SELECTIVE CONTROL OF WILD OATS IN BARLEY WITH AC 84777

A series of field plot experiments showed that AC 84777 (1,2 dimethyl-3, 5-diphenylpyrazolium methyl sulfate) as a postemergence herbicide provided selective control of wild oats (Avena fatua L.) in barley (Hordeum vulgare L.) equal to or better than barban over a growth period of the weed extending from the 3-leaf to the 5-leaf stage. Barban (4-chloro-2-butynyl m-chlorocarbanilate) must be applied at the 2-leaf stage of the wild oats to achieve effective control of the weed. AC 84777 increased in efficacy as the wild oats advanced from the 3- to the 5-leaf stage. Spot applications of AC 84777-C14 showed that the C14 label entered the leaf of wild oats or barley and moved quickly in an acropetal direction. It had concentrated in the leaf area above the point of application in a space of 30 min. Spot applications of AC 84777 made at the mid-point of the first through to the fourth leaf of wild oats resulted in necrosis of the leaf area above the point of application. Application at or below the meristemati...