Pesticides

Weed Killer Dicamba Eyed In Oak Tree Damage Across Iowa, Illinois And Tennessee

Oct 11, 2017
Lou Nelms, a retired biologist, stands next to an oak tree in Atlanta, Illinois, that may have been damaged by herbicide drift.
Darrell Hoemann / The Midwest Center for Investigative Reporting

As soybean and cotton farmers across the Midwest and South continue to see their crops ravaged from the weed killer dicamba, new complaints have pointed to the herbicide as a factor in widespread damage to oak trees.

Monsanto and BASF, two of agriculture’s largest seed and pesticide providers, released versions of the dicamba this growing season. The new versions came several months after Monsanto released its latest cotton and soybean seeds genetically engineered to resist dicamba in 2016. Since then, farmers across the Midwest and South have blamed drift from dicamba for ruining millions of acres of soybeans and cotton produced by older versions of seeds.

Now, complaints have emerged that the misuse of dicamba may be responsible for damage to oak trees in Iowa, Illinois and Tennessee.

Genetically engineered cotton seeds delivered to Missouri farmers in 2015 featured a warning not to spray them with dicamba. The corresponding dicamba herbicide was not approved by regulators until 2017.
File: Kristofor Husted / Harvest Public Media

The herbicide dicamba is thought to have been the culprit in more than 3 million acres of damaged soybeans across the country, destroying plants and leaving farmers out millions of dollars in crops.

The chemical has been in use for decades, so why is it today apparently causing farms so much damage?

Chafer Machinery/Creative Commons

Applying large amounts of pesticides to farm fields can have negative effects on babies born to mothers living nearby, according to new research.

The data-crunching study published in Nature Communications looked at the farm-heavy San Joaquin Valley in California, where a variety of pesticides get applied to dozens of different crops including fruits, vegetables and nuts.

A soybean field in Jasper County, Iowa, in 2016
File: Amy Mayer / Harvest Public Media

Hundreds of Midwest farmers are complaining of damage to their crops allegedly caused by the herbicide dicamba. The total number of damaged acres may come to more than 2.5 million acres, according to data compiled by a University of Missouri researcher.

Most of the damage has been found in the Midwest and South, with complaints of more than 850,000 damaged acres in Arkansas and more than 300,000 damaged acres in both Missouri and Illinois.

An Iowa soybean harvest
File: Amy Mayer / Harvest Public Media

The Missouri Department of Agriculture announced a temporary ban on the sale of agricultural products containing the pesticide dicamba on Friday, following a similar step by regulators in Arkansas.

In the global debate over neonicotinoid pesticides, the company that makes most of them has relied on one primary argument to defend its product: The evidence that these chemicals, commonly called "neonics," are harmful to bees has been gathered in artificial conditions, force-feeding bees in the laboratory, rather than in the real world of farm fields.

Insecticides are used by both farmers and home gardeners to kill bugs.
Nathan Lawrence / for Harvest Public Media

Two of the top questions I get as an agriculture reporter for Harvest Public Media are:

  1. What are pesticides, actually?
  2. How are they used on my food?

From foodies to farmers, pesticides are a sensitive subject.

Roundup, the Monsanto brand-name pesticide built on the chemical glyphosate, is used on farm fields and on lawns and gardens.
File: Grant Gerlock / Harvest Public Media

After court documents unsealed Tuesday raised questions about its research methods, chemical giant Monsanto says it did not ghostwrite a 2000 study on the safety of glyphosate, the active ingredient in its flagship pesticide Roundup.