Evaluation of Rapeseed Genotypes against Alternaria Blight under Field Conditions in Nawalparasi-West, Nepal

Alternaria blight disease causes both yield and quality loss in Brassica crops. A field evaluation of ten rapeseed genotypes against Alternaria blight disease was conducted during November 2018 to February 2019 in Parasi, Nawalparasi-west district. Experiment was laid out in a randomized complete block design with individual plot size of 2.25 m2 with three replications. Post-harvest in-vitro seed infection test was done in a completely randomized design with four replications. Disease scoring was done as percentage of leaf area and pod infection on individual 15 sample plants per plot at seven days intervals. Genotype ICT 2001-35 was found moderately resistant based on categorization of mean leaf AUDPC (308.52) and mean pod infection AUDPC values (391.48) with low seed infection (12.50%). Preeti, Bikash and Pragati showed highly susceptible reactions to both leaf blight and pod infection. Therefore, genotype ICT 2001-35 could be used in a varietal improvement program for disease resistance against Alternaria blight.