ECO-FRIENDLY MANAGEMENT OF SHEATH BLIGHT OF RICE

Abstract

A study was undertaken to evaluate the potentiality of Trichoderma harzianum and Bacillus subtilis against sheath blight disease of rice in the laboratory of the Department of Plant Pathology, Sher-e- Bangla Agricultural University and pot experiment in the net house during October, 2014 to November, 2015. Trichoderma harzianum was isolated from the mushroom substrate and B. subtilis based formulation PRH was collected from local market. In in vitro test, T. harzianum and B. subtilis showed excellent performance and produced inhibition zone against Rhizoctonia solani. At 4 days after inoculation T. harzianum and B. subtilis produced 73% and 68% inhibition zone, respectively. In pot experiment nine treatments were used where seedling root treated and sprayed in the sheath at tillering stage with T. harzianum and Bacillus subtilis based formulation PRH, respectively. On the other hand R. solani treated with Bacillus subtilis based formulation PRH and sprayed at tillering stage on the sheath. Rhizoctonia solani applied in pot soil and inoculated rice plant at tillering stage. Spraying of T. harzianum at tillering stage gave the best performance regarding all parameters viz. decrease incidence and severity of sheath blight, lesion size, number of lesion, and increase grain yield compared to control. Bacillus subtilis also showed good performance. At 75 days after transplanting the lowest incidence (28.69%) and the lowest severity (7.11%) were recorded from soil inoculated with R. solani + tiller treated with PRH and seedling root treated with T. harzianum + tiller inoculated with R. solani, respectively. The highest grain yield of 396.64g/hills was obtained from the treatment where T. harzianum was applied at tillering stage and R. solani inoculated at sheath of the rice plant