Relation of Within-Field Spatial Variation of Plant-Parasitic Nematode Population Densities and Edaphic Factors

Publisher Website
Google Scholar
Abstract
Variations among total nematode population densities, and overwinter changes in population densities of Meloidogyne incognita, Tylenchorhynchus claytoni and Helicotylenchus dihystera, were related to soil parameters in 64 1-m2 contiguous quadrats at 2 sites. Discriminant functions composed of 26 edaphic variables correctly classified 70% of the quadrats into high, medium and low categories of nematode density. Optimum discrimination was provided by 6-8 soil parameters in stepwise-discriminant analyses. Different subsets of the 26 edaphic variables were useful with different species and sites for the discrimination of quadrats according to nematode densities. Quadrats were separated into clusters of high, medium and low nematode densities along edaphic canonical axes. Variation in soil parameters accounted for over 50% of the spatial variation in nematode counts. Clay content and Na and Cu concentrations were particularly useful in explaining spatial variation among population densities of M. incognita, T. claytoni and H. dihystera.