The cooking tests described showed that differences in cooking quality of potatoes do occur in Rhode Island from one season to another, and that the large differences at least are due to climate and variety. Changes in cultural practices which could be applied by the farmer, such as irrigation or different ratios of fertilizers did not produce measurable differences in cooking quality between lots of the same variety. Differences in cultural practices might be shown to affect cooking quality if more carefully controlled experimental conditions were available, but it is doubtful if any differences obtained would have an economic significance.