VIEW ARTICLE

Disease Control and Pest Management

Biological Control of Root-Knot Nematodes (Meloidogyne spp.) on Peach. G. R. Stirling, Department of Nematology, University of California, Riverside 92521, Senior author’s present address: Department of Agriculture and Fisheries, Research Center, Loxton, S.A. 5333, Australia; M. V. McKenry(2), and R. Mankau(3). (2)San Joaquin Valley Agricultural Research and Extension Center, Parlier, CA 93648; (3)Department of Nematology, University of California, Riverside 92521. Phytopathology 69:806-809. Accepted for publication 9 February 1979. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-806.

Meloidogyne spp. appeared to be under natural biological control in some peach orchards on Lovell rootstock in the San Joaquin Valley, CA. The many species of nematode-trapping fungi occurring in these orchards played only a minor role in regulating Meloidogyne populations. Distribution of nematode-trapping fungi was related to factors other than root-knot nematodes. Trapped Meloidogyne larvae were not extracted from soil around Lovell peach, and predation was not stimulated by adding larvae to soil. The fungus Dactylella oviparasitica was a more successful biological control agent against Meloidogyne spp. and occurred in close association with the nematode. Although Meloidogyne eggs were an important food source, the fungus was able to survive without the nematode. D. oviparasitica parasitized most of the eggs in the relatively small egg masses (300–400 eggs) produced by Meloidogyne spp. females on Lovell peach. The fungus was less effective on tomato and grape, rarely parasitizing more than half the eggs in the larger egg masses (1,000–1,500 eggs) produced by the nematode on these crops.