Issue Date: October 19, 2011

An article in the Oct. 5 issue of Ag Alert reported on a presentation by Roger Baldwin, IPM wildlife pest management advisor at the University of California Kearney Agricultural Research and Extension Center. The article contained several errors and misinterpretations. To clarify:

  • For gophers, one means of control is to use a piece of equipment called a burrow builder combined with a poison bait containing either strychnine, zinc phosphide or anticoagulants.
  • Baldwin said gopher tunnels tend to be deeper in the central San Joaquin Valley and shallower in the Napa-Sonoma and Klamath Basin areas. Trapping is typically more practical in those areas where burrow systems are shallow.
  • One effective new trap option is called the Gophinator; trials showed it to work particularly well on larger gophers that may escape some other traps.
  • There are poison baits for each of the pests. Some require multiple feedings, including anticoagulants, which Baldwin said cannot be applied for vole control in alfalfa, although belowground applications are allowable for gophers. Others are "single feeding" poisons including zinc phosphide, which can be used for vole and gopher control, and strychnine, which is only allowable for use on gophers.
  • For vole control, zinc phosphide can be broadcast in alfalfa. Prebaiting with non-toxic oat groats should be done first to verify bait acceptance. If most of the non-toxic bait is consumed, then zinc phosphide can be applied.
  • Fencing material has to be buried about 6 inches and needs to extend 6 to 10 inches above ground. Initial trials suggest that it has been effective at excluding voles in artichokes, although final results are pending.

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.