ground), the less NOW damage
to expect at harvest. Therefore,
higher standards of tree and ground
sanitation are recommended for
orchards in high pressure, higher heat
unit/degree day areas. Growers in
cooler, low pressure areas should still
reduce average mummy nut counts to
two or less per tree and destroy any
mummies that are on the ground.
Pruning
Pruning of mature and young trees
often occurs during the winter months.
Research has shown that reduced
pruning on younger trees can lead
to larger, earlier yields. This is mostly
due to increase canopy that is able
to produce crop. Nevertheless, some
structuring of first and second leaf
trees may be needed to address tight
branch angles and close proximity
of scaffolds, which leads to included
wood and weak branches. These
branches will split when the crop load
begins to increase, typically around
year four or five. Prune only when rain
is not in the forecast to avoid wound
infections by pathogenic fungi that
disperse spores during rain events.
Wounds can be susceptible up to
two weeks after pruning, with larger
wounds taking the longest to heal.
Even with this healing time, pruning
paints are not recommended as they
can slow the healing process. Pruning
as late as leaf out will have no impact
on tree growth.
Mature tree pruning may also be
needed. Many are aware of the
multiple research trials that have
shown no yield benefit from pruning
mature trees. There are, however,
other reasons to prune mature trees,
including: easier access, worker safety,
increasing the amount of light to the
orchard floor to assist with drying, and
to remove broken, dead, and diseased
limbs. Another reason that is often
not discussed it to reduce pest and
disease pressure. UCCE research out
of the Sacramento Valley has shown
a six percent decrease in NOW
infestation in the upper canopy in
pruned trees due to better insecticide
spray distribution in the upper canopy.
Consider Cover Crops
Many operations have moved
away from planted cover crops and
have relied on residual vegetation
for ground cover. Establishing a
cover crop has been shown to
increase soil organic matter, reduce
compaction from equipment, reduce
soil erosion and run-off as well as
improving water infiltration and soil
quality. Recent research has also
found benefits to pollinators without
competing with almond bloom. Further
research is studying the effects of
the cover crop on weed pressure,
water use and frost risk. Although
cover crops come with an expense
and require mowing (around $80 per
acre, total expense including seed),
the benefits should be compared
to compost applications and other
techniques to increase organic matter.
For more information on cover crops,
please visit almondcovercrop.faculty.
ucdavis.edu and Project ApisM.
Soil Sampling for Managing
Water Infiltration
Water infiltration issues are being
observed at a higher frequency. This is
due to a large amount of water being
applied through a limited soil surface
area, leaching the minerals responsible
for maintaining soil aggregation,
causing dispersion. Soil from the
top few inches should be sampled
to determine the appropriate soil
amendments. If issues are not apparent,
then limited sampling should suffice.
If water run-off has been observed,
samples should be pulled from multiple
Maintenance on spray rigs should be performed. With herbicide
rigs, check pumps and pressure, nozzles for wear and the spray
pattern for the proper percentage of overlap. Applications out
of specifications will increase pesticide use and expense.
Planted cover crops provide multiple benefits for orchards,
including increasing soil organic matter, reducing compaction
and run-off, and providing food for pollinizers. Consider adding
them into orchard operations.
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