Managing early leaf spot and stem rot with reduced fungicide inputs on disease-resistant peanut cultivars

Abstract Fungicide inputs are a costly but critical component of peanut production systems in the southeast U.S. Current strategies for reducing fungicide application numbers that are needed to control diseases on peanut include extending application intervals beyond a 2-wk schedule or implementation of a fungicide advisory, such as AU-Pnuts. In this study, fungicide programs with azoxystrobin, chlorothalonil, and tebuconazole, using different application schedules, were compared for the control of early leaf spot and stem rot. Application schedules were the standard 2-wk calendar interval, extended 3- and 4-wk intervals, and applications were made according to the AU-Pnuts leaf spot advisory. Studies were conducted on the disease resistant cultivars DP-1 in 2003 and C-99R in 2004 and 2005. The numbers of fungicide applications for the 2, 3, and 4-wk schedules were 7, 5, and 4, respectively, in 2003 and 2004, and were 6, 5, and 4, respectively, in 2005. One less fungicide application was scheduled accordi...