The Practical Gardener

Sometime before 1910, a paper-shuffler from the Bureau of Indian Affairs decided that the problem with agriculture on the Hopi and Pueblo reservations in the Southwest was that those people just weren’t growing the right type of corn. Their corn was about 3 feet tall, and while each plant produced a respectable number of ears, this Washington bean-counter saw that the yield numbers just couldn’t hold a candle to the number of bushels per acre produced by Iowa corn. The problem, he reasoned, was the inferior varieties being used. So that year, a mandate came from Washington that all corn crops planted on the reservations should be proven Midwestern varieties supplied by the USDA.

That year’s corn crop failed. This is not to take anything away from the Iowa corn (then being grown by River City-type descendants of European emigrants), which had been developed for 1,000 years in a region with deep, rich soil and relatively heavy average rainfall. By contrast, the many dozens of traditional varieties that had developed in the Southwest were selected to be able to be planted deep and to flourish despite getting only limited amounts of water.

By the time Europeans arrived on these shores, all the modern types of corn — popcorn, flint, dent, flour and sweet — were already here. Many hundreds of varieties had been developed by selection on a regional basis, each tailored to grow well in the local soil and climate and to be well-suited to the locally favored cuisine. Most of the precontact indigenous peoples from present day Mexico softened their corn in lye water (made from wood ashes) and ground it to make tortillas; they favored a large and highly productive hard dent corn that could be soaked without getting mushy. Mandans living on the banks of the Upper Missouri River most often used ground corn in stews mixed with variously available beans, pumpkins, chokecherries, gathered roots and meat; their favored flint varieties had big kernels which absorbed stew juices and made an excellent griddle bread when dried and ground. Southwestern peoples grew flour varieties that could be dried and ground without further processing to create baked, fried and grilled breads, or dumplings that would hold together when boiled. All of these peoples grew other types of corn as well — Southwesterners developed colored varieties for specific ceremonials, Mandans grew a gummy type for boiled treats on special occasions, and almost all grew some sort of popcorn.

Corn has been called the supplest genetic tool known to humans. It produces sexually; pollen ripens in the male flowers of the tassel, and when it begins to fall (but never before), sticky silk emerges from the female flowers lower on the stalk to catch the falling pollen. There is nothing else like it in nature. Many nonscientists have made names for themselves in the annals of corn agriculture because the plant is so easy to manipulate and study (which is how a semitropical plant could eventually come to be grown in Canada).

But how, exactly, were these new varieties created?

In 1835, an Ohio farmer named Robert Reid moved to Illinois, taking with him a heavy-yielding dent corn called Gourdseed (an Ohio variety favored for eating fresh off the stalk when young and as hog feed when dried after maturity). The moist new bioregion to which he moved caused a good share of his crop of Gourdseed to rot in the field. Reid filled in the gaps with a local flint variety called Little Yellow. The two varieties cross-pollinated and created something terrific — a hardy, reliable, and heavy-yielding new strain that Reid and his son would develop into Reid’s Yellow Dent. In time, this new variety became the single most important strain in modern America — and it happened by pure chance. And that selfsame serendipitous quality was responsible for an estimated 20,000 varieties being known in the Americas as recently as 20 years ago.

Reid’s work resulted in a simple “single hybrid,” but later experiments around the beginning of the 20th century bred single hybrids with other single hybrids to create “double hybrids” that produced superior yields and had excellent disease resistance. Still, farmers stuck to the old-faithful, open-pollinated varieties that their grandparents had grown. It took a dreadful heat wave/drought in 1936, when hybrids recovered significantly better once the rains came back, to turn the tide in favor of hybrid corn.

After that, hybrid corn was on the rise; and by the late 1960s, corn diversity in the United States had reached an all-time low. Then in 1970, a new strain of blight wiped out every corn crop east of the Rockies. It was a wake-up call on the perils of genetic uniformity in corn. Fortunately, genetic diversity still existed in rural Mexico, so old varieties still grown there could be used to reinvigorate stagnant hybrid strains.

Diversity within a species is what keeps it strong. As we’ve noted before in these pages, old-time varieties of various crops have tremendous culinary, cultural and genetic value in and of themselves. But their value to modern society doesn’t end there, because you can’t keep developing new hybrids without drawing on the storehouse of genetic diversity enshrined in old-time varieties. You just can’t keep making make new hybrids out of old hybrids — at some point, there will be a failure that can only be remedied by going back into the gene pool. And now, corn’s gene pool is being threatened at its very center.

For thousands of years, corn has been the lifeblood of Mexican society. For 100 million Mexicans, corn tortillas play as great a dietary role as wheat bread plays for Americans. Because of this, critics have warned that genetically engineered (GE) corn should never be imported into Mexico. Nonetheless, last September, Mexican officials admitted that an alarming number of GE corn plants had been detected in a widespread area in the state of Oaxaca. The fear is this: Genetic pollution could irreversibly damage the huge number of indigenous corn varieties, as well as corn’s progenitor species teosinte (which has also been used effectively to develop new hybrids).

“Genetic pollution” isn’t some far-fetched, wacko fear propagated by tree-hugging extremists. There are many cases in which weeds and crops in fields adjacent to fields of GE crops have taken on such readily identifiable GE characteristics as herbicide resistance. Within the last year, a fifth-generation Canadian farmer was successfully sued by Monsanto for growing that company’s “Round-up Ready” soybeans from seeds gathered in his own fields, which had been contaminated by genetic drift from a neighboring farmer’s field of Monsanto’s “Round-up Ready” soybean. And corn’s ability to travel by pollination makes it the likeliest candidate to lose its genetic diversity within the next decade — leaving it wide open to the next overpowering disease or blight that comes along.

How did this threat start? Some agronomists fear that Mexican farmers have been planting GE corn that was sold for human consumption, because it was so cheap. Compounding this grassroots genetic pollution is the fact that major overseas corn-buying countries (namely Korea, Japan and parts of Western Europe) are refusing to buy GE corn, and the surplus (and often subsidized) American corn is being dumped on Mexico and various Third World countries that are likely to use it for seed as well as for food.

Another major factor is that since the North American Free Trade Agreement took effect in 1994, Mexico went from producing 98 percent of its own corn to being the number-three importer in the world of corn from the U.S. and Canada. The reason for this is, of course, economics. It costs a family farmer in the U.S. about $3.50 to produce a bushel of corn; it costs a Mexican farmer more than that to produce the same amount. U.S. farmers get about $2 a bushel; you and I pay the rest of the cost in the form of subsidies. With a glut of mostly GE corn going to Mexico, what incentive do south-of-the-border farmers have to grow their own?

There’s a whole lot more to say on this subject, but it will have to wait until another day. For now, let me conclude with this word of warning: The loss of genetic diversity in corn is only one of many critical issues revolving around the insistent and untested barrage launched by advocates and purveyors of genetic engineering.