Stem Rot (White Mold) and Tomato Spotted Wilt Resistance among Peanut Genotypes

Abstract

ABSTRACT Stem rot, also known as white mold (WM), caused by Sclerotium rolfsii Sacc., and tomato spotted wilt, caused by Tomato spotted wilt virus (TSWV), are two major disease problems in Georgia peanut (Arachis hypogaea L.) production. Current fungicides for stem rot control are very effective but expensive, and insecticides usually have little effect on TSWV, which is transmitted by thrips. Consequently, the objective of this study was to evaluate different peanut genotypes for resistance to both of these pathogens. Field test evaluations were conducted for four consecutive years (2010-13) at a site on the agronomy research farm near the Coastal Plain Experiment Station which has a long history of continuous peanut production and a high incidence of stem rot (WM) and TSWV. Results from these field tests showed significant differences among the peanut genotypes evaluated for combined resistance to both diseases. Several genotypes showed low TSWV incidence at mid-season and mid-to-late season. However by late season and after digging, the best combination of stem rot (WM) and TSWV disease resistance and highest consistent yield over years was in the runner-type peanut cultivar ‘Georgia-12Y’, along with ‘York’, ‘Georgia-07W’, and ‘Georgia-10T’.