THE EFFECT OF NITRITE ON ROOT GROWTH OF BARLEY AND MAIZE

Abstract

S ummary When sodium nitrite (1 mM) was added to a nitrate‐based nutrient solution, initially at pH 5, it had a small but consistently adverse effect on elongation of the seminal roots of barley and maize. In larger plants of maize, the length and dry wt of the nodal roots, and the dry wt of the shoots, were also decreased. The roots of both species were more sensitive to nitrite during growth under oxygen‐deficient conditions than when grown in solutions well supplied with air. The concentration of nitrate in the roots of barley plants decreased when 1 to 3 mM nitrite was included in the nutrient solution. It is suggested that nitrite toxicity is unlikely to be of importance in the survival of cereal roots in temporarily waterlogged soils save under the most abnormal circumstances.