Weed of the month: Waterhemp

  • waterhempCommon name: Tall waterhemp, common waterhemp
  • Scientific name: Amaranthus rudis
  • Grass or broadleaf: Annual broadleaf
  • Member of the pigweed family
  • Native to North America, specifically the Midwest, but can range from the western Southwest to East Coast.
  • Even though waterhemp flourishes in wet areas of land, it has become adaptable to other conditions.1
  • Seeds can germinate throughout the growing season and, if not controlled early, the plant can produce anywhere between 300,000 to 500,000 seeds per plant with a possibility of up to a million seeds. Proliferation can result in substantial yield loss.2
  • Plants emerge throughout the growing season, with some not germinating until later in the season. This can make it difficult for farmers to spray and control them as they may arise after first spraying has taken place. However, late-emerging plants produce smaller amounts of seeds that have low impact on yield.3

Waterhemp facts that may surprise you

  • Waterhemp is native to the United States and is now found in 40 states.
  • Waterhemp that grows later in the season is generally waxier, making it harder to kill.4

Fast facts

  • Waterhemp can only grow in shallow seed beds, making it a nightmare for no-till farmers.
  • Waterhemp is a dioecious plant, meaning it has separate male and female plants. This can be a disadvantage for waterhemp as it then must find the counterpart to become reproductive.5
  • Plants can range anywhere from 4 inches to 12 feet, but most are between 4 to 5 feet in agronomic settings.5
  • You can distinguish between the male and female plants by rubbing the mature flowers between your fingers. If you find tiny black seeds, the plant is a female.5
  • Waterhemp and weeds within the pigweed family can be hard to distinguish. Some ways to tell waterhemp apart is by its waxy/shiny appearance of leaves, hairless stem and leaf surfaces, egg-shaped cotyledons and alternate leaves.6
  • During its growing season, waterhemp has the ability to grow 1.5 inches per day.

Waterhemp control/management tips

According to Scott Ditmarsen, field scientist, Dow AgroSciences:

  • Waterhemp is a very prolific seeder and germinates throughout the growing season. It is a competitive weed due primarily to its sheer numbers and fast growth rate.
  • Farmers should implement timely and effective scouting throughout the growing season to identify waterhemp early. This helps farmers plan timely herbicide applications and identify potential problem fields for the following year.
  • Combining aggressive tillage and a program approach to weed control — including soil-applied herbicides followed by postemergence herbicide(s) with multiple, effective modes of action — is the best strategy to control waterhemp.
  • When feasible, physically remove escaped waterhemp plants to reduce competition and seed production.
  • Any cultural practices that improve crop competitiveness will improve the effectiveness of herbicide programs.

Dow AgroSciences weed control solutions:

Corn
SureStart® II herbicide
Resicore® herbicide
Keystone® NXT herbicide
Keystone® LA NXT herbicide 

FulTime® NXT herbicide
Surpass® NXT herbicide 
Durango® DMA® herbicide
Duramax® herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system

Soybeans
Sonic® herbicide
Surveil® herbicide
Durango® DMA® herbicide
Duramax® herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system

Additional information:

More information can be found through these weed science resources:

Waterhemp has emerged; North Dakota State University
Are you ready for weeds?; University of Missouri
Management of ALS-resistant Palmer Amaranth and Waterhemp in the Panhandle; University of Nebraska

Sources:

1North Dakota State University. 2017. Waterhemp has Emerged in 2017. https://www.ag.ndsu.edu/cpr/weeds/waterhemp-has-emerged-in-2017-5-18-17

2University of Missouri Integrated Pest Management. 2015. Are you ready for weeds? https://ipm.missouri.edu/ipcm/2015/9/Are-you-ready-for-the-weeds/

3Lawrence, N. 2017. Management of ALS-Resistant Palmer Amaranth and Waterhemp in the Panhandle.
http://cropwatch.unl.edu/2017/management-als-resistant-palmer-amaranth-and-waterhemp-panhandle

