Effect of Host Growth Stage, Inoculation Time, Inoculation Method, Fungicides and Host hybrid Line on Alternaria Blight Development of Sunflower

Abstract

The severity of Alternaria spp. And their effects on yield depending on host growth stage, inoculation time, inoculation method, fungicides, and host hybrid line were evaluated. Disease development was greatest when sunflowers were inoculated at R1 growth stage, during 0.9-11.00 am, by the method of placing 20-30 grains of sorghum grain culture of mixed inoculation of A. helianthi, A. zinniae, and A. alternate. A foliar spray of iprodione and mancozeb plus with Triton CS-7 reduced the severity of Alternaria blight and increased yield of sunflower which was significant difference from non-sprayed plants. The 3 hybrid lines, Hysun 33, KU line, and Synthetic#3 tested for reaction to Alternaria spp. In the field experiment, were susceptible with no differences on disease severity, 100 seed weight and yield among them. These studies revealed that sunflower that sunflower genotypes can be screened in the field for resistance to infection by Altrernaria spp. Using the techniques described herewith.