Shop online & get crop protection delivered direct.
Aug 22, 2023
Once you decide to conduct a fall burndown application, you must act quickly. The biggest window of opportunity for effective weed control starts the minute you’ve finished harvesting.
This post will help you get started with actionable tips to conduct a successful fall burndown program by exploring how to:
[READ: What to Consider When You’re Selecting a Burndown or Pre-emergence Herbicide]
There are several factors to consider when selecting herbicides for your fall burndown program, including:
Weed identification
Crop rotation
Soil type
Plantback restrictions
Identifying broadleaf or grassy weed species will help categorize their growth habits and life cycles. By tailoring your herbicide choice to target specific species, you’ll reduce weed competition in the upcoming planting season.
Dicamba and 2,4-D are common choices for targeting broadleaf weeds in herbicide formulations designed for soybeans, corn and cotton. This table identifies some of the weeds these herbicides target:
Dicamba | 2,4-D |
Canada thistle | Buckhorn plantain |
Clover | Chickweed |
Dandelions | Clover |
Dandelion | |
Lambsquarters | Nettle |
Marestail | Smartweed |
Pigweed | Thistle |
Purslane | Wild mustard |
Thistles | Wild violet |
Consider using glyphosate or clethodim for grassy weed control. While numerous weeds have expressed resistance to glyphosate, it is recommended that another mode of action is used with it. Here are common weeds targeted by glyphosate and clethodim:
Glyphosate | Clethodim |
Downy Brome | Crabgrass |
Sorghum | Foxtail |
Volunteer oats | Quackgrass |
Volunteer wheat | Sandbur |
| Volunteer corn |
| Wild oats |
| Witchgrass |
| Yellow nutsedge |
When rotating crops from season to season, select products that won’t adversely affect the rotation crop and leave harmful residues in the soil. Some residual herbicides like atrazine* are useful if rotating to corn in the spring. With this in mind, consider an herbicide with short residual activity like glyphosate, glufosinate, or paraquat as other options for rotation crops.
Conducting regular soil tests can help you determine your soil’s texture, structure and nutrient levels, enabling you to more effectively address deficiencies that hinder growth and yield. Different soil types can influence herbicide adsorption, movement and efficacy. For example, some sandy soils may require an herbicide with a lower leaching potential that contains atrazine* or metolachlor. In contrast, clay soils may require different application rates to ensure even coverage.
Plantback restrictions refer to the time between applying an herbicide and planting a new crop in the same field. Following these restrictions ensures that herbicide residues do not negatively affect germination or growth; ignoring them can result in crop injury and reduced yield potential.
When choosing your herbicide, always read the label directions carefully to understand its correct use.
[READ: The Benefits of Fall Burndown]
Adjuvants improve herbicide performance by increasing efficacy and enhancing spreading, sticking and penetrating abilities. When choosing an adjuvant, consider these four key factors:
Adjuvant purpose
Herbicide compatibility
Environmental factors
Weed species and size
Some adjuvants improve herbicide coverage on target weeds, while others enhance herbicide penetration into plant tissues. Prioritizing a specific goal for your adjuvant can help you select the right product to help achieve:
Better coverage
Increased absorption
Improved rainfastness
Be sure to choose an adjuvant that is compatible with the herbicides you plan to use. Many products recommend specific adjuvants directly on their label, while others have very specific restrictions. Always read your label carefully to ensure compatibility with your crops.
You can always find hundreds of herbicide product labels here.
[WATCH: Understanding Adjuvants to Optimize Crop Protection]
The following environmental conditions can influence adjuvant performance:
Temperature
Humidity
Wind speed
Rainfastness
Some adjuvants work better at higher temperatures while others are more effective in cooler temperatures. For example, certain surfactants or oils may cause excessive foaming in cooler weather.
Temperature also influences the behavior of spray droplets, affecting their size, evaporation rate and deposition on target weeds. Spray droplets may evaporate more quickly in warmer temperatures, potentially reducing the amount of herbicide reaching the target weed. Droplets may take longer to evaporate in cooler temperatures, increasing the potential for herbicide runoff or drift.
Humidity levels can also affect adjuvant performance. High humidity creates favorable growing conditions for weed growth, leading to increased weed vigor and resilience. These conditions also lead to excessive foaming during chemical application, causing uneven herbicide distribution and reduced efficacy. With stronger weed resilience and weakened herbicide efficacy, these higher humidity conditions can lead to problematic application scenarios. Higher humidity will extend dry time which is better for the plant.
Alternatively, applying herbicides during lower humidity minimizes the risk of excessive foaming.
Strong winds can cause herbicide drift, damaging neighboring crops and vegetation. To mitigate drift, select an adjuvant with drift-reducing agents (DRAs) or deposition aids which can produce larger droplets. The increased size and weight of the droplets reduce their susceptibility to wind drift. Glyphosate, 2,4-D, and atrazine* all contain DRAs.
Rainfastness refers to an herbicide’s ability to withstand rainfall after application. The right adjuvant can improve rainfastness by enhancing an herbicide’s ability to adhere to the plant surface. Adjuvants that contain surfactants or sticking agents help the herbicide stick to the leaves, preventing it from being washed away by rain or irrigation. Look for an adjuvant that enhances rainfastness to provide adequate control.
