Nutritional factors affecting nitrate accumulation in spinach

Abstract

Moderate deficiencies of P, K, Ca, and Mg had no effect on nitrate accumulation in Spinaoea oleracea cv. America, a savoyed‐leaf type of spinach. Nitrogen supply had a marked effect on nitrate concentration in spinach leaves, but deficiencies of the other nutrients did not interact with N deficiency. Length of exposure of plants to nitrate nutrition was an important factor governing nitrate accumulation in the leaves.