The Catastrophe Lurking In America's Farmlands

In a few weeks, the rich soil of the Midwest will erupt with tender seedlings whose genetic pedigrees are as distinguished as the bloodlines of Grindstone, this year's Kentucky Derby winner. These modern, scientifically bred crop varieties have helped boost the yields of farmers to levels that were once unimaginable. That spectacular success, however, carries a price: The world's harvests face a greater threat from pests and diseases than ever before. Just as a tiny misstep can end the career of a million-dollar racehorse, a minor outbreak of disease can lead to a catastrophic collapse of harvests around the world.

Why? Because the new crop varieties are striking in their genetic uniformity. Millions of acres of the Midwest are planted every summer with endless snaking rows of corn plants that are nearly as alike as identical twins. If one of those plants is vulnerable to a new strain of disease, they all are.

Last summer, that threat nearly became reality. The nation's leading seed company, Pioneer Hi-Bred International Inc. in Des Moines, was setting records with a wildly successful corn variety known as Pioneer 3394. That single variety made up 15% of Pioneer's sales. It was the largest-selling variety of corn in the world, by far. Much of the rest of the corn crop was made up of closely related varieties.

As it happened, Pioneer 3394 and many of its relatives were highly sensitive to a disease called gray leaf spot. With the increasing dominance of these especially vulnerable crop varieties, the conditions were right for gray leaf spot to become an epidemic. And that's precisely what happened. The disease marched across cornfields in Missouri, Iowa, Illinois, and Indiana. In some areas, every cornfield was affected, although the extent of crop losses isn't yet known.

Pioneer argues strenuously that it shouldn't be blamed for the epidemic. The company warned farmers that Pioneer 3394 was susceptible to gray leaf spot, says David Knau, a Pioneer sales manager. Some crop analysts say last year's poor harvest was due mostly to bad weather, not gray leaf spot. It's difficult to separate the two. But the poor harvest should be a warning: Such epidemics will recur, and the next one could be worse.

Potatoes are another crop in crisis. Incredible as it seems, the fungus that caused the Irish potato famine 150 years ago has returned, and it is ravaging American potatoes. "What we've done over the past few years is depend upon fungicides to protect the crop," says John Helgeson, a potato specialist at the Agriculture Dept.'s plant disease unit in Madison, Wis. However, the fungicides are becoming less effective as the fungus mutates and becomes resistant, Helgeson says. He is racing to develop new potato varieties with fungal resistance bred into them. "It might take a million seedlings before you hit the right one," he says. And the process could take anywhere from 5 to 15 years.

PAYING THE PIPER. Potato prices or supply haven't been affected by the crisis yet, but the threat hasn't gone away. "It's going to force growers to spend more money to prevent this problem," says Gary Lucier, an economist with Agriculture's Economic Research Service. "The cost of production is going to go up, and the net revenue will fall."

In the meantime, U.S. farmers are betting that this will not be the year their crops succumb to an epidemic. The farmers might be right. The odds, however, are getting worse each year.

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