TIME TO CONSIDER
34
Almond Facts
JANUARY | FEBRUARY 2017
another chemistry.
Please note that the fungicides
listed are an example, not an endorsement for
use. Please refer to Timing and Efficacy Tables
for full list of tested fungicides
(Attached fungicide
efficacy table).
There are many effective fungicides
not listed in this example.
In 2016 we saw an increase in Green Fruit Rot/Botrytis
infections across California. This was due to long periods
of leaf wetness, poor coverage and incorrect selection
of fungicides. Keep in mind
that FRAC 3 (DMIs) do not
provide any protection for
Botrytis. Develop the fungicide
plan before bloom begins.
There is a lot of information
regarding bloom spray
timings and diseases at www.
thealmonddoctor.com and
ucipm.ucdavis.edu.
Insecticide
applications at
bloom for peach
twig borer (PTB)
Recent research has found that
applications of diflubenzeron
timed at bloom has a negative
impact on bee health. This
insecticide has been shown
to reduce the survival of
immature queens. It is
unknown if other insecticides
“tank mixed” at bloom have
the same effect. Until more
research is conducted, it is
recommended that insecticide
applications at bloom be
removed. Other timings for
PTB include dormant and
the “May Spray,” which may
reduce navel orangeworm
(NOW) populations. Please
keep in mind that insecticides
applied during the dormant
period do not provide any
control for NOW.
Work done more than 20 years
ago has found that Bacillus
thuringiensis (Bt) can be applied at bloom to effectively
control PTB without impacting bees. 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 to 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 timings (which are as effective as in-
season timings). Please see the UC IPM page for PTB for
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