Growing Knowledge

Read the latest insights from our experts as they cover agronomy issues that matter most to you and your operation.

Dealing With Drought

Jason Haegele
Crop Physiologist
A number of states in the northern Corn Belt are experiencing dry weather now or the results of earlier dry weather, especially where I am based in Illinois. Much of the country had a wetter-than-normal spring, which caused delayed planting in many areas. Follow that wet spring with drought conditions and we’re seeing poor, shallow root growth that is perhaps made worse by more recent dry conditions in some areas.
Here’s a look at how drought conditions can affect crops and what you can do to mitigate these stresses.
Crop stress symptoms
It’s important to keep in mind that crop stress due to drought occurs before there are any visual symptoms. Roots in the soil are the first to detect water limitation. When they do, they transmit a signal to the rest of the plant to start shutting down, limiting growth and reproductive development to conserve water. 
A classic visual indication of water limitation is leaf rolling, especially in the middle of the day when it is hottest. Leaf rolling may persist for most of the day if drought conditions continue or worsen.
Limit crop stress
Much of our region is nearing tasseling and silk emergence, which is when a corn plant uses the most water during its life cycle. This tremendous demand for water, about 0.35 inch per day, means that limitations in water have a direct impact on that plant’s growth.   
Biostimulants such as Toggle® help regulate the water balance of the plant, particularly during times of drought or heat stress. This is accomplished by stimulating more responsive stomata, which are responsible for the flow of nutrients and water through the plant, known as stomatal conductance. Essentially, Toggle® helps regulate the flow of water through and out of the plant in a more efficient manner.
Toggle® can be used during a range of growth stages from v5 through tasseling, and can be applied multiple times throughout a growing season when conditions warrant it. Biostimulants such as Toggle® have a direct impact on the gene expression of the plant, which means that the optimal timing is to anticipate stress and apply it early-on. However, the product can still benefit plants if applied later on.  
Farmers can also consider other stress mitigation tools, like strobilurin fungicides, which have shown to not only control diseases but also to have a positive impact on the corn crop’s physiology and final yield potential.
Looking ahead and preparing for next year
Farmers in parts of the country that regularly experience drought stress and/or anticipate stress should use a systems approach to manage water for their crops. That can involve better seed selection (selecting hybrids that are genetically adapted to be more tolerant to stresses like drought or high temperatures). In-season, use best agronomic practices such as biostimulants and fungicides to preserve the yield potential of those genetics. 
To learn more about drought stress mitigation tools, contact your local WinField United retailer

5 Tips for Treating Your Alfalfa Right This Season

Jeff Jackson
CROPLAN® Alfalfa and Forage Specialist

Alfalfa is not an easy crop to grow and requires pretty intense management. However, some farmers don’t give it much attention until it’s time to cut.


I’d argue alfalfa is a high-value crop that deserves to be diligently scouted and managed just like corn or soybeans or sunflowers. No matter how you use or market your alfalfa, it represents a significant investment of labor and money. Take the time to treat it right. Here are five tips for in-season alfalfa management.


1. Put boots on the ground.

It may sound obvious, but you can’t control what you can’t see. Be sure to scout your alfalfa fields, or have your agronomist do it, on a regular basis. For greater insights, pair these scouting efforts with the ag technology your agronomist offers, which can quickly alert you to critical field issues such as depleted biomass, disease and insects.


2. Make a preventive fungicide application.

A fungicide application, performed when your alfalfa is 6 to 8 inches tall, can help protect the plant from diseases such as bacterial leaf spot, spring black stem and lepto leaf spot, and help the plant retain more leaves.


3. Use a residual insecticide. 

Technically, the right answer to the question “When should I spray for insects?” is “After you’ve scouted and if you need to.” Follow integrated pest management practices and spray when there are damaging insects present at a level that will justify the application. Insecticides with residual activity, such as Arctic® 3.2EC insecticide or Grizzly® Too insecticide, provide a longer period of control.  


Be sure to follow label directions for both fungicide and insecticide applications. Also, adhere to preharvest intervals, even if you are pressed for time.


