Biocontrol of Trichoderma gamsii induces soil suppressive and growth-promoting impacts and rot disease-protecting activities.

Plant growth-promoting rhizosphere of associated fungi is often used to improve productivity and crop health. Some biocontrol fungi showed less disease protection efficiency due to environmental factors. Hence, the analysis of biocontrol fungi strains in the field is valuable to analyze their performance in the natural environment. The main objective of this study is to isolate the growth-promoting, rot disease-protecting activities of Trichoderma gamsii RH4 obtained from the rhizosphere of black gram (Vigna mungo). In this study, we evaluated the protective role of 13 fungal strains, including T. gamsii against Fusarium oxysporum in the laboratory experiment (antagonistic assay), greenhouse. The growth-promoting activity of the isolated 13 fungal strains was initially screened and the lytic property was assayed. The T. gamsii showed excellent growth-promoting and lytic properties. Lytic enzyme assays revealed a significant difference in the enzyme yield than other isolates (p < 0.05). The influence of selected plant-growth-promoting fungal strains on the suppression of F. oxysporum rot and wilt black gram was analyzed. Results revealed that these fungal isolates improved black gram growth in greenhouse and significantly reduced wilt and rot disease. The improved growth and yield registered in this study proved growth-promoting and biocontrol properties. The potent T. gamsii was applied in the open field and its effect on green gram was observed. The field trial experiment revealed several growth-promoting effects such as the weight and length of the root and shoot system. The isolated native T. gamsii has the potential to improve the biocontrol properties against rot disease.