Difficult weeds require strong residual herbicides

Chris Pritchett

Chris Pritchett,
Product Manager,
Corteva Agriscience,
Agriculture Division of DowDuPont, Dow AgroSciences

A cold, wet start to spring is making preplant and preemergence herbicide applications challenging to schedule this year. Soybean farmers need to control difficult weeds in a timely manner to preserve yield potential.

Marestail, waterhemp, giant ragweed and Palmer amaranth are among the most difficult weeds to control in many Midwest soybean fields. These weeds have shown resistance to multiple herbicides, including glyphosate. Using multiple modes of action in a timely manner is key for effective control throughout the season.

If your customers still have time to apply a preemergence herbicide, Sonic® herbicide is a valuable tool that offers two nonglyphosate modes of action to provide long-lasting residual control. It’s proven to deliver long-lasting, broad-spectrum control to prevent weeds from invading soybean fields.

If soybeans are already emerging in your area, FirstRate® herbicide is a flexible and economical option for preemergence and postemergence control of broadleaf weeds.

If soybeans are already emerging in your area, FirstRate® herbicide is a flexible and economical option for preemergence and postemergence control of broadleaf weeds. FirstRate can be tank-mixed or applied sequentially with glyphosate to help control common ragweed, lambsquarters and marestail. DuPont EverpreX herbicide also provides a wide application window from preplant to postemergence up to 90 days before harvest. EverpreX helps soybean farmers gain residual control of many weeds and grasses resistant to ALS, PPO and glyphosate.

Visit the retailer-exclusive resource OperationCleanFields.com to learn more about how you can help your customers fight back against high-anxiety weeds in soybean fields.

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. DuPont™ EverpreX™ herbicide, FirstRate 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. Always read and follow label directions. ©2018 Dow AgroSciences LLC

Late corn planting? Stay focused on weed control

On Groundhog Day in February 2018, Punxsutawney Phil saw his shadow, signaling six more weeks of winter. Months later, farmers are feeling the impact of that prediction as prolonged cool weather delayed corn planting across the Midwest. Farmers are making quick progress to remedy the delay, but unfortunately, so are weeds. 

If any weed grows more than a few inches tall, it is difficult to control. Some common weeds, such as marestail, can grow almost any time of the year without being dormant long. Other weeds, such as waterhemp, can grow 1.5 inches per day. It’s critical to scout for these weeds throughout the growing season so you can identify them early and implement an effective herbicide program.

Because of heavy pressure from Palmer amaranth and kochia, Nebraska farmer Blake Johnson sees the importance of early season weed control despite a later start to planting. Johnson usually begins planting corn around April 10, but at that time this year he had just applied a burndown herbicide.

“We’re incorporating Resicore as the corn emerges for good blanket of residual to get the crop to canopy,” Johnson says. “With our corn program, we want to use different modes of action. We’ve always used dicamba in our post application but now we’re using Resicore, which doesn’t have dicamba, to get a different mode of action.”

Recommend herbicides that are proven to perform.
There are a variety of unique corn herbicides to help your customers control weeds pre- and postemergence, including:

  • Resicore® herbicide gives farmers power over weeds deep into the growing season. Introduced to cornfields in 2016, Resicore brings together three modes of action and a wide rate range to fit a variety of agronomic programs, including preemergence, postemergence or split applications.
  • SureStart® II herbicide is proven to give corn a strong start as the first pass to control difficult and herbicide-resistant weeds and grasses. SureStart II can be applied preplant or on up to 11-inch-tall corn, giving your customers the flexibility to overcome unexpected weather delays and cover more ground.
  • DuPont Realm® Q herbicide provides excellent postemergence broadleaf weed control in corn, with a built-in crop safener and multiple modes of action. The convenient dry formulation of Realm Q makes measuring, mixing and cleanup easier, and it eliminates the need for pumps, tanks or meters.
  • DuPont Cinch® ATZ herbicide and Keystone® NXT herbicide are dependable solutions for your customers wanting to apply a residual with atrazine. Both products can be applied from preplant through early postemergence.

In 2017, Nebraska farmer Blake Johnson applied FulTime® NXT herbicide preemergence followed by Resicore® herbicide postemergence to keep his cornfields clean deep into the growing season.

