Abstract
Cu deficiency retards the development of reproductive organs of corn, wheat and cockleburs. The dye 2,3,5-triphenyltetrazolium chloride was only weakly reduced in the Cu deficient plants. Maximum, reduction of TTC was obtained in plants grown on a naturally calcareous soil or an organic soil to which Cu was added. Comparative ascorbic acid oxidase activity, catalase activity and the concentration of Cu and Fe in corn and wheat showed that the reduction of 2,3,5-triphenyltetrazolium chloride in these plants could best be correlated with Cu rather than Fe nutrition.