If you have a Home Orchard or just a few apple trees in your back yard, if you have not thought about how to handle those pest problems you had last season yet, now is the time to actively examine a spray protocol for
your fruit trees! And start right away, before it is too late and the pests have a chance to establish themselves in your trees! The question everyone needs to ask before spraying is
“Do I want to spray or not?” Well, unfortunately, in northern Illinois
we have four main pests that we will almost always have to spray for.
The decision to spray or not depends on how much fruit loss you are
willing to take. That is your threshold. If you can accept some fruit
loss, then the need to spray diminishes greatly. But if you only have a
few trees and some fruit damage may mean losing half your fruit, then
spraying becomes more important. Let’s meet our top four pests in
northern Illinois, southern Wisconsin, and in most of the states east of the Rocky Mountains.
The Four Main Pests
The Four Main Pests
The four main pests that we face in apple orchards here in our climate zone of 5/5A are apple scab, plum curculio, codling moth and apple maggot, in that order. For more information on these and other potential apple tree pests, visit our web site Growing Guide page. But how do we know when to spray for them if it is a last resort to protecting our fruit?
All
tree fruit have several distinct growth stages as the fruit matures.
Knowing and identifying those growth stages is very important for the
home grower because recommendations and spray timing for spray
applications are linked to these specific growth stages. The chart
below shows the common growth stages for apple trees.
Tree Growth Stages (Phenology)
Since
the average home grower does not have access to their own weather
stations or degree day calculators, the fruit tree development stages
play an ever greater role in pest management for the average grower.
Most spray schedules (protocol) follow the tree development stages to
aid in the timing of sprays so they are most effective. It is important
to note that many diseases and some insects can only be controlled by
spraying before they can be seen like apple scab. Spraying less
frequently or at the wrong time will typically result in poor results.
And, spraying more frequently will not necessarily give greater
control.
The tree developmental stages or tree
phenology gives us a guide as to when to spray, but what do we spray if
we have to spray? If we consult some of the various spray guides
available to the home grower, we will find that most of the spray guides
provide us with the tree’s development stages (phenology) and the
insects or diseases that frequently occur during each of theses
stages. So the tree phenology serves as timing guide when the
application of a particular spray is recommended in order to control
specific insects or diseases at the right time. The following spray
guide for apple trees will give us the time to spray based on tree
phenology, the pest to spray for and the product recommendation for that
pest(s).
Apple Spray Guide
This particular spray guide is included in “Managing Pests in Home Fruit Plantings” from the Purdue University Extensions Publication web site or our web site
as a free download. It goes into detail as to the various products
available for spraying that include both conventional and organic
alternatives. The publication includes apples, pears, peach, cherry,
grape, strawberry and raspberry guides as well as the phenology charts
for each fruit type. For recommendations on spray products for the Home Orchard visit our spray product recommendations.
Reference in this publication to any specific commercial product, process, or service, or the use
of any trade, firm, or corporation name is for general informational purposes only and does not
constitute an endorsement or certification of any kind by Royal Oak Farm.
People using spray products assume responsibility for their use
in accordance with current label directions of the manufacturer.
