Micronutrients

Abstract

Barley (Hordeum vulgare L., cv. Stirling) was grown in pots of a sandy soil. Increasing additions of boron (B) to the soil increased symptoms of B toxicity and decreased the growth of shoots and grain yield. Symptoms due to B excess were markedly expressed before plant growth was decreased. With additions to the soil, B accumulated in the older leaves of barley and increased the rate of leaf senescence. Root growth was reduced much more than shoot growth.

Critical toxic concentrations of B in the shoots of barley at booting were in the range of 50–70 μg/g dry weight.

Key words:

• Boron
• critical toxic concentrations