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:
Once hull split initiation is determined: