Non‐toxic control techniques for Microtus spp. in apple orchards1

Abstract

Alternative control techniques to the use of endrin ground spray were investigated in apple orchards in Washington (US). Non‐toxic control strategies using cultural practices proved highly successful in reducing high populations of Microtus montanus to low levels. Early spring raking and mowing followed by the application of herbicides to a strip along the tree line appeared to have the greatest effect. Regular mowing between the tree rows and the maintenance of bare ground under the trees prevented significant build‐up of the population. Similar cultural work also substantially improved the efficacy of subsequent rodenticide applications. The economic impact of the vole damage on apple orchards, even those composed of mature trees, is substantial and the expense of intensive cultural work is justified where high vole populations are possible.