Evaluation of a New Fluridone Premix for Palmer Amaranth Control in Cotton

Fluridone was initially evaluated in the 1970s, but was not brought to market due to lack of control of key weed species at the time and cost of production. The prevalence of glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri) has renewed interest in pursuing fluridone as a weed control product in cotton. In 2014, a Section 18 label was granted for Brake F2 on limited acres in Georgia, South Carolina, North Carolina, and Tennessee. Research was conducted during the 2014 growing season at multiple locations in Tennessee and Georgia to evaluate Brake F2 (fluridone + fomesafen) for efficacy and crop safety. Incremental rates of Reflex and Brake were evaluated in comparison to three comparable rates of the premix herbicide for efficacy and weed control. Individual treatments included Reflex at 4, 8, 12, and 16 fl oz/A, Brake at 3.2, 6.4, 9.6, and 12.8 fl oz/A, and Brake F2 at 16, 24, and 32 fl oz/A. Crop injury and Palmer amaranth control were evaluated at 7, 14, 21, 28, and 35 DAT. Preliminary results indicate a very high crop tolerance to this herbicide, however weed control varied by location.