The effect of calcium nutrition on the incidence of internal rust spot in the potato

Abstract

Summary Tubers produced by potato plants grown in vermiculite and supplied with either 0, 1 or 3 mM calcium chloride solution developed brown necrotic lesions of internal rust spot. Plants supplied with 9 and 27 mM calcium chloride solution did not show the symptoms and had a substantially greater concentration of calcium in the tuber dry matter. It is concluded that internal rust spot is a physiological disorder associated with a low concentration of calcium in the affected tubers.