Greenhouse studies indicated that 3,6-dichloro-o-anisic acid (dicamba) or its metabolic derivative was strongly accumulated in meristematic tissues of Tartary buckwheat (Fagopyrum tataricum(L.) Gaertn.) and wild mustard (Sinapis arvensisL.) following both foliar and root uptake. In barley (Hordeum vulgareL.) and wheat (Triticum vulgareL.), it was distributed throughout the plants. Detoxification of dicamba occurred in all four species though not at equal rates, and a common major metabolite was identified chromatographically as 5-hydroxy-3,6-dichloro-o-anisic acid. A minor metabolite, 3,6-dichlorosalicylic acid, was found in barley and wheat but not in Tartary buckwheat or wild mustard. The four species tolerated dicamba treatment in the order of wheat, barley, wild mustard, and Tartary buckwheat. This ranking corresponds with the ability of the plants to detoxify dicamba and is inversely related to the extent of dicamba absorption and translocation in them.

Summary. The efficacy of NN‐diallyl‐αα‐dichloroacetamide (R‐25788) as an antidote for reducing the injury of various herbicides in corn (Zea mays L.) was tested under controlled conditions in growth rooms. The application of R‐25788 to the soil as a pre‐plant incorporated treatment to corn significantly reduced the toxicity often out of twenty‐two herbicides tested. These ten herbicides were, in order of decreasing effectiveness of the antidote, EPTC, barban, sulfallate, vernolate, molinate, butylate, alachlor, pebulate, linuron and di‐allate. In quartz sand nutrient culture, R‐25788 was more effective as an antidote for barban applied to the foliage of corn than it was for barban applied to the roots. Le NN‐diallyl‐αα‐dichloroacétamide comme antidote de I'EPTC et autres herbicides dans le mais.

A new herbicide antidote, N,N-diallyl-2, 2-Pers.) but not to winter rap (Brassica na

The foliage and roots of Canada thistle (Cirsium arvense (L.) Scop.) readily absorbed 2-methoxy-3,6-dichlorobenzoic acid (dicamba) after which it was translocated by both phloem and xylem. The results are in harmony with a source-to-sink system of dicamba translocation in the phloem. Following foliar application, small amounts of dicamba were exuded by the roots into surrounding soil. Dicamba tended to accumulate in young, growing leaves following both foliar or root uptake. Leaves, but not roots, retained a substantial portion of the dicamba taken up. After 54 days, 63.1% of the recovered radioactivity in the treated leaf was still in the form of unaltered dicamba. The remaining 36.9% was in the form of an unidentified product. In other plant parts, much less change occurred. During a 54-day period, one-fifth of the dicamba applied was recovered as radioactive CO2.