Making Viticulture Sustainable
Although the terms "sustainable agriculture" and "integrated pest management (IPM)" -- and even the designation "organic" -- have been overworked and abused, we have attempted in this report to stay close to the original definitions of these terms.
Sustainable agriculture is "the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs" according to the Sustainable Agriculture Research and Education Program at the University of California, Davis.
For traditional viticulture, this goal would require a fundamental shift on the part of growers to work in concert with, not against, the forces of Nature. In Sonoma and Napa wine country, grape growers now wage an endless battle with chemicals against molds, bugs, gophers and microscopic lice.
Both "good" and "bad" species are decimated by pesticides used in this conflict, creating a biological vacuum into which the most aggressive and crop-specific pests move and grow. This, in turn, leads to increased reliance on pesticides. Switching to sustainable viticultural practices is the only way out of this endless pesticide cycle. Sustainable viticulturists employ various growing practices which, together, encourage beneficial species, utilize the effects of weather on pest populations, and tolerate pest damage that doesn't directly affect productivity or quality.
Organic the Ultimate
Our research of Sonoma-Napa country pesticide use revealed that less than 15% of growers use low amounts of pesticide. Of these, less than 5% are growing grapes organically.
Organic growers don't rely on the chemical crutches that prop up the weak parts of traditional pest control systems. Instead, they restrect themselves to "natural" materials that are considered less (but still) toxic, such as sulfur, copper, soaps, and pytrethrins. But intervention--even with less toxic pesticides--is not their focus. Their aim is to take sustainable viticulture to its fullest potential by creating the most alive and balanced environment possible. Organic growers rely on vineyard health as the backbone of pest control. "The most effective control is to strengthen the vine. If you feed the soil, you feed the vine," says John Williams, who makes wines of organic grapes at Frogs Leap Winery in Napa County.
To "feed the soil" requires sophisticated testing of soil nutrients and highly developed understanding of additives, both of which are readily available to growers interested in practicing sustainable viticulture. Specific additives are available for each soil nutrient deficiency, ranging from cover crops that activate potassium or add nitrogen to additions of specific rock powders. Organic growers and low pesticide users alike add bacterial innoculants, composted manures, predator and parasite organisms and liquid seaweed to encourage growth of a full spectrum of soil species and maximize soil health.
What is IPM
The systemized approach known as Integrated Pest Management (IPM) is not a method in itself but a framework on which different pest control strategies are hung. Each component is integrated into a total pest management system.
Serious practitioners of IPM quickly learn that their success actually depends on minimizing pesticides -- even those considered "least toxic" -- and staying away from engineered organisms which inevitably damage beneficial species by upsetting the ecological balance.
According to ecologist Bill Olkowsky, a longtime IPM advocate and founder of Bio Integral Research Center (BIRC), integrated pest control is not undertaken according to a predetermined calendar schedule. Instead, regular hands-on field inspections by trained observers guide growers to informed pest control decisions.
"One of the most important things to prevent unnecessary pesticide use is to have a good monitoring program in place," says Olkowsky. "This means having an experienced pest management specialist regularly counting the numbers of pests and beneficials present. Without precise numbers there is no way to know exactly how many pests are tolerable; consequently pesticides are often used as insurance."
The object of IPM is not to eradicate pests, which is impossible anyway for established species, but to provide control and keep damage down to a tolerable level. Direct intervention is often not necessary to produce good wine grapes because impeccable looking plants are are not a market factor.
IPM in Practice
At Clos du Bois' 600 acres in Alexander Valley, viticulturist Steve Thomas increasingly relies on sustainable IPM practices to replace calendar pesticide applications he refers to as "expensive and counter-productive."
Pest monitoring is undertaken weekly beginning in April with inspections of 10 leaves in every 5-to-10 acre block, and then increasing in scope and frequency as pest populations grow. Leaf removal and use of pyrellin and soap spray depends on monitoring results and is timed to create the greatest impact on pest populations.
Successful IPM at this vineyard and others depends on a holistic view of the vineyard environment aimed at "creating a more diversified environment with a wider variety of plants and insects interacting with each other," says Thomas. For example, he and other vineyard managers are abandoning the bare earth approach to growing grapes. Instead they plant plum trees along vine rows, cover crops in row centers and buckwheat and deer grass along borders to provide habitat for beneficial insects that prey on pests.
Tolerating Pest Visibility
At Sonoma Valley's Benzinger Family Winery vineyards, manager Barry Sloane introduced a new IPM practice based on the fact that harvest and wine won't suffer if grape leaves look imperfect. He did it while dealing with spider mites, considered one of the most destructive vineyard pests.
"Last summer our decision to tolerate pest damage that would not reduce crop production or quality was put to the test during several heat waves," recalls Sloane. "Mite populations began to rise, and so did visible damage. Every day we were in the vineyard anxiously checking pest numbers, but we held off spraying because we felt the damage was cosmetic and not actually affecting vine health. Finally the weather cooled, mite populations dropped and we survived with only superficial damage -- and without spraying once."
Often the first step in practicing IPM is just getting beyond knee-jerk spraying at the first sight of a pest. "Part of the education process is to get the grower used to some damage," says DeWitt Garlock, wine growing technical manager for Robert Mondavi Winery. " Vines can tolerate a lot of leafhopper feeding injury without the loss of maturity of the fruit or carbohydrate storage."
Organic: The Ultimate
Our research of Sonoma- Napa wine country pesticide use revealed that less than 15% of growers use low amounts of pesticide. Of these, less than 5% are growing grapes organically. Organic growers don't rely on the chemical crutches that prop up the weak parts of traditional pest control systems. Instead, they restrict themselves to "natural" materials that are considered less toxic, such as sulfur, copper, soaps and pyrethrins.
But intervention -- even with the least toxic pesticides -- is not their focus. Their aim is to take sustainable viticulture to its fullest potential by creating the most alive and balanced environment possible. Organic growers rely on vineyard health as the backbone of pest control.
"The most effective control is to strengthen the vine. If you feed the soil, you feed the vine," says John Williams, who makes wines of organic grapes at Frogs Leap Winery in Napa County.
To "feed the soil" requires sophisticated testing of soil nutrients and highly developed understanding of additives, both of which are readily available to growers interested in practicing sustainable viticulture.
Saving Money by Going Organic
Fetzer Vineyards in Mendocino County grows wine grapes organically on 455 acres. Of the growers who sell to Fetzer Winery, "about one-third are organic, one-third are still using pesticides but have cut way back and about one-third are still growing conventionally," says spokesman George Rose. Fetzer actively encourages growers to reduce pesticide use and give organic production a try even though, unlike other organically grown crops, no premium is paid for organic grapes.
Still, Fetzer claims it has lowered growing costs enough to offset the transition from chemically based to organic growing, usually a phase lasting three to five years. Organic viticulturists may be the most practical grape growers around. Many experts, including agricultural economists and researchers for U.C.'s Sustainable Agriculture Research and Education Program, believe that a complete study of costs, production and quality would show that organic viticulture is as economical as traditional chemical viticulture. Grapes, after all, don't have to look pretty since they are squashed beyond recognition in the process of making wine.
Californians for Alternatives to Toxics
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