LAUSR

ABSTRACT Soil samples collected from different fruit orchards of Karnataka were used for isolation of Streptomyces spp. and all the isolates were screened for their plant growth-promoting (PGP) traits including phytohormones production viz. indole-3-acetic acid (IAA) and gibberellic acid (GA3), nutrient (phosphate and zinc) solubilisation, siderophore production, enzyme activities (cellulase, tannase and xylanase) and antagonistic potential against soil borne fungal pathogens. Based on PGP traits as well as compatibilities, the following three Streptomyces spp. ‘S. avermitillis PAN Act2 (NAIMCC-B-01412), S. cinnamonesis PAN Act3 (NAIMCC-B-01413) and S. canus PAN Act5 (NAIMCC-B-01342)’ were selected for Streptomyces consortium (SMC) preparation using lignite as carrier material. Out of three isolates, S. canus registered significantly higher IAA and GA3 production compared to other isolates. All three isolates had the potential to suppress the fungal phytopathogens viz. Cerotocystis fimbriata, Fusarium oxysporum, Macrophomina sp. and Sclerotium sp., with the levels of suppression ranging from 58.0% to 85.0%. The carrier-based SMC was subsequently evaluated in pomegranate to recover the plants from wilt like symptoms under field conditions. From this study, it was found that application of 50 gm of the SMC per plant through soil drenching at regular intervals (once every 2 months) had a significant impact on the recovery of the plant from wilt like symptoms after eight months. The present study is an addition to the growing knowledge on the utility of Streptomyces in fruit production.