Population densities of Meloidogyne incognita and growth of cabbage in pots.

The relationship between initial population densities (Pi) of Meloidogyne incognita host race 1 and growth of cabbage plants was investigated in a pot experiment. Pots were artificially infested with finely chopped nematode-infected tomato roots to give a range of population densities of 0, 0.062, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128 or 256 eggs and juveniles/cm3 soil. The tolerance limit of cabbage to M. incognita was 0.5 eggs and juveniles/cm3 soil and a minimum relative yield for top weight of 0.05 occurred at Pi> 32 eggs and juveniles/cm3 soil. The maximum reproduction rate of the nematode was 68-fold and occurred at the lowest Pi.