Control of plant-parasitic nematodes by a nematicidal strain ofAspergillus niger.

An isolate ofAspergillus niger (designated PD-42) was evaluated in laboratory, greenhouse, and field trials for efficacy in controlling plant-parasitic nematodes. In greenhouse experiments, PD-42 drenches containing spores of PD-42 on oatmeal significantly reduced galling on tomato due to root-knot nematode as compared to untreated controls. In a one-half acre field experiment, PD-42 incorporated in seed coats was associated with significantly increased yield and decreased root-knot galling on pepper. In a second one-half acre field experiment, PD-42 drenches significantly reduced tomato and pepper root galling due toMeloidogyne incognita, and nonsignificant yield increases occurred. In each field experiment, treatment with PD-42 reducedRotylenchulus reniformis populations. The nematicidal components of theA. niger culture filtrates include citric acid, oxalic acid, and undetermined molecules larger than 8000 MW.