4Gullickson, G. 2014. 22 Sobering Need-to-Know Facts About Herbicide-resistant Weeds. http://www.agriculture.com/crops/tech-tour/22-sobering-needtoknow-facts-about_196-ar42485

5Nordby, D., B. Hartzler, and K. Bradley. 2007. Biology and Management of Waterhemp.
https://www.extension.purdue.edu/extmedia/BP/GWC-13.pdf

6Werle, R., L. Sandell, and G. Kruger. 2013. Postemergence Control of Emerged Waterhemp in Soybeans.
http://cropwatch.unl.edu/postemergence-control-emerged-waterhemp-soybeans

 

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. FulTime NXT, Keystone LA NXT and Keystone NXT are federally Restricted Use Pesticides. Enlist Duo herbicide is 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. Duramax, Durango DMA, FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore, Sonic, SureStart II, Surpass NXT and Surveil are not registered for sale or use in all states. FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore, SureStart II and Surpass NXT are not available 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.  ©2017 Dow AgroSciences LLC

Poll of the Month

Stacked herbicide resistance progresses across Midwest

Dave Ruen
Field Scientist
Dow AgroSciences

For nearly two decades, herbicide-resistant weeds have swept across the Midwest. Today, more fields than ever are facing weeds with resistance to multiple modes of action. With new postemergence technologies entering the market, farmers need to remain vigilant and avoid repetitive use of one active ingredient by using residual herbicides in a program approach to control their tough weeds multiple ways.

We’re trying to manage the expansion of glyphosate-resistant weeds — marestail, waterhemp and giant ragweed, for example. There’s no question in my mind that we’ve slowed the advance of glyphosate resistance due to the resurgent use of soil-applied herbicides, such as Sonic® herbicide in soybeans.

Some weeds, such as tall waterhemp, are developing resistance to multiple modes of action, an issue farmers must keep their eyes on.

In Kansas, some tall waterhemp plants are now resistant to HPPD inhibitors, ALS inhibitors and atrazine. Meanwhile in Illinois, tall waterhemp is documented with multiple resistance to PPO inhibitors, ALS inhibitors and atrazine.

In the last few years, we’ve seen a slow expansion of herbicide-resistant weeds, particularly in the upper Midwest. It’s important that we continue to increase the use of residual herbicides and not skimp on rates.

To stop weeds from robbing yield, carefully scout soybean fields and use a targeted program approach this season. Start with a clean field by applying a broad-spectrum, preemergence herbicide that has powerful activity on the Amaranthus species, including pigweeds, waterhemps, and Palmer and Powell amaranth. With two nonglyphosate modes of action, Sonic herbicide is proven to provide 94 percent control of waterhemp and 93 percent control of Palmer amaranth.

For more information about how your customers can take control of herbicide-resistant weeds in their soybean fields, visit OperationCleanFields.com.

®Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. 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. ©2017 Dow AgroSciences LLC

Help three farmers win $10,000 for nonprofits in their communities — vote now!

Ten farmers are in the running to win a trip to their dream sports field and $10,000 for their community from the Power to Do More contest, sponsored by Resicore® corn herbicide. More than 130 farmers entered the contest by uploading a photo that represents the power of their farm, and Dow AgroSciences is excited to introduce the top 10 finalists. The three finalists with the most votes on PowerToDoMore.com by May 21 will win.

The 10 finalists represent a range of farming operations across seven states: Illinois, Iowa, Indiana, Minnesota, Nebraska, Ohio and Wisconsin. From growing corn and soybeans to raising cattle and pigs, each finalist has a shared passion for farming and giving back to his or her community.

Watch the video below to see the 10 finalists’ photos before you cast your vote.

Resicore is designed to help farmers protect their crops from more than 70 tough weeds that rob corn yield, profit and time. With versatility to be applied pre-, post- or split, Resicore is powerful enough to be applied alone. It also gives farmers the ability to add their desired rate of atrazine, glyphosate and other corn herbicide to fit the acre.

