Tag Archives: Industry News

Q&A: Understanding residual control with preemergence herbicides

With soybean fields planted, albeit late in a lot of cases, many farmers and retailers may be wondering how long the preemergence herbicides they applied will hold against tough weeds. It’s an important factor to consider when planning for any potential postemergence herbicide     applications.

Recently, a soybean retailer submitted a timely question via Operation: Clean Fields around expected residual control of a top preemergence herbicide. Chad, a retailer in Minnesota, asked the question, and Jeff Moon, market development specialist with Corteva Agriscience, answered.

Q: When applied as a preemergence, how long of a residual can I expect using Sonic® herbicide?

A: Sonic herbicide has a labeled application rate of 4 to 7 ounces per acre. The length of residual will depend greatly on where your application falls within that rate spectrum. If you apply 4 ounces per acre, you can expect residual control to last between four and six weeks. From there, as a general rule of thumb, you can expect an additional seven to 10 days of control for every ounce per acre that the application rate increases. So, at the maximum rate of 7 ounces per acre, we’ve seen seven to 10 weeks of residual control when applied as a preemergence.

One benefit of that long-lasting residual control is it gives farmers a much wider window to make postemergence applications. It also keeps those later-season weeds small and easier to control, so you can stay on label with planned postemergence treatments.

Of course, both the amount of moisture received after application as well as the soil type can factor into the duration of residual control experienced.

For more information about Sonic, talk with your local Corteva Agriscience territory manager or visit BattleWeeds.com.

soybean field

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Sonic is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2019 Corteva

Nitrogen stabilizers: A refresher course

It’s no secret nitrogen is one of the most important nutrients for a corn crop. Once nitrogen is lost, corn plants themselves may not be far behind. What seems to be a bit more secretive, or at least mysterious, is how nitrogen stabilizers work to keep as much of the nutrient as possible available for those plants.

It all comes down to simple science (well, simple for the scientists anyway; it takes just a little more explaining for the rest of us).

Corn uses nitrogen in two forms: ammonium and nitrate. Ammonium is preferable to corn,   because it’s easier for plants to absorb and it’s less susceptible to loss. Nitrate is more easily susceptible to loss via leaching and denitrification. Unfortunately, there are strains of bacteria that convert ammonium into nitrate to use for their own nutrients.

Corteva Agriscience’s line of nitrogen stabilizers, called nitrogen maximizers, includes N-Serve® and Instinct®. Both products work below the soil to slow down those bacteria, ensuring the nitrogen can stay in ammonium form longer. The maximizers extend the ammonium’s useful life for up to eight additional weeks, keeping nitrogen near the corn’s roots for when the plant is ready to absorb it.

The result is that the corn crop can get the maximum out of the farmer’s nitrogen application and the farmer, in turn, can get the maximum out of his or her investment, leading to a profitable yield.

With an extremely rainy spring across much of the Corn Belt and with planting being significantly delayed, nitrogen is especially vulnerable to loss this season. So, it’s especially important to ensure your customers’ investments are as safe as possible. Nitrogen maximizers can help.

And as you and your customers look ahead to fall nitrogen applications, onward to 2020 planting, it’s a good idea to keep this information top of mind. To learn what nitrogen maximizers can do for your clients’ crops, visit NitrogenMaximizers.com.

corn roots

Nitrogen maximizers keep nitrogen ready for corn’s roots

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Instinct is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Do not fall-apply anhydrous ammonia south of Highway 16 in the state of Illinois. Always read and follow label directions. ©2019 Corteva

Strike out weeds with multiple herbicide modes of action

On a baseball field, few pitchers can keep hitters at bay throwing only one pitch. The most successful pitchers know how to change things up and keep hitters off balance. The same concept applies in farmers’ fields when it comes to weed control.

Successful weed control – both now and in the future – depends on attacking weeds with multiple herbicide modes of action. Retailers can help their customers develop smart game plans and adopt weed management technologies that allow them to keep weeds off balance and in check all growing season long.

