Study of southern leaf blight (Bipolaris maydis) on maize genotypes and its effect on grain yield

Abstract

Southern maize leaf blight is known to be the foremost harmful disease of maize crop which causes significant yield loss. In present investigation, 20 maize genotypes were selected for the test against Southern Leaf Blight (SLB) in the prevailing field conditions at Prithu Technical College, Bangaun, Dang, Nepal with an objective to find the new sources of resistance against southern leaf blight disease. Randomized Complete Block Design (RCBD) was used with three replications as the experimental design. The total percentage of infected leaf area per plant was studied for the disease scoring. It was conducted consequently 5 days of interval, for 5 times after 60 days after sowing and disease severity, mean AUDPC were estimated and yield recorded. The tested 20 maize genotypes differed significantly in mean AUDPC values and based on AUDPC values, genotypes were categorized as highly susceptible, susceptible, moderately resistance and resistance category. Maize genotype Rampur-S03F08 (AUDPC value 65) appeared most resistant followed by Across-0091(AUDP value 67.08) and TLBRSO7F16 (AUDPC value 70.41). Significantly highest yield (1.8 t/ha) was found on genotype Rampur-SO3FO8 (1.8 t/ha) followed by Across-0091 (1.65 t/ha) and TLBRSO7F16 (1.63 t/ha). Thus indicating the high yielding and resistance maize genotypes Rampur- S03F08, Across-0091 and TLBRSO7F16 could be developed as the resistant varieties to southern leaf blight disease.