The effects of nitrogen, phosphorus, potassium and magnesium on the growth of tulips during the second season of treatment and on the chemical composition of the bulbs

摘要

SUMMARYIn factorial nutrition treatments, for a second season, with three rates of nitrogen, phosphorus and potassium, and some additional treatments with magnesium, on two bulb sizes of Golden Harvest and Elmus tulip, the effect of nitrogen was again found to be dominant. Nitrogen deficiency decreased bulb yields, leaf area, stem length (with one exception) and flower size; it also retarded flowering: the majority of small nitrogen‐deficient bulbs produced only single leaves.Deficiencies of phosphorus, potassium and magnesium had more marked effects than in the first season of treatment and generally reduced bulb yields and leaf area; in some instances stem length and flower size were also reduced. High phosphorus advanced the flowering of Elmus bulbs.The relationships between nutrition and mineral composition of the bulbs showed consistent trends determined by rates and duration of treatments, planting size and variet