Effect of fallow and root destruction on survival of root-knot and root-lesion nematodes in intensive vegetable cropping systems

Changes in population densities of root-knot nematodes after short-term clean-fallow periods between successive crops were estimated in intensive vegetable cropping systems for greenhouse and outdoor crops. The effect of root destruction during fallow on population decline of Meloidogyne arenaria race 2 and Pratylenchus neglectus was also determined following a greenhouse-grown bean crop. The average rate of root-knot nematode survival between subsequent crops was 0.50. Survival rates were negatively correlated with increased initial population densities but were not correlated with the length of fallow periods. Fallowing combined with root destruction was more effective (P = 0.05) than following alone in reducing population densities of M. arenaria race 2 and P. neglectus.