Misuse of phenoxy herbicides troubles grape growers
Apr 22, 2009 10:32 AM,
By Steve Byrns
Texas A&M University
Many High Plains grape growers have suffered significant economic losses from misuse of phenoxy herbicides, said a Lubbock viticulture expert.
Teresa Burns, Texas AgriLife Extension Service viticulture advisor, said phenoxy herbicides containing the active ingredient 2,4-D are commonly used to "burn down" unwanted vegetation prior to planting row crops.
“Grapevines are perennial plants that begin growth and put on new leaves early in the spring, often weeks before row crops are planted,” Burns said. “This early leafing leaves them very susceptible to damage by products containing 2,4-D."
They are also sensitive to herbicide damage throughout the growing season, she added.
“Using phenoxy herbicides in close proximity to neighboring vineyards can be devastating,” she said. “Losses as high as $10,000 per acre are possible, because affected vines either die or take several years to recover and regain normal productivity.”
Burns encourages row-crop producers to be considerate when using phenoxy herbicides, especially where there are vineyards close by.
She offers these tips:
– Don’t spray within a mile of vineyards from mid-March until the end of October.
– Use alternative chemicals when possible, but remember glyphosate herbicides can also drift and damage grapevines.
– Always read and follow herbicide label directions.
– Stop or postpone herbicide applications when wind speed is greater than 5 miles per hour or if the wind changes direction.
– Don’t spray when there’s a risk of temperature inversion, or when temperatures exceed 85 degrees Fahrenheit.
– Set herbicide application equipment to deliver large spray droplets, which are less likely to drift.
– Use air-induction or drift-retardant spray nozzles on spray equipment.
– Use a thickener, drift retardant or elasticizer in the herbicide tank.
– Use a less volatile amine formulation of phenoxy herbicide rather than an ester formulation, but be aware that amine formulations also can drift.
“The one applying the herbicide is the one responsible for minimizing the potential for drift that can damage nearby fields,” Burns said. “Just stop, think and use a little common sense and consideration before you start spraying, and you shouldn’t have any problems.”
Grape and wine production contributes close to $1 billion annually to the state's economy, Burns said. There are about 2,900 acres of grapes grown in Texas, with more than half that acreage in the High Plains and West Texas.
For more information or to locate High Plains vineyards, contact Burns at 806-746-6101 or thburns@ag.tamu.edu.
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