Are farm chemicals to blame for Iowa’s sick oak trees?

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Iowa’s state tree is under stress. Visible damage to oak trees in recent years may be caused by farm chemicals, forestry experts say.

Nearly a thousand Iowans have contacted the Iowa Department of Natural Resources this spring after noticing the leaves on their oaks appear to be eaten by insects nearly down to the veins, a problem exacerbated this year because of weather fluctuations.

The good news: the trouble isn’t with insects. The bad news: There’s not much you can do about it, unless herbicide applied to corn and soybean fields is stopped, according to a DNR district forester.

“If that chemical was not there, this wouldn’t happen, if you believe the research,” said Mark Vitosh, who is based in Johnson County.

Officials with Monsanto, which makes chloroacetanilide herbicide products cited in studies, said they haven’t received any complaints and weren’t immediately familiar with research on it, so could not comment.

University of Illinois research in 2004 found a “strong correlation” between a condition called leaf tatters and exposure to chloroacetanilide herbicides, particularly in white oaks.

A 2008 study in Iowa by the DNR and Iowa State forestry experts reported that 11 million pounds of acetochlor and metolachlor (both in the chloroacetamide group of herbicides) was applied in Iowa in 2005 and showed similar correlations to oak leaf tatters.

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post: Iowa’s oak trees are sick, and some say farm chemicals are to blame