For more information about Resicore, visit PowerOverWeeds.com or contact your local Dow AgroSciences sales representative.

To support your favorite finalist in the Power to Do More contest, visit PowerToDoMore.com to vote daily and share the link to the website with your customers, friends and co-workers until May 21.

®Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Resicore is not registered for sale or use in all states. Resicore is not available 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. ©2017 Dow AgroSciences LLC

Giving farmers and their neighbors peace of mind

Excellent weed control is not enough. Farmers need a herbicide solution that stays on target and limits the risk of damaging neighboring plants and crops. Research shows Enlist Duo® herbicide is superior to other technologies because it delivers less drift and near-zero volatility.

Farmers with fields near susceptible crops and plants can use Enlist Duo on Enlist crops with confidence. By applying Enlist Duo according to label directions, they can limit the danger of harmful off-target movement.

Enlist Duo herbicide, a combination of glyphosate and new 2,4-D choline, features Colex-D® technology. This formulation helps Enlist Duo stay on target. In real-world applications across the Corn Belt and the South over the last two years, there have been no reports of off-target movement of Enlist Duo® herbicide damaging neighboring crops.

Performance wins advocates
“In the past, tomato growers have had negative experiences with off-target herbicide movement,” says Steve Smith, director of agriculture at Red Gold, Inc., producers of premium-quality tomato products. “They’re concerned about any pesticide that may damage their crop.”

Dow AgroSciences worked with Indiana-based Red Gold to understand the impact of off-target movement. Red Gold provided tomato plants for field trials to assess the performance of Enlist Duo herbicide near susceptible plants. These trials have helped put concerns about drift and volatility to rest.

“I got a firsthand look at Enlist Duo in lab and field work,” Smith says. “It was really impressive. It’s not the old 2,4-D. Dow AgroSciences has a formulation that limits volatility.”

Benefits show up in the field
Farmers who’ve seen applications of Enlist Duo herbicide realize the advantages it offers. In addition to exceptional weed control, they’re getting a product that helps them mitigate concerns about damage to surrounding susceptible plants.

“Growers can control drift by choosing the right conditions, the proper nozzles, boom height and so on,” says Pat Duncanson, a Minnesota farmer. “But we can’t control the weather after application. The only way to control volatility is to choose a herbicide with extremely low volatility.”

The herbicide that impresses Duncanson is Enlist Duo.

“I’ve seen how stable the Enlist Duo platform is,” says Duncanson, who has attended demonstrations and has tried the Enlist system on his own farm. “Enlist Duo will stay where you put it.”

Widening industry confidence
Smith saw the precision of Enlist Duo® herbicide during trials that placed Red Gold tomatoes next to Enlist soybeans. Enlist Duo was sprayed right next to the tomatoes, and there was no impact on the tomato plants. This collaboration helped show how effective Enlist Duo is at staying on target.

“I was very appreciative of how Dow AgroSciences went about working with us and understanding our concerns,” Smith says. “They opened a dialogue. That’s not normal anymore. I am very appreciative of how Dow AgroSciences is doing business.”

Help customers understand the benefits of Enlist Duo by visiting Enlist.com.

Enlist soybeans growing next to Red Gold tomatoes

When Enlist Duo® herbicide was sprayed on Enlist soybeans growing right next to Red Gold tomatoes, there was no impact on the tomato plants. This field trial shows how effective Enlist Duo is at staying on target.

®™DOW Diamond, Colex-D, Enlist and Enlist Duo are trademarks of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Enlist Duo herbicide is 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. Always read and follow label directions. ©2017 Dow AgroSciences LLC

 

Keep fields clean to produce more bushels

When choosing inputs, farmers need to feel confident they are making a decision that will result in maximum ROI at the end of the season. While unsteady commodity prices may tempt your customers to lower their weed control investment, allowing soybeans to compete with weeds throughout the season will steal dollars at harvest.

