Sclerotinia Blight in Georgia and Evidence for Resistance to Sclerotinia sclerotiorum in Runner Peanuts

Abstract

Sclerotinia blight (Sclerotinia sclerotiorum (Lib.) de Bary) was recently identified in a commercial peanut (Arachis hypogaea L.) field in Appling County, GA. Symptoms were first observed on the cultivars Tifrunner and Georgia 02C. Plant inoculations and a detached leaflet assay were conducted to determine the susceptibility of the cultivars Georgia Green, Georgia 02C, Georgia 03L, AP-3, Georgia 01R, Hull, C-99R, and Tifrunner. For plant inoculations, lesion lengths were greatest for Okrun, the susceptible control, and Georgia 02C; lesion lengths for C-99R and Georgia 01R did not differ significantly from Tamspan 90, the resistant control. Georgia Green, the current commercial standard, exhibited intermediate lesion lengths. Similar results were obtained from the detached leaflet assay. These results suggest that differing levels of resistance to S. sclerotiorum are available in runner cultivars used in the southeastern United States. Accepted for publication 27 March 2006. Published 31 May 2006.