Effects of Night Temperatures and Day Length in the Winter on the Flowering, Yields and Quality of Snapdragon (Antirrhinum majus. L.)

Abstract

The snapdragon (Antirrhinum majus. L.) variety Maryland Pink, Light Pink Butterfly II and Verne were grown under 2 night temperatures (6°C, 11°C) and 2 photoperiods (Natural day, 16-hr day length) in winter with pinching and non-pinching cultivation. In pinching cultivation, the flowering of the stem was accelerated by high night temperature, but that was not accelerated by long day treatment. Yields of cut flowers of Light Pink Butterfly II were the largest when grown under a combination of night temperature of 11°C and long day treatment, while those of Maryland Pink and Verne were not affected by night temperature and long day treatment. Cut flower quality was not affected by long day treatment. In non-pinching cultivation, the whole growth period was accelerated by a high night temperature, but only the flower development was accelerated by long day treatment. The number of plant nodes was decreased by long day treatment. In Light Pink Butterfly II, the node number decreased even high night temperature so.