LEAF ANALYSIS AS A GUIDE TO NUTRITION OF FRUIT CROPS .8. -SAND CULTURE N P K MG EXPERIMENTS WITH BLACK CURRANT (RIBES NIGRUM L)

A study has been made, by means of factorial sand‐culture pot experiments, of the relationship between N, P, K and Mg treatments and their concentrations in the laminae of leaves from the mid‐third region of non‐fruiting shoots sampled in early July, and shoot growth, blossom number, fruit set, berry weight, ascorbic acid content and crop yield. Plants were propagated from hardwood cuttings and grown as biennials. from these studies it has been possible to suggest tentative standards for classifying the nutrient status of black‐currant plants in relation to growth and crop yield. the highest crop yields were associated with the following leaf‐lamina concentrations in July; N, 3.0%; P, 0.3%; K, 1.5% and Mg, 0.15 % in dry matter. Copyright © 1969 John Wiley & Sons, Ltd