For low populations, a single spray made during bloom
should suffice. For moderate to high populations, two
applications applied at the beginning of bloom and
10–14 days later should be considered. Trial work (which
used Javelin WG at 0.75lbs/100 gpa) has shown these
spray timings to be as effective as dormant and in-
season timings using conventional insecticides or growth
regulators. Please see the UC IPM page for PTB for more
information and check with your pest control advisor for
product availability and recommended rates.
If this timing does not fit, PTB can also be controlled
with a “May spray.” This timing occurs about 300–400
after biofix, which falls around the end of April through
the first two weeks of May. Often, this overlaps with
the first flight of navel orangeworm timing (NOW).
Spraying an insecticide during bloom will NOT provide
any NOW control.
Foliar Nutrients at Bloom
Boron and zinc foliar nutrients applied either in the post-
harvest period (e.g. September) or at pink bud have been
shown to increase yield in almond trees in many orchard
situations. Interestingly, applying these products after pink
bud have either failed to increase yield or decreased
kernel yields. Concentration of boron should not exceed
400 ppm of boron in solution, and good results have
been shown with rates between 200–400 ppm
( ~ 0.2–0.4 lbs of boron in 100 gpa), depending on
the tree’s boron status. Zinc applications appear to
have a synergistic effect with boron, meaning that
the combination of the treatments has been shown to
Blossom diseases can occur during wet weather and almond flowers are sensitive to a wide variety of diseases. Fungicides should be
considered when inclement weather is in the forecast.
3 7
J A N U A R Y – F E B R U A R Y 2 0 1 8
