Foliar Auxin Injury Not Good Indicator of Yield Loss

By Jim Steadman|May 1, 2017

Cotton injury from auxin herbicide drift and potential yield loss have been on growers’ minds recently as planters go to the fields.

According to a recent article authored by Texas A&M AgriLife Extension and Oklahoma State cotton and weed specialists, the relationship between injury from dicamba or 2,4-D and potential yield loss is a complex issue, and a definite answer to “How much yield will I lose?” is difficult, if not impossible, to accurately predict.

According to the specialists, many factors play a role in cotton’s yield response after exposure to dicamba and 2,4-D, including growth stage at time of exposure, rate/concentration of herbicide, degree of exposure, and environmental conditions after exposure.

The complete article is available here, including tables illustrating the range of injury estimates and yield loss results of studies evaluating drift rates of dicamba and 2,4-D on cotton in South Texas and the Texas High Plains; pictures illustrating examples of visual injury symptoms from sub-lethal applications of 2,4-D and dicamba at various growth stages; and the corresponding range of injury ratings.