RESUMEN
Spot blotch, caused by Bipolaris sorokiniana (Sacc.) Shoemaker is a major disease of wheat (Triticum aestivum L.), in all the six agro climatic zones of India. Estimation of losses due to this disease vary from location to location, due to diverse environmental conditions. The use of resistant cultivars is the most effective, long-lasting, cost-effective, and environmentally friendly technique for sustainable disease control. The experiment was conducted at Crop Research Centre, Chirodi farm of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U.P.). Among the tested varieties, disease index and AUDPC values varied significantly for both years’ data viz. 2021-22 and 2022-23. In this experiment 32 wheat varieties were screened against B. sorokiniana under artificial epiphytotic conditions in the field. Each variety were sown in two row of three-meter length with three replications, two line of susceptible check RAJ 4015 was sown at every ten genotypes of interval. Among 32 wheat varieties, two varieties were found to be resistant, eleven varieties were found moderately resistant, fourteen varieties were found moderately susceptible and five varieties were found susceptible, none of the variety was found immune and highly susceptible against spot blotch disease. Area Under Disease Progress Curve (AUDPC) calculated for the thirty- two wheat varieties on the basis of disease index. AUDPC varies from 212.90 to 1143.9 and 198.80 to 1144.90 during the 2021-22 and 2022-23 years’ data. The pooled mean, Area Under Disease Progress Curve varied from 205.85 to 1144.40, showing the fast progress of disease in all genotypes. It was observed that different wheat varieties expressed varied type of disease response against B. sorokiniana.