Field Screening of Rajmash Germplasm for Resistant against Sclerotinia sclerotiorum Causes White Mold

Abstract

White rot or stem rot caused by the polyphagous fungus Sclerotinia sclerotiorum (Lib.) de Bary is a serious threat to production and productivity of rajmash (Phaseolus vulgaris). The regular incidence of Sclerotinia blight in different states of India has been recorded as a limiting factor for this pulse crop grown in moister regions and wet years. Sclerotinia infection in pulses leads to stem and pod rot, crop lodging and reduced seed fill and causes considerable yield losses.  Effective disease control measures against S. sclerotiorumcontinues to be a challenge because of the inefficiency of the chemical control in managing this disease and not environmentally safe. Therefore, cultivation of rajmash cultivars highly resistant to Sclerotinia would be most desirable for both ecological and economic reasons. Thirty two genotypes of rajmash, collected from All India Coordinated Research Project on MULLaRP, T.C.A., Dholi were screened against Sclerotinia rot. Out of these entries, Out of 32 genotypes evaluated, only one genotypes, Utkarsh was found to be resistance and five genotypes (RKR 1038-1, RKR 1011, Amber, Arun, and Uday) showed moderate resistance.  Two genotypes i.e. SKUAB 341, and SKUAST WB 1634 exhibited moderately susceptible reaction. However, twenty-four genotypes showed a sensitive and highly susceptible reaction against this disease.