Chlamydospores are the main propagules used as source of inoculum of Pochonia chlamydosporia in biocontrol experiments of root-knot nematodes. The objective of this study was to evaluate the control of Meloidogyne javanica on tomato plants by the soil application of rice grains colonized by Pochonia chlamydosporia containing just mycelium and conidia, without chlamydospores. The fungus (isolate Pc-10) was grown for 15 days at 26°C on grains of rice, previously sterilized in microwave oven. Two experiments were simultaneously carried out under greenhouse conditions. In the experiment 1, 2-L pots were filled with a soil:sand mixture (1:1, v:v) containing 3g kg-1 of soil of rice grains colonized by the antagonist. In the experiment 2, the fungus was added into the soil of 0.5L pots at the doses of 5, 10, 15, 20, 25 or 30g kg-1 of soil. The soil of each pot was infested with 4,000 eggs of M. javanica and one tomato seedling was transplanted in each pot after fifteen days. In the experiment 1, the application of the fungus into the soil reduced the number of galls and eggs of the nematode by 40% and 72.83%, respectively. In the experiment 2, it was observed the reduction of the number of eggs from the dose of 5 g kg-1 of soil and of the number of galls, particularly at the doses of 25 and 30g kg-1 of soil. As a conclusion, P. chlamydosporia controlled M. javanica on tomato plants even when applied into the soil as colonized-rice grains and without chlamydospores.
biological control; nematophagous fungus; root-knot nematode
