Received: 13 th Dec-2013 Revised: 18 th Dec -2013 Accepted: 15 th Jan-2014 Research article POTENTIAL OF TRICHODERMA SPP. AS BIOCONTROL AGENTS AGAINST RHIZOCTONIA BATATICOLA CAUSING DRY ROOT ROT OF CHICKPEA G Amrutha Veena 1 , N P Eswara Reddy 2 , B V Bhasakara Reddy 3 and L Prasanthi 4 1&2 Department of Plant Pathology, S V Agricultural College, Tirupati-517 502., A.P., India. 3&4 Institute of Frontier Technology, Tirupati-517 502., A.P., India. ABSTRACT: Ten Trichoderma spp were isolated from chickpea rhizosphere and root endophytic region by using serial dilution technique and purified by single hyphal tip method. Out of the ten isolates tested against Rhizoctonia bataticola, Trichoderma isolate-7 showed highest inhibition percentage (83.33). In compatability tests with commonly used fungicides, Trichoderma isolate-7 showed highest compatability with validamycin (72.22%) followed by copper oxychloride (66.66%). Key words: Trichoderma, Biocontrol, Rhizoctonia bataticola INTRODUCTION Chickpea (Cicer arietinum L.) is an important food legume crop. In India, it is grown over an area of 8.74 m ha with an annual production of 7.35 million tonnes and productivity of 841 kg ha -1 [2]. In Andhra Pradesh, it is grown in an area of 5.84 lakh ha with an annual production and productivity of 7.19 lakh tonnes and 1233 kg ha -1 respectively [1]. Dry root rot by Rhizoctonia bataticola (Taub.) Butler cause considerable yield losses in chickpea which may be as high as 50 to 71 per cent. Effective and practical chemical control is not feasible. Biological control appears to be the only solution for long-term sustainability and effective management of soil borne diseases. Different Trichoderma species are effective against Rhizoctonia. Testing the compatibility of efficient biocontrol agents with commonly used fungicides against the disease was important for integrated disease management studies. MATERIALS AND METHODS Isolation of native antagonistic mycoflora from root endophytes For isolation of endophytes, five g of root was surface sterilized for 5 min with 70 per cent ethanol and homogenized in 20 ml of sterilized phosphate buffer (0.2M Na 2 HPO 4 + 0.2M NaH 2 PO 4 ) pH 7.0 using mortar and pestle. Appropriate dilutions (10 -4 for fungi) of these suspensions were plated on RBA/PDA for the isolation of Trichoderma / fungi. The plates were incubated for 72 h at 28 ± 2°C [7]. Three days old colonies of mycoflora were picked and purified by hyphal tip method. Identification of potential biocontrol agents The efficacy of antagonistic mycoflora from rhizosphere and root endophytes was determined by dual culture technique [8] under in vitro conditions. Dual culture technique To test the efficacy of antagonistic fungus, twenty ml of sterilized melted PDA was plated in Petri plates (9 cm) and allowed to solidify. Mycelial discs measuring six mm diameter from three day old cultures of both fungal antagonist and the test pathogen were placed at equidistant on sterile Petri plate containing PDA medium. The petri plates with pathogen inoculated at one end alone, served as control. The petri plates were then incubated at 28 ± 2°C. Three replications were maintained in each treatment. Growth of antagonists and pathogen were measured after recording full growth of the pathogen in control plate. Per cent inhibition of mycelial growth of test pathogen was calculated by the formula: International Journal of Plant, Animal and Environmental Sciences Page: 78 Available online at www.ijpaes.com