Effects of spray volume and droplet size on herbicide deposition and common cocklebur (Xanthium strumarium) control

A field study was conducted in 1992 and 1993 to identify the spray volume a nd droplet size combinations to optimize control of common cocklebur (Xanth ium strumarium) from acifluorfen by maximizing target deposition. In many i nstances, acifluorfen controlled common cocklebur better using either small (250 mum) or large (450 mum) spray droplets when applied at the lower carr ier volumes of either 56 or 112 L/ha, When sprays were applied at 169 L/ha, there was little difference in control between droplet sizes. Deposition o f acifluorfen was determined in 1993, Stepwise regression indicated that ac ifluorfen deposition amount is less important than environmental conditions for common cocklebur control. Relative humidity was the most significant v ariable for determining common cocklebur control with acifluorfen.