Iron chlorosis induced by detopping soybeans

Abstract

In work elsewhere it has been shown that detopping soybean seedlings growing in soil that results in Fe deficiency can magnify the Fe deficiency in subsequent new growth. Tests then can be more sensitive for screening of progeny for resistence to Fe deficiency. The hypothesis that nitrate‐N is responsible for the chlorosis was tested. When plants are detopped, more nitrate can be available than usual for the small amount of leaf surface available. When soybean plants were grown to have low availability of nitrate‐N, new growth after detopping did not develop Fe deficiency. In contrast, plants supplied with nitrate did develop Fe deficiency.

Key words:

• Nitrate‐iron interaction
• Bicarbonate
• Screening for Fe efficiency

Notes

The Laboratory of Biomedical and Environmental Sciences is operated for the U.S. Department of Energy by the University of California under contract no. DE‐ACO3–76‐SF00012.