Association of fungi with wilt complex of lentil at different crop growth stages and moisture regimes.

Lentil (Lens culinaris Medik.), the second most important rabi pulse crop of India, suffers heavy plant mortality due to wilt, root rot and collar rot at different stages of crop growth. Congenial soil temperature and moisture during early crop growth, winter rains and terminal drought favour invasion of the crop by many root-invading pathogens. The present study based on 265 samples from 76 districts of seven states of India revealed the involvement of 12 different fungi with the highest association of 30.8% of Fusarium oxysporum f. sp. lentis followed by 17.5 and 15.7% by Rhizoctonia bataticola and S. rolfsii, respectively. Percentage involvement of F. oxysporum f. sp. lentis and R. solani with lentil roots increased with the increase in crop age while that of R. bataticola decreased. S. rolfsii was found to be associated at maximum during the vegetative growth phase. It was further observed that F. oxysporum f. sp. lentis, R. bataticola. R. solani, S. rolfsii and Alternaria sp. were found universally associated at all moisture levels; F. oxysporum f. sp. lentis slightly increased with lower moisture availability while R. solani and R. bataticola were higher at high soil moisture. Other fungi found associated with wilted lentil roots were F. chlamydosporum, F. equisetii, Aspergillus, Penicillium, Helminthosporium, Rhizopus and Trichoderma species. The overall mean plant mortality was 3.5% up to 30 DAS, 7.7% between 30 and 90 DAS and 16.8% above 90 DAS. Similarly, it was 2% at low moisture, 18.5% at optimum moisture and 17.7% at high soil moisture. [ABSTRACT FROM AUTHOR]