Interaction between a vescicular arbuscular mycorrhiza and a root-knot nematode and its effect on growth and chemical composition of tomato

Abstract

An important aspect of vesicular arbuscular (VA) mycorrhizal research, which is attracting attention, is the possible use of mycorrhizal fungi as biological control agents (Schenck, 1981; Dehne, 1982). Baltruschat et al. (1973) indicated that Endogone mosseae had an antagonistic effect on Meloidogyne incognita in tobacco. In a survey of soybeans in Florida, Schenck and Kinloch (1974) found that spore counts of endomycorrhizal fungi were consistently low when associated with high population densities of root knot nematodes. The sequence in which plants become colonised by mycorrhizal symbionts and infested by nematodes may affect the interaction between these organisms (Hussey and Roncadori, 1982). A study conducted earlier in this laboratory indicated that inoculation with VA mycorrhiza followed by root knot nematodes reduced galling on tomato (Bagyaraj et al., 1979). This paper reports further observations on the effects of successive application of a VA mycorrhizal fungus, Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe and the root knot nematode, Meloidogyne incognita (Kofoid et White) Chitw. on the development of each other and their effects on the growth and chemical composition of tomato plants.