SIZE OF TUBER PROPAGULE INFLUENCES INJURY OF KENNEBEC POTATO PLANTS BY CONSTANT LIGHT

Chlorosis and necrotic spotting develop on the foliage of particular c ultivars of potato (Solanum tuberosum L.) when grown under constant li ght. 'Kennebec', a cultivar severely injured by constant light when pr opagated from tissue-cultured plantlets, also was injured when plants were propagated from small tuber pieces (approximate to 1 g). However, plants did not develop injury when propagated from large tuber pieces (approximate to 100 g). Plants from large tuber pieces grew more rapi dly than plants from small tuber pieces. The role of plant vigor and c arbohydrate translocation in controlling injury development is discuss ed.