Response of plant species to concentrations of zinc in solution. I. Growth and zinc content of plants

Abstract

When eight plant species were grown in a flowing culture system over a range of constant zinc concentrations, all species produced maximum yields at concentrations of zinc in solution below those usually considered adequate for plant growth. All species made good growth at a concentration of 0.01 µM zinc and maximal growth at 0.25 µM zinc or less. Toxicity effects were also induced at lower concentrations (1–6 µM) than previously reported. Differences in yield response among species did not agree in all cases with previously reported responses in standard culture and in the field. Disagreement between results in the flowing culture method used here and the standard methods of nutrient culture may arise from the contrasting characteristics of zinc supply under which deficiency develops. It is considered that results from both methods have relevance to the absorption of zinc by plants from soil solutions.