1.5 pt Folicur 3.6F 0.45p Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 1.4 lb Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 0.4 lb PEANUT DISEASE CONTROL FIELD TRIALS 2002 25 TABLE 1, CONTINUED. EFFECT OF RECOMMENDED FUNGICIDE PROGRAMS FOR THE CONTROL OF DISEASES ON DRYLAND PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Cultivar Treatment and rate per acre Bravo Ultrex 1.4 pt Bravo Ultrex 1.4 pt Abound 2SC 1.2 pt Bravo Ultrex 1.5 pt Abound 2SC 0.75 pt Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Headline 6.4 fl oz LSD (P = 0.05) 1 Application timing 1-7 1,2,4,6,7 3,5 1,2,6,7 3,4 5 1,2,6,7 3,4,5 Leaf spot rating1 2 b 2 b 2 b 2 b 0.73 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). TABLE 2. EFFECT OF RECOMMENDED FUNGICIDE PROGRAMS ACROSS CULTIVARS FOR THE CONTROL OF DISEASES ON DRYLAND PEANUT, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.5 pt Folicur 3.6F 0.45pt Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 1.4 lb Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 0.4 lb Bravo Ultrex 1.4 pt Bravo Ultrex 1.4 pt Abound 2SC 1.2 pt Bravo Ultrex 1.5 pt Abound 2SC 0.75 pt Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Headline 6.4 fl oz LSD (P = 0.05) 1 Application timing 1,2,7 3-6 1,2,4-7 3 1,2,7 3-6 1-7 1,2,4,6,7 3,5 1,2,6,7 3,4 5 1,2,6,7 3,4,5 Southern stem rot1 2.3 ab 2 b 1.7 b 3.6 a 2.4 ab 2.3 ab Yield (lb/ac) 3086 a 2928 a 3088 a 2892 a 3035 a 3035 a 2 b 1.4 2950 a 280 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 26 ALABAMA AGRICULTURAL EXPERIMENT STATION Recommended Fungicide Programs for the Control of Diseases on Irrigated Peanut Objective: To compare the effectiveness of recommended fungicides programs for the control of leaf spot diseases and southern stem rot on selected cultivars of peanut under irrigation. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: C-99R, Georgia Green, and Virugard Planting: Date: May 22, 2003 Experimental Design: Split plot on a randomized complete block design with four replications. Peanuts line were whole plots and fungicide programs were subplots. Subplots consisted of four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Prowl 3 pints + Strongarm 0.45 ounce per acre (May 7) Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 10, August 24, and September 12. Application of Treatments: Fungicides were applied with a tractor-mounted boom sprayer with three TX-8 hollow cone nozzles per row calibrated to deliver approximately 15 gallons per acre of spray volume. Applications were made as follows: 1= June 25, 2= July 9, 3= July 23, 4= August 6, 5= August 21, 6= September 3, and 7= September 17. Disease Assessment: Early and late leaf spot were rated together using the Florida peanut leaf spot scoring system on September 13 on Virugard, September 30 on Georgia Green, and October 17 on C-99R. Counts of southern stem rot loci were made on September 24 on Virugard, October 4 on Georgia Green, and October 17 on C-99R immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots planted with Virugard were dug on September 24; Georgia Green, October 4; and C-99R, October 17. Plots were harvested on September 30, October 8, and October 23, respectively. Yields were reported at 10.2% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 27 OVERALL CULTIVARS MEAN FOR LEAF SPOT, SOUTHERN STEM ROT DISEASES RATING AND PEANUT YIELD OF THE C ULTIVARS C-99R, GEORGIA GREEN, AND VIRUGARD, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.5 pt Folicur 3.6F 0.45pt Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 