Canada Fleabane Control Strategies in Soybean

Summary

  • Successful management of Canada fleabane requires effective weed control in each crop in the rotation.
  • Effective burndown in early spring or aggressive tillage are important to kill early-season rosettes.
  • Use of a residual herbicide is important to provide weed control through the critical weed free period in soybean.
  • A fall burndown treatment or tillage pass may be needed if fall Canada fleabane pressure is present.
Photo of a Canada fleabane weed.
Canada fleabane ( Conyza canadensis) is an annual weed that can follow a winter annual or summer annual lifecycle and often becomes a problem in no-till systems.
 

Introduction

  • Glyphosate-resistant weeds such as Canada fleabane have become increasingly difficult to manage across Ontario.
  • Conventional herbicides and tank mix strategies with multiple modes of effective action are important to maintaining clean fields through the critical weed-free period (Figure 1).
  • Effective early season kill, coupled with a residual herbicide program, is key for achieving satisfactory control of difficult weed species such as Canada fleabane.
Chart showing soybean yield associated with maintenance of weed-free conditions through a range of soybean growth stages.

Figure 1. Soybean yield associated with maintenance of weed-free conditions through a range of soybean growth stages. (Average of 9 experiments; P.H. Sikkema, Univ. of Guelph.)

Canada Fleabane Control in Glyphosate-Tolerant and Conventional Systems

Key Components in this system:

  1. Effective pre-plant weed control, which could consist of a tillage pass or burndown treatment such as Eragon® herbicide or 2,4-D.
  2. Residual herbicide component such as DuPont™ Canopy® Pro herbicide, which contains two modes of action with residual activity, to provide season-long control of this weed (Figure 2).
    • Chlorimuron-ethyl (active ingredient of DuPont™ Classic® herbicide)
    • Metribuzin (active ingredient of Tricor® herbicide)

Canada Fleabane Control with Roundup Ready 2 Xtend® Technology

  • Pioneer® brand soybeans with Roundup Ready 2 Xtend® technology provide an excellent tool for managing glyphosate-resistant weeds.
  • This system allows the application of low-volatility
  • dicamba products such as DuPont™ FeXapan™ herbicide Plus VaporGrip® Technology on soybeans. Dicamba is an excellent option for Canada fleabane control.
  • Producers must be careful stewards when spraying dicamba products around sensitive crops and always follow label guidelines

Key Components of Roundup Ready 2 Xtend® Technology:

  • Effective pre-plant weed control, which could consist of a tillage pass or burndown treatment of DuPont™ FeXapan™ herbicide Plus VaporGrip® Technology or another approved low-volatility dicamba product.
  • A residual herbicide component such as DuPont™ Canopy® Pro to help keep soybeans weed-free through the critical weed-free period.
  • An early post-emergence application of an approved low-volatility dicamba product such as DuPont™ FeXapan™ herbicide Plus VaporGrip® Technology.
Select herbicide programs and estimated costs for managing glyphosate-resistant Canada fleabane in soybean.

Table 1. Select herbicide programs and estimated costs for managing glyphosate-resistant Canada fleabane in soybean. (Click on the image above for a larger view.)

74 Days After Application

Soybean plot not treated for Canada fleabane.

Non-Treated

4-D Ester + glyphosate.

DuPont™ Canopy® Pro herbicide + 2,4-D ester + glyphosate

Figure 2. Soybean plot treated with DuPont™ Canopy® Pro herbicide + 2,4-D Ester + glyphosate compared to a non-treated plot 74 days after application in a DuPont research trial (Grimsby, ON; 2014).

Important Considerations

  • A weed management program that incorporates multiple modes of action can help reduce the probability of additional herbicide-resistance development. This is particularly important when managing weed species that have already demonstrated a propensity for developing herbicide resistance.
  • Do not forget about the other weeds in your fields when developing an effective weed management plan. Your primary target may be Canada fleabane but make sure you have a broad program that will set you up for success. DuPont™ Canopy® Pro provides effective control of a long list of weed species and is a very useful tool for helping keep soybean fields clean through the critical weed-free period.

Authors: Erik Sharpe & Phil Emmott, DuPont Territory Managers

November 2017

 


DO NOT APPLY DICAMBA HERBICIDE IN-CROP TO SOYBEANS WITH Roundup Ready 2 Xtend® technology unless you use a dicamba herbicide product that is specifically labeled for that use in the location where you intend to make the application. IT IS A VIOLATION OF FEDERAL AND STATE LAW TO MAKE AN IN-CROP APPLICATION OF ANY DICAMBA HERBICIDE PRODUCT ON SOYBEANS WITH Roundup Ready 2 Xtend® technology, OR ANY OTHER PESTICIDE APPLICATION, UNLESS THE PRODUCT LABELING SPECIFICALLY AUTHORIZES THE USE. 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 soybeans with Roundup Ready 2 Xtend® technology.

ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Soybeans with Roundup Ready 2 Xtend® technology contain genes that confer tolerance to glyphosate and dicamba. Glyphosate herbicides will kill crops that are not tolerant to glyphosate. Dicamba will kill crops that are not tolerant to dicamba.

Roundup Ready 2 Xtend® is a registered trademark of Monsanto Technology LLC used under license.


DuPont™ FeXapan™ herbicide plus VaporGrip® Technology may not be registered for sale or use in all states. Contact your DuPont retailer or representative for details and availability in your state. For additional information, visit fexapanapplicationrequirements.dupont.com.

IT IS A VIOLATION OF FEDERAL AND STATE LAW TO MAKE AN IN-CROP APPLICATION OF ANY DICAMBA HERBICIDE PRODUCT ON SOYBEANS WITH Roundup Ready 2 Xtend® technology, OR ANY OTHER PESTICIDE APPLICATION, UNLESS THE PRODUCT LABELING SPECIFICALLY AUTHORIZES THE USE.

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 soybeans with Roundup Ready 2 Xtend® technology and follow all pesticide product labeling.

This reference guide is not intended as a substitute for the product label for the product(s) referenced herein. Product labels for the above product(s) contain important precautions, directions for use, and product warranty and liability limitations, which must be read before using the product(s).

Applicators must be in possession of the product label(s) at the time of application. Always read and follow all label directions and precautions for use when using any pesticide alone or in tank-mix combinations.

Soybeans and cotton with Roundup Ready 2 Xtend® technology contain genes that confer tolerance to glyphosate and dicamba. Glyphosate herbicides will kill crops that are not tolerant to glyphosate. Dicamba will kill crops that are not tolerant to dicamba.

VaporGrip®, Roundup Ready 2 Xtend® (Monsanto), VaporGrip® Technology is used under license from Monsanto Technology LLC.

 

The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.