INTERACTION OF VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI AND PHOSPHORUS WITH MELOIDOGYNE-INCOGNITA ON TOMATO

  • 1 January 1983
    • journal article
    • research article
    • Vol. 15  (3) , 410-417
Abstract
The influence of 2 vesicular-arbuscular mycorrhizal fungi and P nutrition on penetration, development, and reproduction by Meloidogyne incognita on ''Walter'' tomato was studied in the greenhouse. Inoculation with either Gigaspora margarita or Glomus mosseae 2 wk prior to nematode inoculation did not alter infection by M. incognita compared with nonmycorrhizal plants, regardless of soil P level (either 3 .mu.g [low P] or 30 .mu.g [high P] available P/g soil). At a given soil P level, nematode penetration and reproduction did not differ in mycorrhizal and nonmycorrhizal plants. Plants grown in high P soil had greater root weights, increased nematode penetration and egg production per plant and decreased colonization by mycorrhizal fungi, compared with plants grown in low P soil. The number of eggs per female nematode on mycorrhizal and nonmycorrhizal plants was not influenced by P treatment. Tomato plants with split root systems grown in double-compartment containers which had either low P soil in both sides or high P in one side and low P in the other, were inoculated at transplanting with Gigaspora margarita and 2 wk later 1/2 of the split root system of each plant was inoculated with M. incognita larvae. Although the mycorrhizal fungus increased the inorganic P content of the root to a level comparable to that in plants grown in high P soil, nematode penetration and reproduction were not altered. In a 3rd series of experiments, the rate of nematode development was not influenced by either the presence of G. margarita or high soil P, compared with control plants grown in low P soil. Supplemental P (30 .mu.g/g soil) alters root-knot nematode infection of tomato more than Glomus mosseae and Gigaspora margarita.