Investigation of enhancement of growth in Sorghum bicolor by inoculation with plant growth-promoting microbes

Abstract

Hybrids of Sorghum bicolor (L.) Moench have potential as second-generation biofuel feedstock crops in Canada. This study's objective was to screen five plant growth-promoting microbial strains (Gluconacetobacter diazotrophicus PAL5T, G. azotocaptans DS1, Azospirillum lipoferum N7, A. brasilences N8 and Penicillium bilaii) for growth-enhancing effects on four sorghum genotypes. Two greenhouse studies and one field study were conducted. Glocanoacetobacter diaztrophicus (PAL5T)-treated CSSH 45 cultivar showed a significant increase in shoot dry weight by 19%, in N content by 27% and in P content by 37% compared to uninoculated control plants in one of the greenhouse studies. None of the microbial inoculants significantly increased growth of the sorghum in the field, although Azospirillum brasilense (N8) treated genotypes consistently had the highest mean shoot dry weight. According to the overall results of the study, PAL5T and N8 may offer the greatest potential for use as growth-promoting bacteria in sorghum production.