Genetic differences in the copper nutrition of cereals. I. Differential responses of genotypes to copper

Abstract

Seven wheat genotypes, one or barley and one of oats were compared for their sensitivity to sub optimal supplies of copper, and their ability to recover from copper deficiency when copper was applied at defined stages of growth Copper deficiency delayed maturity, reduced the straw yield and severely depressed the gram yield In all genotypes. Genotypes differed considerably in their expression of deficiency symptoms, and In then- responses to the rate and time of copper application. For all genotypes, the supply of copper needed for maximum grain yield was significantly higher than that for maximum shoot growth. Halberd wheat and Clipper barley were less sensitive to copper deficiency than wheat cultivars Gabo, Glaive, Pinnacle, Chotilerma, UP-301, Duramba, and oats cultivar Avon. Genotypes with relatively higher yield potential were less sensitive to copper deficiency than those with lower yield potential, and the ability of hexaploid wheal to recover from deficiency increased with the increase in the number of days to heading of the normal plants There was no apparent association between dwarfness and sensitivity to copper deficiency in wheat.