SummarySeven trials conducted over four years on sites naturally infested with the white potato cyst nematode established that potato clones bred for resistance toGlobodera pallidaallowed significantly less nematode multiplication than conventional cultivars under field conditions. Nematode multiplication was inversely related to initial infestation level. The nematicide, aldicarb, significantly reduced nematode multiplication. However, nematode multiplication on nematicide treated susceptible cultivars was greater than on untreated partially resistant clones, indicating that resistance may offer more effective control ofG. pallidathan chemical treatment. Integration of host plant resistance and nematicide treatment is discussed.