Non-target drift of herbicides is an ongoing concern to winegrape growers. The use of certain herbicides can pose a significant threat to the growth of grapevines. The source of herbicide exposure comes from a variety of sources, including applications in nearby crops, road and utility maintenance, forestry, residential and winery landscape maintenance, and self-inflicted damage by misuse of herbicides in the vineyard. As growers, it is important for you to be aware of the impacts that herbicide drift can have on vines when using herbicides in your own vineyards and be sure to communicate this with other vineyard staff and neighboring farmers.

Many of the potentially damaging herbicides are readily available to most farmers, landscapers, and homeowners without special licensure through the Oregon Department of Agriculture. These products can be found at your local garden storeand home improvement centers, so it is important to know which products to avoid by looking for active ingredients such as 2,4-dichlorophenoxy-acetic acid (2,4-D), triclopyr, 2-methyl-4-chlorophenoxyacetic acid, or dicamba. A more complete list of potentially damaging herbicide active ingredients can be found here. Keep in mind that the product names are different from the active ingredient name, and you must check the product label to determine if it contains a potentially damaging active ingredient. Some commonly used products that contain such active ingredients include Crossbow, Banvel, Weed-B-Gone, and certain “weed and feed” products.  

Although grapevines are susceptible to herbicide exposure and damage for the entire growing season, they are most vulnerable early in the growing season during bud-break, bloom and fruit set. Damage occurs when the aforementioned pesticides drift onto vines by spray droplets or vapor as a result of volatilization. In warmer weather, volatile compounds can travel several miles by wind, sometimes damaging vines several days after the initial application. 

In an effort to educate herbicide users and lessen the frequency of damage caused by spray drift, the OWB, OWRI, ODA and other partnering organizations have developed information explaining how and why drift occurs and how users can safely apply these products.

A sample letter, several documents prepared by the Extension Service, information from the Oregon Department of Agriculture, and other resources are below to assist you in communicating with your neighbors about the impacts of non-target drift on grapevines. 

Information for the Wine Industry

Drift Education Letter to Vineyard NeighborsCommunication and education are the main tools growers can use to reduce the likelihood of being the victim of a drift event. OWA has provided a sample letter that can be used by commercial vineyards to inform neighbors about the potential hazards that spray drift can have on their vines.  

PNW Weed Management Handbook- The vineyard weed control section contains relevant information on how to properly administer pesticides. 

Traning Module- How to choose spray nozzlesThese resources from Ohio State University are for training, self-improvement, and professional development for industry professionals. 

 

Oregon Department of Agriculture chemical drift regulations- Oregon Department of Agriculture (ODA) helps educate pesticide users on how to avoid direct drift and volatilization (sometimes referred to as vapor drift. 

ODA spray drift brochure on broadleaf herbicides- They are pesticides that kill broadleaf or “dicot” plants. They typically do not affect grasses and therefore are important toolsin agriculture, forestry, landscaping, and right-of-way weed control, but must be carefully managed.

OWB Spray Drift Stakeholder Communication- Information from the Oregon Wine Board on spray drift.

Information for Herbicide Applicators (commercial and consumers)

Oregon Winegrowers Association fact sheet: Please Use Caution When Applying Herbicides near Wine Grapes. It includes basic information about spray drift and alternative chemicals that farmers can use that are less prone to drift. 

Preventing Herbicide Drift and Injury to GrapesOregon State University Extension bulletin EM 8860. A comprehensive fact sheet about herbicide drift and methods of prevention. 

Managing Pesticide Drift- University of Florida Extension. This drift management document focuses on the broader aspects of drift, non-herbicide applications and offers principles of drift and factors that influence it. 

How to Keep Specialty Crops Safe From Herbicide Drift- Ohio State University Extension Fact Sheet. 

New Nozzles for Spray Drift Reduction- Ohio State University Extension Fact Sheet. 

For more information, contact:

Jana McKamey, Government Affairs & Member Relations, Oregon Winegrowers Association
4640 SW Macadam Ave, Suite 240, Portland, OR 97239. Tel: 503.228.8336
Email: jana@oregonwine.com

Mark Chien, Program Coordinator, Oregon Wine Research Institute
4017 ALS, Oregon State University, Corvallis, OR 97331. Tel: 541.737.1273
Email: mark.chien@oregonstate.edu