These are, for the most part, general measures designed
for the overall health of the Orchard. Occasionally additional measures
may be useful for a specific Pest that has gotten out of control. The
objective is to have an overall strategy that maintains a healthy
ecosystem for plants, critters, and people,and encourages beneficials.
It's called IPM (Integrated Pest Management). The point of the
Newsletter is to help you keep your trees healthy and vigorous by good
cultural methods, so they can resist disease with a minimum of
additional intervention.
A - "Keeping it Simple!"
Make
sure the Team has done a good job on the "Clean-up," and check for any
"mummies" left on the tree. Remove any residual leaves and hose off the
tree using a pressure-spray nozzle. It's beneficial to see that all dead
leaves are removed from the tree, and raked up. For the Apple Trees;
cut a 3 inch wide strip from a corrugated cardboard box, and wrap it
tightly around the trunk (so the little tubes are vertical),
just below the first branch (or about a foot and a half above the
ground). Remove the band on December 1st, put it in the garbage pail
(not for garden composting).
* If
there has been a severe infestation of soft bodied insects or scale a
"Horticultural Oil" can be sprayed during the Christmas Vacation period,
when children are away, and when the Tree is dormant.
B - "More in Depth"
OK - The
Corrugated Cardboard band will catch Codling Moth Larvae as they travel
down to the ground to pupate. Removal in early December should catch
some of the larvae in the little corrugations. Best to burn, or dispose
of these with trash. This will help reduce the Codling Moth population
in the coming season, although, if you had a heavy infestation we'll
have more suggestions for Winter and Spring.
* Spraying of pesticides
(organic or chemical) should only be done if there is evidence of
disease uncontrolled by the physical and mechanical techniques. There is
always the risk of upsetting the natural balance by injuring the
beneficial insects and microbials. When appropriate however, spray
strategies can be used.
If you're concerned about the level of disease in some trees, call your County Master Gardener office and request a visit from one of the Master Gardeners. The School holiday weekends and holiday weeks during November, December, and January are the best times to use preventive sprays (like Horticultural Oil), and to deal with a School Orchard disease problem.
If you're concerned about the level of disease in some trees, call your County Master Gardener office and request a visit from one of the Master Gardeners. The School holiday weekends and holiday weeks during November, December, and January are the best times to use preventive sprays (like Horticultural Oil), and to deal with a School Orchard disease problem.
C - "Why is that ?"
Many
insects and pests (soft bodied insects, scale, etc.) over-winter in the
crotch of branches, in the bark, and even in the bud tips. Although
dormant, they need to respire (breathe). The Oil will smother them if
the coverage has been complete. Horticultural Oil may also be called
"Narrow-range" or "Superior" Oil. This technique, is relatively safe and
has minimal adverse environmental impact. AdditionallyIt's important to
realize that most control measures are only effective at certain stages
of a pests life cycle. Oil is most effective during dormancy, at other
times the effect may be negligible.
For Deciduous
Trees, spraying in the Dormant season has many benefits: The days are
cooler and moister, when sprays are less phytotoxic (harmful to
plants). The elements of the tree most likely to suffer damage (leaves,
blossoms, new shoots etc.) are safely out of the way. Bees, and other
pollinators are relatively safe.
For School Orchards that have Citrus trees, Columbus Day weekend would be a safe time to use Horticultural Oil spray. You don't want to do it any later in the year, and be sure that the trees are well watered before any spray operation. If they have been a problem; this treatment will help control Scale, Aphid, White Fly and other soft bodied insects that overwinter in the tree.
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