Probability of Penetration and Infection by Root-Knot Nematode, Meloidogyne Arenaria, in Grape Cultivars

Abstract

Phenology of the root-knot nematode Meloidogyne arenaria is influenced by host cultivar-specific penetration and infection processes which reflect host status. The relationships between number of nematodes penetrating or establishing infection sites in roots and physiological time (DD₁₀) was described by logistic functions for eleven grape cultivars. In three root-knot nematoderesistant rootstocks, a few larvae penetrated during the first 50 DD₁₀ and then apparently left the root. Cultivars could be grouped according to their susceptibility to penetration and infection. Susceptible cultivars were Carignane, Barbera, French Colombard, Ruby Cabernet, Cabernet Sauvignon, Zinfandel, and the rootstocks AXR1 and St. George; moderately resistant were Tokay, Thompson Seedless and Perlette; and highly resistant or immune were Dog Ridge, Salt Creek and Harmony.