Vernalization of Lettuce

Abstract

Gray¹ and Simpson² have both reported experiments on the vernalization of lettuce, and these observers agree that low (2–8°) temperature treatment of the swollen seeds for varying periods, while not affecting the date of heading, reduces the period for which the plants remain in the heated stage and accelerates flowering by fourteen to twenty days. Experiments carried out here indicate the importance of the timing of these vernalization treatments.