By John Ippolito, Regional Crops Specialist, Ministry of Agriculture, Regional Services, Kindersley
Weed Survey
Agriculture and Agri-Food Canada staff conducted a weed survey across Saskatchewan during the 2014 and 2015 growing seasons. The weed surveys were conducted in the major field crops during July and August so it was recording the weeds that were present after weed control operations had been done.
In total there were 2242 fields sampled with these fields categorized by crop grown and the eco-region that the fields were situated in. Weeds were counted in 20 quadrats within each sampled field to arrive at a number of ratings. These ratings were:
– Frequency – % of fields with species present
– Uniformity – % of quadrats within a field that had the species
– Density – average density of species in all fields in number per m2
These are then combined to arrive at an abundance rating for each weed.
On a province wide basis the top three species were green foxtail, wild oats and wild buckwheat. These have been the top three since the start of weed surveys in the 1970s. Part of the reason for conducting these surveys is to document shifts in weed species over time and changes in management practices. Three species that have been shown to increase in surveys since the 1980s are foxtail barley, dandelion and narrow-leaved hawk’s-beard.
There were 378 fields surveyed in west central Saskatchewan as part of this survey. The regional results from this survey are somewhat different from the provincial results. The chart below shows the top 10 weeds based on abundance for the west central region and ranking based on the whole province.
| Weed Species | Relative abundance in West Central Region | Saskatchewan (ranking by abundance) |
| Green foxtail | 42.0 | 1 |
| Canola/rapeseed | 35.3 | 4 |
| Wild oats | 27.9 | 2 |
| Narrow-leaved hawk’s-beard | 24.6 | 9 |
| Wild buckwheat | 22.8 | 3 |
| Lamb’s-quarters | 13.9 | 8 |
| Spiny annual sow-thistle | 13.1 | 6 |
| Canada thistle | 10.3 | 5 |
| Stinkweed | 9.6 | 11 |
| Wheat | 8.2 | 13 |
Extreme weather events may partially explain some of the results seen in the west central results in particular. As an example volunteer canola may have emerged at a time when control was not possible in some crops.
This is relatively preliminary data and further work is being done to study the management practices of the fields in the survey. This may shed some light on some of the results.
For more detailed information on the 2014 – 2015 Weed Survey contact your Regional Crop Specialist.