This article was published in the February/March 2000 Wedge newsletter. The following information may be outdated.

Potatoes, Pesticides, and Genetic Manipulation

Potatoes are popularly regarded as a "comfort food", and with good reason. Researcher Judith Wurtman of MIT says that potatoes raise the level of the neurotransmitter serotonin in the brain, decreasing the likelihood of depression, binge eating, and insomnia. Kathleen Des Maisons, a nutritionist and author of the book "Potatoes, not Prozac," claims potatoes protect against overeating and addictions such as alcoholism. French researchers declared potatoes a "diet food" because they make people feel full. Australian researchers developed a "satiety index" that rates potatoes as the most "satisfying" food around, outranking bread and ice cream. And, as any cook knows, potatoes are extremely versatile. They can be baked, fried, mashed, scalloped, made into salads, used as an ingredient in soups or stews, and matched with a worldwide variety of complementary seasonings.

Since potatoes are such a simple and inexpensive food the tendency is to buy conventionally grown ones, even if one buys other, more flamboyant, vegetables organically. After all, a potato, is a potato, is a potato, right? Think again.

Growing potatoes in the modern world of agribusiness implies a clockwork schedule of pesticide application. Before the crop is even planted, the soil is treated with insecticides to kill wireworms. Potato "seeds" (actually tubers) are routinely drenched with fungicide immediately after cutting to prevent the spread of blight. Systemic insecticides, which penetrate the entire potato plant, are generally applied at "hilling" time, when the young potato plants are covered with dirt.

Potatoes are prone to two major viruses, potato virus Y (PVY) and potato leafroll virus (PLRV), and "early" and "late" blight, which are generally spread by aphids. These viruses are either controlled by aphicides (which are sprayed directly on the infestation but are only effective for a couple days) or by newer, systemic insecticides such as Admire, or Temik. Potatoes are also prone to "early" or "late" blight, which destroy plant leaves before proceeding to the tubers. Blight is generally attacked by broad-spectrum fungicides, which put a protective barrier on the foliage. Systemics are sometimes used, but require special permission. When weather conditions are especially conducive to the spread of blight (warm and wet) fungicides are applied prophylactically. In the Willamette Valley, where it's always wet (if not warm) this means every potato crop is virtually guaranteed a fungicide bath.

Potatoes are harvested after the vine dies off. In nature this happens on its own schedule, but on the modern farm it is generally helped along by chemical dessicants, often with diesel fuel and herbicidal oils added to the mix. This combination is so toxic farmers generally wear protective gear when applying it. Once potatoes are in storage more fungicides are sprayed on to prevent sprouting.

Various factors are conspiring to increase pesticide use, which has virtually doubled in Oregon since 1990. As many as 60% of potatoes are explicitly grown for the processed food industry, and research continues into new ways to chip, dehydrate, and french- fry potatoes. Growth of demand in Asia is fueling the demand for processed potatoes. McDonalds opened its first fast food restaurant in China in 1991; now there are 220. According to Potato Grower magazine (Oct. '99) "Potatoes are becoming a necessary object of trade." The potato business is becoming increasingly centralized. J.R. Simplot of Boise, Idaho, and Farm Frites, a Dutch company, recently formed an international alliance giving them control of one-quarter of the world's potato processing capability.

Large potato processors demand different qualities in a potato than those we might prefer as individual consumers. The most important qualities to potato processors are uniform shape, high yield, disease resistance, and storability. High starch potatoes such as Russets are preferable for processing. While potatoes sold for the fresh market can be lower in starch, ease of picking and storability still drive breeding choices. Taste finishes a distant third. While nature has provided us with potatoes in abundant shapes and colors, the varieties grown by agribusiness are extremely limited. Russet Burbank, a dry, high solid low sugar content, uniformly round potato (ideal for processing) comprises 40% of US production. Another type of Russet, the Norkotah, is most popular for fresh marketing. A smaller quantity of red potatoes are grown conventionally; while they are better for salads they are low in solids and high in sugar, and thus harder to harvest and store. These monocultures of potatoes encourage the development of resistant pests and viruses, and increase the likelihood that one pest infestation will wipe out the entire crop.

