Fungicide Placement and Selection Impact Target Spot Control and Cotton Yield in 2014

In 2014, efficacy of Headline 2.09SC and Quadris 2.08SC when applied with broadcast and drop nozzle spray equipment was evaluated at two irrigated Alabama sites for the control of target spot caused by Corynespora cassiicola on the cotton varieties Phytogen 499 and Deltapine 1252. At the SW AL site, the level of target spot control observed with each fungicide at the final rating date differed by cotton variety. Overall, defoliation levels were higher on Phytogen 499 than Deltapine 1252. When compared with the nonfungicide treated control, Quadris 2.08SC failed to reduce target spot-related defoliation on Phytogen 499 but proved as efficacious as Headline 2.09SC on Deltapine 1252 in controlling this disease. Defoliation levels for the Headline 2.09SC-treated Phytogen 499 and non-fungicide treated Deltapine 1252 were similar. At the Central AL site, target spot control was influenced by cotton variety and fungicide selection but not fungicide placement. Higher defoliation ratings were recorded for Phytogen 499 than Deltapine 1252. While the non-fungicide treated control suffered the highest level of defoliation, lower ratings were noted for Headline 2.09SC compared with Quadris 2.09SC. Similar disease control was obtained with broadcast and drop nozzle spray equipment. Treatment impact on yield at both study sites will also be discussed.