Proceedings of the Vertebrate Pest Conference

This field efficacy trial using aluminum phosphide tablets for controlling the valley pocket gopher was conducted on land farmed by California State Polytechnic University, Pomona, California. The treatment blocks were located in moderate to heavily infested cover crops in deciduous orchards. Each of 2 treatment blocks contained 10 study plots, as did 2 control blocks. All burrows in the treatment blocks as well as a 100-foot-wide buffer were treated by placement of 2 to 4 Fumitoxin® tablets in each of 1 to 3 probed holes. Both treatment units had a 90% decline in pocket gopher activity, judged by the open hole census method, after the first treatment, and 100% reduction after burrows missed in the first treatment were treated. All burrows in the control plots remained active throughout the entire trial. All treatment points in the study plots were flagged and 33%, including 6 burrows remaining active in the 2-day post-treatment period, were examined for proper tablet placement. The importance of proper aluminum phosphide tablet placement is discussed.