Fruit Tree Maintenance


KPOV – The Point

Gardening: Get Good At It

Apple Dreams – Disease & Insects

June 23, 2015

If you’ve heard my first two gardening broadcasts here on The Point , you know I’m dedicating this year to growing an apple or two in my yard. In the past months w e’ve talked about selecting and planting the best varieties for Central Oregon and how to train my trees for the best crop.

Now I’m going to learn how to manage disease and insects. I’m going to combine a number of techniques. In addition to using pesticides, there are cultural and biological practices that can help me.

When I chose my trees, I considered the Central Oregon climate and soil. Some varieties are more resistant to disease than others, and even the best variety will have a poor fruit set and higher disease rate if the spring is too wet.

I’ll need to water and fertilize properly. Over-watering can lead to root rot, while overfertilizing can increase disease and insect problems. A soil test is a good first step.

Last month I described pruning to improve my crop. But proper pruning to open tree canopy will also improve air circulation and reduce the opportunity for some diseases.

Insects and disease hate good sanitation. If I remove and burn diseased branches and leaves, remove and destroy old fruit from the tree and the ground , I’ll be removing the protected home that insects love.

I’m studying OSU publications to know which pests are likely to attack my trees, and when they might appear. If I check my trees regularly, I can use Pheromones and sticky traps to alert me to infestations.

T he OSU publication “Managing Disease & Insects”, tells me that Codling Moth is in most of Oregon, so I’m going to plan a spray schedule for it. To avoid excess chemical residues, I ’ll check the pesticide labels for the necessary time between spraying and harvest. Those labels have so much information on them; they’ll be a huge part of my successful apple harvest.

Good pest management means good coverage - thoroughly wetting the leaves, twigs, and branches.

Both organic and synthetic formulations of pesticides are available. Since many are variations with the same active ingredie nt, I’m going to look for pesticides that can be

used on a wide range of fruits, vegetables, and ornamentals, so I can limit the number of pesticides I’ll need to purchase and store.

As a Master Gardener, I know to mix the pesticide at the recommended rate on the label, mixing only the volume needed to do the job. If I pay attention to the instructions, I won’t be putting excess pesticide into the environment. After I finish I’ll clean the sprayer immediately and dispose of the rinse water properly. My wonderful granddaughter shouldn’t be endangered by my sloppy housekeeping!

I plan to apply pesticides at the right time and under the right weather conditions and temperatures below 85

. Applying pesticides when it’s windy could cause drift of the chemicals off the target area. If I’m careful with my choice of pesticide and, especially, the time I spray, I won’t harm the beneficial insects that I need for pollination. Two summers ago a Willamette Valley spraying killed thousands of honeybees because they did it when the blooms were open and attracting the bees! By reading my pesticide labels I intend to avoid ever making that mistake.

So I’ve chosen the best apple trees for Central Oregon, started pruning for a good crop and designed a maintenance schedule for the heathiest harvest. Now, with a little sunshine and some busy honeybees, we should be eating some homegrown apples soon.

For more information on this or any other gardening topic, call the Master Gardeners at

541-548- 6088 or go to our website and click on the KPOV tab on the orange bar. This has been Gardening: Get Good at it on KPOV, The Point .


EC 631: Managing Diseases and Insects in Home Orchards