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. DuPont Cinch® ATZ, FulTime NXT and Keystone NXT are federally Restricted Use Pesticides. DuPont Cinch® ATZ herbicide, DuPont Realm® Q herbicide, FirstRate, Keystone NXT, SureStart II and Resicore are not registered for sale or use in all states. FulTime NXT, Keystone NXT, SureStart II and Resicore 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. ©2018 Dow AgroSciences LLC

Follow checklist to keep Enlist™ herbicides on target

Help your customers keep herbicide applications on the intended target to ensure better weed control results. For crispy weeds and clean fields, use the tips below to apply Enlist One herbicide or Enlist Duo® herbicide to Enlist corn, cotton or soybeans.

Application window: Ensure your crops are within the right growth stage window for an application of an Enlist herbicide.

Tank-mix partners: Before adding any other products to the sprayer, check EnlistTankMix.com for qualified tank-mix partners for each Enlist herbicide.

Nozzles: Use only nozzles and pressure combinations listed on the labels for Enlist One herbicide and Enlist Duo herbicide.

Wind speed and direction: The wind speed should be between 3 and 10 mph when making an application. Do not apply during a temperature inversion.

Susceptible crops: Make sure the wind is blowing away from susceptible crops. There is not an acceptable buffer for an application of an Enlist herbicide if the wind is moving in the direction of susceptible crops, such as cotton without the Enlist trait.

Sensitive areas: Leave a 30-foot downwind buffer to sensitive areas, such as woods, pastures, grass ditches and lawns.

Sprayer contamination: To avoid sprayer contamination, clean the sprayer out thoroughly before making an application. Pay attention to screens, nozzles and hoses and make sure they are cleaned, as well.

For on-target herbicide application and efficient weed control, use only nozzles and spray pressure settings listed on the herbicide label.

Spray pressure: Apply Enlist One herbicide and Enlist Duo herbicide at the right pressure based on the label and current environmental conditions.

Spray rate: Check that you are applying Enlist One herbicide at 2 pints per acre or Enlist Duo herbicide at 4.75 pints per acre.

Spray volume: For best results, use a spray volume of 10 to 15 gallons of water per acre.

Boom height: Consult the nozzle manufacturer for optimum boom height when applying Enlist herbicides.

Cleanout: Fill at least 10 percent of the tank volume with clean water and flush the sprayer. Be sure to triple-rinse the sprayer when you complete an application of an Enlist herbicide.

For more information, visit Enlist.com or check out this quick video on sprayer cleanout processes.

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. 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 on Enlist crops. Always read and follow label directions. ©2018 Dow AgroSciences LLC

Don’t get trapped by a temperature inversion

A thin layer of fog sits atop a young crop in the early morning hours. It has a peaceful appearance, but these conditions may provoke horizontal movement of surface-level air, causing any trapped particles — such as pesticides — to move into neighboring fields.

What you see may be a temperature inversion. A layer of warm air covers a layer of cooler air and acts like a lid, preventing the cooler air from rising and mixing with the upper atmosphere.

According to the National Oceanic and Atmospheric Administration (NOAA), temperature inversions commonly form when the air near the ground cools at night. Calm winds, clear skies and long nights increase the likelihood of a temperature inversion occurring.

Gases trapped near the surface can’t mix with the warmer air above and dissipate naturally, so they hover near the ground and often drift sideways. Pesticides hanging in this layer of air can move into neighboring fields, lawns and gardens with unintended consequences.

“We want a light wind — 3 to 10 miles per hour — when making a herbicide application,” says Haley Nabors, Enlist field specialist. Within a temperature inversion, applied products can move great distances. “Furthermore, the direction the trapped air will move is unpredictable.”

Warn growers about temperature inversions
You can remind customers or anyone applying crop protection products to watch for common conditions that create temperature inversions. If these conditions occur, avoid applying any herbicides until the environment is favorable for a successful, on-target application.

Temperature inversions are most likely to occur when wind speeds are less than 3 mph and/or if the temperature is within five degrees of the nighttime low. That’s why spraying in wind conditions of zero to 3 mph is never recommended.

Technology helps identify conditions
All applicators should plan to check local weather conditions before making any herbicide application.

“If you identify a temperature inversion, do not make an application,” Nabors says. “The spray particles may never hit the intended surface, which makes the application less effective for your crop. If it doesn’t reach the weeds, you’re wasting your herbicide dollars.”

