Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
Soybean, Glycine max, is susceptible to a large number of disease agents such as seedling and root pathogens that cause serious damages to this crop plant. One of these soil-borne pathogens is Macrophomina phaseolina, the causal agent of charcoal root rot. In this study, two bacteria, Pantoea agglomerans and Bacillus sp. BIN, and a fungus, Trichoderma harzianum T100, as potential biocontrol agents, and maneb fungicide, were evaluated against soybean charcoal rot disease in In Vitro and greenhouse conditions. All antagonists inhibited growth of the pathogen in dual culture test by 73.8, 63.3 and 55.3 %, respectively. Data from greenhouse experiments showed that in the presence of pathogen all antagonists increased the growth indices of soybean in both pasteurized and non-pasteurized soil. Reductions of microsclerotia coverage on soybean root and stem by P. agglomerans, Bacillus sp. and T. harzianum were up to 62.5, 87.6 and 62.5 %, respectively and for maneb fungicide was 87.6 % in pasteurized soil. The overall results of this study show high capability of used antagonists in reduction of initial inoculums for next season of this monocyclic disease.