4. Evaluate plant nutrient levels by tissue testing.

Optimal timing for taking alfalfa tissue samples is at the beginning of bud stage, right before you cut. Your agronomist should remove the top 6 inches of the plant for testing. After you cut, wait for 6 inches of regrowth, and then do a foliar application of essential nutrients that testing has found to be deficient. Remember, lack of moisture will limit the benefits nutrients bring. Talk with your agronomist about whether nutrient applications make economic sense at various points of the year, depending on weather conditions.


5. Choose varieties with appropriate tolerance that fit your goals for next year. 

Disease and insect tolerance differ widely among varieties, but are found to some degree in conventional alfalfas, Genuity® Roundup Ready® alfalfas and HarvXtra® Alfalfa with Roundup Ready® Technology. HarvXtra® Alfalfa varieties offer more flexibility in cutting schedules to achieve greater yield potential or improved forage quality. Geography often determines what stresses will be most prevalent in your area. As you think about your goals for 2018, work with your agronomist to choose varieties that fit your specific needs.


Don’t treat your alfalfa crop as an afterthought. Proactively manage it to optimize yield potential and make sure it’s an important part of your whole-farm crop management strategy.



Genuity and Roundup Ready are registered trademarks of Monsanto Technology LLC.

HarvXtra is a registered trademark of Forage Genetics International, LLC.


Growers must direct any product produced from HarvXtra® Alfalfa with Roundup Ready® Technology seed or crops (including hay and hay products) only to United States domestic use. In the following states, use of HarvXtra® Alfalfa with Roundup Ready® Technology is subject to a Seed and Feed Use Agreement, noting that this technology can only be used on farm or otherwise be used in the United States: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. In addition, due to the unique cropping practices do not plant HarvXtra® Alfalfa with Roundup Ready® Technology in Imperial County, California, pending import approval in China and until Forage Genetics International, LLC (FGI) grants express permission for such planting. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their product purchaser to confirm their buying position for this product.


Visit for the full legal, stewardship and trademark statements for these products.

Playing Dietician to Your Plants

Jonathan Zuk
Regional Agronomist
A strong plant nutrition program starts with identifying your plants’ needs early in the season and continuing with “check-ups” throughout key growth stages. Tissue sampling allows us to pinpoint exactly what’s going on in a plant so real-time nutrient adjustments can be made to optimize yield potential.
Like people, each crop has unique nutritional needs. Here are some considerations for keeping corn, soybean and wheat plants healthy through the rest of the season.
Corn takes up the majority of its nutrients between V8 and VT, so paying close attention to both macro- and micronutrient deficiencies ahead of these stages is critical. Sixty-six percent of more than 17,500 corn tissue samples taken nationwide in 2016 through the NutriSolutions 360® system were low in nitrogen, which can be combatted with a side-dress application.
On the micronutrients front, 72 percent of corn samples were low in zinc. In 2015, I applied a quart of MAX-IN® Zinc micronutrient at V5 on acres showing zinc deficiencies, and the results led to a 4.55-bushel-per-acre increase. As a result, I recommend taking a tissue sample of the uppermost collar leaf at V5. If samples show a deficiency, spray as quickly as possible to feed plants when they need it most.
Remember that nutrient deficiencies change from year to year and certain hybrids respond to nutrient applications better than others. Working with your agronomist to procure quality test plot data, including response-to-nitrogen and response-to-fungicide scores, can help you create a balanced fertility program for your corn crop.
I recommend taking a tissue sample starting at V4 to V6 to get a baseline measurement of soybean plant health and another sample at R2, working with your agronomist to correct deficiencies as appropriate for your crop and operation. If you experienced wet weather this spring, keep an extra eye on boron and sulfur levels, as they may have depleted.
There’s a lot of work being done when it comes to in-season management for wheat. Copper was a common deficiency in wheat in 2016. However, we’ve found through the Answer Plot® Program that wheat is highly responsive to copper applications in the spring as well as at flag leaf emergence. That said, taking tissue samples prior to jointing and again at flag leaf emergence to assess copper and other nutrient levels can help optimize yield potential for wheat.
Remember, the earlier you can diagnose nutrient needs, the better. Collaborating with your agronomist to determine the right timing for tissue sampling and applications will go a long way in protecting the health of your crops.

