Evaluation of Trichoderma virens and Burkholderia cepacia for antagonisticactivity against root-knot nematode, Meloidogyne incognita

The bacterium Burkholderia cepacia (strain Bc-2) and the fungus Trichoderma virens (strain G1-3) were investigated for activity against the nematode M eloidogyne incognita. Culture filtrates from Bc-2 and G1-3 contained extrac ellular factors that inhibited egg hatch and second-stage juvenile (J2) mob ility. Size fractionation results and lack of detectable chitinase or prote ase activities from Bc-2 and G1-3 culture filtrates suggested that the inhi bitory factors in the in vitro assays were non-enzymic. Tomato root explant cultures of M. incognita treated with T. virens culture filtrate had 42% f ewer eggs and J2 per g of roots than cultures treated with control medium t hat had not been inoculated with T. virens. In glasshouse tests with tomato , Bc-2 and Gl-3 were applied individually as seed coatings and as root dren ches in both viable and non-viable formulations. At the 65-day harvest, non -viable B. cepacia was the only treatment that suppressed eggs and J2 per g of roots (29% suppression) compared to water controls.