Abstract: A bioassay and a pot experiment were conducted to study the nematocidal activities and the controlling effects of Ricinus communis extracts and Paecilomyces lilacinus against Meloidogyne incognita. It was observed that ricinine had no impact on the germination of P. lilacinus spores, whereas both ricinine and P. lilacinus had strong nematocidal activities. In treatment ricinine, the inhibition rate of egg-hatching and the mortality of the second stage juveniles of M. incognita were 61.7% and 59.2%, respectively, being significantly higher than those in control treatment. In treatment ricinine plus P. lilacinus, the mean number of the root-knots per plant of tomato seedlings inoculated with M. incognita was 15±3, which was significantly lower than that (37±2) in the control, and the plant height, fresh mass, and root length of the seedlings were increased by 38.5%, 44.0%, and 57.0%, respectively, as compared to the control. The results suggested that R. communis extracts and P. lilacinus could mitigate the harm of M. incognita, and also, have obvious effects in controlling M. incognita.

Key words: Cumulative phosphorus, Chemical depletion, Soil