Effects of the nematode-trapping fungus, Monacrosporium ellipsosporium on Meloidogyne incognita populations in field soil

Monacrosporium ellipsosporiwn was frequently observed associated with Meloidogyne egg masses in some field soils and in potted cultures of the nematode. Six geographic isolates varied in their relative predacity toward larvae emerging from egg masses. An aggressive isolate, chosen for rapidity and abundance of trap formation in vitro, was tested in greenhouse and field tests for protection of tomato from M. incognita. A test of tomato in potted field soi1 inoculated at 1, 5 and 10 g fungal inoculum/l5 cm pot, 15 days before nematode inoculation, showed significant reduction,in plant damage at the 5 and 10 g levels, but none at the 1 g rate. Galling was reduced 42 Oo and 49 “0, respectively, in the 5 and 10 g fungal treatments. Larvae in the soi1 and females/plant were also similarly reduced, but were the same as controls at the 1 g rate. In a tïeld test using two levels of fungus on wheat grain substrate mixed into transplant holes for tomato seedlings, the improved plant growth and M. incognira reduction obtained at harvest were also in direct relationship to amounts of the fungus used, but the treatments did not differ statistically from the control.