Use of Trichoderma harzianum and Trichoderma viride for the Biological Control of Meloidogyne incognita on Tomato

Trichoderma harzianum and Trichoderma viride were tested for their capacity to reduce the incidence and pathogenicity of the root-knot nematode Meloidogyne incognita on tomato. In vitro studies demonstrated that all tested isolates were effective in causing second-stage juvenile (J2) mortality compared with the control. However, a slight increase in J2 mortality coincided with the use of Trichoderma harzianum (Th3) when compared to the other Trichoderma isolates. Trichoderma slightly reduced nematode damage to tomato in vivo. Treatment of the soil with the biocontrol agents slightly improved nematode control when applied one week before transplanting, but not at transplanting time. The Trichoderma isolates could not be re-isolated from the endorhiza, but were successfully re-isolated from the rhizosphere 45 days after fungal inoculation. Only slight increases in plant growth could be measured. The mutualistic endophyte F. oxysporum162, used as positive control, was significantly more effective in root-knot nematode biocontrol than the Trichoderma isolates