“We need to make sure we’re doing everything we can to produce bushels,” says Jeff Moon, market development specialist, Dow AgroSciences. “Starting with a sound herbicide program is one of those things that’s going to help us do that.”

Soybean farmers can start with Sonic® herbicide in spring to protect their yield potential in fall. Sonic can be applied preemergence up to three days postplant for long-lasting residual control to prevent broadleaf weeds from invading soybean fields.

Watch this video for tips on how your customers can maximize their return on investment this spring. Plus, visit OperationCleanFields.com for weekly articles and agronomic videos to help your customers battle their toughest weeds this season.

®Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. 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. ©2017 Dow AgroSciences LLC

6 tips to build a weed management program

Following a program approach to weed control can help farmers control the weeds that challenge crops this year while preserving the effectiveness of herbicide technologies into the future. Retailers can help farmers develop a well-thought-out weed control program that can help them achieve successful weed control, improved yield and higher profits in years to come.

Jonathan Siebert, Ph.D., Dow AgroSciences Enlist field sales leader, offers these six tips that retailers can consider when helping customers with weed control strategies.

  1. Know the field history. “It’s important to reference the past, especially the previous year, when laying out a weed control program,” Siebert says. “If a field harbors marestail or Palmer amaranth, you’ll need to select herbicides that are effective against those species.”
  2. Start with a clean seedbed. “Your goal should be to have no weeds in the field at planting,” Siebert says. “Most fields benefit from a burndown program that can include effective herbicides such as glyphosate and new 2,4-D choline, the ingredients in Enlist Duo herbicide.”
  3. Use herbicides with residual activity. “Adding residual herbicides at burndown, preemergence or both can provide additional modes of action that help control weeds in the current year and preserve the efficacy of our postemergence herbicide technologies,” Siebert says.
  4. Rotate modes of action. “To prevent the development of herbicide resistance, we need to rotate the modes of action available to us,” Siebert says. “Weed control needs to be prescriptive: We must scout fields and, when weeds emerge, hit them with postemergence herbicides, remembering to rotate modes of action.”
  5. Keep the borders of fields clean. Siebert suggests farmers make sure they’re controlling weeds in ditches and turn rows to prevent weed escapes. Weeds in these areas can develop resistance because they’ve avoided exposure to full rates of effective herbicides.
  6. Adopt a zero-tolerance policy. Controlling weeds effectively throughout the growing season is essential to curbing the expansion of herbicide resistance.

“We have to be good stewards,” Siebert emphasizes. “Longevity of our herbicide technologies is key to effective long-term weed control.”

Siebert says growers may need to pull rogue weeds to keep those that escape herbicides from eventually overwhelming technologies. “The best practice is to keep the farm free of weeds,” he says. “A field that’s clean helps protect more of the yield potential of every seed we plant.”

The fate of glyphosate is a lesson agriculture can’t forget. “As glyphosate has become less of a silver bullet, it’s had a negative impact on economics and profitability,” Siebert says. “Abusing and losing weed management tools costs time and money. With tight margins, farmers need to do all they can to maximize yield and profits by keeping weeds from shrinking income.”

Sound weed management plans — with retailers providing assistance to customers as they develop these plans — is vital to boosting farmers’ opportunities for long-term profitability.

“We need to be proactive in our approach to weed control,” Siebert says. “Weed control and resistance management take a long-term commitment just like soil fertility requires a long-term view. We have to look five or 10 years down the road. Successful weed management can help farmers achieve long-term productivity.”

tractor spraying herbicide

Rotating herbicide modes of action can help growers achieve better weed control with the current crop while also helping sustain effective herbicide technologies for use in coming years.

®™Enlist and Enlist Duo are trademarks of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Enlist Duo herbicide is 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. Always read and follow label directions. ©2017 Dow AgroSciences LLC