The effects of rates of supply of nitrogen, phosphorus, potassium and magnesium on leaf and stem growth, flowering and ‘topple’ of Golden Harvest and Elmus tulip

Abstract

SUMMARYIn factorial nutrition experiments with three rates of nitrogen, phosphorus and potassium—with some additional treatments with magnesium—on two bulb sizes of Golden Harvest and Elmus tulip, the effect of nitrogen was outstanding. Flowering was retarded by low and high rates of nitrogen supply. Increased nitrogen decreased the length of the first internode of Elmus. Mineral deficiency symptoms in leaf and stem showed minor varietal differences.Elmus tulips receiving amounts of calcium normally considered adequate developed ‘topple’ when given no nitrogen especially when combined with high potassium: these treatments also induced stem contortion in Golden Harvest, which appeared to be an analogous disorder to ‘topple’.