Survey and screening of tomato germplasm against early blight disease caused by Alteernaria solani

Abstract

Early blight disease caused by Alternaria solani is the most catastrophic disease causing losses both at pre and post-harvest stages in tomato growing places of India. Roving surveys were conducted during Kharif 2017 in tomato growing belt areas of Southern Karnataka covering viz., Kolar, Chikkballapur, Ramanagara and Tumakuru districts to assess disease prevalence. Disease severity (Per cent Disease Index) ranged from 28.75 to 57.50. Maximum mean PDI of the disease was recorded in Kolar (50.43%) followed by Chikkaballapur district (42.75%) and least in Tumkur (31.75%). The highest PDI was recorded in Chowdadenahalli village of Kolar district (57.50) and lowest PDI of 28.75 was recorded in Janapanahalli village of Tumkur district.In an another experiment, field screening of tomato germplasm against early blight disease was taken up during Kharif 2017. Among the 50 genotypes screened, ten genotypes viz., COHB-3, 12, 11, 66, 52, 133, 30, 27, 177 and 186 were resistant whereas thirty genotypes were moderately resistant. Ten genotypes were susceptible and one genotype was highly susceptible.