EFFECTS OF TEMPERATURE OF PLANT RAISING AND NITROGEN NUTRITION ON THE GROWTH AND FLOWERING OF LEEK
Leeks cv. Tilina plants were raised at 9, 12, 18 and 24°C for various periods and supplied with two levels of nitrogen during seedling growth, then transplanted in the field in April and harvested after 800 and 1 100 day degrees ›6°C had accumulated from transplanting. Plant weight at harvest was directly related to transplant weight and was unaffected by previous history. However, the inflorescence formation was influenced by the previous history of the transplants. Whilst, in general the percentage of plants initiating inflorescences was positively correlated with transplant size at planting it was significantly greater the lower the temperature of plant raising and virtually absent in crops grown from transplants raised at 18°C and 24°C. Plants appear to be receptive to cold at least as early as the two-true-leaf stage. Examination of the data suggested that the promotive effect of N on inflorescence formation was simply due to the effects of N on plant size.
Gray, D. and Steckel, J. R.A. (1990). EFFECTS OF TEMPERATURE OF PLANT RAISING AND NITROGEN NUTRITION ON THE GROWTH AND FLOWERING OF LEEK. Acta Hortic. 267, 235-240