Influence of High Surfactant Oil Concentrate Adjuvants and Oil Rate Response to Spray Volume on Herbicide Efficacy

Abstract

There is limited research on High Surfactant Oil Concentrates (HSOC), so studies were conducted for their evaluation. Multiple MSO-based (HSMOC) and POC-based (HSPOC) HSOCs were tested with glyphosate plus dicamba or glyphosate plus tembotrione. The addition of HSMOCs provided greater indicator species control HSPOCs when added to either herbicide tank-mix. When multiple experimental oil to surfactant ratios were added to glyphosate plus dicamba or glyphosate plus tembotrione, there were no differences among experimental HSOC ratios when added to either tank-mix by 28 days after application. Since oil adjuvant rates can be based on either treated area or percent of spray solution, oils were added to either dicamba or tembotrione to evaluate rate methods. There were few differences in species control when oils were added to dicamba. Quinoa and amaranth control were more consistent when using the percent volume-based rates with tembotrione.