With Great Dicamba Power Comes Great Responsibility

Andrew Schmidt
Regional Agronomist
Costly lessons were learned last year when off-label dicamba formulations were applied to dicamba-tolerant soybeans. In Missouri alone, 45,000 acres of sensitive soybeans were officially reported as damaged due to off-target dicamba movement, with another 100,000 acres of soybean crops estimated to be unofficially damaged, according to Kevin Bradley at the University of Missouri.1 Along with soybeans, damage extended to a variety of fresh market crops, homeowners’ gardens, trees and more.
The most important takeaway was that crops outside of the new dicamba-tolerant system are inherently sensitive to extremely low concentrations of dicamba. While assessing the damage caused in 2016, it’s important to learn from these mistakes in order to successfully incorporate the new dicamba-tolerant soybean technology into our weed-control arsenals.
Respect the Herbicide
The most obvious cause of last season’s problem was the use of off-label dicamba treatments. While new dicamba-tolerant seed was available in 2016, dicamba herbicides for use with this technology were not yet labeled for use. With a growing number of tough, resistant weeds threatening soybean yields, some operations jumped the gun by making off-label applications with older dicamba formulations.
Along with applying off-label dicamba formulations, several other factors likely played a role in setting the stage for damage to neighboring crops, including the use of the wrong-size spray tips, which allowed fine spray droplets to easily drift off target. Other causes may have been application timing errors, such as spraying when conditions were conducive to temperature inversions. Another culprit could have been the use of ammonium sulfate (AMS) as a water conditioner in the tank mix, which would have increased the potential for volatility.
Follow Specific Guidelines
During spray clinics conducted by WinField United agronomists this winter, we provided some recommended practices for use with dicamba-tolerant soybeans to help farmers successfully add this new weed-management tool to their production system. These guidelines include the following:
  1. Only use newly registered dicamba formulations labeled for use with dicamba-tolerant soybeans. Older dicamba formulations are more volatile, making off-target movement more likely.
  2. Read and understand the new dicamba product labels. These labels are the law and closely define how the product must be used.
  3. Consider the required combinations of products listed on the labels. XtendiMax® With VaporGrip® Technology for example, requires an approved drift reduction agent like AG16098 from WinField United, which reduces driftable fines, in the mixture when certain other herbicides and adjuvants are used.
  4. Avoid adding AMS to the spray tank.
  5. Use the correct nozzle type listed on the label to achieve coarse droplets. Also use the labeled pressure rate and don’t exceed the pressure limit.
  6. Keep boom heights at no higher than 24 inches above the target. A lower boom height helps spray droplets stay out of the wind and remain on target.
  7. Slow down. Maintaining the right ground speed helps control boom height and keeps spray pressures in check.
  8. Understand your surroundings. Wait until the wind changes direction to spray if sensitive crops are downwind. Or if a highly susceptible crop is nearby, do not spray dicamba products. Use other labeled herbicides to treat your field.
  9. Maintain buffer zones when sensitive areas are downwind. Follow buffer recommendations listed on the label.
Dicamba-tolerant soybean technology can be an excellent part of an overall weed management strategy, but we all need to pay close attention to application details to maintain its effectiveness. Always work with your local agronomist and retailer to determine the appropriate products and practices for your operation.
1. Dr. Kevin Bradley. “A Season to Remember: Our Experiences with Off-Target Movement of Dicamba in 2016.” Available at: Accessed June 12, 2017.

Staying Ahead of Soybean Diseases

Joel and Kyle
Hosts, WinField
Hosts Joel and Kyle tackle soybean disease issues facing farmers on this episode of The Deal With Yield®. Discover what diseases to be on the lookout for this year, the benefits of fungicide applications and the value of experiencing a little bit of failure.
Season 9: Episode 6 – Staying Ahead of Soybean Diseases

The Deal With Yield is a podcast series covering the issues that matter most in crop production.

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