Short-term exposure to low temperature in the fall affects field performance of seed tubers

Field trials were conducted in Alberta and Ontario with Norchip, Norland, Russet Burbank, Sangre and Superior potato cultivars to determine response to short-term exposure of seed tubers to below freezing temperatures in the fall. Exposure of the dormant seed tubers to -1 C for up to 48 hours did not affect the yield or growth characteristics of the cultivars. However exposure of seed tubers to -5 C temperatures for 6 or 12 hours caused marked (P < 0.05) reductions in marketable yield, marketable tuber number, maturity and vine size. Exposure to -5 C for periods longer than 12 hours resulted in severe freezing damage and subsequent decay of most of the tubers.