Farmers Add Herbicides to Arsenal Created by rrummel on 4/29/2014 4:10:32 PM
The Wall Street Journal
U.S. farmers are dousing
their fields with a wider array of herbicides, helping some turn a corner in
the war on super weeds but adding new costs and environmental concerns.
Farmers for a decade have fought weeds that developed resistance to the nation's
dominant weed killer, glyphosate, which is widely sold by Monsanto Co. MON
+0.55% as Roundup. Now they're finding success deploying larger quantities of
other, sometimes older herbicides.
About 42 million acres of soybeans planted in 2012 were treated with
non-glyphosate herbicides, double the 2006 total and equivalent to 57% of all
soybean acres, according to a U.S. Department of Agriculture report this year.
Farmers increasingly have turned to some herbicides considered harsher than
glyphosate. In 2012, they used more than six million pounds of 2,4-D, nearly
four times the 2005 level, according to USDA data. Use of dicamba more than
doubled to 87,000 pounds over the same period.
Farmers are having to brush up on their chemistry. Travis Starnes, 36 years
old, who grows corn, wheat and soybeans near Monroe, N.C., said he's again
relying on a notebook of chemical recipes his family compiled in the early
1990s, before Roundup became dominant, to plan his herbicide use.
"Basically, it's like history repeats itself," Mr. Starnes said.
The trend has been a boon to companies that sell herbicides, including Dow
Chemical Co., BASF SE, Bayer AG, DuPont Co., Syngenta AG and Monsanto, which
offers products other than Roundup. They are concocting and seeking regulatory
approval for new formulations of old chemicals that are designed to be
friendlier to the environment, and for corresponding herbicide-resistant seeds.
Thanks to the bigger arsenal, some farmers now say they are gaining ground in
their war against the super weeds. In the South—where a longer growing season
and warm climate have made it the battle's front line—fewer cotton and soybean
acres were lost last year to invaders such as pigweed, marestail and ryegrass,
according to farmers, academics and industry officials.
"Most [farmers] feel like they are either winning or fighting to a
draw," said Bob Scott, a weed science professor at the University of
Arkansas. "They're not losing fields anymore."
But success is costly. Some farmers' herbicide expenses have doubled or tripled
since resistant weeds set in, cutting deeper into budgets at a time when corn
prices are down 38% from their 2012 peak and soybean prices are off by 16%.
U.S. soybean growers spent on average $25.10 per acre on crop-protecting
chemicals in 2012, up 51% from 2006 after adjusting for inflation, according to
the USDA. Chemicals represented about 12% of soybean farmers' operating costs
in 2012. U.S. farmers spent $13.7 billion that year on all agricultural
chemicals, the most on record and nearly two-thirds higher than in 2002.
"It's an expensive battle," said Bo Stone, who grows 2,300 acres of
corn, wheat and soybeans near Rowland, N.C.
Mr. Stone estimates that he has boosted spending $15 to $20 per acre over the
past five years on herbicides to control palmer amaranth, known as pigweed,
which can grow 3 inches a day. Average soybean revenue in his region is $328 an
acre, according to federal data.
St. Louis-based Monsanto revolutionized the pesticide business when it began
selling genetically modified seeds in the mid-1990s. Some seeds were altered to
withstand sprays of glyphosate, which kills plants by halting their internal
Farmers embraced Monsanto's Roundup, which could destroy many weeds while
leaving crops unscathed. Among U.S. soybean growers, glyphosate rose from 15%
of herbicide use in 1996 to 89% in 2006. At that time, about two-thirds of
domestic soybean fields relied solely on glyphosate to control weeds. In 2012,
glyphosate dropped to 83% of herbicide use in soybeans, according to the USDA,
with about 42% of U.S. soybean acres being treated solely with glyphosate.
The USDA's data on herbicide use is no longer collected annually due to budget
constraints, an agency spokeswoman said.
Monsanto sells $4.5 billion a year of pesticides—mostly Roundup, analysts
say—and billions of dollars' worth of corn and soybean seeds genetically
engineered to survive them.
Scientists for decades have observed weeds capable of withstanding herbicides,
but applying Roundup to the same fields every year speeded up the development
of immunity in some weeds, researchers say.
Broader use of herbicides is reviving concerns over their effects. Two major
Roundup alternatives, both developed decades ago, are dicamba, which kills by
spurring uncontrollable growth that outpaces a weed's nutrient supply, and
2,4-D, which disrupts plant cells that carry water and nutrients.
Environmental groups and some farm activists fear that increased use of the
harsher chemicals will make more people sick and destroy more delicate crops,
like grapes, that may be located nearby. Monsanto and Dow say the products are
safe if used properly, and that new formulations will be less likely to affect
other fields than older versions. Inhaling the products poses little health
risk to humans. However, drinking some forms of 2,4-D has been found to harm
kidneys and skeletal muscles in humans, while dicamba is moderately toxic to
eyes and can cause diarrhea and abdominal pain if swallowed in large amounts,
according to the National Pesticide Information Center.
Glyphosate, which studies have shown strongly adheres to soil and poses lower
health risks for humans, is considered milder.
Monsanto is seeking federal approval for a new version of dicamba, and for
soybean and cotton seeds capable of withstanding it. Dow aims to introduce a
new version of 2,4-D, along with related corn and soybean seeds. The companies
say the products are safe.
Meanwhile, some farmers have returned to an expensive, but proven, method of
weed control: the hoe.
Hand-weeding, which can cost farmers up to $150 an acre, has again become
common in some parts of the country.
Last summer, Heath Whitmore, who farms rice and soybeans near Pine Bluff, Ark.,
spent a week chopping down palmer amaranth plants that had survived his
chemicals. "That's what my dad and my grandfather used to do," he
said. "That's what it's reverted back to."