Return to Canola Council HomeKey Result
The combination of implementing harvest weed seed control (which focusses on managing weed seeds retained in the field at crop harvest) through the use of early maturing crop rotations and incorporation of swathing can reduce, and limit, long-term wild oat populations (and may lengthen the effective lifetime of available herbicides).
Project Summary
Overview
Harvest weed seed control (HWSC) is a new theory of weed management developed in Australia that focusses on managing weed seeds retained in the field at crop harvest that would otherwise be spread by the combine. There is interest in using HWSC methods in western Canada such as the integrated Harrington Seed Destructor, the Seed Terminator, or other HWSC methods like chaff lining. Previous research has indicated a number of good target weeds, however, our primary herbicide resistant weed in the Prairies, wild oat, has been identified as a poor target because of early seed shed.
Objective
This project looked to determine if you could target a higher proportion of wild oat seed by growing early maturing crops in your rotation, compared to a normal canola-wheat rotation, or to later maturing crops.
Results
Preliminary analysis indicates that wild oat density and biomass is lowest after two years of early maturing crops with HWSC implemented. This suggests that by combining HWSC with early maturing crops, wild oat may be targetable, and therefore manageable with these techniques. This increases the suitability of HWSC for western Canada and the likelihood of adoption by Prairie producers.
Conclusions
The results of the project indicate that it may be possible to increase the proportion of wild oat available for management by harvest weed seed control methods. This increases the viability of harvest weed seed control as a new weed management method for Canadian producers. This may increase interest in incorporating HWSC methods into production systems.
In the long run, incorporation of HWSC methods could increase the usable effective lifetime of our herbicides, and reduce selection for new herbicide resistant biotypes. It may also limit the spread of current resistant biotypes that are geographically limited. The indication that swathing will increase wild oat management over straight cutting is against the current trend where producers are shifting to a higher proportion of straight cutting in their harvest methods. Therefore, producers will have to consider where weed control ranks on their priority list when making decisions about how they will proceed with harvest decisions in the future.
