Vertical distribution of Pratylenchus neglectus, P. crenatus and Tylenchorynchus dubius associated with maize roots and the effect of aldicarb residues

SUMMARY Depth samples on a field trial on forage maize revealed consistent differences in the numbers of Pratylenchus neglectus, P. crenatus and Tylenchorynchus dubius at different depths after treatment with aldicarb the previous year. Pratylenchus was more numerous lower down in residual‐treated soils but more evenly distributed in untreated soils. T. dubius , although less numerous after aldicarb, was more numerous in the upper layers of the soil. Aldicarb and benomyl applied the previous year had no residual effects on yields.