Screening and bioformulation of potential Trichoderma atroviride isolates against Phomopsis canker disease

Abstract

The present study deals with screening of efficient indigenous biocontrol agent Trichoderma spp. against P. theae to control the disease incidence in southern India tea plantations. The rhizosphere soil samples were collected from a total of 30 commercial tea planting estates covering six major planting districts of southern India viz. Valparai, Coonoor, Munnar, Vandiperiyar, Gudalore and Koppa. Among the total of 74 indigenous Trichoderma isolates were obtained, six potential isolates were selected for further analysis and it as identified as Trichoderma atroviride through molecular techniques. DNA sequence details were deposited to Genbank, NCBI (Bethesda, Maryland, United States) and was provided with Accession number (JQ580975-79 and JX298678). Tvl isolate obtained from Valparai tea planting district exhibited the highest radial growth for all abiotic studies with an optimal growth at pH 4.5, temperature 20-25C and diffused day light under room temperature. Moreover, it showed higher antagonist activity with percentage of inhibition of 71.48 through dual culture assay. Among the several carrier materials tested for mass multiplication of T atroviride, talcum powder was foimd to be highly suitable with longer shelf-life period.