Nearly 60 West Texas grape growers are suing Monsanto – the former agriculture chemical giant that’s now owned by Bayer – for damage to their crops they say was caused by the company’s herbicides.
The growers say the herbicide dicamba, used by nearby soybean and cotton farmers, is drifting into their vineyards. Dicamba can destroy grapevine leaves. And in that part of Texas – where an estimated 80% to 85% of the state’s wine grapes are grown – there’s concern that if the chemical drifts continue, it could hurt vineyard production.
Pierre Helwi is a viticulture regional specialist for Texas A&M AgriLife Extension in West Texas. He told Texas Standard the symptoms of dicamba’s impact are obvious when looking at grapevines; the herbicide stunts their growth.
Dicamba drifts from fields where it is sprayed into vineyards where it can harm vines, Helwi says.
“Once it’s sprayed, this product can go into the atmosphere, and can land on another property and can cause also damage,” he said. “So it can fly hundreds of miles away.”
Helwi says growers should apply dicamba according to manufacturer’s instructions to avoid drift. These include using certain kinds of nozzles to spray the herbicide, and only spraying under certain weather conditions, at specified wind speeds. Helwi says newer versions of dicamba are also supposed to be better at combating the effects of drift.
“If you follow the label, I think it will not drift so far,” he said.
The intensity and frequency of dicamba exposure determines how severe the impacts are to grapevines, Helwi says.
“If a vintner got hit by multiple times, early in the season, with a high amount of dicamba, this can cause a reduction in yield and also can cause a reduction of the lifetime of a vine,” he said.
Vines that would usually be expected to live 30-50 years could have significantly shorter lifespans because of dicamba drift, he explains.
Helwi suggests that farmers who use dicamba, and the grape growers affected by it, should communicate more about the impacts of the herbicide on vines, and how those impacts could be minimized. Helwi says more regulation of dicamba might be needed if communication among the affected parties doesn’t solve the problem.
