Plant-parasitic nematodes in new zealand

Abstract

Nematodes attack a wide variety of economic plants in New Zealand. This paper lists the major pest species and discusses the extent of crop losses. The most economically important crop nematodes are the potato cyst nematodes Globodera pallida and Globodera rostochiensis, which threaten both yield and export status. The problems caused to the potato industry by the lack of nematode survey information, the high costs of diagnosis, and the limited control options are discussed. In pasture, white clover productivity, competitive ability, and N-fixation are limited by clover stem nematode {Ditylenchus dipsaci), root-knot nematode (.Meloldogyne hapla), and clover cyst nematode {Heterodera trifolu). Research on these nematodes is described, including recurrent selection of white clover for resistance, field-based selection for tolerance, the study of nematode biology and life cycles, and the study of rhizosphere micro-organisms antagonistic to the root nematodes. Research into nematode parasites of pasture grasses and lucerne is summarised. Outlines are given of research into the ecology and systematics of plant-parasitic nematodes. © 1994 Crown.