The key? Develop a program approach that takes advantage of different herbicide modes of action. For instance, the Enlist weed control system is designed for burndown applications, preemergence residual applications and postemergence applications enabling the use of three or more modes of action to every field. Helping customers identify and use multiple modes of action gives them the opportunity for clean, weed-free fields.

Cover all the bases
A good weed control program starts will a clean field at planting. Burndown applications are important, even when weather issues delay planting. Retailers can help customers by recommending effective burndown herbicides such as Elevore®, Enlist One® or Enlist Duo® herbicides.

After planting, preemergence herbicides can add another mode of action. This can pick off weeds that have escaped or resisted the burndown treatment. Throwing a curve ball at weeds can subdue them and help the crop get off to a good, strong start.

“We need to get residual herbicides on the crop to suppress weeds, even when weather may tempt us to skip our preemergence applications,” says Shawna Hubbard, Trait Herbicides Product Manager for Corteva Agriscience, Agriculture Division of DowDuPont. “Be consistent in using appropriate rates for weed pressure in the field. This ensures we’re helping prolong control of weeds until we’re ready to make postemergence applications.”

Remind customers to consider preemergent herbicides that offer solid residual activity AND offer a different mode of action than their burndown or postemergence herbicides. For instance, Sonic® herbicide offers two modes of action while Trivence® herbicide delivers three modes of action.

A good scouting report
Once the crop has emerged, farmers need to scout their fields and act promptly when weeds begin to appear. Follow label directions; however, it’s generally best to hit weeds when they’re small and more likely to succumb to the postemergence treatment.

Timing is critical to maximize control of any postemergence application. Make sure customers are basing decisions on the size of the weeds and not the calendar alone.

“Sometimes, we may need to make an initial postemergence herbicide application earlier than we had planned,” Hubbard says. “With Enlist One or Enlist Duo herbicides, farmers should apply when weeds are no more than 6 inches tall.”

Get the bullpen ready
If you need to follow up with a second postemergence application due to a later flush of weeds, the Enlist weed control system gives you flexibility. The wider application window helps hit weeds when they are vulnerable. In addition, both Enlist herbicides feature 2,4-D choline with inherently low volatility. For two modes of action, choose either Enlist Duo with glyphosate or tank mix Enlist One with glufosinate.

Farmers who learn to change up their herbicide modes of action can keep striking out weeds all summer long. The result can be a sweet victory celebration at harvest.

Learn more about the Enlist weed control system at Enlist.com or by using the Enlist Ahead resource. Also check out the YouTube channel or Twitter at @EnlistOnline.

Using an array of herbicides that offer multiple modes of action goes a long way in producing a farmer’s “field of dreams.”

™®Elevore, Enlist Duo, Enlist One, Sonic and Trivence are trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Enlist Duo and Enlist One herbicides are not registered for sale or use in all states or counties. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your area. Enlist Duo and Enlist One are the only 2,4-D products authorized for use with Enlist crops. Consult Enlist herbicide labels for weed species controlled. Sonic is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2019 Dow AgroSciences LLC

Q&A: Herbicide resistance in the Upper Midwest

Herbicide-resistant weeds are top threats to corn and soybean yield potential. Jeff Moon, market development specialist with Corteva Agriscience, Agriculture Division of DowDuPont, recently shared insights on the state of resistant weeds and herbicide options. Moon works with retailers and territory managers with Corteva Agriscience in Minnesota and Wisconsin. Read the Q&A below for Moon’s advice to control resistant weeds this season.

