SDSU will lead multi-state look at whether herbicides injure trees

Bob Mercer
Farm Forum Correspondent

RAPID CITY — South Dakota State University can proceed in a lead role with the state Department of Agriculture investigating whether herbicides are injuring trees, the state Board of Regents decided on Oct. 3.

The agreement ends May 31, 2020. Illinois, Indiana, Iowa, Missouri and Nebraska also will collect leaves. Fifty to 200 samples will be taken in each of the six states.

SDSU will lead the work with John Ball as principal investigator. The state department will provide $38,490 to SDSU. The university will cover the remaining $9,199.

The matter was part of the regents’ consent agenda, so there wasn’t discussion.

The narrative for the agreement notes: “Glyphosate, atrazine, 2,4-D, and dicamba are widely used agricultural herbicides with some of the highest usage, measured in pounds per acres, in the croplands of the Midwestern and Great Plains states.

“The past several years there has been an increase in herbicide drift complaints from small communities surrounded by agricultural fields and landowners with crop windbreaks or woodlots, as the use of glyphosate-resistant crops became common place.

“The problem became compounded with the introduction of dicamba-resistant soybeans.

“During 2017, thousands of herbicide drift complaints alleged damage to community trees, windbreaks, and rural woodland, due to the suspected application of dicamba to soybean fields throughout the region.

“No reliable information exists to describe characteristic symptoms on common tree species, or the concentration threshold between symptomatic (injured) and asymptomatic (non-injured) trees.”

Sampling starts in May and will finish by August. Analysis will be completed by fall 2019, and a public report will be completed by May 2020, according to a timeline presented to the regents.