The scariest trend is the spread of "transgenic" potatoes, which have been genetically modified to increase pest resistance by splicing in genes from other organisms. Monsanto leads this charge into the brave new world of vegetables but many other biotech companies are also engaging in research and development. Monsanto cleverly markets transgenic potatoes under the "Naturemark" label, and touts them as the "environmentally responsible" choice because their "built-in pest protection" allows farmers to decrease pesticide use. However, their claim is disingenuous because the potatoes are generally resistant to only one disease or pest, such as the Colorado potato beetle. Plenty of herbicides and fungicides are still needed to protect against other diseases. Long-term environmental effects, such as the proliferation of resistant pests, remain unknown. Genetically modified organisms (GMOS) such as Naturemark potatoes can crossbreed with other potatoes grown nearby. The European Commission Research Center has measured large amounts of GMO releases, with potato releases secondary only to corn and rapeseed (the basis of canola oil). Once released into the environment GMOs permanently change the world's ecology. Unlike pesticides, they cannot be recalled if found to be dangerous.

Monsanto has mounted a worldwide marketing campaign to promote transgenic potatoes, spending one million dollars in Britain alone. While farmers in Europe remain resistant to GMOs Americans and Far East buyers exhibit no such reluctance. There is no requirement that GMOs be labeled, so if you buy a conventionally grown potato, there's always the possibility a foreign gene is lurking inside.

Organic potatoes constitute a tiny proportion of the market at present but organic cultivation is definitely possible. In collaboration with the World Wildlife Fund, Wisconsin potato growers have voluntarily cut the use of eleven high-risk pesticides and switched over to Integrated Pest Management (IPM) systems, reducing pesticide usage by 60%.

Organic potatoes should be planted early, so that they can be harvested before most pests become active. Strict sanitation during the tuber storage/ planting process is essential, and any virus-infected tubers should be culled out. Well-fertilized and well-watered but good draining soil promotes healthy plants with a high natural resistance to disease. Crop rotation is extremely important. If potatoes are rotated with other crops in a three-year cycle, it is much less likely that pests will take hold. Once the potatoes are picked they cannot be stored as long as conventionally grown, fungicide-drenched spuds. However, they can be held for two to three months before any sprouting begins, and a small amount of sprouting does not connote a spoiled potato. While more labor-intensive, organically grown potatoes can actually be more profitable than conventional due to the reduced cost for off-farm chemical inputs. Organic farmers are their own entity, less dependent on the vagaries of multinational corporations such as Monsanto.

Freed of the constrictions of the processing industry, a world of potatoes, multicolored and interestingly shaped, opens up. Probably the most commercially available are Yukon Golds, a firm, high starch potato with a lovely yellow color and great flavor. Yellow Finns are also lusciously buttery in appearance and wonderful for mashing and scalloping. Blue potatoes are soft, moist, nutty and sweet and can be roasted, steamed, or used in salads. Purple Peruvian and Ruby Crescent Fingerlings are small, dense and waxy. They don't need to be peeled and are good roasted, in salads, au gratin, or in stews. Cherries Jubilee Red and Red Thumb are tender and sweet, good for steaming and salads. All of these potatoes pack a flavor punch that puts mealy conventional potatoes to shame. Food Front currently stocks about eight varieties of organic potatoes. And should you absolutely crave those frozen fries, Cascadian Farms puts out a line of organic processed spuds.

Organically grown potatoes require more tender care than potatoes drenched in sprout-killing fungicide. They should be stored in a cool, dark place (a loosely closed paper bag works really well) and used within two to three weeks. Don't refrigerate them; then the starch turns to sugar, making the potato excessively sweet. Cut off any sprouts or green colored portions.