Pathogenicity Study of Sclerotium rolfsii Isolates on Popular Lentil Varieties in Net House Condition

Background: Collar rot of lentil caused by Sclerotium rolfsii became a major problem for early sown lentil in North-eastern plain zones of India, as it associated with high yield losses every year. The disease cause huge loss in yield due to which, area under this crop is consistently decreasing. In global perspective, losses of 10-20 million dollars associated with S. rolfsii with yield depletion ranging from 1-60% in fields. The resistance and susceptibility of a potential host plant depends on the virulence of isolates of S.rolfsii. So the objectives of this study is to observe the potentiality of different isolates those were collected from major lentil growing districts of West Bengal and tested their virulence on three popular varieties of lentil. However the pathogenecity of S.rolfsii in this region never been tested before. This information could be a strong background for effective management of pathogen for future research.Methods: Collar rot infected samples were collected from different geographical locations of West Bengal during (Nov-Dec, 2018). And then the collected samples were isolated in Department of Plant Pathology, BCKV, Nadia, W.B. and were confirmed by their morphological characters. Result: The isolates from different geographical locations showed differences in their virulence. Among the all isolates SRC2 considered as most virulent as it causes highest diseases incidence as well as mortality percentage in all selected varieties of lentil. Two varieties, HUL-57 and BM-6 not so much popular among the farmers but can be consider as resistant to collar rot in case of early sowing condition.