UC IPM Online UC ANR home page UC IPM home page


SKIP navigation



Almond hull split, less than 3/8 inch (1 cm).

Identify Hull Split

Identifying hull split is critical in an almond integrated pest management program. If summer navel orangeworm applications are necessary, they are timed relative to the beginning of hull split and the occurrence of egg laying.

Hull split also exposes nuts to peach twig borer invasion and hull rot fungi. The longer the nuts remain on the tree after hull split, the longer the interval that they are exposed to these invaders. Therefore, harvest your almond crop as early as possible to reduce the time it will be exposed to these pests and to avoid complications caused by early rains. If the threat of navel orangeworm is severe, the orchard can be harvested twice; once to remove the early ripening nuts and the second time to remove the later ripening ones.

The exact timing of hull split initiation is complicated. Ripening does not occur in all fruit simultaneously. It begins in the upper and outer parts of the tree, in the southwest quadrant, later extending through the lower and inner sections (nuts at eye level will be less mature than those at the tree tops). Almonds should be harvested when 95 to 100% of the hulls have split.

Check for initiation of hull split:

  • Check harvest timing for your variety. The start of almond harvest varies from year to year and district to district, but usually begins in early to mid-August.
  • Check for the beginning of hull split in early to mid-July.
  • Use pole pruners to cut small branches from the top southwest portion of 5 to 6 trees in the orchard and see if hull split has begun.

Once hull split initiation is determined:

  • Continue monitoring trees until 95 to100% of the fruit at eye level are visibly split.
  • Shake a few trees to determine if nut removal is satisfactory. If not, try again in a few days.
  • Harvest blocks with poorest sanitation first.
Various stages of hull split
Header photo.
Unsplit almond
Header photo.
Initial separation stage
Header photo.
Deep V, unsplit stage
Header photo.
Almond hull split, less than 3/8 inch
Header photo.
Initial drying stage
Header photo.
Completely dry stage

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2016 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/C003/m003fchullsplit.html revised: June 24, 2016. Contact webmaster.