1.4 lb Bravo Ultrex 1.5 pt Bravo Ultrex 1.5 pt + Moncut 70DF 0.4 lb Bravo Ultrex 1.4 pt Bravo Ultrex 1.4 pt Abound 2SC 1.2 pt Bravo Ultrex 1.5 pt Abound 2SC 0.75 pt Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Headline 6.4 fl oz LSD (P = 0.05) 1 Application timing 1,2,7 3-6 1,2,4-7 3 1,2,7 3-6 1-7 1,2,4,6,7 3,5 1,2,6,7 3,4 5 1,2,6,7 3,4,5 ——Disease ratings—— Leaf Southern spot 1 stem rot2 4.6 a 3.4 b 2.7 c 3.6 b 3.6 b 3.6 b 13.3 b 4.5 e 4.5 e 17 a 10 c 7 d Yield lbs/ac 3630 cd 4616 a 4586 a 3057 e 3894 bc 4086 b 2.6 c 0.5 17 a 2.4 3273 de 360 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 28 ALABAMA AGRICULTURAL EXPERIMENT STATION Calendar Schedule and AU-Pnut Advisory Compared in an Irrigated Peanut Production System Objective: To compare the effectiveness of recommended fungicides applied on a standard calendar program and using the AU-Pnut leaf spot advisory for the control of leaf spot diseases and southern stem rot as well as on peanut yield. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green Planting: Date: May 20, 2002 Experimental Design: Randomized complete block with four replications. Plot size was four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Field with peanut-cotton-peanut rotation. Site has a history of southern stem rot and peanut root-knot nematode on peanut. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 7, August 19, and September 7. Application of Treatments: Fungicide were applied on a 14-day calendar schedule and according to the standard AU-Pnut leaf spot advisory rules. A tractor-mounted boom sprayer with three TX-8 hollow cone nozzles per row calibrated to deliver approximately 15 gallons per acre of spray volume was used to apply all fungicides. Disease Assessment: Early and late leaf spot were rated together on September 19 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 1 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Peanut were dug on October 1 and harvested until October 7. Yields were reported at 10.7% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 29 EFFECT OF THE CALENDAR SCHEDULE AND AU-PNUT ADVISORY IN AN IRRIGATED PEANUT PRODUCTION SYSTEM, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Headline 6.4 fl oz LSD (P = 0.05) 1 ————Application———— Schedule Days after planting 14 day AU-Pnut 3 14 day AU-Pnut 14 day AU-Pnut 14 day AU-Pnut 35, 63, 94, 103, 121 49, 79 28, 79, 121 49, 94 35, 49, 121 63, 79, 94, 103 28, 121 49, 79, 94 35, 49, 63, 79, 94, 103, 121 28, 49, 79, 94, 121 35, 49, 103, 121 63, 79, 94 28, 121 49, 79, 94 ———Disease rating——— Leaf spot1 Southern stem rot2 3.7 d 5.5 ab 4.5 c 5.7 a 3.7 d 6.2 a 3.2 d 4.8 bc 0.8 17.0 a 15.5 a 12.7 a 13.2 a 12.7 a 17.7 a 17.2 a 16.3 a 5.0 Yield lb/ac 3594 a 3186 ab 3360 a 3110 a-c 3223 a 2436 d 2694 cd 2710 b-d 486.9 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 3 AU-Pnut leaf spot advisory rules specify that the first application be made immediately after six or more rain events and the second and subsequent applications immediately after three rain events. 30 ALABAMA AGRICULTURAL EXPERIMENT STATION Evaluation of Abound 2SC in Calendar and AU-Pnut Leaf Spot Advisory Programs Objective: To determine if modifying the rules for the AU-Pnut leaf spot advisory system can reduce fungicide use on peanut cultivars that have partial resistance to leaf spot diseases without jeopardizing peanut yield or crop quality. