Evaluation of Trichoderma virens and Burkholderia cepacia for antagonistic activity 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 Meloidogyne incognita. Culture filtrates from Bc-2 and G1-3 contained extracellular factors that inhibited egg hatch and second-stage juvenile (J2) mobility. Size fractionation results and lack of detectable chitinase or protease activities from Bc-2 and G1-3 culture filtrates suggested that the inhibitory factors in the in vitro assays were non-enzymic. Tomato root explant cultures of M. incognita treated with T. virens culture filtrate had 42% fewer eggs and J2 per g of roots than cultures treated with control medium that 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 drenches 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.