Repository logo

Implication of reduced herbicide rates on resistance enrichment in wild oat (Avena fatua)

dc.contributor.authorBeckie, H.J.
dc.contributor.authorKirkland, K.J.
dc.description.abstractModel simulations predict that lowering herbicide efficacy by reducing the application rate would slow the rate of enrichment of herbicide-resistant individuals in a weed population, but the resulting increase in density of susceptible plants would reduce crop yield and increase the weed seedbank. A study was conducted at three sites in Saskatchewan from 1997 to 2000 to examine the implication of reduced rates of Group 1 herbicides in a 4-year crop rotation, in conjunction with variable crop seeding rates, on the enrichment of resistant wild oat in a mixed (resistant and susceptible) population. Main plot treatments were crop (barley, canola, field pea, spring wheat), subplot treatments were crop seeding rate (recommended and high), and sub-subplot treatments were Group 1 herbicide rate (0, 0.33, 0.67, and 1.0 times the recommended rate). Herbicide rate frequently interacted with seeding rate in affecting wild oat seedling density, seed return, the viable fraction of the weed seedbank, and crop seed yield. As simulation models predict, reduced herbicide efficacy decreased the proportion of resistant individuals in the population. The high crop seeding rate compensated for a one-third reduction in herbicide rate by limiting total wild oat seed return and by reducing the number of resistant seedlings recruited from the seedbank. In a diverse cropping system, the level of resistance in the seedbank can be reduced without increasing the total (resistant plus susceptible) seedbank population by manipulating agronomic practices to increase crop competitiveness against wild oat when Group 1 herbicide rates are reduced to a maximum of two-thirds of that recommended.en_US
dc.description.versionNon-Peer Reviewed
dc.relation.ispartofSoils and Crops Workshop
dc.rightsAttribution-NonCommercial-NoDerivs 2.5 Canada*
dc.subjectherbicide resistanceen_US
dc.subjectintegrated weed managementen_US
dc.titleImplication of reduced herbicide rates on resistance enrichment in wild oat (Avena fatua)en_US
dc.typePoster Presentationen_US


Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
H.J. Beckie and K.J. Kirkland, 2003.pdf
143.05 KB
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
2.29 KB
Item-specific license agreed upon to submission