Biological control of rice blast disease with Trichoderma harzianum in direct seeded rice under medium low land rainfed conditions.

摘要

An investigation was carried out to control blast disease of rice with bio-inoculants in direct seeded rice under medium low land rainfed conditions. The use of bio-inoculants for management of plant diseases has been proved to be effective against seed and soil born diseases of crops. Numerous genera of fungi such as Trichoerma, Penicillium, Rhizopus were commonly used as bio-inoculent. Trichoderma spp. emerged as a potential biological control agent has been found to be effective against many economically important plant pathogenic fungi. Blast caused by Magnaporthe grisea is one of the most devasting diseases of rice and account for yield loss up to 65% in susceptible cultivars of rice. Seed treated with Trichoderma harzianum significantly improved seed germination, while it significantly reduces days to 50% flowering, days to maturity and disease intensity as compared to their control. Trichoderma treated seed of Sahbhagi dhan (96.67%) showed maximum seed germination percentage followed by IR-64 sub 1 (95.0%) compared to untreated control 71.67 and 41.67%, respectively. It increases 25 to 53% seed germination percentage while reduces days to 50% flowering and maturity by 5 to 7 days. The Trichoderma treated seed showed 23.30 to 30.55% disease intensity compared to untreated seed 40.50 to 48.09%, hence, it reduces the approximately 10-25% disease intensity, suggested that Trichoderma spp. may be used as bio-inoculants for controlling of biological diseases and to reduce the use of fungicides for the management of crop disease.