Seed production and retention at maturity of blackgrass ( Alopecurus myosuroides ) and silky windgrass ( Apera spica-venti ) at wheat harvest
Blackgrass ( Alopecurus myosuroides Huds.) and silky windgrass [ Apera spica-venti (L.) P. Beauv.] are becoming a significant problem in Europe. Due to the development of herbicide-resistant biotypes and unwanted side effects of herbicides, there is a need for new integrated weed management strategies to control weeds. Therefore, reducing weed infestations by targeting seed production during crop harvest should be considered. In 2017 and 2018, we estimated the fraction of the total seed production of A. myosuroides and A. spica-venti in a field that potentially could be collected by a grain harvester during winter wheat ( Triticum aestivum L.) harvest. Twenty plants of each species were surrounded by a porous net before flowering to trap shed seeds during reproductive development. Seeds were collected and counted weekly up until and immediately before wheat harvest, and the ratio of harvestable seeds to shed seeds during the growing season was determined. Alopecurus myosuroides produced on average 953 seeds plant −1 in 2017 and 3,337 seeds plant −1 in 2018. In 2017 and 2018, 29% and 37% of the total A. myosuroides seeds produced, respectively, were retained on plants at maturity. Apera spica-venti produced on average 1,192 seeds plant −1 in 2017 and 5,678 seeds plant −1 in 2018, and retained 53% and 16% of the seeds at harvest, respectively. If a grain harvester potentially collected approximately 30% of the total seed production of the two grass weeds and removed or killed them, it would reduce seed input to the soil seedbank. However, such methods cannot stand alone to reduce weed pressure.
Weed Management in Seed Corn Production
Weeds can be more competitive in seed production fields than in conventional corn fields because inbred corn plants typically do not have the vigor and strength of commercial corn products. The goal is to prevent weeds from emerging in seed production fields. If weeds emerge, it is important to eliminate them in an efficient manner that does not affect the overall production of seed corn.
Q. What are the challenges of controlling weeds in seed corn production?
Controlling weeds in seed production fields can be more challenging than in conventional corn fields due to reduced canopy closure and potential herbicide sensitivities of specific inbred lines. Seed corn does not produce a tight canopy, particularly after de-tasseling, allowing light to penetrate to the soil resulting in the potential for further weed flushes later in the season. Some inbred corn lines can also be sensitive to various herbicides, which can reduce the potential herbicide options for managing weeds. However, most herbicides registered in field corn are likely safe to use on seed corn inbreds, but screening should be conducted to prevent injury. Some corn herbicide labels have precautionary statements regarding the use of the product on corn inbred lines. Labels may state to verify the selectivity of the product on the inbred line before using.
Q. What is a successful weed management program in seed corn production?
To control weeds in seed corn, a successful program involves an integrated weed management approach, which includes herbicide use along with early-season tillage, the use of cover crops, and diversified rotations. It is important to use herbicides that provide good soil residual activity on the weeds being targeted in a particular seed production field. Starting with a clean seedbed, a preemergent herbicide with residual activity should be used at planting to provide early-season weed control. This should be followed up with postemergence herbicide applications to control weed escapes and provide residual weed control later into the season. Rotation of herbicides with different sites of action and tank-mixing whenever possible should be practiced to reduce the selection of herbicide-resistant weeds. It is imperative to read and follow the herbicide product labels and communicate with seed production company representatives as they may have additional guidelines and testing results relating to specific corn inbred lines.
Q. What Bayer herbicide products should you consider using for weed management in seed corn production fields?
The following Bayer herbicide products are labeled for use in seed corn and should be applied at the preferred timings in the listing:
Bayer is a member of Excellence Through Stewardship® (ETS). Bayer products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with Bayer’s Policy for Commercialization of Biotechnology-Derived Plant Products in Commodity Crops. Commercialized products have been approved for import into key export markets with functioning regulatory systems. Any crop or material produced from this product can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. 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 grain handler or product purchaser to confirm their buying position for this product. Excellence Through Stewardship® is a registered trademark of Excellence Through Stewardship.
ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. It is a violation of federal and state law to use any pesticide product other than in accordance with its labeling. NOT ALL formulations of dicamba or glyphosate are approved for in-crop use with Roundup Ready 2 Xtend® soybeans. NOT ALL formulations of dicamba, glyphosate or glufosinate are approved for in-crop use with products with XtendFlex® Technology. ONLY USE FORMULATIONS THAT ARE SPECIFICALLY LABELED FOR SUCH USES AND APPROVED FOR SUCH USE IN THE STATE OF APPLICATION. Contact the U.S. EPA and your state pesticide regulatory agency with any questions about the approval status of dicamba herbicide products for in-crop use with Roundup Ready 2 Xtend® soybeans or products with XtendFlex® Technology.
FOR SOYBEANS, EACH ACCELERON® SEED APPLIED SOLUTIONS OFFERING is a combination of separate individually registered products containing the active ingredients: BASIC Offering: metalaxyl, fluxapyroxad, and pyraclostrobin. STANDARD Offering: metalaxyl, fluxapyroxad, pyraclostrobin, and imidacloprid.
FOR CORN, EACH ACCELERON® SEED APPLIED SOLUTIONS OFFERING is a combination of separate individually registered products containing the active ingredients: BASIC plus Poncho®/VOTiVO® Offering for corn: metalaxyl, prothioconazole, fluoxastrobin, clothianidin, Bacillus firmus I-1582. ELITE plus Poncho®/VOTiVO® Offering for corn: metalaxyl, clothianidin, and Bacillus firmus I-1582; prothioconazole and fluoxastrobin at rates that suppress additional diseases. BASIC Offering for corn: metalaxyl, prothioconazole, fluoxastrobin, and clothianidin. ELITE Offering for corn: metalaxyl, and clothianidin; and prothioconazole and fluoxastrobin at rates that suppress additional diseases. BioRise® Corn Offering is the on-seed application of BioRise® 360 ST. BioRise® Corn Offering is included seamlessly across offerings on all class of 2016 and newer products.
The distribution, sale, or use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. Not all products are approved in all states.
B.t. products may not yet be registered in all states. Check with your seed brand representative for the registration status in your state.
IMPORTANT IRM INFORMATION: RIB Complete® corn blend products do not require the planting of a structured refuge except in the Cotton-Growing Area where corn earworm is a significant pest. See the IRM/Grower Guide for additional information. Always read and follow IRM requirements.
Roundup Ready® 2 Technology contains genes that confer tolerance to glyphosate. Roundup Ready 2 Xtend® soybeans contain genes that confer tolerance to glyphosate and dicamba. Products with XtendFlex® Technology contains genes that confer tolerance to glyphosate, glufosinate and dicamba. Glyphosate will kill crops that are not tolerant to glyphosate. Dicamba will kill crops that are not tolerant to dicamba. Glufosinate will kill crops that are not tolerant to glufosinate. Contact your seed brand dealer or refer to the Bayer Technology Use Guide for recommended weed control programs.
Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.
Services and products offered by The Climate Corporation are subject to the customer agreeing to our Terms of Service. Our services provide estimates or recommendations based on models. These do not guarantee results. Before making financial, risk management and farming decisions, agronomists, commodities brokers and other service professionals should be consulted. More information at http://www.climate.com/disclaimers.
Insect control technology provided by Vip3A is utilized under license from Syngenta Crop Protection AG. Herculex® is a registered trademark of Dow AgroSciences LLC. Agrisure Viptera® is a registered trademark of a Syngenta group company. LibertyLink® and the Water Droplet Design®, Poncho® and Votivo® are trademarks of BASF Corporation. Respect the Refuge and Corn Design® and Respect the Refuge® are registered trademarks of National Corn Growers Association.
Acceleron®, Bayer, Bayer Cross, BioRise®, DroughtGard®, Lewis Hybrids and Design®, Lewis Hybrids™, RIB Complete®, Roundup Ready 2 Technology and Design™, Roundup Ready 2 Xtend®, Roundup Ready 2 Yield®, Roundup Ready®, SmartStax®, Trecepta®, VT Double PRO®, VT Triple PRO® and XtendFlex® are trademarks of Bayer Group. Climate FieldView™ is a trademark of The Climate Corporation. ©2022 Bayer Group. All rights reserved.