THE METABOLISM OF A SERIES OF CHLOROPHEN-OXYALKYL ACID HERBICIDES IN BIGLEAF MAPL. E,ACER MACROPHYLLUM PURSH.*

Summary. Studies of the metabolism characteristics of 2,4-D, 2,4,5-T, dichlorprop and fenoprop were made to gain a better understanding of the differential response of a woody Plant, big leaf maPl. e, to certain phenoxy-type herbicides. In one test in which detached leaves were used, it was established that decarboxylation is not an important detoxification mechanism in treated foliage. This same test showed the phenoxyacetic herbicides to be more stable than the α-phenoxypropionic herbicides in treated leaves. In intact Plants 2,4,5-T was consistently more stable than 2,4-D, but the relative amount of metabolism of the herbicides varied with the Plant part. The results are discussed with respect to the differential response of bigleaf maPl. e. Métabolisme d'une série d'herbicides du groupe des acides chlorophénoxyalkylés dans l'érable à grandes feuilles Acer macrophyllum Pursh.