Pistachio > Year-Round IPM Program > Dormancy to Delayed-Dormancy

Pistachio

Why is dormancy to delayed-dormancy important in an IPM program?

Dormant male bud.

Early bud swell.

Green tip.

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.

The dormant stage begins around December 1 and ends when bud growth begins, about March 15th, depending on region, variety, and weather.

The dormant stage is a critical period for several pests. Be aware that pesticide sprays are more likely to runoff during this time. Pest management activities include:

• Removing and destroying mummy nuts from the trees and orchard floor for management of navel orangeworm and Botryosphaeria panicle and shoot blight.
• Pruning out dead or infected wood, and removing or destroying pruned wood and brush piles from the orchard floor to reduce overwintering sites for leaffooted plant bug and Botrytis blossom and shoot blight and Botryosphaeria panicle and shoot blight.
• Managing pests such as scales. Pesticide applications at this time of year are most effective because leaves are off trees allowing better coverage. Also, beneficial insects are less likely to be harmed.
• Monitoring for vertebrate pests and managing if needed.
• Managing orchard weeds. Before making weed applications, mechanically remove leaves from the orchard floor so that herbicide can penetrate the soil.