No abstract

Rice (Oryza sativa L.), as a cereal grain, is the most widely consumed staple food for a large part of the world’s human population, especially in Asia and Africa. Rice production is often subjected to several biotic and abiotic stresses. Rice sheath blight is one of the most destructive diseases causing economic losses in rice yields and affecting quality worldwide. Twenty soil samples were collected from the rhizosphere of rice crop from different regions of Northern Karnataka. Trichoderma spp. were isolated from the rhizospheric soil samples. The antagonistic potential of Trichoderma spp. was studied using dual culture technique. Among twenty strains of Trichoderma the highest inhibition (>50%) was recorded in nine strains which ranged from 54.20 to 65.10 per cent. Trichoderma harzianum recorded highest seed germination (100%), root length (13.73 cm), shoot length (8.64 cm) and seedling vigour index. In pot culture experiment, the Trichoderma strains significantly improved the growth parameters such as root length, shoot length and number of tillers per plant. Among the different treatments, seed treatment + root dipping + foliar spray with T. harzianum strain was highly effective in increasing the shoot length, root length and seedling vigour index at 30, 60 and 90 days after sowing. This strain was found highly effective in inhibiting the pathogen and promoting the growth of rice plants.