CONTROL OF PLANT-PARASITIC NEMATODES BY A NEMATOCIDAL STRAIN OF ASPERGILLUS-NIGER

An isolate of Aspergillus niger (designated PD-42) was evaluated in la boratory, greenhouse, and field trials for efficacy in controlling pla nt-parasitic nematodes. In greenhouse experiments, PD-42 drenches cont aining spores of PD-42 on oatmeal significantly reduced galling on tom ato due to root-knot nematode as compared to untreated controls. In a one-half acre field experiment, PD-42 incorporated in seed coats was a ssociated with significantly increased yield and decreased root-knot g alling on pepper. In a second one-half acre field experiment, PD-42 dr enches significantly reduced tomato and pepper root galling due to Mel oidogyne incognita, and nonsignificant yield increases occurred. In ea ch field experiment, treatment with PD-42 reduced Rotylenchulus renifo rmis populations. The nematicidal components of the A. niger culture f iltrates include citric acid, oxalic acid, and undetermined molecules larger than 8000 MW.