Cotton Yield Response and Target Spot Control with Selected Fungicides

The fungicides, Miravis Top @ 13.7 fl oz/A, Miravis Top @ 13.7 fl oz/A + Quadris @ 5.47 fl oz/A, Propulse @ 13.7 fl oz/A, Provost Silver @ 13 fl oz/A, Aproach @ 6 and 9 fl oz/A, and Revytek @ 8, 12, and 15 fl oz/A were compared with the Priaxor @ 4 fl oz/A and Priaxor @ 8 fl oz/A + Bravo WeatherStik @ 1 pt/A for the control of target spot on Stoneville 6182GLT and Stoneville 4550GLTP in 2019 and 2020, respectively AL. Trials were maintained according to the recommendations of the Alabama Cooperative Extension System and irrigated as needed. The experimental design is a factorial arranged with four replications. Individual plots had four 25 ft rows spaced 3 ft apart. Fungicides were broadcast with a high clearance sprayer at the 3rd and 5th week of bloom except the Priaxor + Bravo WeatherStik positive control with applications scheduled at the 1st, 3rd, 5th, and 7th week of bloom. A non-fungicide treated control was included. Target spot intensity was assessed at 2-week intervals. Over two study years, significant reductions in target spot-incited defoliation compared with the no fungicide control were provided by Miravis Top alone or tank mixed with Quadris, Priaxor, 8, 12, and 15 fl oz/A Revytek, 6 but not the 9 fl oz/A Aproach, and Priaxor + Bravo WeatherStik. Revytek @ 8 and 15 fl oz/A along with Miravis Top alone, which had similarly low defoliation values, gave better target spot control than Provost Silver, Propulse, and both Aproach programs. The former programs also matched the high level of disease control obtained with the Priaxor + Bravo WeatherStik positive control. Equally effective target spot control was also obtained with the 8, 12, and 15 fl oz/A rates of Revytek. Yields will be reported later.