Managing potato cyst nematodes to minimize nematicide use

Potato cyst nematodes (PCN), Globodera rostochiensis and G. pallida, are widespread in the ware potato‐growing areas of the UK. Traditionally they were controlled by rotation but more intensive production methods have increased the PCN threat, especially from G. pallida. G. rosrochiensis has become less important since cultivars fully resistant to it were introduced but, where both species are present in a mixture, the G. pallida portion comes to dominate. It is possible to control G. pallida as effectively as G. rostochiensis if cultivars partially resistant to G. pallida are grown with nematicide treatment. Where nematicide is not used, control of G. pallida is more variable. In some years, some cultivars achieve good control but the results are not consistent. In general, G. pallida has increased on untreated plots about 5‐fold in trials in the last 3 years.