Managing Weed Seed in 2020
In 2019, South Dakota endured one of the wettest years on record. These conditions caused some fields to not be planted and had no weed control measures accomplished all season. This gave way to some prevent plant fields to be over taken by various types of weeds, such as Waterhemp, Kochia, Marestail and other annuals. As a result, producers need to plan in advance on how to deal with these fields that contain an overabundance of weeds. Weeds in these bare fields have deposited significant amount of seeds on the soil surface, which can easily germinate when adequate moisture and temperature are available. Managing the weed seed bank involves managing weed seed production and germination. Producers need to limit the production of weed seeds. This will in turn limit opportunity for weed seed germination in the field.
Tillage often is performed as an option to destroy all visible weed growth, but at the same time burying or planting weed seeds that may cause issues, not only in the current growing season but also in the future. Any disturbance of the soil surface may initiate weed seed germination. No-till fields give ample opportunity to control weeds through fall application of residual herbicides or a spring burn-down. In a properly managed no-till field weed seeds stay on or near the ground surface and are open to predation and decay. Also, keeping weed seeds near the surface of the ground increases the effectiveness of soil applied herbicides.
How to Manage Weedy Fields in 2020
It can be an effective option to consider planting those fields last that had high weed density in 2019. This will give more opportunity to control early emerging weeds with burn-down and pre-emergent herbicides. Making sure of proper control of these early weeds before planting is extremely critical. Use a multi-step approach to weed control through the use of pre-emergent herbicides with overlapping residuals, with a tank mix of herbicides with multiple sites of action. If possible use an herbicide with separate sites of action for the post-emergent application. Under lower weed pressure situations, one herbicide site of action may be sufficient all growing season. Cover crops in-between cash crops or on prevent plant ground could also help suppress weeds, decrease an overabundance of water and give a healthy soil structure to plant later in the spring. Always scout fields before and after application of herbicides to determine what herbicide to use and if there will be a need for additional control measures.
As we look forward to the next growing season, it is very likely that there will be fields or areas within fields that will be inaccessible to field equipment. There are some burn-down herbicides that may be used by aerial application to help suppress weeds in those fields. Information on aerial application can be found on the herbicide label.
Deposit Bushels, Not Weed Seeds
At the end of the season, the only deposits you should make are bushels into the combine or ROI into your bank account – not seeds into the weed seed bank. Weeds can hurt your corn crop each season with stunted crop growth and lower yield potential. But if weeds have a chance to go to seed, they can create even more problems for you and your ROI potential for years to come.
Once tough weeds begin producing seeds, weather, machinery, livestock and wild animals spread the seeds around, causing additional hurdles and potential resistance issues for your crop to overcome in the future. And since these weed seed banks can multiply exponentially, this is a problem that can get out of control quickly and do serious damage to your bottom line.
- Waterhemp can produce around 100,000 seeds per plant, and the seeds can survive in the soil for 7-10 years.
- Palmar amaranth is capable of producing up to 500,000 seeds per plant and remains viable in the seed bank for up to 6 years.
According to The Ohio State University, the better your weed control using both herbicides and agronomic best practices is, the lower your weed seed banks. Conversely, when control slips and a few plants start going to seed, the impact can be substantial.
With stats like these, it’s critical that growers adopt a zero-tolerance policy towards weeds. That means starting the year off clean and keeping fields clean all the way through harvest. To do this, we recommend Acuron® herbicide. Watch our interactive video to see how Acuron compares to competitors in terms of farm fit, performance and ROI potential, then decide for yourself.
Acuron controls more than 70 tough, yield-robbing weeds that other products can miss, creating cleaner fields until crop canopy and beyond. In addition to reducing future weed seed bank problems, the longest-lasting residual in Acuron helps fully protect yield potential. When applied preemergence and at the full label rate, replicated Syngenta and university trials show Acuron outyields competitors by 5-15 bushels an acre.*
With Acuron in their fields, growers can avoid weed seed bank deposits and focus on protecting their ROI.
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*Acuron yield advantage range based on 2016 Syngenta and university replicated trials comparing Acuron to Corvus®, Resicore®, SureStart® II and Verdict® applied preemergence and at full labeled rates. For more information on Acuron versus an individual product, ask your Syngenta representative.
All photos are either the property of Syngenta or are used with permission.
Syngenta hereby disclaims any liability for third party websites referenced herein.
Performance assessments are based upon results or analysis of public information, field observations and/or Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.
The trademarks or service marks displayed or otherwise used herein are the property of a Syngenta Group Company. All other trademarks are the property of their respective owners.
Keep Your Weed Seed Bank Account Low
Advancements in digital farming have provided growers with a number of new tools to help better manage operations and increase yields. But even now, there are still some tried and true methods growers can incorporate to maximize outputs. Weed seed bank management is one such tool that should be a top focus as we approach this year’s corn and soybean harvest.
The weed seed bank is one account that growers need to keep as low as possible to remain profitable. Deposits are made to the bank from the reserve of weed seeds developed from unmanaged infestations. Once the deposits are made into the ground, seeds can grow and mature into more weeds, creating a cycle that can be hard to stop. As this happens, fields are at higher risk for resistance to develop and herbicide applications become less effective, year over year.
This past season, wet weather delayed or prevented many herbicide applications, meaning weed escapes were more common. These escaped weeds had a higher likelihood of going to seed. The size of this bank can grow quickly. For some species, just 1 plant can produce hundreds of thousands of seeds.
Here are 4 ways you can minimize the risk of the seed bank building in your fields:
- Scout fields for problem areas and identify weeds.
- Use full-labeled rates of herbicides to optimize coverage and control.
- Apply post-emergence herbicides before the largest weed in the field reaches 4” in height.
- Clean equipment between fields to prevent seeds from spreading.
Preemergence herbicides like Boundary ® 6.5 EC, BroadAxe ® XC and Prefix ® in soybeans, followed by an early post-emergence application of Tavium ® Plus VaporGrip ® Technology herbicide can kill weed escapes before they’re able to go to seed. In corn, Acuron ® or Acuron Flexi corn herbicides will help fields start clean and protect them from weeds prior to emergence. Acuron delivers 5 to 15 more bushels per acre than competitors*, because it kills weeds that other products miss. Acuron and Acuron Flexi can be followed by Halex ® GT herbicide, for season-long control of tough weeds.
Sign up for the Know More, Grow More Digest to receive twice-monthly agronomic e-mail updates pertinent to your area.
All photos are either the property of Syngenta or are used with permission.
Syngenta hereby disclaims any liability for Third Party websites referenced herein.
©2019 Syngenta. The trademarks or service marks displayed or otherwise used herein are the property of a Syngenta Group Company. All other trademarks are the property of their respective owners.
*When applied preemergence and at full label rates. Yield advantage range based on 2016 Syngenta and University trials comparing Acuron to Corvus ® , Resicore ® , SureStart ® II and Verdict ® . For more information on Acuron versus an individual product, ask your Syngenta representative.