RESPONSE OF PEACH SCION CULTIVARS AND ROOTSTOCKS TO MELOIDOGYNE-INCOGNITA IN-VITRO AND IN MICROPLOTS

The response of the peach scion cultivars, Jerseyqueen, Redhaven, Comp act Redhaven, and Rio Oso Gem and rootstocks 'Lovell' and 'Nemaguard' to inoculation with Meloidogyne incognita was compared in vitro and in microplots. One or more parameters monitored in vitro correlated with at least one parameter monitored in microplots, 4 years after tree pl anting (1989). A range of responses was observed from highly susceptib le in Lovell to resistant in Nemaguard. In vitro and microplot data su ggest high and moderate levels of resistance to M. incognita in Compac t Redhaven and Redhaven, respectively. Both Jerseyqueen and Rio Oso Ge m were susceptible to M. incognita, but not as susceptible as Lovell. The response of self-rooted peach cultivars and rootstocks to M. incog nita in vitro appears to be a reliable method for predicting the react ion of each to these nematodes under field conditions.