TOXICITY OF GLYPHOSATE APPLIED TO ROOTS OF BARLEY SEEDLINGS

Abstract

The toxicity of glyphosate to barley seedlings when applied to the entire root system in water culture was such that at pH 7.5 the minimum lethal dose was around 15 mg l−1; 3 mg l−1 caused a 23 % decrease in shoot dry wt. Barley and wheat seedlings did not differ significantly in susceptibility. The growth of seminal roots with a short (5 mm) length of the tip exposed to 500 mg l−1 glyphosate in culture solution was decreased by about 50%. Unless a large amount of the root system of an establishing crop came into contact with the rhizomes of couch grass which had been treated with glyphosate, herbicide release by the rhizomes seems likely to be unimportant. Copyright © 1982, Wiley Blackwell. All rights reserved