ASK THE AGRONOMIST BLOG

Stine’s Ask the Agronomist blog is your source to the latest information from our expert team, including advice and insight on field practices, product recommendations, planting and harvest updates, new technologies, crop management, innovative research and information about how to keep your farm operation running smoothly year round. 

  • Mike Smith Image

    Part 2: Management Strategies for Difficult-to-Control Weeds (Driver Weeds) in Soybeans

    October 24, 2019

    Posted by Mike Smith in Crop Management

    For part two of our discussion on herbicide-resistant and other hard-to-control weeds (driver weeds), we’re examining waterhemp. This article highlights the strengths and weaknesses of waterhemp and the strategies available to control this driver weed.  

    The Bad News (Strengths)

    • Waterhemp typically grows in clumps or patches with large numbers of the plant concentrated in limited areas.
    • The University of Missouri has demonstrated that more than 20 plants per square foot can reduce soybean yields by 44 percent. Even late-emerging waterhemp (after 5th trifoliate) can reduce yields significantly.
    • Waterhemp is also an extremely productive weed, with the ability to grow 1.25 inches per day and produce between 250,000–500,000 seeds per plant.
    • As a dioecious weed, waterhemp grows male and female flowers on separate plants, allowing for more genetic diversity in single populations and rapid development of herbicide-resistant genes.

    The Good News (Weaknesses)

    • Waterhemp seed may overwinter in the soil for a few years, but research demonstrates that less than 15 percent of that seed will remain viable for longer than four years.
    • Seed that is emerging or recently emerged is easier to control than plants that have had the opportunity to grow and harden off in adverse weather conditions.
    • Shading — the inability to capture sunlight — growing seedlings can greatly inhibit waterhemp’s prolific tendency.

    Management Strategies

    • Know your resistance profile. Test your waterhemp population to know which herbicides will be effective. Current known herbicide resistance includes Groups 5 (triazines), 2 (ALS), 14 (PPO inhibitors), 9 (glyphosate), 27 (HPPD inhibitors) and cross resistance (single population resistant to both Groups 9 and 2). 
    • Start clean with tillage and/or effective burndown control that eliminates actively growing weeds.
    • Use an effective soil residual herbicide. Consult your local agronomist or university extension office for specific recommendations. Note that use of soil residual herbicides in multiple sequential applications is encouraged, where possible, to delay and diminish the germination and emergence of waterhemp and to allow soybeans a competitive advantage in row closure, canopy and plant density.
    • In some cases, narrow-row soybeans may be warranted to increase photosynthetic competitiveness and decrease waterhemp growth habits.
    • Cover crops have also shown an increased ability to lessen weed seed bank populations and delay emergence.
    • Manual eradication in severe infestations may be necessary for a few years to control the population.
    • Using a conventional herbicide system that relies on multiple passes with soil-applied residuals and effective post-applied herbicides with current broad-spectrum herbicides can be an effective strategy. This system is generally costly; however, increase in yield from reducing weed competition generally outweighs the cost of treatment.

    Trait System Usage
    Use trait systems that provide the ability to apply multiple, effective modes of action simultaneously to combat herbicide resistance. For instance, the Enlist E3® system allows the use of Enlist One® with 2,4-D choline to be applied with both glyphosate and glufosinate and additional tank-mix partners to eliminate and delay further waterhemp emergence. This system combines many of the strategies discussed into a flexible platform.

    To learn more about waterhemp and how to manage this hard-to-control driver weed on your farm, contact your local Stine agronomist or university extension specialist.

    Resources and Citations
    University of Arkansas Division of Agriculture Research & Extension https://www.uaex.edu/farm-ranch/pest-management/weed/field-crops.aspx

    Take Action www.takeactiononweeds.com

    Waterhemp Management in Soybeans https://weedscience.missouri.edu/publications/50737_3_TA_FactSheet_Waterhemp.pdf

    Ohio State University Weed Management https://u.osu.edu/osuweeds/super-weeds/

    Ohio State University Extension https://agcrops.osu.edu/newsletter/corn-newsletter/2014-20/postemergence-control-giant-ragweed-soybeans

  • Grow Stine Short-Stature Corn, Increase Yield
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    Grow Stine Short-Stature Corn, Increase Yield

    October 17, 2019

    Posted by Stine Seed in High-Population Corn

    Short-stature corn has been making headlines as of late. Recently, Bayer-Monsanto executives told ag media that they believe short stature corn will be the future of corn production. Among the benefits are better standability, adaptation to narrow rows and, ultimately, increasing populations. An October 3, 2019, article in Farm Journal’s AgWeb states that the company says its first short-stature corn will be introduced in Mexico next year, with hopes to introduce it in the United States in the coming years.

