Why Is the Dormant/Delayed-Dormant Season Important in an IPM Program?
Dormant season is an excellent time to monitor and assess scales, aphids (if a treatment was not applied in November), and some mites, since their populations are concentrated on the twigs and spurs at this time of year.
Dormancy is generally defined as the period from leaf fall until growth resumes in spring. Delayed dormancy is the period from the resumption of growth, indicated by bud swell, until green tip.
Water quality issues. Organophosphate insecticides applied during the dormant season for aphid, scale, and peach twig borer control are particularly likely to run off into waterways after winter rains and should be avoided. See specific pest sections in the UC IPM Pest Management Guidelines: Plum for up-to-date alternatives for managing these pests.