Individual Plant Variability in Susceptibility to Potassium Deficiency: Some Observations on Capeweed [Arctotheca calendula (L.) Levyns]

Abstract

Individual plants in an apparently uniform set of capeweed seedlings were found to differ markedly in susceptibility to potassium deficiency when grown in solution culture at a constant potassium concentration of 2.6 µM. Large differences were found in dry weight of tops (8-218 mg), tissue potassium concentration (0.3 - 4.8 %) and total potassium in the tops (23-10 500 µg potassium). Dry weight and percentage potassium were positively correlated (r = 0.859, P<0.001) at 2.6 µM potassium but not at higher potassium concentrations. The nature and possible exploitation of such variability in cross-fertilized forage plants are briefly discussed.