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: C-99R Planting: Date: May 20, 2002 Experimental Design: Randomized complete block with four replications. Plot size was four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Field with peanut-cotton-peanut rotation. Site has a history of southern stem rot and peanut root-knot nematode on peanut. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on August 7, August 19, and September 7. Application of Treatments: Fungicide were applied on a 14-, 21-, and 28-day calendar schedule, as well as according to the standard June 3 and modified August 4 and October 5 AU-Pnut leaf spot advisory rules. In all calendar programs, two applications of Abound 2SC at 18.2 fluid ounces per acre were made approximately 60 and 90 days after planting. A tractor-mounted boom sprayer with three TX-8 hollow cone nozzles per row calibrated to deliver approximately 15 gallons per acre of spray volume was used to apply all fungicides. Disease Assessment: Early and late leaf spot were rated together on September 19 using the Florida leaf spot scoring system. Counts of southern stem rot loci were made on October 18 immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Peanuts were dug on October 18. Yields were reported at 10.6% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 31 EFFECT OF ABOUND 2SC IN C ALENDAR AND AU-PNUT L EAF S POT ADVISORY PROGRAMS, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt LSD (P = 0.05) 1 ————Application———— Schedule Days after planting 14-d calendar 21-d calendar 28-d calendar 6/3 8/4 10/5 3 ———Disease rating——— Leaf spot1 Southern stem rot2 3.0 c 5.3 a 3.7 b 3.7 b 4.0 b 3.8 b 0.5 10.3 b 14.2 a 11.3 ab 8.5 b 9.7 b 9.0 b 3.4 Yield lb/ac 3287 a 2565 a 3416 a 3489 a 3440 a 3069 a 501 35, 49, 77, 100, 119 64, 92 35, 77, 119 56, 100 35, 119 64, 92 28, 64, 119 49, 92 34, 119 64, 92 43, 119 77, 92 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 3 Number of rain events required to trigger first fungicide application/number of rain events to trigger second and all subsequent fungicide applications according to standard and modified AU-Pnut leaf spot advisory. 32 ALABAMA AGRICULTURAL EXPERIMENT STATION Impact of Temik 15G Application Rate On The Control Of Peanut Root-Knot Nematode And The Yield Of Selected Commercial Peanut Cultivars Objective: To determined the susceptibility of selected commercial peanut cultivars to the peanut root-knot nematode and their response to insecticidal and nematicidal rates of Temik 15G. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Agra-Tech 1-1, Agra-Tech 201, C-99R, DP-1, Georgia Green, Georgia Hi Oil, Southern Runner, and Virugard. Planting: Date: May 30, 2002 Experimental Design: Split plot on a randomized complete block design with four replications. Peanut lines were whole plots and fungicide programs were subplots. Subplots consisted of six 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five to six seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25) Fungicides: Bravo Ultrex 1.4 pounds per acre (July 1), Folicur 3.6 0.45 pint per acre (July 15, August 12, September 9, and September 23), and Abound 2SC 1.6 pints per acre (July 29 and August 26). Insecticides: See table. Nematicides: See table. Irrigation: 1 inch applied on July 11, August 8, and August 14. Application of Treatments: Temik 15 G treatments were applied at planting time. Disease Assessment: Severity of early and late leaf spot was simultaneously assessed using the Florida peanut leaf spot scoring system on September 24 for early maturity, September 30 for intermediate maturity, and October 8 for late maturity peanut lines. Counts