Control of Common Goldenweed with Herbicides and Associated Forage Release

Abstract

Common goldenweed, an aggressive half-shrub, is rapidly increasing as a management problem on south Texas rangeland. Control with conventional foliar-applied herbicides has been erratic, with the extent of success apparently dictated primarily by growth conditions, especially soil moisture, at the time of treatment. After exceptionally high rainfall, applications of 2,4-D at 1.12 kg/ha in the spring or fall effectively controlled common goldenweed. When conditions were less than optimum for weed response, the addition of dicamba at 0.28 kg/ha with 2,4,-D or 2,4,5-T improved results compared to applications of phenoxy herbicides alone. Picloram was more effective than phenoxy herbicides or phenoxy/dicamba mixtures for common goldenweed control. Equal ratio combinations of picloram and 2,4,5-T were also effective and would be preferred where common goldenweed occurs with certain problem woody species. Within 1 year of treatment, 4.6 to 10.4 kg/ha of oven-dry forage was produced for each percentage unit of common goldenweed foliar cover removed by broadcast sprays. Successful treatments were effective for at least 3 years.