2013 Highlights: UC IPM Annual Report
New vole IPM program in artichokes
UC IPM Advisor Roger Baldwin has developed an IPM plan for voles, the primary vertebrate pest affecting California’s $48 million artichoke crop. The IPM plan uses monitoring, cultural practices, exclusion, baiting, and fumigation to prevent damage from voles feeding on artichoke plants.
Baldwin’s research on ways to monitor for voles found that vole feeding on wax bait blocks is the best way to know if voles are in the fields.
If voles are in the fields in late spring, cultural control practices and burrow fumigation can be used at the end of the growing season. Chopping, a cultural practice that removes aboveground vegetation after harvest and kills voles, substantially reduced the number of voles found in the field. Following this with aluminum phosphide fumigation further reduced vole numbers. If a field will be replanted, discing also successfully reduced the number of voles.
Once voles are removed from the field, Baldwin suggests installing fences around fields to slow vole reinvasion. Black plastic mesh and aluminum flashing work well, especially if surrounded by bare soil.
When monitoring indicates vole numbers are increasing or fencing is not practical, Baldwin recommends using chlorophacinone-treated artichoke bracts in the winter.
Treating bracts with this rodenticide is a standard treatment for vole control. A 2001 study showed that voles in the Castroville area were not well-controlled using chlorophacinone. However, Baldwin observed in his recent research that chlorophacinone-treated bracts are still the most effective bait registered for vole control in artichokes. Starting baiting no later than mid-February gives the best control.
The Vertebrate Pest Control Research Advisory Committee sponsored Baldwin’s research project.