Enhance understanding of cleavers populations in western Canada
Posted on 14.02.2022 | Last Modified 26.05.2025
Lead Researcher (PI): Breanne Tidemann
Institution:
Agriculture & Agri-Food Canada
Total WGRF Funding:
$103,600
Co-Funders:
Alberta Canola Producers Commission, Saskatchewan Oilseeds Development Commission
Start Date:
2021
Project Length:
4 Years
Objectives:
Evaluate presence of cleavers biotypes on the Prairies based on emergence phenology, whorl/branch number close to maturity, seed production, and Total Kernel Weight (TKW). Evaluate emergence timing of cleavers populations. Determine if any of the above characteristics are affected by maternal environment. Screen collected populations for quinclorac resistance.
Project Summary:
- Moisture drives cleavers emergence. If you are in an area with a lot of cleavers populations and you have a wet fall, scouting for cleavers emergence is recommended. In an open fall cleavers can reach an advanced stage prior to snow cover (8-10 whorls were counted in Lacombe), and they begin growing as soon as snow melt occurs. This could put the cleavers above labelled stages for many herbicides by the time a pre-seed burn-off occurs. Heavy densities of fall emerged cleavers may need to be managed with fall herbicide applications in order to apply when they are within labelled stages.
- Cleavers are a flushing weed. Even if you don’t have a lot of cleavers at pre-seed burn-off timing, subsequent precipitation events can lead to emergence and they should be scouted for prior to in-crop herbicide applications, and if a second in-crop is being considered.
- Maternal environment may also drive emergence – more work to be done here with the data but it seems like drier conditions may increase germinability/viability, or wetter conditions at seed set may increase dormancy and increase see longevity. Unclear exactly what is happening here, but maternal environment may be one to pay attention to.
- Applications of quinclorac may not always result in cleavers death. Scouting post-application is crucial as many of our surviving plants in our trials set abundant seed after quinclorac application. As there is some suggestions, we may be seeing developing resistance it is important that we are watching for these populations and initiating secondary management strategies if needed before they become a significant problem.