“We are the most efficient producers in the world, but that doesn’t mean it’s easy,” is how Mike Henderson, Executive Vice President, Central U.S. Crops, with Atticus, puts it.
Rain-delayed plantings meant growers’ first priority was to get crops in the ground — or forgo planting certain fields altogether — often compromising their weed management programs in the process.
“I don’t know that we have ever seen the scope of prevent-plant acres and the damage that we saw in 2019,” Gail Stratman, FMC Regional Technical Service Manger – Heartland, tells CropLife® magazine. “I’ve been in this business 35 years. We had some wet years, but we didn’t have years where we fought it from March clear through October.”
“The unfortunate outcome of all this is that it created a situation we may have to live with for several years,” says Dane Bowers, Technical Product Lead of Herbicides with Syngenta. “There was more weed seed deposited in the soil that we may deal with in 2020, and it could go beyond that, depending on the length of dormancy.”
There was substantial production of weeds in some fields and replenishment of the soil seedbank by both winter annual and summer annual weeds, according to an online post by Dr. Mark Loux with The Ohio State University Extension about the importance of fall herbicides this year. Applying herbicides this fall can compensate for increased weed populations and make life easier in the spring, Loux says.
“We have applied into late December and still eventually controlled the weeds present at time of application,” he says. “Once hard freezes start to occur, there is usually a substantial change in the condition of certain weeds, such as dandelion and thistle, that renders them less sensitive to herbicides.”
The situation will require growers to be extra diligent and even change their practices, Stratman cautions. The higher seed bank that growers will likely face means they will need to be astute about using full application rates on fields in order to fight more intense weed pressure.
“It will be interesting in 2020 what new problems or issues creep up that we’re probably not aware of here in October 2019,” Stratman says, such as fallow syndrome due to unplanted areas and a learning curve for growers who experimented with cover crops for the first time this year. Those challenges could include timely cover crop termination, difficulty planting into growing cover crops, and potentially higher insect pressure. Some growers may encounter weeds they haven’t seen in 20 years because they haven’t had fields go untouched that long, he adds.
Despite the unique challenges presented in 2019, the same principles used in prior years will still apply in 2020, including the use of a strong residual preemergent treatment up front and overlap of sequential residuals thereafter to keep weeds at bay during the season. “Keeping applications early on small weeds is the most imperative strategy and probably the difference between good or great control and fair or less-than-desired control,” Stratman says.
Ryan Wolf, Agronomy Services Manager with WinField United, says that by applying a preemergent herbicide in the fall, “we take that whole sense of urgency and weeds that jumpstart in spring off the table.”
He adds: “On the prevent-plant acres, I’ve been hearing from growers, ‘We might not farm these acres next year.’ You’re still going to need some weed control there or you’re going to have bigger problems to deal with the following season.”
As low commodity prices have created a crunch at the farm level, there is pressure for growers to reduce costs in weed control programs, Bowers adds. However, “most of the time, you get what you pay for. We need to be careful in making decisions to reduce rates or to cut out residual applications or spray post only, as those have very negative consequences.”
We are verging on too much of a good thing when it comes to sorting out the soybean market, according to several people with whom we spoke.
“What has really surprised me is probably the lack of clarity and confusion on the grower and even the dealer level between some of these different trait packages,” Wolf says.
“You could have up to six different trait packages of soybeans planted in the same area between different farmers, which creates a lot of logistical issues as far as tank clean-out and drift. That’s going to be the biggest challenge for dealers and growers: How do they manage recordkeeping, along with spraying technologies and drift control,” Wolf says.
Among these trait packages, the standout for 2020 is Corteva Agriscience’s Enlist Duo, a combination of 2,4-D choline and glyphosate. Enlist One herbicide is a straight-goods 2,4-D choline that offers additional tank-mix flexibility with other products such as glufosinate. The company projects that Enlist E3 soybeans will be planted on at least 10% of U.S. soybean acres in 2020.
For dicamba-tolerant soybeans, Syngenta has Tavium Plus VaporGrip Technology herbicide, the market’s first premix residual dicamba herbicide. It controls both preemergent and post-emergent weeds for up to three weeks longer than dicamba alone and provides two active ingredients — dicamba and S-metolachlor — and two sites of action in one product.
From FMC, pending EPA and state registrations, is Authority Edge herbicide, with two effective modes of action to combat resistant weeds in soybeans, dry shelled peas, and sunflowers. The new formulation provides an optimized ratio of sulfentrazone and pyroxa-sulfone targeting long residual control of small-seed broadleaf weeds, including waterhemp and Palmer amaranth. The company is actively seeking tank mix approval for all its post in-crop 2,4-D, and dicamba products before next season, according to Stratman.
FMC now has 23 herbicides, fungicides, and insecticides listed on either the Enlist Duo and/or the Enlist One herbicide websites as approved tank-mix partners.
On the corn side, generic player Atticus announced a round of new additions to its portfolio of crop protection products, including StreliuS II herbicide, which utilizes S-metolachlor to fight competition from a broad spectrum of early-season grasses and many broadleaf weeds. Another new product, Cavallo 4 SC, features mesotrione, while the new Inflame 280 SL herbicide with glufosinate is ideal for rapid burndown control, the company says.
For soybeans, Atticus is expanding its suite of pre-emerge and PPO herbicide products. This includes the new Aquesta family of herbicides featuring sulfentrazone and combined supplementary ingredients like cloransulam, metribuzin, and chlorimuron. It also unveiled the Zaltus herbicide line offering residual control via flumioxazon and supplementary active ingredients.
Lastly, it will launch the MetalliS family of herbicide products that utilize S-metolachlor and complementary AIs to control many broadleaf, grass, and sedge weeds.
Latest on Dicamba
In October the Illinois Department of Agriculture (IDOA) announced additional restrictions on dicamba application for the 2020 growing season, including a cut-off date of June 20 and an 85-degrees Fahrenheit temperature cut-off. It is the first state to set regulatory changes for next season.
“The number of off-target complaints received during the 2019 growing season rose dramatically, and the department is taking action to reduce those numbers,” says John Sullivan, Director, IDOA.
No state saw more dicamba-related injury complaints this year than Illinois — 590 of them, nearly double the prior year’s 330 complaints and about three times the complaints the state fielded in 2017, the technology’s debut year.
Associate Professor Dr. Aaron Hager, in a post on the University of Illinois website, called the widespread occurrence of dicamba symptoms on soybeans for the third straight year troubling but says he was just as concerned about the “feeble theories” being put forth to explain the cause of soybean leaf cupping.
“It appears science continues to be sacrificed for sales,” Hager says. Company representatives have incorrectly attributed the leaf cupping to causes such as dry weather stress, Liberty+ammonium sulfate (AMS), and tank contamination, he says. Further, some have claimed that multiple causes are involved when entire fields are uniformly cupped.
“If contamination is the cause of even half the instances of soybean leaf cupping, commercial applicators might question the prudence and legal ramifications of applying a product that seemingly cannot be removed from their chemical formulation, transportation, and application equipment,” Hager says, adding, “Multiple university weed science programs have demonstrated volatility of these dicamba formulations can be detected for up to four days after application, yet these results seem to be largely ignored by industry as another possible source of exposure.”