Races of potato blight,Phytophthora infestans(Mont.) de Bary, in New Zealand

Abstract

A small survey of blight races present in New Zealand was conducted in 1956-57 The common race 0 was present in several commercial crops in different regions, and was found also on the native species Solanum aviculare from Auckland and S. laciniatum from Lincoln. On a crop near Dunedin only race 4 was found. Races 2; 4 and 2,4 were found in breeding plots at Lincoln. In similar plots at Otahuhu, races 2 and 4 were found at an earlier collection and races 2; 3; 4; 1,3; and 2,4 at a later date. It is suggested that in view of the probable genetic constitution of the races found, there is a strong possibility of all races occurring now or in the future in New Zealand, and a more extensive survey would show many races to be widespread in commercial crops.