Yield of Susceptible and Resistant Pepper in Microplots Infested with Meloidogyne incognita

The relationships between a geometric series of 13 initial densities (Pi) of Meloidogyne incognita between 0 and 128 eggs and juveniles/cm soil and yields of a susceptible and a resistant genotype of sweet pepper (Capsicum annuum) were investigated in 40-L microplots. A Seinhorst model, y = m + (1-m)z{(Pi-T)0, was fitted to yield and plant weight for each genotype. In this model, y is the yield or plant weight, m is the minimum relative yield, and T is the tolerance limit. Both genotypes showed a tolerance limit of 0.3 eggs and juveniles/cm soil. Maximum growth suppression of the susceptible and resistant genotypes was 84% and 50%, respectively, and occurred in both genotypes at Pi 16 eggs and juveniles/cm soil. Maximum nematode reproduction was 584-fold at the lowest Pi in microplots planted with the susceptible cultivar, Yolo Wonder, but was 1 at all Pi's in microplots planted with the resistant Line 89422.