Plant Disease Research

Stem rot of berseem caused by Sclerotinia spp. is one of the most destructive soil-borne plant pathogen and is responsible for significant amount of green fodder and seed yield losses (20-25%) in the forage crop. The present investigation was aimed to study the etiology and epidemiology of stem rot disease of berseem. The stem rot causing pathogen was isolated from the diseased samples collected from various berseem growing areas of district Kangra (Himachal Pradesh) and pathogenicity of the associated pathogen was proved through sick soil method. On the basis of symptoms, the disease was identified as stem rot and on the basis of morpho-cultural and molecular identification (ITS 1/4 primer pairs) the pathogen was identified as Sclerotinia sclerotiorum. The disease severity was found to be higher during June than May due to the favourable environmental conditions. Temperature was observed as the most important meteorological factor in the disease development having significant negative correlation (-0.948) with disease severity. The coefficient of determination (R²) revealed that selected weather variables contributed 92.00 and 89.00 per cent towards disease severity as calculated through simple and stepwise regression, respectively