In addition, you run the risk of damaging susceptible plants in nearby fields, lawns and gardens.

Nabors urges you to check conditions before every application and even during applications. Weather apps for smartphones and tablets can be useful tools to monitor changing weather throughout a herbicide application. Always monitor conditions while you are in the field. In addition to weather apps or websites, an inexpensive windsock shows wind direction. An anemometer provides wind speed. A quick check of the temperature also is a good idea.

If you prefer a visual sign, releasing smoke or powder can indicate particle movement. The smoke or powder should drift gently with the wind. If it gathers in a stationary, suspended cloud, that indicates a temperature inversion, which may cause an application to move far and wide.

“With Enlist herbicides, we recommend a minimum wind speed of 3 mph,” Nabors says. “This allows some stirring in the atmosphere to dissipate any potential inversion layer.”

Remember, a complete lack of wind is a warning. Do not apply herbicides. Wait until later in the day and check again for a more favorable application environment.

Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. Enlist 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 herbicides are the only 2,4-D products authorized for use in Enlist crops. Always read and follow label directions. ©2018 Dow AgroSciences LLC

Pre-sidedress soil testing can combat spring weather yield impacts

Spring 2018 has been tough for corn growers. The Corn Belt specifically experienced unusually cold weather throughout April while other parts of the country saw late-spring snow, excessive precipitation and, oddly in some areas, drought. These atypical weather events delayed the majority of corn planting, prompting many farmers to ask: How will this affect my yield?

Historical data indicates that abnormally cold Aprils lead to below-average yield. While such weather and yield impacts are beyond farmer control, there are a few steps farmers can take to help combat potential negative effects.

  • A pre-sidedress soil nitrate test is a great option for farmers to determine the nitrate nitrogen available in the soil after the spring precipitation period and before the period of major nitrogen demand by corn. This test will show how soil was impacted by spring weather events and the late planting start and will inform more accurate sidedress nitrogen recommendations.
  • Best practices are to sample corn when it is 6 to 12 inches tall, or in late May to early June. Farmers should sample areas that are similar and 10 to 20 acres in size. This test works best if farmers avoid previous fertilizer application bands, including starter and anhydrous ammonia bands. Farmers should also take 15 to 20 cores per sample.
  • Tactful sidedress planning, along with use of a nitrogen stabilizer, such as Instinct® or N‑Serve®, can be a great option for farmers looking to optimize their yield despite negative spring weather impacts. This allows farmers to apply more nitrogen for peak growth at critical nutrient uptake stages and helps protect applied nitrogen by keeping it in the root zone longer where and when corn needs it most.

For additional details on nitrogen stabilizers, such as Instinct and N-Serve, visit MaxInMaxOut.com or contact your local Dow AgroSciences sales representative.

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. 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. ©2018 Dow AgroSciences LLC

Dow AgroSciences donates $10,000 to Feeding America

As part of its focus on the 4R Nutrient Stewardship program, Dow AgroSciences donated $10,000 to Feeding America to encourage farmer usage of the program’s nutrient management best practices.

The donation was a result of farmer pledges at the most recent Commodity Classic, which took place Feb. 27 to March 1 in Anaheim, California. While at the company’s booth, farmers were asked to pin the location of their farm on an oversized map of the United States. The pin signified a pledge to their commitment to the 4Rs, which focuses on applying the right source of nutrient, at the right rate, at the right time and in the right place.

For each pin on the map, Dow AgroSciences donated $100 to Feeding America, the show’s official charity partner. With 100 total farmer commitments, Dow AgroSciences donated $10,000.

 Dow AgroSciences’ donation to Feeding America helped solve hunger issues across the nation via food banks, disaster food assistance and senior-, school- and children-specific programs. A $10,000 donation provided 100,000 meals secured by Feeding America on behalf of member food banks.

In addition to the donation at the show, farmers learned how using the right nitrogen stabilizer, such as Instinct® or N-Serve®, in conjunction with 4R practices can provide better protection against uncertain environmental conditions. Furthermore, by observing 4R practices, farmers are able to keep nitrogen in the right place up to eight weeks longer, maximizing their growth.

To learn more about the 4Rs, visit www.nutrientstewardship.com/4rs. For additional details on nitrogen stabilizers such as Instinct and N-Serve, visit MaxInMaxOut.com or contact your local Dow AgroSciences sales representative.