    The good news is, the future of corn production is already here. Stine was the first seed company in the industry to introduce the ag world to commercially available narrow-row, HP Corn® in 2012, and we’ve been expanding our lineup ever since. In August 2016, Successful Farming magazine ran a cover story on company founder Harry H. Stine and his quest to revolutionize farming with the development of a new breed of short-stature, high-density corn hybrids.

    Stine has spent decades researching planting populations and row widths through our one-of-a-kind corn breeding program. That research has lead us to develop genetics that produce shorter, more efficient and higher yielding plants that thrive in higher populations. In fact, if you’ve visited any of our corn plots lately, you’ve likely noticed that Stine hybrids tend to be shorter than our competitors’ hybrids.

    Here’s why.  

    A more compact structure tends to produce strong roots and stalks, creating a sturdier plant that can often thrive in higher populations and in varying growing and environmental conditions. With shorter corn, you can benefit from more efficient nutrient uptake which leads to a stronger, healthier plant. Our research also indicates that this can lead to more efficient pollination, with the tassel and ear being closer together than in taller plants. And, with shorter corn and narrower rows, there’s more flexibility to operate equipment in and around fields for easier in-season applications.

    Many of our industry competitors have recently recognized this trend and are beginning to produce their own shorter-stature hybrids, but Stine is already well ahead of the curve. If you look at our data, the average height of our hybrids was roughly 105 to 110 inches in 1996. Today, we’re trending around 90 inches for 105- to 115-day relative maturity hybrids. In fact, even Stine’s tallest hybrids are still shorter than most of our competitors’ hybrids. 

    We at Stine commend our competitors as they begin down the path toward shorter, high-density corn production. We’re proud of our leadership position in this, which has positioned us to provide growers the hybrids of the future, faster.   

  • Mike Smith Image

    Management Strategies for Difficult-to-Control Weeds (Driver Weeds)

    October 10, 2019

    Posted by Mike Smith in Crop Management

    There is a tremendous push in the agricultural industry to find solutions to problems such as herbicide-resistant weeds and other hard-to-control weeds — driver weeds — by utilizing a simple, one-pass system. However, if you listen to weed scientists from leading agricultural universities, you quickly learn that a simple, one-pass system is difficult, if not impossible, to achieve without further exacerbating the problem. 

    So, what is a “driver weed”? A driver weed is a troublesome weed in your operation that you find difficult or impossible to control with traditional chemical means. Therefore, driver weeds drive your buying decisions as well as your willingness to try new practices to control them. In this new, biweekly blog series, we will discuss several driver weeds and consider options ranging from chemical control to management practices and trait systems to control them. Key driver weeds include Waterhemp, Palmer Amaranth, Marestail, Giant Ragweed and Kochia.

    Background
    The prevalence of herbicide-resistant weeds and the spread of these weeds steal headlines, but there are some weeds that are simply harder to control because of their biology and evolutionary resistance to certain control measures. Our pattern has been to find new chemical control measures that work and continue to use them year after year, season after season, and in all rotational crops. This strategy is a formula for disaster as it exponentially increases the rate at which selection for herbicide resistance can occur. For years, we have said “if” herbicide resistance occurs when we should say “when” herbicide resistance occurs because of our cultural and management practices. In this series, we will look at the biology, strengths and weaknesses of these driver weeds and examine alternative cultural and management practices that can be utilized in conjunction with trait systems to manage these weeds. We’ll discuss questions such as:

    • What are the biology considerations of driver weeds?
      • When does it emerge?
      • What are its strengths?
      • What are its weaknesses?
      • What system type strategies can I use to eradicate this species from my farm?
    • What herbicide technologies and trait systems will fit best for my strategy to control these driver weeds?

    Stay tuned in the coming weeks for the next conversation in our series on driver weeds. And remember, if you have problems with hard-to-control weeds on your farm, you can always reach out to your local Stine agronomist for assistance.