Comparison of the internal and external requirements of wheat, oats and barley for copper

Abstract

Wheat, oats and barley were grown with several levels of copper application on a copper-deficient soil. Differences among cereals in growth responses to applied copper appeared to be due to differences in copper uptake rather than to differences in internal copper requirements. Critical concentrations of copper in the youngest fully emerged leaf were approximately 1.3 ¦g g-1 for all three species.