Weed type and size will also influence your adjuvant choice. For broadleaf weeds, a non-ionic surfactant like IN-Zorb™ 90 can help reduce water's surface tension, improving coverage and absorption.
A crop oil concentrate (COC) or methylated seed oil (MSO) will be effective for grassy weeds. Crop oil concentrates contain petroleum-based oils and help to improve herbicide penetration into the plant’s cuticle, which is the protective layer on the leaf surface. MSOs, which are derived from vegetable oils,improve absorption and efficacy by penetrating the waxy cuticle like COCs.
[READ: Adjuvants 101: Understanding the “Extras” in Your Tank]
A good foundation for a successful burndown program includes non-selective herbicides, such as glyphosate and glufosinate, and an auxin, such as dicamba or 2,4-D. You may consider other chemistries for your farm depending on your location, cropping plan and the weather in your recent forecast.
Here are a few potential burndown programs worth considering:
Start your corn burndown program with:
OR
Start your soybean burndown program with:
OR
OR
Start your oats burndown program with:
Start your wheat burndown program with:
[READ: How Long Will Your Residual Herbicide Actually Last?]
Starting clean is critical to maximizing production. A successful fall burndown application sets the stage for spring planting by eliminating existing weeds and reducing competition for emerging crops. As you think ahead, you’ll want to consider the pre-emergence herbicides you’ll need for spring planting.
A pre-emergence herbicide application will provide:
Extended weed control
Residual control
Weed resistance management
Improved crop establishment
Flexibility in plant timing
Finding the right herbicides and adjuvants for your burndown program will set you up for success.
With detailed product labels, transparent pricing, straightforward online ordering and direct-to-farm delivery in three days or less, FBN Direct can help you get the herbicides you need for effective weed control and crop protection.
For farmers in the U.S., here are some popular products that can be paired as recommended or required based on each product label:
Product | Pair With | Notes |
Adjuvant is FBN® Suggested | ||
An Adjuvant is label recommended. | ||
An Adjuvant is label recommended. | ||
An Adjuvant is label required. | ||
An Adjuvant is label required. | ||
An Adjuvant is label recommended. |
For Canadian farmers, here is a list of popular products to help with a fall burndown application:
Written by Norm℠, reviewed and edited by Mark Wilson.
© 2014 - 2023 Farmer's Business Network, Inc. All rights Reserved. The sprout logo, “Farmers Business Network”, “FBN”, “FBN Direct”, “Farmers First” are service marks, trademarks or registered trademarks of Farmer's Business Network, Inc. ICON and FALCON are registered trademarks of Norac Concepts, Inc.
*RESTRICTED USE PESTICIDE Due to acute toxicity. For retail sale to and use by certified applicators only - NOT to be used by uncertified persons working under the supervision of a certified applicator.
FBN Direct products and services and other products distributed by FBN Direct are offered by FBN Inputs, LLC in the United States and Farmer’s Business Network Canada, Inc in Canada and are available only in states/provinces where FBN Inputs, LLC/Farmer’s Business Network Canada Inc. is licensed and where those products are registered for sale or use, if applicable. Not available in Quebec. If applicable, please check with your local extension service to ensure registration status. Nothing contained on this page, including the prices listed should be construed as an offer for sale, or a sale of products. All products and prices are subject to change at any time and without notice. Terms and conditions apply.
ALWAYS READ AND FOLLOW LABEL DIRECTIONS. It is a violation of federal and state/provincial law to use any pesticide product other than in accordance with its label. The distribution, sale and use of an unregistered pesticide is a violation of federal and/or state/provincial law and is strictly prohibited. We do not guarantee the accuracy of any information provided on this page or which is provided by us in any form. It is your responsibility to confirm prior to purchase and use that a product is labeled for your specific purposes, including, but not limited to, your target crop or pest and its compatibility with other products in a tank mix and that the usage of a product is otherwise consistent with federal, state and local laws. We reserve the right to restrict sales on a geographic basis in our sole discretion. You must have a valid applicator license to use restricted use pesticides. Please consult your state/provincial department of agriculture for complete rules and regulations on the use of restricted use pesticides, as some products require specific record-keeping requirements.
All product recommendations and other information provided is for informational purposes only. It is not intended to be a substitute for consulting the product label or for specific agronomic, business, or professional advice. Where specific advice is necessary or appropriate, consult with a qualified advisor. Neither Farmer's Business Network Inc. nor any of its affiliates makes any representations or warranties, express or implied, as to the accuracy or completeness of the statements or any information contained in the material and any liability therefore is expressly disclaimed.
This content is a result of a collaborative effort between NormSM, FBN’s artificial intelligence (AI) Ag Advisor, and human writers to deliver valuable content to our FBN members. Our process involves using AI to aid in the drafting and refinement of content, which is then reviewed and edited by human subject matter experts. While we take efforts to ensure accuracy, relevance, and coherence, FBN does not guarantee the accuracy or completeness of this content. As such, this material should be used for informational purposes only and not as a substitute for professional or expert advice. If you have any questions or feedback about the content, please feel free to contact us or visit our FAQ.
Aug 22, 2023