Interactions of Diclofop-Methyl and 2,4-D in Cultivated Oats (Avena sativa)

Abstract

The chlorophyll levels and growth of oat (Avena sativaL. ‘Elgin’) seedlings were drastically reduced after foliar application of diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate}. The leaves were chlorotic and necrotic with the newly emerging leaves being most affected. Plants treated with 2,4-D [(2,4-dichlorophenoxy)acetic acid] were similar to the controls. When 2,4-D was applied to intact plants in combination with diclofop-methyl the toxicity symptoms produced by diclofop-methyl were reduced. Diclofop-methyl disrupted membrane integrity and inhibited chlorophyll formation in excised leaf segments. Addition of 2,4-D with diclofop-methyl did not change the effects produced by diclofop-methyl alone in excised leaf segments.