of southern stem rot loci were made immediately after inversion on September 24 (early maturity), October 3 (intermediate maturity), and October 8 (late maturity). Harvest: Early maturity peanuts were dug on September 24, intermediate maturity on October 3, and late maturity on October 8. Yields were reported at 10.4% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 33 TABLE 1. DISEASE RATING ON SELECTED COMMERCIAL PEANUT CULTIVARS, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Not treated Temik 7 lb Temik 13.3 lb LSD (P = 0.05) Mean Not treated Temik 7 lb Temik 13.3 lb LSD(P = 0.05) Mean Not treated Temik 7 lb Temik 13.3 lb LSD (P = 0.05) Mean Not treated Temik 7 lb Temik 13.3 lb LSD (P = 0.05) Mean 1 Agra-Tech 1-1 7.25 7.5 7.5 7.4 1 1 1 1 0.5 0.5 0.75 0.6 8.25 7.63 7.13 7.7 Agra-Tech 201 7.5 7.5 7.25 7.4 3.75 2.5 2.75 3 4.5 5.75 5.75 5.3 8.88 8.38 8.25 8.5 C-99R 5.25 5.5 5 5.3 2 1.75 1.75 1.8 2.75 2.5 1.25 2.2 8.13 8 7 7.7 DP-1 1 Georgia Green 6 6 6.5 6.2 2.75 2.25 2 2.3 3 3 4.25 3.4 8 7.88 7 7.6 Southern Runner 6 5.67 6 5.9 2 2.33 2 2.1 5 3.75 3.5 4.1 8.63 8.25 8 8.3 Virugard 6.25 6 6 6.1 1.25 1.25 1.25 1.3 0 0.5 0.25 0.3 7.5 6.63 6 6.7 Mean 6.07 a 6.07 a 6.11 a 0.25 Leaf spot rating 4.25 4.25 4.5 4.3 2.25 2.25 2.5 2.3 1.25 0.75 1.25 1.1 7.63 7.25 6.75 7.2 Peanut rust rating2 2.15 a 1.89 b 1.89 b 0.25 Southern stem rot incidence3 2.43 a 2.39 a 2.43 a 0.85 Root-knot damage rating 8.14 a 7.71 b 7.16 c 0.18 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Rust ratings made using the ICRISAT 1-9 scale (1= no disease, ... 9= 80 100% of leaves diseased or withered). 3 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 34 ALABAMA AGRICULTURAL EXPERIMENT STATION TABLE 2. YIELD1 OF SELECTED COMMERCIAL PEANUT CULTIVARS, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Not treated Temik 7 lb Temik 13.3 lb LSD (P = 0.05) Mean 1 Agra-Tech 1-1 2317 2257 2311 2295 Agra-Tech 201 1452 1652 1452 1519 C-99R 2378 2033 1954 2122 DP-1 2850 2638 2710 2733 Georgia Green 1773 1500 1615 1630 Georgia Oil 659 647 653 653 Southern Runner Virugard 2299 2620 2801 2573 2674 2747 2729 2717 Mean 2050 a 2012 a 2028 a 140 Yield is in pounds per acre. PEANUT DISEASE CONTROL FIELD TRIALS 2002 35 Impact of Selected Fungicide Programs on Disease Control on Commercial Peanut Lines Objective: To determine the impact of fungicides inputs on reaction of selected standard, mid-oleic, and high oleic cultivars to TSWV, leaf spot diseases, and southern stem rot as well as yield response. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Norden, Hull, DP-1, C-99R, Georgia Hi Oil, Georgia Green, and Virugard Planting: Date: May 28, 2002 Experimental Design: Split plot on a randomized complete block design with four replications. Peanut lines were whole plots and fungicide programs were subplots. Subplots consisted of four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart + Strongarm 0.45 ounce per acre (April 25). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15G 14 pounds per acre. Irrigation: 1 inch applied on July 11, August 8, and August 14. Application of Treatments: Broadcast application of all fungicides were at two-week intervals with a tractormounted sprayer with three TX-8 hollow cone nozzles per row that were calibrated to deliver 15 gallons per acre of spray volume. Fungicide treatments were applied on July 1, July 15, July 29, August 12, August 26, September 9, and September 23. Disease Assessment: Early and late leaf spot were rated together using the Florida peanut leaf spot scoring