Border Treatment to Reduce Insecticide Use in Seed Potato Production: Biological, Economic, and Managerial Analysis

Worldwide, Myzus persicae (Sulzer) is considered the key vector of Potato leafroll virus (PLRV). In the northern Great Plains, introduction of PLRV into seed potato fields is coincident with mid-summer dispersal of winged M. persicae from local crop and weed hosts. Initial colonization of potato fields tends to occur at field margins. In 2003, experiments were conducted in 23 seed potato fields to evaluate effectiveness of targeted methamidophos applications for M. persicae control. These applications provided excellent control (>94%) of colonizing aphids in the borders, slowed subsequent within field spread, and necessitated treatment of 95% fewer hectares than would treating entire fields. Across entire fields, control costs averaged $4.22 per ha for border treatments compared to a hypothetical $58.91 per ha for applying methamidophos to entire fields. Thus targeted insecticide applications can provide effective M. persicae control in seed potato fields while greatly lowering insecticide use and application costs overall.