The last survey of weeds populating fields in Ontario was conducted in 1988. Therefore, I felt it was time to do another survey and compare the weed species populating corn, soybeans and winter wheat found in 1988 versus 2014 (see tables further down).
In general, the abundant species identified in 1988 were also abundant in 2014. However, there were some notable changes. Quackgrass, which was the third-most abundant weed in the 1988 survey, was much less abundant in the 2014 survey. There were also a number of species that were identified in the 2014 survey and at notable levels of abundance that did not show up as abundant species in the 1988 survey, specifically Canada fleabane, purslane speedwell, tufted vetch and annual bluegrass.
Acknowledgements: I’d like to thank Meghan Grguric and Meghan Moran, who surveyed all the fields, and to Carole Ann Lacroix (OAC herbarium) for identifying several “unknown” samples that were found during the survey.
Have a question you want answered? Hashtag #PestPatrol to @cowbrough or email Mike at [email protected].
