Unveiling the bioherbicidal potential of weed suppressive bacteria to control growth of Echinocloa crusgalli in maize crop

Abstract

Excessive use of tillage and chemical herbicides in intensive agricultural systems has produced many issues related to environment, human health, food quality and sustainability of natural resources. Additional non-conventional tools for weed management must be explored and/or strengthened in order to minimize the crop losses caused by weeds and produce healthier food. Present work has explored rhizosphere of barnyard grass (Echinochloa crusgalli) (BYG) and maize to find out weed suppressive bacteria (WSB) and demonstrate their bioherbicidal potential. A large collection of rhizobacteria from maize and barnyard grass was characterized for production of cyanide, inhibition of Escherichia coli, release of siderophores and indole-3-acetic acid, activities of chitinase, catalase and oxidase, and effects on germination and seedling growth of BYG and maize. Six promising strains were evaluated for control of BYG and implications on growth of maize under axenic conditions of growth room. We found that all strains were suppressive to germination (), shoot length (-59%), root length (-63%), fresh biomass (-64%) and dry matter (-63%) of BYG with respect to control. Three of our strains did not affect germination, growth and chlorophyll content of maize crop significantly while other three strains significantly increased these parameters with respect to control. Hence, these strains may be used as bioherbicides to selectively suppress growth of BYG in maize crop.