Control of Palmer Amaranth with 2,4-D and Dicamba As Affected By Stage of Growth and Spray Droplet Size

With the commercial release of 2,4-D and dicamba herbicides for use in Enlist and XtendFlex cotton, many growers have begun to use these herbicides as a part of their weed management programs for cotton. These new herbicide formulations require the use of specific spray nozzle designs which produce large spray droplets to reduce the risk of off-target movement due to spray drift.  While large spray droplets are desirable for reducing spray drift, their impact on herbicide performance is not fully understood in many cases. Field experiments were conducted at Corpus Christi, TX to investigate any impacts of spray droplet size on the performance of 2,4-D and dicamba on Palmer amaranth at various sizes.