The Manitoba Potato Breeding Program was begun at the University of Manitoba in 1942, for the purpose of developing potato varieties suitable to Manitoba conditions, and for improving the quality of potatoes grown in the province. By 1946, several promising selections had been made. A number of varieties had also been introduced by the United States Department of Agriculture, the Dominion Experimental Farm Service, and private potato breeders in Canada. In order to obtain a measure of the cooking quality of such selections and of recently introduced varieties under Manitoba conditions, the study reported here was undertaken during 1946 and 1947. The soil of the University of Manitoba experimental plots is Red River clay. This soil is not representative of all areas of the province where potatoes are a crop of economic importance. Therefore it became necessary to determine the differences in degrees of cooking quality of the varieties and selections when grown in areas outside of the Red River Valley. No experimental work had been done in the province, prior to this date, to determine whether or not differences in cooking quality developed when the same variety was grown in different areas...