EVALUATION OF ORGANIC AMENDMENTS AGAINST Alternaria brassicae CAUSING ALTERNARIA LEAF SPOT ON MUSTARD UNDER In vitro AND POLY HOUSE CONDITIONS

Background and Objective: Oilseed Brassica is a major crop all over the world, cultivated mostly for both human consumption and animal feed alike with India being the third largest producer in the world. Alternaria brassicae (Berk.) Sacc. causing Alternaria leaf blight in Brassica are being known for its wide-scale destruction of both production and productivity. The current research was aimed to study the suppressive property of different organic amendments and its efficacy in reducing the severity of Alternaria leaf blight in Brassicae juncea.

Material and method: Experiments were conducted under in vitro and poly house condition to evaluate some commonly known Organic composts for anti-fungal properties against A. brassicae. Seven organic composts viz., Vermicompost, Farm Yard Manure, Neem compost, Bone meal compost, Coir pith compost, Vesicular Arbuscular Mycorrhizae, and Seaweed extract were undertaken for the study.

Result: Highest inhibition of fungal mycelium under in vitro condition was recorded in Vermicompost (47.43 per cent) and the least inhibition being observed in Neem compost (16.02 per cent). Poly house study revealed that all the compost-amended treatment reduced the disease severity of Alternaria leaf blight, with lowest severity recorded in Neem compost (23.70 per cent) and highest severity in Coir pith compost (54.07 per cent).

Conclusion: The experiment has highlighted the efficacy of organic composts against foliar pathogen A. brassicae in Brassica juncea crop. With the growing concern for ecological harm due to high and unjust use of chemical fungicides, organic amendments can be used as an alternate tool for managing fungal disease in crop production.