MAINESTAY - A HIGH-YIELDING, ROUND WHITE POTATO VARIETY FOR FRESH-MARKET

The Mainestay potato variety is high-yielding and late-maturing produc ing attractive, round, white-skinned, white-fleshed tubers with medium -shallow eyes. Its major use is expected to be as a maincrop tablestoc k variety. Mainestay appearance ratings are similar to those of Katahd in, and greening in Mainestay tubers is less than in Kennebec. Most bo il and bake qualities were rated. equal to Katahdin in at least half o f the tests, and Mainestay usually has a low incidence of internal def ects. However, purple streak, heat necrosis, vascular discoloration, a nd heat sprouts have been seen on occasion. Mainestay tubers do not sh ow the net necrosis caused by potato leafroll virus, and have shown ve ry little hollow heart or blackspot bruising. Mainestay is susceptible to common scab and acid scab, but moderately resistant to verticilliu m wilt (Verticillium albo-atrum and V. dahliae), early blight (Alterna ria solani), rhizoctonia (Rhizoctonia solani), dry rot (Fusarium sambu cinum), and pink rot (Phytophthora erythroseptica). It is moderately s usceptible to the common race of late blight (Phytophthora infestans), Mainestay tubers are slow to mature after vine kill, and additional t ime is required prior to harvest in order to allow for proper periderm development and to reduce storage losses.