  1. What are the top three herbicide-resistant weeds affecting corn and soybean farmers in your area?
    Waterhemp, giant ragweed and lambsquarters, in that order. Waterhemp is in the pigweed family, which has known resistance issues, so it seems to be the focus of conversations right now.
  2. Which herbicide-resistant weeds have most recently shown up?
    The further west you go, kochia becomes an issue. We’re also having discussions about Palmer amaranth moving in and the concerns about that. In the heart of corn and soybean country, the herbicide-resistant weeds we mostly see are waterhemp, giant and common ragweed and lambsquarters.
  3. When new resistance is found in your area, what is the first step to combating it?
    It starts with a discussion between the retailer and farmer. They both pay attention to local conditions, agronomy news and university research. Farmers are on the look-out for new threats and will make an adjustment if needed. Before changing products, they might just tweak their current program to make it better. This means they might change herbicide rates or if they’re doing one pass, they’ll adjust to a two-pass or change the tank mix.
  4. Which herbicides are particularly effective on these herbicide-resistant species?
    We are fortunate to have several residual and burndown products from Corteva Agriscience, Agriculture Division of DowDuPont, that fit the way growers want to farm.

    If your customers are using a multi-product approach in corn, one of the best ways to control resistant weeds is to use SureStart® II herbicide or Resicore® herbicide pre- or postemergence. I’ve seen farmers have success putting Surpass® NXT herbicide or Keystone® NXT herbicide down first, then use SureStart II or Resicore over the top on the second pass to control remaining weeds and add a residual layer. This is a great one-two punch to get corn to canopy.

    In soybeans, it starts with a strong preemerge. Sonic® and Surveil® herbicides are great options to control broadleaf weeds early. In a burndown situation, DuPont Enlite® herbicide can burndown emerged weeds and provide residual activity. Another burndown option is Elevore® herbicide, which prevents regrowth of many resistant weeds, including marestail. Elevore has a low use rate and fits well in reduced or no-till systems.

Talk with your local territory manager from Corteva Agriscience or go to Corteva.US to learn more about corn and soybean herbicides that can help your customers control herbicide-resistant weeds.

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Keystone NXT is a Restricted Use Pesticide. Keystone NXT is not registered for sale, distribution or used in all states. Elevore, Resicore, Sonic, SureStart II, Surpass NXT and Surveil are not registered for sale or use in all states. Keystone NXT, Resicore, SureStart II and Surpass NXT are not registered for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2019 Dow AgroSciences LLC

Survey says … this weed is the most challenging in soybean fields

While there are dozens of common weeds that threaten soybean yields, a recent survey found a clear winner when it comes to robbing retailers of more sleep — and farmers of more yield potential.

Corteva Agriscience asked a group of 100 retailers from across 12 north-central states this question: “What is the most challenging herbicide-resistant weed in your area?” The definitive winner was waterhemp — which was named by 58 percent of retailers — more than all other weed species combined.

Marestail was a distant second, at 23 percent, followed by giant ragweed at 7 percent, and Palmer amaranth and kochia, both at 6 percent.

herbicide resistant weed chart

Jeff Moon wasn’t surprised by the results.

“It’s consistent with recent conversations we’ve had with customers, whether out in the field or at industry events,” Moon says. “We work diligently to keep tabs on the currently challenging weed issues, so we can be ready to help with tailored solutions.” 

Why it’s challenging, and tips for more effective management
Waterhemp is seen as the most challenging for a couple reasons. First, it’s become resistant to multiple herbicides — not just glyphosate. In fact, researchers have identified a waterhemp population in Missouri that is resistant to a record-breaking six herbicide mechanisms of action.1 Second, it shows no signs of slowing its spread to infest soybean fields in new states. 

Of particular concern is that this season many farmers could be looking at a one-two punch from marestail and waterhemp. That’s because it’s expected that marestail will emerge in high numbers this spring after the cool, wet conditions many areas experienced last fall. These conditions, along with a delayed harvest, provided an ideal situation for winter annuals like marestail to germinate and become established. If farmers pass on a burndown application, marestail can be expected to quickly cause problems in soybean fields. 

