CHIP COLOR, SUGAR CONTENT AND YIELD OF SUMMER POTATOES DURING GROWTH IN SOUTHERN ONTARIO

Abstract

Tubers of five summer potato cultivars were monitored weekly for chip color, reducing sugars, sucrose, and marketable yield for 4 wk commencing 3 July, about 80 d after planting, in 1985 and 1986 at Harrow and Simcoe, Ontario. Atlantic and Conestoga tubers generally contained the lowest sugar levels, were the only cultivars to produce acceptable colored chips by 3 July, and had lighter chip color than all cultivars, even lighter than the standard cultivar, Superior. Conestoga yields by 3 July (about 13 t ha−1) exceeded those of Superior (about 10 t ha−1), but Atlantic required 7–10 d more growth to produce comparable yields. Atlantic and especially Conestoga may be more suitable than Superior for use as main summer chipping cultivars in southern Ontario.Key words: Solanum tuberosum L., cultivar, chip color, sugar content, marketable yield, maturity