Determination of tuber sizing and accumulation of total solids contents of four potato varieties harvested at several dates

Summary

A determination of the tuber sizing and the accumulation of total solids content during the growing season of potato varieties is considered an important phase of the Ontario Regional Trials. Data on the above are reported for four varieties over a four-year period 1957–60. In all years, the total solids contents of the “early” varieties reached a maximum by mid-August. The maximum number and yield of Ontario No. 1 size tubers of these was also attained during this period or shortly after. In three out of four years the “late” varieties also reached a maximum solids content by mid-August, but the number and yield of Ontario No. 1 size tubers of the “lates” usually continued to increase into September. In the Guelph region of Ontario the period of greatest yield gains was from mid-July to mid-August for the earlies and from early August to early September for the lates. Following the peak period of total solids content, generally occurring in mid-August, a levelling off (sometimes a decline) in the solids content was most frequently noted. It is suggested that Ontario potatoes which are to be stored may be harvested earlier with little reduction in yield and no reduction in total solids. This is particularly important when the potatoes are to be processed.