system. Peanut rust was assessed using the ICRISAT rust rating scale. Leaf spot and peanut rust were rated on September 30 for early maturing (Virugard), October 8 for intermediate maturing (Georgia Green, Norton, and Georgia Hi Oil), and October 17 for late maturing peanut cultivars (DP-1, C-99R, and Hull). Southern stem rot hits counts was recorded immediately after digging on October 3 for early maturing, October 8 for intermediate, and October 17 for late maturing cultivar. Harvest: Early maturing peanut cultivars were dug on October 3, intermediate maturing on October 8, and late maturing on October 17. Yields were reported at 10.4% moisture. 36 ALABAMA AGRICULTURAL EXPERIMENT STATION EFFECT OF SELECTED FUNGICIDE PROGRAMS ON DISEASE CONTROL ON COMMERCIAL PEANUT LINES, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Cultivar Norden Treatment and rate per acre Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.5 pt Folicur 3.6F 0.45 pt Headline 0.75 pt Application —————Disease rating————— timing Leaf spot1 Rust2 SSR3 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1-7 1,2,7 3-6 1,7 2,4,6 3,5 1 d 3 a 1 d 1 d 1 d 1 d 1.3 cd 1.5 b-d 1.3 cd 1 d 2 b 1 d — — — 1.3 cd 1.8 bc 1.5 b-d 1 d 1d 1 d 0.4 5.5 b-c 5.8 a-c 5 c-e 4 e-h 4.8 c-f 4.3 e-h 3.3 h 4.5 d-g 3.5 gh 4 e-h 4.8 c-f 4.5 d-g — — — 6.5 ab 6.8 a 4.8 c-f 3.8 f-h 5 c-e 3.5 gh 0.3 14.3 ab 12.3 ab 14 ab — — — 16.8 ab 14.5 ab 16 ab 18.3 ab 15.5 ab 18.8 ab — — — 23.3 a 14.8 ab 14.8 ab 19 ab 8.5 b 9b 4.2 Yield lb/ac 2202 b-f 2263 b-f 2293 b-f 1446 fg 2390 a-f 2045 d-g 2922 a-d 2825 a-d 3170 ab 3104 a-c 3346 a 2608 a-d 1948 d-g 1071 g 1458 fg 2105 d-f 2172 c-f 2269 b-f 1531 e-g 1954 d-g 2456 a-e 994 Hull DP-1 C 99R Georgia Hi Oil Georgia Green Virugard LSD (P = 0.05) 1 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 2 Rust ratings made using the ICRISAT 1-9 scale (1= no disease, ... 9= 80 100% of leaves diseased or withered). 3 SSR=Southern stem rot. SSR was assessed at inversion as the number of disease loci per 60 feet of row. PEANUT DISEASE CONTROL FIELD TRIALS 2002 37 Comparison of Calendar Schedule and AU-Pnut Advisory for Disease Control in a Dryland Peanut Production System Objective: To compare the effectiveness of recommended fungicides that are applied on a standard calendar program and using the AU-Pnut leaf spot advisory for the control of leaf spot diseases and southern stem rot as well as the effecton peanut yield and quality factors. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: Georgia Green, Virugard, and C-99R Planting: Date: May 22, 2002 Experimental Design: Split plot on a randomized complete block design with four replications. Peanuts line were whole plots and fungicide programs were subplots. Subplots consisted of four 30-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Field with history of peanut-cotton rotation. Cultural Practices: Herbicides: Sonalan 1 quart per acre (May 16). Fungicides: See table. Insecticides: See nematicides. Nematicides: Temik 15 pounds per acre. Irrigation: None. Application of Treatments: Fungicides were applied on a 14-day calendar schedule or according to the standard AU-Pnut leaf spot advisory leaf spot advisory rules. Applications dates for the recommended 14-day calendar program were June 26, July 9, July 23, August 8, August 23, September 5, and September 20 compared to June 18, July 9, July 23, August 23, and September 20 for the AU-Pnut leaf spot advisory. A tractor-mounted boom sprayer with three TX-8 hollow cone nozzles per row calibrated to deliver approximately 