Tree Stress from Salts and Herbicides

Abstract

Trees are damaged from both salts used in deicing highways and herbicides used for weed control. Aerial salt sprays lifted by traffic are more damaging to trees than soil accumulations. Salt injury can be reduced by applying antidesiccants, constructing physical barriers, leaching soils, incorporating activated charcoal and planting high and away from salt spray and runoff. The most damaging pre-emergence herbicides include simazine and dichlobenil while dicamba, 2,4-D and related compounds are the most harmful post-emergence chemicals. Prevent injury from herbicides by proper chemical selection, application at desired rate, with accurately calibrated equipment on a day when drift is minimized. Avoid soil residues, treating susceptible cultivars and treating under plant stress conditions. Activated charcoal can be used to detoxify many herbicides in the soil.