Evaluation of wheat genotypes for resistance against spot blotch disease

Abstract

Spot blotch caused by Bipolaris sorokiniana (Sacc.) Shoem is most important disease\rof wheat in North Eastern plain zones (NEPZ) representing warm and humid climate in\rIndia. It is also increasing in North Western plains zones (NWPZ), due to climate\rchanges and causes considerable losses in susceptible varieties. A field study was\rconducted during Rabi, 2011-12 and 2012-13 crop seasons at Main Experiment Station,\rNDUA and T, Kumarganj, Faizabad to test the resistance of 250 genotypes against\rBipolaris sorokiniana under artificial epiphytotics conditions. Each genotype was\rsown in last week of November in single row of one meter length. Variety Raj 4015 was\rused as check and was sown after every 20 genotypes. Pure culture of pathogenwas\rinoculatedon genotypesby using cleaned sprayer, at evening. Disease data was recorded\rusing double digit scale based on per cent blighted area on flag leaf and one leaf just\rbelow. Out of 250 genotypes, one namely KARAWANI/4NIF-3/SOTY/NAD63/CHRIS\rwas found immune, 20 genotypes were found resistant, 146 were moderately resistant,\r75 were moderately susceptible and 8 were found susceptible against spot blotch\rdisease of wheat.