Farmers Add Herbicides to Arsenal Created by rrummel on 4/29/2014 4:10:32 PM
The Wall Street Journal
U.S. farmers are dousingtheir fields with a wider array of herbicides, helping some turn a corner inthe war on super weeds but adding new costs and environmental concerns.
Farmers for a decade have fought weeds that developed resistance to the nation'sdominant weed killer, glyphosate, which is widely sold by Monsanto Co. MON+0.55% as Roundup. Now they're finding success deploying larger quantities ofother, sometimes older herbicides.
About 42 million acres of soybeans planted in 2012 were treated withnon-glyphosate herbicides, double the 2006 total and equivalent to 57% of allsoybean acres, according to a U.S. Department of Agriculture report this year.
Farmers increasingly have turned to some herbicides considered harsher thanglyphosate. In 2012, they used more than six million pounds of 2,4-D, nearlyfour times the 2005 level, according to USDA data. Use of dicamba more thandoubled to 87,000 pounds over the same period.
Farmers are having to brush up on their chemistry. Travis Starnes, 36 yearsold, who grows corn, wheat and soybeans near Monroe, N.C., said he's againrelying on a notebook of chemical recipes his family compiled in the early1990s, 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 DowChemical Co., BASF SE, Bayer AG, DuPont Co., Syngenta AG and Monsanto, whichoffers products other than Roundup. They are concocting and seeking regulatoryapproval for new formulations of old chemicals that are designed to befriendlier to the environment, and for corresponding herbicide-resistant seeds.
Thanks to the bigger arsenal, some farmers now say they are gaining ground intheir war against the super weeds. In the South—where a longer growing seasonand warm climate have made it the battle's front line—fewer cotton and soybeanacres 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 adraw," said Bob Scott, a weed science professor at the University ofArkansas. "They're not losing fields anymore."
But success is costly. Some farmers' herbicide expenses have doubled or tripledsince resistant weeds set in, cutting deeper into budgets at a time when cornprices 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-protectingchemicals in 2012, up 51% from 2006 after adjusting for inflation, according tothe USDA. Chemicals represented about 12% of soybean farmers' operating costsin 2012. U.S. farmers spent $13.7 billion that year on all agriculturalchemicals, 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 ofcorn, wheat and soybeans near Rowland, N.C.
Mr. Stone estimates that he has boosted spending $15 to $20 per acre over thepast 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 anacre, according to federal data.
St. Louis-based Monsanto revolutionized the pesticide business when it beganselling genetically modified seeds in the mid-1990s. Some seeds were altered towithstand sprays of glyphosate, which kills plants by halting their internalprotein production.
Farmers embraced Monsanto's Roundup, which could destroy many weeds whileleaving 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 ofdomestic 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 budgetconstraints, an agency spokeswoman said.
Monsanto sells $4.5 billion a year of pesticides—mostly Roundup, analystssay—and billions of dollars' worth of corn and soybean seeds geneticallyengineered 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 developmentof immunity in some weeds, researchers say.
Broader use of herbicides is reviving concerns over their effects. Two majorRoundup alternatives, both developed decades ago, are dicamba, which kills byspurring uncontrollable growth that outpaces a weed's nutrient supply, and2,4-D, which disrupts plant cells that carry water and nutrients.
Environmental groups and some farm activists fear that increased use of theharsher chemicals will make more people sick and destroy more delicate crops,like grapes, that may be located nearby. Monsanto and Dow say the products aresafe if used properly, and that new formulations will be less likely to affectother fields than older versions. Inhaling the products poses little healthrisk to humans. However, drinking some forms of 2,4-D has been found to harmkidneys and skeletal muscles in humans, while dicamba is moderately toxic toeyes 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 lowerhealth risks for humans, is considered milder.
Monsanto is seeking federal approval for a new version of dicamba, and forsoybean and cotton seeds capable of withstanding it. Dow aims to introduce anew version of 2,4-D, along with related corn and soybean seeds. The companiessay the products are safe.
Meanwhile, some farmers have returned to an expensive, but proven, method ofweed control: the hoe.
Hand-weeding, which can cost farmers up to $150 an acre, has again becomecommon 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 hischemicals. "That's what my dad and my grandfather used to do," hesaid. "That's what it's reverted back to."