Application Variables and Their Influence on Forest Herbicide Efficacy and Selectivity: Gaining Understanding and Control

Available research is reviewed on the interactions of application variables, herbicides, and species. Objectives of this review are to gain insights into why variation occurs with herbicide performance, how current knowledge might be applied to enhance efficacy and consistency, and research pathways that should foster integration of applicationefikacy models. A historical context is provided on southeastern forestry herbicide applications. Adoptable application technology from agronomy and right-of-way sectors are explored. To enhance consistency and performance, increased rates and optimized timing hold most promise. Optimizing droplet size spectrums and new surfactants also have potential. Multidimensional efficacy functions are needed for the commonly abundant species and often-used tank mixes by rate and timing. Integratable research is the key to advancement.