{I am very excited to announce Alison Wiediger of Au Natural Farms as our newest ongoing contributor. Alison and her husband Paul are visionary Kentucky farmers. Be sure to check out her full bio at the end of this post!}
GMO – a “new” buzzword for farmers market customers and consumers in general.
More and more we are hearing about Genetically Modified Organisms, or sometimes, GEO (genetically engineered organisms). What does GMO mean, and as an informed consumer, what should you know?
GMO seed is a big player in the conventional farming sphere. In 2011, 94% of the soybeans and about 85% of the corn (as well as other major commodity crops such as canola, cotton, sugar beets, and alfalfa) being grown in the US were GMO varieties. Basically, the crops have gene sequences from other organisms inserted into them for a particular purpose. In the case of soybeans, it is to make them resistant to Roundup—a commonly used herbicide—so the fields can be sprayed with it to kill the weeds without killing the crop. These are usually called “Roundup-Ready.” In the case of corn, there are Roundup-Ready varieties (herbicide resistant) as well as Bt varieties. The Bt varieties express Bacillus thuringiensis—a toxin affecting Lepidoptera (caterpillars)—in every cell of the plant, so if a caterpillar eats any part of the plant, it dies. Some corn varieties have both herbicide resistant and Bt traits engineered into them. Although approved as safe by the USDA, some people prefer to avoid eating GMO food whenever possible. A great way to do this is purchasing certified organic grains, as they are not produced with GMO seed, and are usually tested for contamination by cross pollination from other nearby crops which may be GMO.
So, what about buying at farmers markets? Since most farmers market customers are not purchasing grains at their market, it may seem a very safe place to buy food for those who wish to avoid GMO products and, for the most part, it is. There are very few vegetables which are genetically modified (or sometimes called transgenic). However, there are a couple of major vegetables to be aware of right now, with more on the horizon. The first is summer squash. There are a few transgenic varieties of summer squash with gene sequences inserted for resistance to viral diseases. They can usually be recognized by a Roman numeral after the variety name—as in Dasher II.
The second major vegetable to be aware of is sweet corn. For the same reason as for field corn—caterpillars which damage the ear—there are some varieties of Bt sweet corn. Because the Bacillus thuringiensis is expressed in every cell of the plant, Bt sweet corn will have almost no earworms in the ear. When the tiny caterpillar hatches and eats its first kernel of corn, it dies. This is a huge thing! No one likes worms in their corn, and Bt varieties will have few or none, so the farmers often advertise them as “un-sprayed,” because they haven’t been sprayed with chemicals. Therefore, as a consumer, if you wish to avoid GMOs, you need to be aware of variety names (Attribute and Performance series for sweet corn) and/or, ask the farmer. If the sign says the corn is unsprayed, and it is worm free, you might want to ask about growing practices.
Note: Some organic/sustainable farmers who wish to avoid earworms in their sweet corn, don’t want to grow GMO sweet corn, and don’t want to spray chemicals, use the old technique of putting a drop of oil in the top of the ear, which smothers the worm egg or newly hatched worm. This technique requires great attention to the timing of the application, but can be quite successful. The technique has been updated and made easier using an applicator called a Zea-Later. Using the Zea-Later, vegetable oil, and, optionally, Bt, an organic grower can have as great as 95% worm free sweet corn. It is more labor intensive than spraying chemicals, as each ear of corn must be treated, but also much more earth friendly.
And, lastly, you may already know that organic farmers have been using Bt for decades to help minimize caterpillar damage on crops—particularly brassicas such as broccoli, cabbage, and cauliflower. How is this use of Bt different? When Bt is applied to a crop as a spray, it has a very short effective life on the plant leaf. Typically just a day or two. But when it is part of every gene of a plant, it doesn’t “disappear quickly.” Some research shows it persisting in the soil for months and also in the guts of bees (from the pollen) and earthworms (from crop debris).
Takeaway Information: A few GMO vegetable crops exist. Your best defense if you wish to avoid them is to know your farmer, and ask questions. Or, if that is not possible or practical, choose certified organic vegetables since certified organic producers are not allowed to use GMO seed for their crops.
{Editor’s Note: For information on the GMO debate, visit the Non-GMO Project and Just Label It, a campaign to label genetically modified foods that are sold at retail.}
