Trichoderma based biological management of major fungal diseases in pulse crops

摘要

Pulses are an integral part of Indian agriculture due to their multiple utility in human food, animal feed and soil health. India has the distinction of being the top producer of pulses in the world. About 8–10 grain yield of pulse crops are annually lost due to various diseases. Majority of the fungal diseases are soil and seed borne in nature therefore, difficult to manage by conventional management practices consisting of growing resistant cultivars and use of fungicides. Among the various typesof biological control agents, Trichoderma species have been extensively exploited. They were found to be effective against large number of soil, seed and air borne fungal plant pathogens. The ideal characteristic features like high reproductive capacity, rhizosphere modification ability, survival ability under adverse conditions, nutrients utilization efficiency, aggressiveness against plant pathogens and promoting plant growth and defense mechanism makes Trichoderma as a successful biocontrol agent. Seed and soil application bio-formulations were developed from different potential species of Trichoderma to increase shelf life and efficacy. Pusa 5SD a seed dressing formulation and Pusa Biopellet (PBP) a soil application formulation showed longer shelflife. The efficacies of newly developed bio-formulations were evaluated in pot and filed experiments against several diseases of pulse crops namely, dry (Rhizoctonia bataticola) and wet root rot (R. solani) of mungbean and ckickpea, wilt (Fusarium oxysporum f. sp. ciceris) of chickpea and root rot (Rhizoctonia solani) and damping off (Pythium ultimum) complex in French bean. T. harzianum based formulations were found superior over others against R. bataticola and Fusarium species whereas, T. virens based formulations were found superior against R. solani. A combined application of PBP 10G (T. harzianum) in soil and Pusa 5SD + carboxin as seed treatment showed superiority over any other formulations alone in reducing the dry root rot incidence and increasing grain yield of mungbean and chickpea. Soil application of PBP 4G (T. viride) and seed treatment with Pusa 5SD (T. harzianum) + carboxin provided the highest yield attributing parameters with the lowest wilt incidence in chickpea. T. virens based Pusa 5SD and PBG 6 were found effective in reducing wet root rot and increasing yield in mungbean and chickpea. Seed treatment proved superiority over soil application for all the parameters recorded. Both the formulations (soil and seed treatment) showedgrowth promoting ability. During validation, Pusa 5SD (T. harzianum) alone and in combination with Vitavax power (carboxin + thiram) reduced the wilt incidence and enhanced the grain yield of chickpea at 8 different locations across the country. Frenchbean seeds treated with T. harzianum based Pusa 5 SD + P. fluorescens provided the highest seed germination, root and shoot lengths, dry plant weight, pod yield and the lowest disease incidence. Further, combined application of Pusa 5SD (T. harzianum), PGPR strain P. fluorescens, M. ciceri and Vitavax power as seed treatment gave extreme protection to germinating chickpea plants with the highest grain yield and the lowest wilt incidence.