IN YOUR ORCHARD
Water Infiltration Issues
Water infiltration problems are becoming more common
due to increased water applications, low quality water,
reduced cover crop usage, compaction, and varying
soil characteristics. After an irrigation, are there visible
puddles and signs of soil crusts
?
Does water appear to
run off the field
?
Does the water create saturated zones
underneath the emitters
?
These problems are not easy to
resolve, but reducing and preventing is critical to maintain
high yields. Areas with problems should be sampled to
identify the underlying soil chemistry issue. The irrigation
water should also be sampled.
Appearance of Salt Toxicity
Are leaves exhibiting signs of brown, crispy, or “burnt”
edges
?
This could be evidence of sodium or chloride
toxicity. Review leaf tissue samples from July to determine
the element of concern. Sample soils to compare to
previous year’s samples to identify any emerging salinity
issues. Utilize this information to develop a leaching
program, which may include early winter irrigations
to refill the profile and leach and applications of soil
amendments to assist with the leaching process.
Underperforming Areas
Trees that are growing at a slower rate than other areas
could be indicative of a soil texture change or poor
irrigation distribution. It is difficult to manage soil texture
differences, but emitters could be changed to apply
water over a larger wetting pattern to increase the soil
volume. In these cases, try not to change the emitter
flow as this may impact distribution uniformity (DU).
Pump and irrigation line maintenance will help improve
DU. Check pressure at the emitter to determine if flows
are reduced. If lower pressures are observed, check the
flow rate of the pump to see if it may have dropped
or not properly set, inspect lines for leaks and clogged
screens and emitters for precipitation build-up, and flush
the lines.
Timing of Orchard Pruning
Over the past few years, there has been an increase
in wood canker pathogens infecting pruning wounds,
wind cracks, and damaged areas of young almond
trees. Infections start off slow, but eventually girdle
limbs, killing scaffolds and impacting production.
These pathogens are most active right before, during,
and immediately after rain events as they require the
humidity to sporulate and the wind-splashing of rain to
spread. To prevent pruning wound infections, pruning
of young trees should not occur when rain is in the
forecast. Cutting of limbs on primary scaffolds of mature
trees should also not occur at this time.
Planning to prune young trees around the weather may
delay pruning. Research performed in Yolo County
has shown no impact when pruning as late as full leaf
expansion (late March). In this study, the growth was
followed over three years and no differences were
observed in the various treatments, including a winter
dormant pruned control. Research on how early
pruning can begin isn’t as clear. Starting too soon
can spur unwanted growth. Pruning once the days are
cooler and shorter should reduce the risk of secondary
bud break.
Pruning of mature trees can begin shortly after harvest.
Pruning should be minimized as multiple long-term
studies have found that it can reduce yield and increase
orchard operation expenses. Nevertheless, limbs that
Soil crusting and reduced water infiltration rates are common in
irrigated orchards. Soil samples from the top few inches should be
analyzed to determine which amendments should be applied.
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A L M O N D F A C T S
