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

The response of the peach scion cultivars, Jerseyqueen, Redhaven, Compact 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 planting (1989). A range of responses was observed from highly susceptible in Lovell to resistant in Nemaguard. In vitro and microplot data suggest high and moderate levels of resistance to M. incognita in Compact Redhaven and Redhaven, respectively. Both Jerseyqueen and Rio Oso Gem were susceptible to M. incognita, but not as susceptible as Lovell. The response of self-rooted peach cultivars and rootstocks to M. incognita in vitro appears to be a reliable method for predicting the reaction of each to these nematodes under field conditions.