EPA Approves Ultra Blazer in Sugarbeet (06/10/21)
The Environmental Protection Agency (EPA) approved our request for a Section 18 emergency exemption on June 2, 2021 for Ultra Blazer for control of waterhemp in sugarbeet in Minnesota and North Dakota. Section 18 exemption is for one application per season with ground operated equipment and targets waterhemp less than 4-inch tall in sugarbeet greater than 6-lf stage. Do not apply after July 31, 2021. Contact your sugarbeet cooperative agriculturalist or NDSU/UMN extension for more information.
Ultra Blazer (acifluorfen, group 14) is a postemergence broadleaf herbicide effective for control of redroot pigweed, waterhemp, common cocklebur, and smartweed and nightshade species. Ultra Blazer may provide some control of kochia, although results have been inconsistent in my experiments. Ultra Blazer is a contact herbicide activated by exposure to sunlight to form oxygen compounds, destroying plant tissue by rupturing plant cell membranes. Destruction of cell membranes results in a rapid browning (necrosis) of plant tissue. Herbicide injury symptoms can occur in one to two hours on a bright and sunny day. The emergency exemption is for control of waterhemp in sugarbeet that has escaped control due to inadequate rainfall to incorporate soil residual herbicides or in fields with a glyphosate resistant biotype.
Ultra Blazer will be applied at 1 pt/A with non-ionic surfactant at 0.125% v/v or 1 pint per 100 gallon water alone or with glyphosate in 15 to 20 gpa water volume through flat fan nozzles producing a droplet spectrum to promote good coverage in sugarbeet. Consideration should be taken on environmental conditions at application since risk of injury increases with air temperatures greater than 80F and sudden changes from a cool, cloudy environment to a hot, sunny environment.