Biofumigation potential of Indian mustard ( Brassica juncea ) to manage Rhizoctonia solani

In Egypt, Rhizoctonia solani is an economically important fungal pathogen on many crops such as common bean causing serious yield losses. Biofumigation with Indian mustard ( Brassica juncea ), as a potential alternative to the restricted fumigant methyl bromide, is gaining attention in sustainable vegetable production. In this study, laboratory and greenhouse experiments were conducted to evaluate the biofumigation effect of B. juncea , used as dry plants, seed meal, seed powder, methanol extract, and fresh plants (at the vegetative and flowering stages), against R. solani. Results showed that hexane defatted seed meal was the most efficient one, followed by the seed powder, fresh plants at the flowering stage then fresh plants at the vegetative stage. The fungal inhibition rate was 61.5, 50.2, 49.9, and 47.7%, respectively. While the dry plants at both flowering and vegetative stage recorded the lowest suppressive effect (44.3 and 39.1%, respectively). The findings open up the possibility of using the B. juncea in managing the root rot fungus, not only as a common green manure but also as a defatted seed meal.