Abstract
Root-knot nematodes contribute to significant yield loss in tomato production, with limited management options available to farmers. The study was carried out to determine the control efficacy of six native Trichoderma isolates from Ghanaian soils against root-knot nematodes. Root-knot nematode juveniles (J2) and different Trichoderma isolates were extracted from infected roots and soil samples, following standard laboratory protocols. Roots of tomato seedlings were coinoculated with 1000 J2 of root-knot nematodes and 107 spores per gram of soil of individual Trichoderma isolates. Plant height, stem girth, and number of leaves were measured on different days after treatment. Root gall severity, egg mass numbers, final nematode population, and biocontrol efficiency of isolates were determined at harvest. Significant differences in root galls, egg masses, final nematode population, root fresh weight, shoot fresh weight, plant height, stem girth, and leaf number were found between Trichoderma-treated plants and their control. Three Trichoderma isolates, P34-5, OKK3, and Tech10, were highly effective against root-knot nematodes and need further evaluation and potential formulation as biocontrol products against root-knot nematodes attacking tomatoes.