timization of culture media with agroindustrial sources for the growth of white yam (Dioscorea rotundata Poir).

Abstract

Microbial inoculants are a suitable alternative for counteracting the adverse environmental effects of synthetic agrochemicals due to their capacity for promoting plant growth and increasing crop yield in an ecologically sustainable manner. To benefit from these advantages, microbial inoculants production must offer products of high quality and low cost using environmentally sustainable sources that provide rich nutrients for microbial and plant growth. In this study, we assess the production of cytokinins by the rhizobacteria strains DSC1 (Bacillus licheniformis), DSC21 (Brevibacillus laterosporus) and DCR11 (Azotobacter vinelandii) in nine culture media that contains agro-industrial residues. We identified three culture media (medium B, C and D) that promote rhizobacteria growth and phytohormone production. The fermented rhizobacteria products were inoculated at different doses (0 mL, 2 mL, 4 mL, and 6 mL) in white yam apical cuttings under net house conditions. 2 mL^-1 of DSC1 B. licheniformis increased fresh storage root biomass by 31.67% and 22.22% of the aerial dry weight. Fresh aerial biomass was increased by 33.22% by DCR11 A. vinelandii in doses of 6 mL^-1, increasing the production of photosynthetic pigments by 7.36%. We demonstrated that inoculation of white yam plants with fermented products from agroindustrial residues has the potential to increase plant growth.