Suppression of Rhizoctonia solani Damping-off in Soybean (Glycine max L.) by Plant Growth Promoting Rhizobacteria Strains

Document Type : Original Article


1 Agricultural Microbiology Department, Soil, Water and Environment Research Institute, Agricultural Research Center, Egypt.

2 Microbiology Department, Faculty of Agriculture, Mansoura University, Egypt.

3 National Research Council of Italy, Institute of Sciences of Food Production (CNR-ISPA), Bari, Italy.


In vitro and in pots experiments were performed at Sakha Agriculture Research Station of Kafr El-Sheikh (Egypt) to evaluate the antagonistic activity of plant-growth-promoting rhizobacteria (PGPR) strains of the Bradyrhizobium japonicum, Bacillus megaterium var. phosphaticum, Methylobacterium aminovorans, M. rhodinum, and Trichoderma viride species against Rhizoctonia solani, causing soybean damping-off. All tested strains showed in vitro a notable ability to inhibit mycelial growth of R. solani on different growth media. T. viride and M. rhodinum showed the highest rate of antagonism against R. solani. In pots, all the treatments of PGPR notably decreased damping-off and increased healthy plants, as compared to the control (infested soil). As compared to the un-inoculated NPK fertilized control, higher growth parameters for shoot and root dry weight (g plant-1), number of nodules and dry weight of nodules (mg plant-1), chlorophyll content and NPK % of shoot and root, were recorded for the T11 (inoculation with B. japonicum 110 + M. aminovorans ML3 + B. megaterium var. phosphaticum B6 + T. viride) and T12 (inoculation with B. japonicum 110 + M. rhodinum ML12 + B. megaterium var. phosphaticum B6 + T. viride) treatments. Seeds yield of soybean plants attained higher values. The PGPR bacterial bioagents herein tested could participate in reducing the incidence of damping-off of soybean besides avoiding the use of excess fungicides. Such biocontrol approach should be included in the integrated pests and disease management programs.


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