Influence of Root-Knot Nematodes on Verticillium Wilt of Maples
Frank S. Santamour, Jr.
Abstract: Young plants grown from rooted cuttings of four Norway maple cultivars and three red maple cultivars, as well as seedlings of six maple species, were inoculated with combinations of Verticillium dahliae and several root-knot nematodes (Meloidogyne spp.). The Verticillium-susceptible Norway maples ('Crimson King1 and 'Greenlace') were resistant to the nematodes but some plants were killed by the wilt fungus. Of the wilt-tolerant cultivars, 'Parkway' was also tolerant or resistant to the nematodes and the plants did not exhibit wilt symptoms. However, the death of several plants of the supposed wilt-tolerant 'Jade Green1, which was susceptible to some of the nematodes, indicated a synergism between the two pathogens. The red maple cultivars were highly susceptible to most of the nematodes, but they did not wilt. Seedlings of Norway maple also showed evidence of the synergistic effect of the fungus and the nematodes.