15 gallons per acre of spray volume was used to apply all fungicides treatments. Disease Assessment: Early and late leaf spot were rated together using the Florida peanut leaf spot scoring system on September 19. Counts of southern stem rot loci were made on September 23 on Virugard, October 4 on Georgia Green, and October 18 on C-99R immediately after plot inversion (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Harvest: Plots planted with the cultivar Virugard were dug on September 30; Georgia Green, October 8; and C99R, October 23. Yields were reported at 10.4 % moisture for Georgia Green and 10.1% for Virugard and C-99R. 38 ALABAMA AGRICULTURAL EXPERIMENT STATION TABLE 1. EFFECT OF CALENDAR SCHEDULE AND AU-PNUT ADVISORY ON LEAF SPOT DISEASES IN DRYLAND PEANUT PRODUCTION SYSTEM, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Cultivar C-99R Treatment and rate per acre Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Headline 6.4 fl oz ——————Application—————— Schedule Timing (DAP) 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut Leaf spot rating1 3 3 3 3.25 3 3.5 3 3.25 3 4 3.5 5.25 3.25 5 3.25 3.75 2.75 3.25 3.25 4.5 3 4 2.75 3.5 0.6 35, 48, 78, 106, 122 32, 93 28, 48, 122 62, 93 35, 48, 122 62, 78, 93, 106 28, 48 62, 93, 122 35, 48, 62, 78, 93, 106, 122 28, 48, 62, 93, 122 35, 48, 106, 122 62, 78, 93 35, 48 62, 93, 122 35, 48, 78, 106, 122 32, 93 28, 48, 122 62, 93 35, 48, 122 62, 78, 93, 106 28, 48 62, 93, 122 35, 48, 62, 78, 93, 106, 122 28, 48, 62, 93, 122 35, 48, 106, 122 62, 78, 93 35, 48 62, 93, 122 35, 48, 78, 106, 122 32, 93 28, 48, 122 62, 93 35, 48, 122 62, 78, 93, 106 28, 48 62, 93, 122 35, 48, 62, 78, 93, 106, 122 28, 48, 62, 93, 122 35, 48, 106, 122 62, 78, 93 35, 48 62, 93, 122 Georgia Green Virugard LSD (P=0.05) 1 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). PEANUT DISEASE CONTROL FIELD TRIALS 2002 39 TABLE 2. SOUTHERN STEM ROT INCIDENCE AND YIELD MEAN OF CULTIVARS C-99R, GEORGIA GREEN, AND VIRUGARD IN DRYLAND PEANUT PRODUCTION SYSTEM, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment and rate per acre Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Abound 2SC 1.15 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Folicur 3.6F 0.45 pt Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Bravo Ultrex 1.4 lb Headline 6.4 fl oz Bravo Ultrex 1.4 lb Headline 6.4 fl oz LSD (P = 0.05) 1 ——————Application—————— Schedule Timing (DAP) 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 14-day calendar AU-Pnut 35, 48, 78, 106, 122 32, 93 28, 48, 122 62, 93 35, 48, 122 62, 78, 93, 106 28, 48 62, 93, 122 35, 48, 62, 78, 93, 106, 122 28, 48, 62, 93, 122 35, 48, 106, 122 62, 78, 93 35, 48 62, 93, 122 Southern stem rot count1 3.7 ab 3.2 ab 3.1 b 3.2 ab 3.3 ab 3.3 ab 4.3 a 4.2 ab 1.2 Yield lb/ac 4112 b 4102 b 3985 bc 4427 a 4025 bc 3749 c 3769 c 4152 ab 296 Southern stem rot was assessed at inversion as the number of disease loci per 60 feet of row. 40 ALABAMA AGRICULTURAL EXPERIMENT STATION Reaction of Commercial Peanut Lines to Diseases and Yield Response, 2002 PVT Test Objective: To evaluate the sensibility of commercial peanut lines to TSWV, leaf spot diseases, and southern stem rot. