The Influence of Cultivar and Chlorimuron Application Timing on Spotted Wilt Disease and Peanut Yield

Abstract

Abstract The effects of chlorimuron application timing on the development of spotted wilt disease of peanut caused by tomato spotted wilt tospovirus was studied in fifteen field trials in Georgia from 2000 through 2007. Chlorimuron at 9 g ai/ha was applied to new peanut cultivars at various intervals ranging from 60 to 105 days after emergence (DAE) under weed-free conditions. When averaged over chlorimuron application timings, AP-3, and Georgia-02C had less spotted wilt incidence than Georgia Green but only AP-3 produced yields equivalent to Georgia Green. AT-201 had significantly higher levels of spotted wilt and 44% lower yields when compared to Georgia Green. Spotted wilt incidence of Georgia-03L did not differ from Georgia Green but the yields of GA-03L were 24% lower than Georgia Green. Differential tolerance of peanut cultivars to chlorimuron was not observed. When averaged over cultivars, chlorimuron applied at 60–69 DAE, 70–79 DAE, or 90–99 DAE increased the incidence of spotted wilt by 6–9%. However, peanut yields were not reduced by any application of chlorimuron.