Grape farmers in Wisconsin are facing a growing threat, and in many cases it is coming from their own neighbors.
Herbicides that are used to kill weeds in crops such as corn and soybeans can be deadly to other plants, including grapes. Food or wine grape vines exposed to the chemicals may shrivel up, turn colors and grow strange, elongated new leaves.
“It just becomes a bizarre, distorted structure,” said Judy Reith-Rozelle, a consultant and horticulture researcher at the University of Wisconsin-Madison. “The grape farmers are real worried.”
Wisconsin’s grape industry is growing fast. A U.S. Department of Agriculture survey released this spring shows that the number of farms has doubled since 2005, and the state adds an average of nine new vineyards each year.
There are now more than 100 commercial vineyards in the state. Wisconsin grapes are mainly used for wine, though some growers produce table grapes and grapes for juice.
The UW-Extension estimates the industry generates about $200 million a year in sales and labor.
Grapes are, however, highly sensitive to a commonly used class of herbicides known as plant growth regulators, which kill broadleaf plants. Vineyards located near corn and soybean producers are at risk if the herbicides drift onto their crops.
Ryan Prellwitz, president of the Wisconsin Grape Growers Association, said he frequently hears complaints from grape farmers.
“It’s a problem that, if not dealt with, could cause a significant economic impact to the vineyards and wineries around the state,” Prellwitz said.
The state Department of Agriculture, Trade and Consumer Protection is trying to address the problem.
The agency is encouraging specialty crop farmers to register on DriftWatch, an online database created by Purdue University. The goal is to increase awareness and reduce the misuse of herbicides by neighboring farms.
DATCP recently hired a part-time employee to encourage specialty farmers with sensitive crops to sign up with DriftWatch and for applicators to consult the registry before applying herbicides.
Ann Marie Ames, DATCP’s new employee, networks with farmers and helps them add their farms to the database. She said 329 producers are registered on the site, including 86 vineyards.
“It’s not going to stop pesticide drift, but it gives us a pretty good way to talk about it,” Ames said.
She said grapes are not the only specialty crop at risk. Beekeepers, fruit and berry farmers, hop growers and organic farmers also can register on DriftWatch.
“This isn’t the end-all be-all solution — this is one tool,” Ames said, adding that ultimately, “the responsibility falls back on the producers to speak up for themselves.”
Farmer against farmer
At issue is a class of commonly used growth-regulating herbicides including dicamba and 2,4-D.
“Any time you’ve got this confluence of two major forces, there’s likely to be some conflict,” said Donna Gilson, DATCP spokeswoman. “I think it’s the rise of the grape growing industry, and it’s happening in a lot of the corn and soybean growing country in Wisconsin.”
When applied selectively to corn and soybean crops, the chemicals kill weeds such as thistle, burr and wild mustard and leave the crop unharmed.
But when the herbicides are applied, the spray can drift with the wind or be evaporated and dispersed, potentially landing on the grapevines in nearby vineyards. Even tiny amounts one hundred times lower than the recommended application of these herbicides can cause injury to grapes.
Some studies show vineyards several miles away from the application site can be affected. Vines can be injured, deformed or even die.
“The issue is that grapes, in particular, are very sensitive to growth regulator herbicides,” said Jed Colquhoun, UW-Madison horticulture professor. “So it only takes a very low dose to cause damage and … that can be quite expensive when it does happen.”
These types of herbicides have been used for a long time, and Colquhoun said this is a not a new problem.
“Herbicides are used very commonly across the landscape and in crop production, and the cases of drift are very, very rare,” he said. “The issue is that grapes, in particular, are very sensitive to growth regulator herbicides.”
Prellwitz said with the growing number of specialty crops in Wisconsin, including grapes, the chance for drift damage is increasing. “I would expect the number of incidences to increase over time unless there’s something done on the state level to eliminate some of the issues that could be potentially caused by drift,” he said.
