Physical-Mechanical controls are good against the spread of Plum Pox virus disease. Sacrifice the sick trees to protect the healthy ones.

First, identify infected trees, quarantine the orchard, then bulldoze and burn the trees.

Also, remove weeds from land between healthy orchards. This will rid the area of aphid habitat.

A drawback to this approach is erosion. The removal and burning of large areas of vegetation can damage a watershed. If you choose this approach, be sure to consider erosion prevention.