Abstract
The main effects and interactions of N, P, K and Mg on cane growth, leaf nutrient composition and crop yield of red raspberry, grown in sand culture, were investigated. Results indicated that leaf‐lamina samples taken from non‐fruiting canes from late June to early August may be used as an index of the nutritional status of the crop. Leaf nutrient concentrations at this growth stage were related to crop yield in the following season. Optimum leaf‐lamina concentrations in late July were thought to be: K, 1.5%; Mg, 0.3%; N, > 2.3%; P, > 0.2% in dry weight.