Evaluation of some growth promoting bacterial strains exist on Eggplant root Solanumm elongena L. against Rhizoctonia solani

Abstract

In this study, six plant growth promoting bacterial strains were tested against eggplant root rot disease caused by Rhizoctonia solani. The bacterial strains were evaluated for their ability to promote growth and control R. solani in eggplant under greenhouse conditions. The results of antagonistic activity of the bacterial strains against R. solani showed that the tested strains controlled the radial growth of R. solani ranging from 24.66 to 40.33 mm, of these, Bacillus subtilis was the most promising strains which recorded 24.66 mm. Results of the treatment eggplant seeds with the bacterial suspension of the six strains showed that all tested strains significantly increased the percentage of seeds germination as compared to control treatment, B. subtilis strain was the best which recorded 92.16% as compared to 69.56% for control treatment. The greenhouse experiment revealed that the plants treated with B. subtilis recorded maximum (Shoot length, root length, fresh and dry weight of plant, rate of fruits weight, plant productivity). All these parameters were increased by 93.83 cm, 26.50 cm, 589.30 g/ plant, 163.03 g/ plant, 101.63 g, 1180 g/ plant respectively, also the results showed B. subtilis significantly decreased disease incidence and severity of eggplant infected by R. solani which recorded 34.06, 0.23 respectively as compared to both positive without pathogen and negative with pathogen control treatment (4.4 %, 77.33), (0.07 %, 0.71) respectively.