Response of Runner, Spanish, and Virginia Peanut cultivars to Imazethapyr

Abstract

Abstract Field experiments conducted in 1992 and 1993 in Georgia and Texas evaluated response of five runner-, three virginia-, and four spanish-type peanut cultivars to imazethapyr applied early-postemergence (EPOST) at 71 g/ha. Visual injury was less than 11% at Tifton and no visible injury on any cultivar was noted later in the season. Canopy width was similar with or without imazethapyr for each cultivar at Tifton in 1992. In 1993, all cultivars at Tifton exhibited a linear canopy width response and regression coefficients were less for Florunner, Southern Runner, Sunrunner, NC 7, and NC-V11 treated with imazethapyr indicating slower canopy closure. The only significant effect on peanut grade factors and yield was the main effect of cultivar. The occurence of late and early leafspot, tomato spotted wilt, and southern stem rot was independent of both cultivar and imazethapyr. In Texas, the cultivar Spanco had higher canopy height and width 3 weeks after treatment (3 WAT) when treated with imazethapyr. ...