CHARACTERISTICS OF MIXED MELOIDOGYNE-ARENARIA AND MELOIDOGYNE-INCOGNITA POPULATIONS IN FLUE-CURED TOBACCO

Two years of field experiments were conducted to characterize the asso ciation of Meloidogyne arenaria race 2 (populations Pelion and Govan) and M. incognita race 3 in tobacco resistant to M. incognita races 1 a nd 3 and tobacco susceptible to both Meloidogyne species. Experiments also studied whether host resistance to M. incognita races 1 and 3 was modified by M. arenaria infection. Tobacco plants were simultaneously inoculated with eggs of M. incognita and M. arenaria. Species identit y of Meloidogyne was determined at harvest by lengths of second-stage juveniles. M. arenaria race 2 infection did not predispose the M. inco gnita-resistant tobacco to M. incognita parasitism. Root galling of M. incognita-resistant tobacco was more severe with the M. arenaria popu lation Pelion than with Govan. In infestations of susceptible tobacco with M. arenaria and M. incognita, M. arenaria Govan proportions at en d season were greater (P = 0.05) than Pelion proportions in similar tr eatments.