Weed antagonistic bacteria stimulate growth, physiology and yield of wheat (Triticum aestivum L.) in multiple field experiments: A study of selectivity for sustainable weed control

Abstract Differential effects of biological weed control agents should be established before they are recommended for application in field conditions. Our previous studies have reported five strains of weed antagonistic bacteria (WAB) controlling three most noxious weeds of wheat. This work has evaluated selectivity of these strains through study of growth, physiology and yield of wheat in weed free conditions in one pot trial and three field trials. It was found that no strain caused any harm to crop by disturbing its growth, yield, physiological and chemical parameters. Three of our strains including O 0 10 (Pseudomonas aeruginosa), T42 (P. putida) and W9 (P. alcaligenes) caused non-significant effects on these parameters of wheat while strain 7O0 and L9 (both identified as P. fluorescens) significantly improved these parameters of wheat in all the experiments. Strain 7O0 and L9 increased grain yield of wheat up to 34.3 and 40.3% in pot trial, 18.1 and 23.2% in field trial-I, 23.0 and 30.1% in field trial-II, and 18.2 and 22.1% in field trial-III, respectively. Hence, these 5 strains of WAB, being strictly selective in controlling invasion of broadleaved dock, littleseed canarygrass and wild oat in wheat, can be widely utilized to control these noxious weeds. Strain 7O0 and L9 can be utilized for weed control as well as growth promotion of wheat indicating multitude of benefits in sustainable and ecofriendly production of food.