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivars: Agra-Tech 201, Andru II, C 34-24, C-99R, C156-47, Carver, DP-1, Florunner, Ga 01 R, Ga 02 C, Georgia Green, Ga Hi-Oil, GP-1, Gregory, Hull, NC-V11, Norden, Southern Runner, VA 98R, VA-C92R, Virugard, and Wilson Planting: Date: May 6, 2002 Experimental Design: Randomized complete block with four replications. Plot size was four 20-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Five seed per foot of row. Crop History: Field with history of peanut-cotton-cotton rotation. Cultural Practices: Herbicides: Sonalan 1.1 quarts + Strongarm 0.45 ounce per acre, and Select 8 ounces + Crop Oil 1 quart per acre. Fungicides: Bravo Ultrex 1.4 pounds per acre (June 3, June 18, September 26), Folicur 3.6F 0.45 pint per acre (July 1, July 15, July 29, August 12). Insecticides: Temik 15G 6.7 pounds per acre (May 6), Orthene 97 0.5 ounce per acre (May 22), Karate Z 1.6 ounces per acre (August 9). Nematicides: None. Irrigation: 0.5 inch applied on July 27; 0.7 inch on August 6; 0.8 inch on May 8, July 8, August 19, August 28; and 1 inch July 16. Disease Assessment: Early and late leaf spot were rated together using the Florida peanut leaf spot scoring system on September 11 for early maturity, September 18 for intermediate maturity, and October 4 for the late maturity peanut lines. TSWV loci counts was recorded on August 29 for early maturity, September 11 for the intermediate, and October 4 for the late maturity peanut lines (one locus is defined as < 1 consecutive foot of diseased plant[s] per row). Counts of southern stem rot loci were made on September 13 for early maturity, September 20 for intermediate maturity, and October 8 for the late maturity peanut lines. Harvest: Peanuts were dug on September 13 (early maturity), September 20 (intermediate maturity), and October 8 (late maturity) and harvested 3 to 5 days later. Yields were reported at 7% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 41 REACTION OF COMMERCIAL PEANUT LINES TO DISEASES AND YIELD RESPONSE, 2002 PVT TEST, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment Agra-Tech 201 Andru II C 34-24 C-99R C156-47 Carver DP-1 Florunner Ga 01 R Ga 02 C Ga Green Ga Hi-Oil GP-1 Gregory Hull NC-V11 Norden Southern Runner VA 98R VA-C92R Virugard Wilson LSD (P = 0.05) 1 2 Peanut type 1 R R R R R R R R R R R R R V R V R R V V R V Maturity2 (2) (1) (3) (3) (2) (2) (3) (2) (3) (2) (2) (2) (1) (2) (3) (2) (2) (3) (2) (1) (1) (2) TSWV (# loci/40 ft) 7 e-h 5.3 gh 4.3 h 7 e-h 5 gh 7 e-h 4.3 h 17 ab 4.3 h 7.5 e-h 13 b-d 5.8 f-h 11 c-g 3.8 h 9.3 c-h 14 a-c 8 d-h 11 c-f 10 c-g 19 a 6 f-h 13 b-e 5.7 Leaf spot rating3 5.25 b-e 4.5 d-g 4.75 c-g 4.75 c-g 5.5 b-d 5 b-f 4 fg 5.75 a-c 4 fg 3.75 g 4.75 c-g 4.75 c-g 5.75 a-c 6.75 a 5.25 b-e 5.5 b-d 4 fg 4.25 e-g 5 b-f 4.5 d-g 4.5 d-g 6 ab 1 Southern stem rot (#loci/40 ft) 1.25 d-f 0.25 f 2 d-f 3.5 cd 0.75 ef 1.75 d-f 1.25 d-f 5 bc 1 d-f 0.75 ef 1 d-f 0.5 ef 2 d-f 2 d-f 1.5 d-f 7.5 ab 1.75 d-f 3 c-e 5.25 a-c 3 c-e 1.25 d-f 7.75 a 2.6 Yield lb/ac 6089 ab 5899 a-c 5073 c-f 5590 b-e 4946 d-f 6207 ab 4910 d-f 3675 g 6561 a 5708 a-d 4737 ef 5590 b-e 5454 b-f 5291 b-f 5436 b-f 5091 c-f 5137 c-f 5363 b-f 5382 b-f 5127 c-f 5654 a-e 4510 fg 949 Peanut type: R= Runner and V= Virginia. Maturity of peanut line 1= early maturity, 2= intermediate maturity, and 3= late maturity. 3 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead). 