April 25, 2024

Fast-growing weed threatens Iowa farms

DES MOINES (AP) — A fast-growing, tough-to-control weed that has tormented farmers in the southern U.S. has been found in Iowa.

Agronomists are trying to determine whether the Palmer amaranth weed found in five counties is herbicide-resistant. The weed can carry 1 million seeds and grow up to 7 feet tall, according to the Des Moines Register.

Agronomists say even a moderate infestation can rob farmers of two-thirds of their corn and soybean yields. That would amount to a total loss in Iowa of about $11 billion from last year’s $16 billion in corn and soybean receipts

The loss would also affect some of the state’s most important agricultural businesses, including DuPont Pioneer, Sukup Manufacturing Co. and Deere & Co. Economists estimate that one-fourth of Iowa’s $166 billion gross domestic product is tied to farming.

It also means that farmers may have to use more chemicals — with potentially greater toxicity — to battle the aggressive weed.

Agribusinesses are introducing a new lineup of herbicides and seeds to fight off the weed, though environmental groups worry that those proposed solutions will only worsen the problem.

“Increased herbicide use on the new engineered crops will speed up weed resistance, leaving no viable herbicide alternatives,” said Doug Gurian-Sherman, a senior scientist with the Union of Concerned Scientists. “This is a dangerous chemical cocktail that, when combined with the current farming system, it’s a recipe for disaster.”

Iowa State University agronomy professor Mike Owen said the weed could cause prices to rise for sodas, cereals, fuels and other goods derived from corn.

“People don’t recognize almost everything they touch, whether they eat it or they wear it or drive it, has corn or soybeans in it,” Owen said.

Access to high-quality, low-cost readily available food is “all a function of an effective agricultural system that a weed like the Palmer amaranth could significantly impact,” Owen said.

Nearly 20 weeds in Iowa have developed resistance to herbicides that include glyphosate, a once-in-a-century chemical that Monsanto brought to the market in 1976 under the name Roundup.

Seed companies later introduced genetically modified soybeans, corn, cotton and other crops that were tolerant to glyphosate and other herbicides. It enabled farmers to spray fields for weeds without harming crops.