The notoriously volatile weedkiller dicamba was blamed for 3,500 incidents of "off-target" damage this year, including to more than 1 million acres of soybeans, said the EPA on Tuesday. The regulator said it was reviewing whether dicamba "can be used in a manner that does not pose unreasonable risks" and said it would help states that wish to restrict use of the herbicide.
Often cited as a way to reduce erosion or improve soil quality, cover crops are also useful in controlling weeds that have developed an herbicide tolerance, said a survey of farmers by the Conservation Technology Information Center on Wednesday.
Farmers and pesticide applicators can use the weedkiller dicamba until July 31, the EPA announced on Monday as it canceled its approval of the herbicide, as required by an appellate court decision announced last week. The so-called existing stocks order will allow use of the chemical on GE cotton and soybeans this crop year — the goal of farmers facing the loss of a potent weed control tool with the growing season already underway.
Farmers can no longer spray the controversial pesticide dicamba over the top of genetically modified soybeans and cotton, the U.S. Ninth Circuit Court of Appeals ruled Wednesday. Dicamba is a weedkiller whose use has skyrocketed in recent years after agribusiness giant Monsanto introduced genetically engineered soybean and cotton seeds that resist the herbicide. The ruling means that farmers will have to immediately cease using dicamba on an estimated 60 million acres of crops across the Midwest and South. (No paywall)
Dicamba-tolerant corn seeds aren’t available yet. But if the seeds reach the market, and tens of millions more acres are sprayed with dicamba, there’s good reason to expect a repeat of the soybean disaster, in which the highly volatile weedkiller drifted off-target and damaged 5 million acres of conventional soybeans and an untold number of other crops.(No paywall)
In a new study, published in the December 2017 issue of the journal Weed Science, University of Wyoming weed scientist Andrew Kniss finds that GE corn does not produce increased herbicide resistance in weeds relative to non-GE crops, but that soybean and cotton plantings do — but only to a limited extent. (No paywall)
In the wake of this summer’s widespread damage to soybeans and other crops caused by the unintended drift from applications of the weedkiller dicamba, Reuters reports that EPA regulators told state officials that they are considering a ban on use of the herbicide after a cutoff date early next year. The idea would be to limit spraying to early spring, before soybeans emerge from the ground.
With more than 500 complaints of weedkiller misuse from Arkansas farmers, Gov. Asa Hutchinson approved an 120-day ban on use of the herbicide dicamba on row crops and forwarded the emergency step to the state's Legislative Council for a final decision. Hutchinson also assented to increasing the fine for egregious misuse of herbicides to a maximum of $25,000 and sent it to the council as well.
The second-most widely used weedkiller in the country, atrazine, poses potential chronic risk to birds, mammals and fish due to runoff and spray drift, said a draft ecological-risk assessment by the EPA. The assessment is part of a review that started in 2013 on whether to extend use of the broad-spectrum herbicide in the U.S. for 15 years.
One of the greatest threats to cotton and soybean producers is Palmer amaranth, an invasive and aggressively growing weed. The weed has developed resistance to the widely used weedkiller glyphosate and now Palmer amaranth populations in Arkansas are resistant to a class of herbicides known as PPO inhibitors, compounding the challenge of weed control, says a University of Illinois researcher.