42 ALABAMA AGRICULTURAL EXPERIMENT STATION Severity of Leaf Spot Diseases, Southern Stem Rot, and Tomato Spotted Wilt on Experimental Peanut Lines, UPPT 2002 Objective: To assess the yield response and disease susceptibility of experimental peanut lines. Location: Wiregrass Research and Extension Center, Headland, AL Soil Type: Dothan sandy loam (OM <1%) Cultivar: NC7, Florunner, UF 98326, UF 00620, UF 98511, GA 942516, GA 962533, A 962569, TX 977006, TX 977053, VT 9506102-6, C156-47, C11-2-39, and Georgia Green Planting: Date: May 6, 2002 Experimental Design: Randomized complete block with four replications. Plot size was four 20-foot rows spaced 3 feet apart. Land Preparation: Conventional tillage practices. Seeding Rate: Six seed per foot of row. Crop History: Field with cotton-cotton-peanut rotation. Cultural Practices: Herbicides: Sonalan 1.14 quarts + Strongarm 0.45 ounce per acre, and Select 8 ounces + Crop Oil 1 quart per acre. Fungicides: Bravo Ultrex 1.4 pounds per acre (June 3, June 18, September 26), Folicur 3.6F 0.45 pint per acre (July 1, July 15, July 29, August12), and Echo 720 1.5 pints per acre (September 9). Insecticides: Temik 15G 6.7 pounds per acre (May 6), Orthene 97 0.5 ounce per acre (May 22), Karate Z 1.6 ounces per acre (August 9). Nematicides: None. Irrigation: 0.5 inch applied on July 27; 0.7 inch on August 6; 0.8 inch on May 8, July 8, August 19, August 28; and 1 inch July 16. Disease Assessment: Counts of tomato spotted wilt (TSWV) loci (one locus is defined as < 1 consecutive foot of diseased plant[s] per row) were made on August 29 for early maturity, September 11 for the intermediate maturity, and October 4 for the late maturity peanut lines. Severity of early and late leaf spot was simultaneously assessed using the Florida peanut leaf spot scoring system on September 11 for early maturity, September 18 for intermediate maturity, and October 4 for late maturity peanut lines. Counts of southern stem rot loci were made immediately after digging on September 13 (early maturity), September 20 (intermediate maturity), and October 8 (late maturity). Harvest: Peanuts were dug on September 13 (early maturity), September 20 (intermediate maturity), and October 8 (late maturity) and harvested 3 to 5 days later. Yields were reported at 7% moisture. PEANUT DISEASE CONTROL FIELD TRIALS 2002 43 SEVERITY OF LEAF SPOT DISEASES, SOUTHERN STEM ROT, AND TOMATO SPOTTED WILT ON EXPERIMENTAL PEANUT LINES, WIREGRASS RESEARCH AND EXTENSION CENTER, HEADLAND, AL, 2002 Treatment NC7 (ck) Florunner (ck) UF 98326 (Hull) UF 00620 UF 98511 (Norden) GA 942516 GA 962533 GA 962569 TX 977006 TX 977053 VT 9506102-6 C156-47 C11-2-39 Georgia Green (ck) LSD (P = 0.05) 1 2 Peanut type 1 V R R R R V R V R R V R R R Maturity2 (1) (2) (3) (1) (2) (3) (2) (1) (2) (2) (1) (2) (3) (2) Leaf spot rating3 5.5 c-e 5.75 cd 4.25 f 6.25 a-c 4.75 ef 6 bc 4.25 f 4.25 f 7 a 6.75 ab 5 d-f 5.75 cd 5 d-f 5 d-f 0.8 Southern stem rot (#loci/40 ft) 3.75 ab 5 a 1.75 b-e 0 e 2.75 a-d 1 c-e 0.5 de 0.75 de 3.25 a-c 2.5 b-d 1.25 c-e 1 c-e 0.5 de 1.5 b-e 2.4 TSWV (#loci/40 ft) 15.3 a-c 16.8 ab 5.75 de 8.75 c-e 11.5 b-d 5.25 de 5 de 8 de 18.8 a 18.8 a 9.25 c-e 6.5 de 3 e 7.25 de 6.5 Yield lb/ac 6144 b-d 3911 f 5999 b-d 6289 a-c 5000 e 6171 b-d 6407 ab 7060 a 5980 b-d 5554 c-e 6461 ab 5418 de 5663 b-e 6389 a-c 841 Peanut type: R= runner-type and V= Virginia-type peanut line. Maturity of peanut line 1= early maturity, 2= intermediate maturity, and 3= late maturity. 3 Early and late leaf spot were assessed using the Florida leaf spot scoring system (1= no disease, 2= very few lesions in lower canopy, 3= few lesions in lower and upper canopy, 4= some lesions with slight defoliation, 5= lesions noticeable in upper canopy with some defoliation (<25%), 6= lesions numerous with significant defoliation (<50%), 7= lesions numerous with heavy defoliation (<75%), 8= very numerous lesions on few remaining leaves with heavy defoliation, 9= very few remaining leaves covered with lesions, and 10= plants dead).