However, Bob Oleson, executive director of the Wisconsin Corn Grower’s Association, said he has not heard any complaints of drift impacting vineyards or other specialty crops and said it is not an issue for corn growers.
“They just don’t plant [vineyards] next to corn fields so there isn’t the possibility of drift. Furthermore, with the modern technology we’re just not seeing instances of drift we saw many, many years ago.”
Scientists in the industry do not dispute the well-documented side effects of herbicidal sprays.
“The symptoms are very clear. It’s difficult to mistake this for other things,” said John Jachetta, a crop scientist who until his retirement in July worked in regulatory sciences and government affairs at Dow AgroSciences, a leading herbicide producer.
Lee Van Wychen, director of science policy at the Weed Science Society of America, an industry group, agreed that the symptoms grapes exhibit when they are exposed to these herbicides is hard to mistake.
He said while other pesticides and herbicides can sometimes impact sensitive crops like grapes, “If there’s a case that occurs with 2,4-D or dicamba … it would be much easier to come to the conclusion that there was spray drift damage.”
As a grape expert, Reith-Rozelle hears complaints regularly from Wisconsin farmers who are experiencing what they perceive to be a crisis.
“The anxiety is still very high,” Reith-Rozelle said. ”It’s a big concern wherever corn and soybeans are grown.”
The human impact
The problem of chemical drift onto grape farms has even led to litigation.
In 2007, Ted Kearns, a vineyard farmer near Platteville, won a civil case against a nearby grain producer. The case was settled in Lafayette County Circuit Court for about $150,000 according to Kearns’ lawyer, Ted Warpinski.
A few years earlier, a farm pasture at nearby Spensley Grain was sprayed with RangeStar, a combination of 2,4-D and dicamba, that drifted on the wind and volatilized in the air, eventually landing on Kearns’ grapes and causing them to die.
Kearns said he first noticed the problem one morning in 2004. The leaves on his grape vines had shriveled up and changed colors. The crop was ruined.
“I cried. I actually cried,” said Kearns, a Vietnam veteran who said starting a vineyard was his dream. “I spent 12 hours a day, seven days a week for 12 years on this vineyard and winery, trying to make it work.”
Kearns, a political conservative with an “I Stand With Walker” sign on his door, said he has had drift damage six out of the past nine years and is contemplating additional litigation. Now, he hopes to sell the property he bought 14 years ago but fears it has lost a lot of its value.
Meantime, he said all he can do is hope that the neighboring farms use the herbicides according to the label on the products.
“If I don’t get a crop this year,” Kearns said, “I’m going to have to go out of business.”
The label is the law
Farmers who use commercial herbicides are required by law to follow the label on those products. But that may not be as simple as it sounds.
The label for Roundup Ready, a popular herbicide for agricultural use made by Monsanto, is complex. In order to meet regulations set by the U.S. Environmental Protection Agency, applicators must consider a variety of weather conditions and use a particular kind of nozzle when spraying.
The 13-page label requires farmers to apply the chemical several times for it be effective, avoid trees, vines, citrus fruit, nuts, olives and vineyards and avoid spraying during times of humidity and heat, along with an array of other specifications.
Reith-Rozelle said those requirements are complex and hard for farmers to follow.
“The farmers may go out when the temperature is a little too hot and the wind is blowing more than the allowed limit per hour (8 to 10 miles) and sometimes they’ll spray because they don’t have other options,” she said.
She added that farmers are not the only herbicide applicators to blame — vineyards located near residential areas are also subject to drift from chemicals used on lawns and golf courses.
DATCP often can do little to enforce the law when it comes to herbicidal drift because the origin of the drift is hard to track, especially if it volatilizes rather than being carried by the wind, Gilson said. The agency can ask local prosecutors to issue fines or criminal charges against those violating label directions. DATCP also can put restrictions on their licenses to apply herbicides.
“The label is the law,” Gilson said. “You are expected to follow that label and you’re responsible for following that label.”
The UW-Extension offers an annual applicator training program for farmers, commercial and private herbicide applicators.