Temperature Responses of Three Potato-Cyst Nematode Populations From New Zealand

Abstract

The effect of temperature on 'survival', fecundity, and multiplication rate of three New Zealand populations of potato cyst-nematodes - CM006, Globodera rostochiensis Rol from Canterbury; CM001, G. pallida Pa3 from Canterbury; and FP001, G. pallida Pa2 from Pukekohe - was studied in the laboratory. Temperature ranges for population increase were: G. rostochiensis 10° to approximately 25°, G. pallida Pa3 9° to 23°, and G. pallida Pa2 8° to 22°. The optimum temperature lay between 15° and 20° for all three populations, but G. rostochiensis increased more rapidly over this range than G. pallida; only below 13°-14° did G. pallida increase more rapidly than G. rostochiensis. The slight but significantly lower temperature range of G. pallida Pa2 than Pa3 may have been a pathotype difference, but could also have been an adaptation of that population to repeated winter cropping with potatoes in soil temperatures of 6°-14° at Pukekohe.