IN YOUR ORCHARD
TOP 5 THINGS TO CONSIDER
BEFORE HULL-SPLIT
Hull-split is a time when all the various orchard activities
come together — and may end up impacting one another.
Proper irrigation, nutrient management, pest control and
orchard monitoring are critical functions to maximize almond
quality. To assist during this busy season, we’ve pulled together
a list of the top five things to consider before hull-split.
1. Properly Detect Hull-Split
This may seem like an obvious one, but proper detection is the
first step in effectively managing the potential for myriad pest
and rot issues that may occur following hull-split.
• Hull-split typically begins towards the beginning of July in
the early growing regions and spreads to later growing
regions accordingly. The splitting of blank nuts (as much
as three to five percent of the almonds) will occur about
a week ahead of hull-split and serve as a heads up that
split will soon occur.
• A key to identifying hull-split is to look for an initial split
in the upper and outer portions of the canopy, particularly
the southwest quadrant. Once the fruit splits, hull-split
has begun.
2. Spraying to Target Navel Orangeworm (NOW)
The most effective time to spray for NOW is during its
second flight, which coincides with the initiation of hull-
split. As a confirmation that flight activity is coincident
with the beginning of hull-split, check to see that eggs
are being laid on egg or pheromone traps. Then, when
spraying, make the application no later than one percent
hull-split.
If your orchard experiences high NOW populations, a
second insecticide application may be needed two to
three weeks after the initiation of hull-split. As noted in
the UC IPM guidelines, be sure to consider the following
points before conducting a second application:
• Varieties in the orchard
• Anticipated harvest dates
• Pest pressure noted from egg and pheromone traps
• Overwintering mummy load
• Proximity to an external NOW source, such as
neighboring pistachio orchards
As indicated in the UC IPM guidelines, Intrepid
(methoxyfenozide) and Altacor (chlorantraniliprole) are
preferred materials for hull-split sprays. Pyrethriods have
been used in the past, but their use should be considered
with caution as NOW resistance to these materials has
emerged, and pyrethriods are toxic to beneficials. If
pyrethroids are used, it should only be once per season.
Hull-split may be identified when the fruit begins to
split (less than 3/8 inch) in the upper and outer parts
(in the southwestern quadrant) of the tree.
If you’re conducting a spray, specific reduced-risk
products are preferred to prevent harm to beneficial
insects and/or resistance issues in NOW.
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A L M O N D F A C T S