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. 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. ©2018 Dow AgroSciences LLC

Weed of the month: Lambsquarters

  • lambsquartersVarious types: Common1
  • Scientific name: Chenopodium album1
  • Grass or broadleaf: Broadleaf
  • Found in all states
  • Germination timing: Summer annual. Lambsquarters emerges in the spring, sets seed in late summer/fall and dies.2
  • Competitiveness: Common lambsquarters is a highly competitive weed. Michigan State University reports 13 percent yield loss in corn with one lambsquarters plant per 1½ feet of row and 25 percent yield loss in soybeans with less than one plant per foot of row.2
  • Lambsquarters grows to 3½ feet in height and produces thousands of seeds.3

Fast Facts

  • Lambsquarters is a cool-season, early germinating annual broadleaf weed that can be most problematic in northern areas, says Jeff Ellis, field scientist, Corteva Agriscience, Agriculture Division of DowDuPont, Dow AgroSciences. Identify lambsquarters by looking for a white, “frosted” appearance of upper leaves.
  • According to WeedScience.org, the first confirmation of triazine-resistant lambsquarters in the United States occurred in Michigan in 1975. Today, lambsquarters is resistant to one or more sites of action in 22 states.
  • Cotyledons of common lambsquarters and redroot pigweed are similar; however, redroot pigweed cotyledons have a prominent midvein while lambsquarters cotyledons do not.3

Resistance statistics:*

  • Herbicide classes

    *Resistance confirmation does not include all weeds and may vary among different areas of each state.

Weed management tips:

Ellis says:

  • It’s important to scout for lambsquarters early because it tends to germinate early in the spring under cooler conditions.
  • Lambsquarters is difficult to control with glyphosate, especially when it grows larger than 3 or 4 inches.
  • The most effective lambsquarters control strategy requires a program approach with preemergence herbicides followed by early postemergence herbicide applications.

Corteva Agriscience, Agriculture Division of DowDuPont, weed control solutions:

Corn

DuPont Cinch® ATZ herbicide
DuPont Realm® Q herbicide
Durango® DMA® herbicide
Elevore herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system
Enlist One herbicide, as part of the Enlist weed control system
FulTime® NXT herbicide
Keystone® LA NXT herbicide
Keystone® NXT herbicide
Resicore® herbicide
SureStart® II herbicide

Soybean

Durango® DMA® herbicide
Elevore herbicide
Enlist Duo® herbicide, as part of the Enlist weed control system
Enlist One herbicide, as part of the Enlist weed control system
DuPont EverpreX® herbicide
DuPont Trivence® herbicide
FirstRate® herbicide
Sonic® herbicide
Surveil® herbicide

Additional information:

For more information, read these weed science resources:

Sources:

1U.S. Department of Agriculture Natural Resources and Conservation Service. 2018. Plant Profile: Chenopodium album L. lambsquarters. http://plants.usda.gov/core/profile?symbol=chal7
2MSU Department of Plant, Soil and Microbial Sciences. 2018. Common Lambsquarters. https://www.canr.msu.edu/weeds/extension/common-lambsquarters
3University of Missouri Division of Plant Sciences. 2018. Common Lambsquarters. https://weedid.missouri.edu/weedinfo.cfm?weed_id=60

®™Trademark of The Dow Chemical Company (“Dow”) or E. I. du Pont de Nemours and Company (“DuPont”) or affiliated companies of Dow or DuPont. DuPont Cinch® ATZ, FulTime NXT, Keystone LA NXT and Keystone NXT are federally Restricted Use Pesticides. DuPont Cinch® ATZ herbicide, DuPont EverpreX herbicide, DuPont Realm® Q herbicide, DuPont Trivence®, Durango DMA, Elevore, FirstRate, FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore, Sonic, SureStart II and Surveil are not registered for sale or use in all states. FulTime NXT, Keystone LA NXT, Keystone NXT, Resicore and SureStart II 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. Enlist Duo and Enlist One herbicides are not registered for sale or use in all states or counties. Contact your state pesticide agency to determine if a product is registered for sale or use in your area. Enlist Duo and Enlist One herbicides are the only 2,4-D products authorized for use in Enlist crops. Always read and follow label directions. ©2018 Dow AgroSciences LLC