On a country road southwest of Lawrence, a blue and white sign reminds passers-by to “Protect Kansas’ Sensitive Crops” by not letting your pesticides drift. Despite the reminder, grapevines growing on the hillside nearby exhibit damage consistent with herbicide injury for the fourth year in a row.
The vineyard owners, Rick and Debby Hird, are more than a little frustrated to see their grapes suffer. Since some widely used herbicides travel easily in wind and/or high temperatures, they are uncertain of where the problem could be originating.
“We’ve got good neighbors here,” Rick says. “One neighbor calls and tells me what he’s spraying and when. He is right on the other side of the tree line.”
Hormonal-type herbicides like 2,4-D, dicamba, picloram, MCPA and others may travel miles away from the application site. Certain formulations, called esters, are even more likely to volatilize and drift than other formulations.
Pesticide drift occurs in urban areas as well as rural. Commonly used weed-and-feed products can drift (even in dust from granular formulations) and cause injury to nearby sensitive plants.
Grapes, tomatoes and redbud trees are often thought to be the most sensitive plants to herbicide injury in this area.
The Hirds grow their grapes using conventional methods, so they are not concerned about the presence of pesticides affecting organic certification, like some growers. They are simply concerned about the loss of their crop.
“A third of the vineyard was killed in 2008. It’s just heartbreaking. Every one of these vines were hand-planted,” Rick says as he looks at the distorted, yellowing leaves.
New growth is more affected than growth lower on the vines. Leaves are curled onto themselves with their veins stretched and pulled into a parallel formation. Stems are thickened and in some places fascinated — looking like green ribbons bound together with plant tissue. On the old growth, leaves have yellowed and browned in some places.
Symptoms are similar on other sensitive plants.
Hird is hoping that growers of sensitive crops like him can compromise with area farmers. “If we can figure out peak susceptibility times, we can protect the grapes but still allow farmers to protect their crops.”
The Kansas Department of Agriculture maintains a registry of growers of sensitive crops and works with county extension offices to get the “Don’t Drift” signs to growers who meet the criteria. For registration, a crop must be grown for commercial purposes and be known for its propensity for damage. If organic, it must be grown under a certification program. Growers of sensitive crops must request to be on the registry.
Private and commercial pesticide applicators can locate properties growing sensitive crops by visiting the online registry on the Kansas Department of Agriculture website, or by contacting their local Extension office.
The Douglas County Noxious Weed Department has a map of registered sensitive crop locations in their office to share with property owners purchasing herbicides. County staff are also conscientious of sensitive crops when maintaining road easements.
In the end, Hird is thinking about more than his grape crop. “Wineries have the potential for great economic development in Douglas County. They bring in tourists who spend money here. If we are going to promote wineries — and I think there is great potential — we’re going to have to meet in the middle.”
Thirty-three Douglas County growers are listed on the Kansas Sensitive Crop Registry.
— Jennifer Smith is the Horticulture Extension Agent for K-State Research and Extension in Douglas County. She can be reached at 843-7058.