Effects of pre-emergence herbicide on targeted post-emergence herbicide application in plasticulture production

Smart spray technology developed at the University of Florida was designed to reduce off-target applications when applying postemergence (POST) herbicides for weed control in plasticulture systems. A trial was conducted in the fall of 2021 and spring of 2022 to evaluate smart spray technology in row middles in a banana pepper field at the Gulf Coast Research and Education Center in Balm, FL. The objective of this study was to evaluate the efficacy of targeted POST-herbicide applications in plasticulture pepper row middles in the presence or absence of a pre-emergent (PRE) herbicide. Flumioxazin reduced broadleaf and overall weed densities in both seasons and lowered grass density in the spring. Two targeted applications reduced the nutsedge density in spring compared to the two banded applications. No significant pepper damage was observed in any treatments. Applied POST herbicide volume following PRE-herbicide was reduced by 84% and 54% for fall and spring respectively. In the absence of a PRE herbicide, targeted applications reduced POST-herbicide volumes by 30% and 45% for fall and spring respectively. No reduction in weed control or pepper yield was observed when comparing targeted with banded applications. Overall, the use of smart spray technology for POST herbicides in row middles reduced applied spray volume with no reduction in weed control, significant injuries on pepper, or negative effects on yield.