Effect of the root-knot nematode Meloidogyne incognita on parsley.

A screenhouse experiment was conducted in 1000 cm3 plastic pots to evaluate the effect of increasing population densities of M. incognita race 1 on yield of parsley cv. Double Curled. Initial nematode densities were: 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128 and 256 eggs + second stage juveniles (J2) cm-3 soil. Fitting the Seinhorst model, y = m+(1-m)zPi-T, to average plant top and total fresh weight and top dry weight, gave tolerance limits (T) of 0.17, 0.02 and 0.025 eggs + J2 cm-3 soil. The minimum relative yields (m) were 0.5 at Pi > 16 eggs + J2 cm-3 soil, 0.55 at Pi > 2 eggs + J2 cm-3 soil and 0.34 at Pi > 4 eggs + J2 cm-3 soil for top fresh weight, total fresh weight and top dry weight. The maximum nematode reproduction rate was 37-fold at Pi = 0.25 eggs + J2 cm-3 soil and an equilibrium density was estimated at 5 eggs + J2 cm-3 soil. Anatomical modifications observed in galled roots were similar to those induced by this root-knot nematode species in other hosts.