Effectiveness of glyphosate mixed with soil-active herbicides

Abstract

Broadcasting mixtures of glyphosate and soil-active herbicides over loblolly pine (Pinus taeda L.) seedlings may control established weeds and emerging weed seedlings better than either glyphosate or soil-active herbicides alone. However, herbicides will injure young pines if applied improperly. To examine seedling injury, we broadcast two rates of glyphosate, 0.4 and 0.8 lb acid equivalent per acre, alone and mixed with hexazinone, oxyfluorfen, or simazine, over newly planted loblolly pine seedlings and herbaceous competitors. Oxyfluorfen and simazine did not increase pine mortality, but glyphosate alone or in mixtures did. Glyphosate and hexazinone applied alone or mixed produced the most promising results for weed control.