| Abstrakt: |
Volatility reducing agents (VRAs) are now required for all in-crop dicamba applications. The University of Arkansas System Division of Agriculture has continued to evaluate potassium tetraborate tetrahydrate (potassium borate) as a VRA and boron (B) nutritional. A greenhouse and field experiment were conducted in Fayetteville, Ark., in 2021, to ensure the crop safety of postemergence mixtures containing dicamba and potassium borate. For each experiment, potassium borate was applied at six rates (0, 0.1, 0.2, 0.3, 0.4, and 0.5 lb B/ac) alone or in combination with the XtendiMax formulation of dicamba at 0.5 lb ae/ac. Additionally, a mixture of XtendiMax, Roundup PowerMax, and Dual II Magnum, as well as Liberty, Roundup PowerMax, and Dual II Magnum at labeled field use rates, were used as a comparison for cotton injury. Treatments were applied in the greenhouse on 1-to 2-leaf cotton and at the pinhead square growth stage in the field. At 3 days after treatment (DAT) for the greenhouse experiment, only three-way mixtures caused injury, showing that potassium borate is not injurious to cotton when applied alone or with dicamba. Biomass collected 28 DAT also reflected that treatments containing potassium borate were comparable to those that were not mixed with the additive. In the field, injury to cotton was not observed for any treatment, possibly due to a later growth stage at application. Based on these findings, it is unlikely that potassium borate would cause unacceptable levels of injury to cotton if utilized in the Xtend system. [ABSTRACT FROM AUTHOR] |
