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MANAGEMET OF ROOT DISEASES WITH BIO-AGENTS: STRATEGY OF TECNOLOGY DEVELOPMENT BY CONSERVATION AND MANIPULATION OF NATURAL ENEMIES.
MANAGEMET OF ROOT DISEASES WITH BIO-AGENTS: STRATEGY OF TECNOLOGY DEVELOPMENT BY CONSERVATION AND MANIPULATION OF NATURAL ENEMIES. AK BANDOPADHYAYl AND MK DASGUPTA 2 lCentral Research Institute for Jute and Allied Fibres, Barrackpore, West Bengal-743101, India; 2Department of Plant Protection, Visva Bharati,Institute of Agriculture, Sriniketan, WB-751236, India. Background and objectives. Root diseases of varied crops due to soil-borne Vascular wilt, Cottical rotting plant patgogens of diverse taxonomic identity are persistent problem for control. Heterogeneous organic amendments and management tactics integration prevent root infecting fungi, bacteria, nematodes, protozoa in soil depending upon ameliorant decomposition products, suppressive bioagents, activity reduction of pathogen and physiology of host tolerance [1].Some fungal, bacterial or viral agents, utilized as biofertilizer, or energizer [2) of non-conventional hosts or growth regulator capable of affecting pathogen, may be exploited for phylosophy and practice of a comprehensive natural control through conservation and manipulation. Resufts and conclusion. Sunnhemp wilt by Fusarium udum f.sp.crotalariae was controlled upto 48% by neem cake [NC) 0.5 --- 1.0 ton/ha soil drench andRhizobium japonicum cowpea group [Rjc<] culture inoculation pelleting seed coat increasing 45% root modulation, 25% fibre yield,rhizobacteria saprophytic, mycoparasitic fungi and fatty acid in rhizosphere. Fungal lysis occurred with 3% NC extract, 0.4% neem seed kernal suspension, leaf extract and oil. Rhizobium together with Azospirillum, VA Mycorrhiza, Rice Necrosis Mosaic Virus [RNMV], revealed positive effect reducing YAft incidence [WI] by 35--37% increasing modulation by 25--45% and plant biomass by 18--30%, plant growth regulator [PGR] Giberellic acid (GAI and Ascorbic acid [AA] seed soaking and Rjc promoted nodule and biomass production highly by 45-55%. AA alone could reduce34% Wi. Rjc antagonized fungal pathogen colonizing on mycelium. Sunnhemp seedling blight and Jute root rot by Rhizoctonia bataticoia declined with NC, Azospirillum, Azotobactor, Phosphobactor, VAM, RNMV; bacterial wilt of field crops by Raistonia burkhoidaria with neem cake, groundnut cake; rootknot of vegetables by Meloidogyne incognitawith mixed/companion cropping with marigoidlCratalaria, rice hull and neem cake 2.5 ton/ha which are widely accepted. Antifungal sulphur containing oleic acid, limonoids rich neem products azadiractin, rhizobiotoxin like substance containing modulation and plant growth promoting --rhizobacteria[PGPR], plant growth promoting RNMV[PGPV]. fungi, VAM, antioxidant vitamin ascorbic acid [PGR], other potential agents can be conveniently manipulated for available, economic, eco-friendly appropriate integrated disease management [AIPM] based on sound ecological' perspective which is sure to go long way leading to an Appropriate Integrated Management System [AIMS]. References [1] Bandopadhyay AK, Dasgupta MK 1997. Abstract.. 3rd IFOA --ASIA Scientific Conference Food Security In Harmony with Nature, pp. 125 -126. [2] Ghosh SK 1982. Ptanta 155, 193 - 198.