Yield Relationships and Population Dynamics of Meloidogyne spp. on Flue-cured Tobacco

The complex nature of nematode-induced diseases of tobacco, the relationships between nematode levels and damage, the methods of determining these relationships, and the evolving nematode communities on tobacco in eastern North Carolina are described. Crop damage associated with these pathogens varies with nematode race and species, crop cultivar, microflora, and environmental conditions. Root-gall indices as well as initial and mid-season numbers of Meloidogyne spp, in soil are useful for estimating nematode-induced damage on tobacco. The increased occurrences of M. arenaria, M. javanica, and M. incognita races 2 and 4 on tobacco during the last 20 years in North Carolina are having an important economic impact on growers and pose new challenges to researchers.