Volunteer Roundup Ready winter canola may cause problems for farmers but effective herbicides and other strategies are available to control volunteer canola.
With the growing presence of a new crop, winter canola, in the Southern Plains states as a rotation with winter wheat to help control weeds, agricultural producers are asking questions about how to control volunteer winter canola.
Information on control of winter canola, including Roundup Ready varieties, can be found on page 11 of the Great Plains Canola Production Handbook, produced by Oklahoma State University, Kansas State University and the University of Nebraska. Copies of the handbook can be obtained by contacting OSU Extension County Educators, representatives of the universities' Extension Service and from Producers Cooperative Oil Mill field representatives.
The handbook is co-edited by Mark Boyles and Dr. Thomas Peeper, OSU Department of Plant and Soil Sciences and Michael Stamm, with OSU and KSU. The handbook covers all aspects of producing winter canola in the Southern Plains states.
Recommendations from the handbook covering volunteer winter canola control in winter wheat include:
- Although canola has been reported as volunteer for several years, problems with volunteer canola are not common.
- The seed has little dormancy and typically germinates after summer rains and can be eliminated by tillage or in no-till by herbicides.
- Herbicide recommendations for controlling volunteer canola are rated for effectiveness, based on research where herbicides were applied either in the fall or spring to actively growing canola. Dormant canola is much more difficult to control.
- 2,4-D ester and MCPA Extra, both at 1 pint per acre, gave good to excellent control in fall applications and fair to good control in spring applications.
- Bronate at 1pint per acre gave excellent control in fall applications and fair to good control in spring applications.
- Finesse at 0.3 ounces per acre gave excellent control in the fall and good to excellent control in spring applications.
- Ally Extra at 0.5 ounces per acre gave excellent control in both fall and spring applications.
- Amber at 0.56 ounces per acre gave excellent control in the fall and good to excellent control in spring applications.
- All post emergence herbicides were applied with recommended adjuvants. Ratings are based on one to two years of research by OSU and KSU.
- "Volunteer canola will compete with the succeeding crop and may affect yield, depending on the volunteer density. Steps should be taken during swathing and combining operations to minimize canola seed losses. For no-till small grains, consider adding a labeled herbicide to the glyphosate (Roundup) burndown application to control emerged glyphosate-resistant volunteer canola.
- Volunteer canola that emerges before or with the crop may be very large by the time the post emergence herbicide application is made. Volunteer canola becomes much more difficult to control with herbicides once plants reach the six-leaf to bolting stage. There are some herbicides that provide excellent control of small volunteers, but provide poor control of bolting canola.
- Volunteer canola will be controlled best when the herbicide is applied by the three to five-leaf stage and the canola plants are actively growing.
For more pertinent information on controlling volunteer canola, contact Gene Neuens or Heath Sanders, PCOM field representatives, at 405-232-7555. Neuens' email address is email@example.com. His cell phone is 405-760-4205. Sanders' email is firstname.lastname@example.org. His cell phone is 405-678-2754. Boyles can be emailed at email@example.com. Boyles' office phone is 405-744-9600.