Biological control of the root-knot nematode using nematode-trapping fungi and its susceptibility to agricultural chemicals.

摘要

The ability to capture Meloidogyne incognita was compared among 17 species of nematode-trapping fungi isolated from soil in Okinawa Island, Japan. In particular, Monacrosporium ellipsosporum had not only the highest trapping ability but also formed many trapping organs per unit area (1 mm2), catching nematodes more rapidly than other trapping fungi. A test for selection of the optimum medium for proliferation of M. ellipsosporum revealed that 1% glucose . yeast extract . malt extract (GYM) liquid medium was the most suitable. This fungus produced 5.2x1010 cells (hyphal bodies) in shaking culture (200 rpm/min, 25 degrees C, 100 ml). When a mixture of culture medium including viable cell and vermiculite was mixed into soil at the rate of 10, 20, 30 or 50 g per plot, root-knot indexes of tomato roots after 3 months of cultivation were 40, 10, 15 and 10 for the 10, 20, 30 and 50 g treatment plots, respectively. The index was 50 in the control. A granular nematicide, fosthiazate had an index of 5.0. Fosthiazate, cadusafos and oxamyl had no effect on the in vitro hyphal growth of Monacrosporium ellipsosporum.