Aerial spray drift from different formulations of glyphosate

Glyphosate and similar herbicides have facilitated low and no-till producti on systems through more effective management of winter weeds before plantin g spring-seeded crops. Crop cultivars tolerant to specific herbicides are a lso more readily available. Increased use of these systems and their requir ements for timely herbicide applications have increased the acreage of herb icides applied by aircraft. Manufacturers of glyphosate have also made some changes in rite product formulations in an effort to provide improved effi cacy, and convenience. A combination of these and other factors have increa sed the incidence and raised awareness of spray drift from aerial applicati ons of glyphosate. This study was conducted to provide information in respo nse to those concerns. Four spray mixes of glyphosate from three different formulations were included in an extensive field study to determine relativ e drift propensity of the spray mixes from the different formulations. Ther e were no meaningful differences in spray deposition, spray drift, and atom ization in a wind tunnel between the glyphosate formulations of Rounndup(R) and Roundup Ultra(R).