Comparison of Development, Reproduction, and Aggressiveness of Meloidogyne incognita Races 3 and 4 on Cotton.

Meloidogyne incognita (Kofoid and White) Chitwood has been separated into four races (R l -R4) based on the ability of different populations to parasitize 'NC95' tobacco and 'Deltapine 16' cotton (7). Since the designation of races within this species, several workers have at tempted to characterize them on the basis of reproduction on a common host. Araujo et al. (1) compared the reproduction of R1 and R4 on susceptible and resistant tomatoes at 32.5 C. No difference between the races was observed on susceptible tomatoes, but R4 produced significantly more egg masses than did R 1 on five of seven resistant tomato cultivars. Swanson and Van Gundy (6) reported that R1, R3, and R4 had significantly greater reproduction on 'Pickett' soybean than did R2. On 'Centennial'