Among the sucking pests, whitefly (Bemisia tabaci) and green leafhopper (Jassids) (Amrasca biguttula biguttula) cause significant yield loss in Bt cotton. Microbial volatile organic compounds (mVOCs) are semiochemicals that can attract or repel the insects, stimulate oviposition, mimic plant hormones, or even induce plant resistance. The aim of this project was to develop eco-friendly and cost-effective microbial volatile formulation for field application to enhance plant growth promotion and management of whiteflies and jassids in Bt cotton.
Twelve short-listed microbial-based volatiles in 150 combinations were tested using yellow (YST). white (WST), and blue (BST) sticky traps. Overall, YST was found to trap more sucking pests compared to WST and BST. These 12 microbial-based volatiles as seed treatment and foliar application was found to significantly enhance the cotton seedling vigour, along with improvements in plant defense enzyme activities and soil biological properties.
Bacterial strains were screened for their effectiveness in attracting/repelling the whiteflies and jassids, through the production of microbial volatiles (mVOC). Among the different solvents tested for their mVOC (extraction efficiency), Dichloromethane (DCM) and Diethyl ether (DE extracted more mVOC. Field trap catch using yellow sticky trap swabbed with 48 h broth grown bacterial cultures (108 cells/ml) indicated 28%- 126% increase in whiteflies and 13%-60% increase in jassids catch compared to control.
This project aims to develop multi-species microbial biofilm formulation to enhance cotton root colonization, thereby expected to enhance plant innate immunity against pests and diseases, apart from enhancing plant and soil health attributes.
Based on the three-year insect bioassay, five bacterial isolates for each lepidopteran pest were short-listed for management of Pink bollworm, American bollworm, Fall army worm and Cotton leaf worm. Among these, Pantoea agglomerans, Enterobacter cloacae, Enterobacter sp., Enterobacter hormaechei showed higher Pink bollworm ovicidal activity (47%-71%). Field inoculation of selected bacterial isolates as seed treatment showed increased plant growth attributes (plant height, sympodial branches, SPAD values, LAI, boll numbers, yield and fibre quality) compared to the control.
The present study aims to isolate calcium dissolving bacteria, and to develop consortia of calcium dissolving bacteria for dissolution of pedogenic CaCO3 in soils through exogenous application to improve soil properties enhancing soil and plant productivity.
Increase in soil CaCO, content due to calcium carbonate solubilizing bacteria (CSB) affected the root and shoot attributes. Significant enhancement in root characteristics and yield attributes were observed in plants inoculated with CSB consortia and CSB-1 compared to the uninoculated plants (RDF).