“A good burndown herbicide application — either in fall or early spring — is very effective against actively growing winter annuals like marestail,” Moon says. “Elevore herbicide provides excellent control of marestail up to 8 inches tall, and works in challenging conditions.”

But burndown herbicides won’t work on later-emerging summer annuals like waterhemp. For that, Moon recommends farmers scout often, implement a diverse action plan and use a program herbicide approach with multiple modes of action. Below he provides several tips for better waterhemp management:  

  • Scout early and often. It’s critical to identify waterhemp early, then continue to check fields through midsummer. Ongoing scouting helps farmers plan timely postemergence herbicide applications. While scouting, make note of potential problem spots for the following year. Waterhemp is often misidentified with its cousins in the pigweed family, such as Palmer amaranth. When identifying waterhemp, check the leaves. Waterhemp leaves are generally longer and more lance-shaped than other pigweeds.  
  • Reduce row spacing at planting. Planting narrower rows can help suppress waterhemp growth by reducing the time it takes for crops to reach canopy closure. 
  • Layer residual herbicides. Layering residual herbicides keeps fields clean longer, typically through crop canopy closure, to manage the waterhemp seedbank. In soybeans, Moon recommends Sonic® herbicide for two modes of action preemergence, followed by an application of EverpreX herbicide over the top of soybeans for an additional mode of action. Farmers may also add glyphosate, in areas where waterhemp isn’t resistant, to increase the modes of action. 
  • Keep weeds from going to seed. Just a few waterhemp weeds left in a field can mean significant problems next season. Waterhemp that goes to seed in soybean fields can potentially cross-pollinate with a population in another field and build additional resistance. Tillage also can help lower waterhemp populations because in order to germinate and emerge, its seeds must be in the top inch of soil and they are relatively short lived. 
  • Maximize application technology. Pay close attention to herbicide labels to maximize the efficacy of the product. Not every herbicide can be applied in the same manner with the same nozzle, water volume, pressure and adjuvant.
  • Rotate crops. Waterhemp requires herbicide control and effective cultural practices, like rotating crops. This should be planned for more than a single year at a time, Moon says. Rotating crops also allows farmers to alternate modes of action and adjust tilling plans for corn and soybean fields.

“It’s critical to start with a strong treatment plan for winter annuals like marestail, then be ready with a diverse plan of action for waterhemp,” Moon says. “Otherwise, you risk a significant drop in yield potential, and the weeds will only get tougher to control down the line.”

For more information, including product labels, visit Sonic® herbicide, EverpreX herbicide and Elevore® herbicide.

waterhemp

Waterhemp can be a giant pain in soybean fields without effective management

1Shergill, L.S., B.R. Barlow and M.D. Bish. 2018. Investigations of 2,4-D and Multiple Herbicide Resistance in a Missouri Waterhemp (Amaranthus rudis) Population in Weed Science Vol. 66, Issue 3.

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Arylex is a registered active ingredient. Elevore and Sonic are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. EverpreX is not registered in all states. See your DuPont retailer or representative for availability in your state. Always read and follow label directions. ©2019 Dow AgroSciences LLC

Be inspired by the Power to Do More winners

The Power to Do More contest recognizes worthy farmers not only for what they produce in their fields but also for their exceptional commitment to the communities in which they farm. Farmers often spend as much time and effort working with local organizations as they do ensuring their cornfields stay clean through harvest.

In 2018 we asked farmers to submit photos that embody what gives them the power to do more on their farms. Online voting determined the top three winners, who each saw donations made to their nonprofit of choice from the corn herbicides portfolio of Corteva Agriscience, Agriculture Division of DowDuPont.

These inspiring documentaries show how these three families have the power to do more — in their fields and in their communities. Click the links below to meet the Schroeders from Iowa, the Krauses from Minnesota and the Gutterys from Kansas.

