Tomato is one of the important vegetable crops grown worldwide, valued both for its nutritional content and economic significance. However, its productivity is frequently constrained by soilborne pathogens. Therefore, present study aimed to isolate indigenous antagonistic microorganisms from tomato-growing soils of Karnataka and evaluate their efficacy against key soil-borne pathogens.
Ten Trichoderma isolates were recovered from eight tomato growing areas of Karnataka and investigated for their biocontrol activity against fungal pathogens (
Fusarium oxysporum f. sp.
lycopersici, Sclerotium rolfsii and
Rhizoctonia solani) and the bacterial wilt pathogen (
Ralstonia solanacearum). Dual culture assays revealed significant inhibition of fungal mycelial growth by all
Trichoderma isolates, with inhibition ranging from 45–88%
against F. oxysporum, 48–73% against
S. rolfsii, and 34–64% against
R. solani. Among the isolates, UHSBF1 exhibited the highest inhibition of
F. oxysporum (88.23%) and
S. rolfsii (73.56%), while UHSCF2 demonstrated maximum suppression of
R. solani (63.98%). In addition, agar well diffusion test against
R. solanacearum showed that UHSBF1 produced the largest inhibition zone (22.12 mm), followed by UHSCF2 (19.78 mm) and UHSTF1 (18.48 mm). These findings demonstrate the strong biocontrol potential of indigenous
Trichoderma isolates, particularly UHSBF1, UHSCF2, and UHSTF1, against multiple soil-borne fungal and bacterial pathogens of tomato. The results highlight the scope for exploiting these isolates in sustainable agriculture to reduce dependence on chemical pesticides and promote sustainable tomato production.
