The term “sustainable agriculture” is not easily understood, and in fact has been substituted with the term “environmentally enhanced agriculture” in some instances to give the average person a better understanding of its definition.  Washington wine grape growers have learned that their success is derived from an adherence to a philosophy of Integrated Pest Management (IPM) and use of other sustainable practices.

The growth of Washington’s premiere wine industry will be accomplished through continued education on vineyard stewardship.  While we don’t have a catchy name for the sustainable agricultural systems, Washington wine grape growers are extremely familiar with the term and you will find some form of sustainable practices in every vineyard in the state.  Growers have been quick to adopt these practices as they’ve become available. 

Area growers will have several opportunities throughout the year to fine-tune their skills through a series of workshops and annual summer tour sponsored by the Washington Association of Wine Grape Growers (WAWGG).  Central to this is the Washington State University research station at Prosser.  One focus of these programs is the economic management of pests with minimal environmental disruption. Pest management specialists including entomologists and plant pathologists feature hands-on, interactive, educational events on recent developments.  Sessions take place in the classroom, laboratory, and vineyard.

Growers are quick to point out that good management practices begins even prior to planting a vineyard, including site selection, crop history, slope, drainage, quality nursery stock and pest-free plant materials.  All of which come into play. 

Washington wine grape growers are concentrating their resources in this area and continually are trying to find innovative ways to become more efficient, cut costs, and increase profitability.  Washington wine grape growers have a genuine desire to seek true solutions to problems through research.  This need to enhance sustainable practices is fueled by its economic viability to growers and the continued loss or threat of losing more traditional methods for controlling pests and other problems. 

However, development and implementation of improved biological control strategies and other research does not happen overnight.  It is tedious, complicated, and requires progressive evaluation, all of which take time and resources.  It is important to continually demonstrate and promote the success of these practices and low input approaches to the growers, industry leaders, decision-makers and the general public.

Integrated Pest Management (IPM) is a sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks.  For many generations, insecticides have been a relatively inexpensive first line of defense for most pests of grapes.  That is rapidly changing and compared to other agricultural commodities in Washington and other grape-growing regions of the world, Washington has fairly limited pest problems and generally growers use fewer pesticides.  Progress to improve this situation even further is slowly being made, but there is still a great deal researchers are learning about the biology and ecology of grape pests and their natural enemies in Washington state.  This information is essential to the development of ecologically stable IPM programs.  IPM as a tool development is a high priority of the industry and is supported with research funding. 

Insect Management-Only leafhoppers and cutworms can be considered “key” insect pests, meaning they occur in all WA growing regions and often at a level that causes economic injury.  Mealybugs, thrips and mites also occur naturally at damaging levels but only occasionally get to economically important levels as their populations are often effectively regulated by predators, parasitoids and pathogens.  Some speculate that mealybug and mite problems will largely disappear in most Washington vineyards once pesticide inputs are either lessened, tailored not to be harmful to natural enemies, or completely removed. 

Information researchers need on the impact of current and new pesticides on the beneficial fauna of central Washington, has not yet been available.  A program is now underway and is being co-funded by the Washington wine grape industries as well as the State Commission for Pesticide Registration.  Results from this research will provide an important plank for development of biological control and IPM strategies in wine grapes. 

Mildew Control can be a challenge in Washington vineyards.  Some approaches are useful in regaining control of mildew if the disease is getting out of hand; others are preventive and must be applied before symptoms are present.  In the past, growers had to operate under a “spray and pray” schedule, this is now slowly being modified with the advent and verification of mildew models. 

Depending on the weather, growers can save a few fungicide sprays if they use mildew models like the Gubler-Thomas and Pearson powdery mildew models available from the Public Agricultural Weather Service (PAWS) stations.  The models, which track moisture and temperature, are useful for telling growers when a mildew infection period starts and if pressure is high and spray intervals need to be shortened.

Development of alternative ‘soft’ pesticides for mildew is also a research priority.  For example, petroleum spray oils may have a role to play as stand alone fungicides as well as effective when combined with conventional fungicides.  They are also good companion products and can eradicate young mildew colonies or help a plant’s resistance to infection.  Coupled with an accurate modeling system, effective eradicant sprays may allow the producer to spray when needed, rather than on a schedule.  Key reasons for these tools are to help growers meet their goals of reducing chemical application, increasing efficiency and reducing resistance build-up.

Cover Crops are an area Washington wine grape growers have been leaders, perhaps because they are a necessity for most eastern Washington vineyards.  Without them, topsoil is blown away and allows weeds to dominate.  However, growing cover crops, in an arid climate and sandy soil conditions, is challenging and there is still a lot to learn about specific crop/site interactions.  A cover crop can increase or deplete nitrogen from the soil by adding organic matter.  And, perhaps most importantly, a cover crop can help encourage a diverse ecosystem within the vineyard.

Cover crops compete with the vine for water.  Depending on whether stress to the vine is desired, cover crop competition can be a problem.  The cover crop must match the site and vine vigor and growers need to be aware of cover crop/vine interactions and how they change as the vine matures.

Given increasing drought concerns, there is so much more work to be done in this area including the study of annual cover crops, which won’t compete as much for water as perennials. To prevent overgeneralizations, many successful field trials on different types of crop species are needed to help see what meets the needs of Washington wine grape vineyards.  The biggest challenge with cover cropping has been to find beneficial cover crops that work well within a drip irrigation system with no supplemental water during the season.

Water management is an area where Washington wine grape growers are continually making great strides.  Water is an important element when examining sustainability practices.  Water management is vital to vine growth and therefore impacts management costs, fruit quality, early fruit ripening, and susceptibility to pests.  Wine grapes are one of the most efficient water users, allowing growers the rare opportunity to turn a minimal amount of water into a high value crop.  A great deal of viticulture research to date has focused on irrigation techniques, indicating it is an obvious priority to the industry.  Water conservation practices implemented by growers include irrigation scheduling, soil moisture monitoring and regulated deficit irrigation.  Water management is more than conserving water during drought conditions; it’s the most important quality management tool for Washington growers!