Corteva Agriscience is proud to showcase these winners and to support all American farmers with a lineup of corn herbicides dedicated to delivering the power to do more every season:
Resicore® herbicideSureStart® II herbicideDuPont Realm® Q herbicideDuPont Cinch® ATZ herbicide and Keystone® NXT herbicide.

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Cinch ATZ and Keystone NXT are Restricted Use Pesticides. Keystone NXT is not available for sale, distribution or use in all states. Resicore and SureStart II are not registered for sale or use in all states. Keystone NXT, Resicore and SureStart II are not registered for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2019 Dow AgroSciences LLC

Timely Residual and Enlist™ Herbicide Applications Foil Weeds

They say timing is everything. When it comes to weed control, that’s close to the truth. Timing certainly is important.

Farmers who put together a successful weed control program need to make timely herbicide applications from before planting through their postemergence applications. Retailers can help their customers make plans that allow for these timely applications.

Into the field earlier
Changes in planting dates may require changes in traditional herbicide application dates, says Shawna Hubbard, Product Manager for Corteva Agriscience, Agriculture Division of DowDuPont.

“As we plant earlier and earlier, farmers need to adjust their herbicide applications,” Hubbard says. Any operation applying growth regulators – such as glyphosate, 2,4-D or dicamba – early in the year needs to ensure the temperatures are warm enough that weeds are actually growing. If they’re not actively growing, these herbicides will be less effective.

“We also need to get residual herbicides on before weeds can gain a foothold,” Hubbard says. “Because we’re applying residuals earlier, we may need to consider using higher rates: We’re often asking them to control weeds an extra two, three or four weeks before we apply postemergence treatments.”

Weeds dictate application timing
Timing is critical for postemergence applications as well. Hubbard suggests applicators base treatments on the size of the weeds, not the calendar.

“It’s better to go a little earlier than you traditionally would,” she says. “For instance, with Enlist One or Enlist Duo herbicides, we should be applying when weeds are no more than 4 to 6 inches tall. If you’re worried about a second flush of weeds after your postemergence application, you have a couple of solutions.”

Adding a qualified residual herbicide to your postemergence tank mix can extend protection. Qualified herbicides for tank-mixing with Enlist One and Enlist Duo® herbicides are listed at EnlistTankMix.com. In addition, if farmers apply postemergence herbicides a bit early, they can always come back with another round of an Enlist herbicide or glufosinate over Enlist cotton or Enlist soybeans.

“Don’t wait for late flushes of weeds to make your first postemergence application,” Hubbard says. “Weather could delay that application and put a lot of pressure on your residuals to hold the fort.”

Spring delays in 2018 meant some growers never got a residual down. That, in turn, required early postemergence applications. Wet field conditions meant some of these applications couldn’t be made until weeds were considerably larger than ideal for complete control.

Time to start planning
For 2019, Hubbard cites four goals that can help make a weed control program more successful:

  • Start with a clean field at planting.
  • Use residual herbicides that feature more than a single mode of action.
  • Make timely applications of postemergence herbicides. For Enlist herbicides, this means spraying before weeds reach 4 to 6 inches.
  • Add an appropriate residual herbicide to your postemergence product to extend the efficacy of this application.

Farmers who keep weeds under wraps all season long reap benefits in the fall. A weed-free field at harvest not only makes it easier to combine the crop but also limits the spread of weed seed.

Find out more by talking to a Corteva Agriscience field rep, by going to Enlist.com or by using the Enlist Ahead resource. Also check out the YouTube channel or Twitter at @EnlistOnline.

dead weed

Timely herbicide applications, from preplanting to postemergence, can help put tough weeds in their place.

™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. Enlist Duo and Enlist One herbicides are not registered for sale or use in all states or counties. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your area. Enlist Duo and Enlist One are the only 2,4-D products authorized for use with Enlist crops. Consult Enlist herbicide labels for weed species controlled. Always read and follow label directions. ©2019 Dow AgroSciences LLC