One Winegrower's Take on GMOs

Support for genetically modified organisms or GMOs got quite a boost this summer when the National Academy of Sciences released their most recent report on GMOs, concluding that, compared to “conventionally” farmed crops, GMOs have had generally, but not uniformly, positive effects on producer income and that they are safe to eat. To be sure, the NAS committee comprehensively reviewed the literature comparing GMOs with conventionally farmed crops, so from this perspective, it fulfilled its narrow statement of task. But many winegrowers will view the scope of the report as limited, comparing two largely technologically driven agricultural methods but leaving out more ecologically-based methods that rely on diversified ecosystems to improve quality and increase yields.

What we now call conventional farming has its origins in the Green Revolution, an effort led by Nobel laureate Norman Borlaug to increase crop yields, defined as the number of calories produced per acre of agriculture. Relying on high yield, disease resistant varieties, mechanization, and inorganic fertilizers, the then new agriculture virtually eliminated famine in India, China, and Latin America in the years following World War II. But these techniques also came with challenges. The focus on a few varieties reduced genetic variation and thus increased susceptibility to some diseases. Widespread use of pesticides resulted in increasing resistance to them among the very insects and weeds they were intended to treat, and overuse of fertilizers has polluted ground and other waterways, including the Chesapeake Bay.

GMO technology is largely intended to solve the problems associated with now conventional farming while continuing the search for increasing yield. After a quarter century of experience with crops modified to resist insect pests and herbicides, which represent the majority of commercially available GMOs, some progress is being made. Bt maize is a type of corn modified to secrete a natural bacterial toxin effective against corn borer caterpillars. Use of Bt maize has been shown to increase yields by about 9%, and because it is associated with reduced use of alternative, broader spectrum pesticides, its use also appears to be associated with increased diversity of beneficial insects in farm fields. The benefits of herbicide (usually glyphosate) resistant crops are less apparent. Yields have not increased in most cases, and because the gene has “drifted,” many weeds are now also resistant to this once useful product. And our colleagues Claude and Lydia Bourguignon have shown that use of these herbicides has reduced microbiological activity in soil by as much as 85%, reducing both quality and pest resistance among food crops.

In contrast to the genetic techniques that produce GMO crops, agroecological methods (the approach that we take at Dodon) blend respect for traditional farming with modern tools. For example, creating a diverse agricultural ecosystem that provides habitat for beneficial insects appears to reduce dependence on chemical insecticides. According to Miguel Altieri, Professor of Environmental Science, Policy, and Management at the University of California in Berkeley, these methods have increased yields by 30-50% when compared with conventional methods, much better than the 9% increase seen in studies of GMOs. Altieri has also documented similar benefits using agroecological techniques at Benziger Family Vineyards in Sonoma.

At Dodon, we’re very concerned about some of the unintended consequences of GMOs that were not considered in the NAS report. As weeds have become resistant to glyphosate, several seed companies have created crops that are also resistant to broadleaf, growth regulator herbicides such as 2,4-D, dicamba, and triclopyr. Drift of these herbicides, sometimes over many miles, is common, and they are highly toxic to grapevines. Indeed, we have already seen what we think is triclopyr injury in some of our younger Chardonnay blocks. The source of the triclopyr isn’t clear; it could be a neighboring farm using it in a no-till system, a lawn care company, or a tree company clearing road or power line rights-of-way. What is clear is that widespread adoption of herbicide resistant crops will only increase use of these products on farms, and hence the associated risk to our vines. It’s an issue that keeps me awake at night.

 Healthy Chardonnay leaves are shown on the left; on the right note the curled edges and differences in color and lobulation that could be the result of triclopyr exposure.

Healthy Chardonnay leaves are shown on the left; on the right note the curled edges and differences in color and lobulation that could be the result of triclopyr exposure.

The focus on yield and a few other traits, such as shelf life, has resulted in striking loss of genetic variation in food crops. Before the Green Revolution, about 30,000 varieties of rice were cultivated around the world. Currently just ten varieties make up the vast majority of rice production. GMO crops are likely to reduce this further. Yet there is a price to pay. Think about the taste of tomatoes at chain grocery stores compared to those you get at the local farmers’ market. Food, like wine, is an ambassador of its community, reflecting the tastes, values, and traditions of the people who live there. When we lose the unique qualities of our local food, we lose something of ourselves.

This is not to say that GMOs are intrinsically bad. They are powerful tools that should be used in appropriate circumstances. Similar genetic methods are being studied to treat cancer, hemophilia, cystic fibrosis, and many other diseases. In agriculture, the Golden Rice Project is a global effort to use genetically modified rice to reduce Vitamin A Deficiency, a global public health problem that causes 500,000 cases of blindness and 2 million deaths in the developing world each year. It is this opportunity that recently caused more than a hundred Nobel laureates to endorse the project. If GMOs can help solve a problem of this magnitude, then by all means consider them. But do so in the context of all the alternatives.

A long time ago, another Nobel laureate, Arno Penzias, told me that the measure of a scientist is the quality of the questions she asks, not the quality of the answers she provides, advice that has served as a guiding principle in many parts of my life. The NAS understands this principle very well, and in response it has designed processes to ensure that its committees ask the most salient questions to examine from all perspectives scientific issues of national and global importance. Above all else, this comprehensive, balanced approach is the reason that the nation’s leading scientists give freely of their time to serve on NAS committees.

But in the case of its GMO report, the NAS seems focused on whether or not to accept GMOs, a dichotomy that I would expect from the manufacturers of GMO seeds and the environmentalists who seek to ban them, but not from an authoritative source like the NAS. It would be better to ask who, what, when, where, and how GMOs should be used. When and in what contexts do they offer the best alternative to the problem to be solved? What criteria should be used to make decisions about their use, and who should make those decisions? How do they stack up against alternatives? As Dr. Penzias admonished, the most important thing is to ask the right questions.