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Apple orchards with reduced crop

It's been a tough spring, and the weekend of April 28-29 brought cold temperatures that caused extensive bud damage, in addition to previous cold events. It will be difficult to tell if any crop will set until fruit set in the middle to late May, possibly June in later districts. Until then, here are some thoughts to consider:

• Apple scab infections need to be prevented until the end of primary scab season. Maintain protection on new growth to reduce overwintering inoculum and keep trees in good health for next year. Verify there are no scab lesions before reducing your fungicide program.
• Powdery mildew can cause extensive damage to susceptible varieties like Gala, Honeycrisp, Jonagold, Idared, Cortland, Paulared, etc. Choose fungicides that will control scab as well as powdery mildew, and continue until terminal bud set.
• Fire blight is a big risk as the weather changes to hot and humid. Run MaryBlyt or CougarBlight, and apply streptomycin when risk is high. Watch for rattail bloom, and keep those blossoms protected. Apogee, when used the higher rates, starting at king bloom petal fall, helps in reducing fire blight damage.
• Direct insects like plum curculio, Oriental fruit moth, Oblique-banded leaf roller and codling moth, if left uncontrolled, might become resident in the orchard, and difficult to manage next year. Monitor for sustained moth catch and follow recommendations on pages 48, 50 and 59 of Pub. 360. One or perhaps two insecticides may be required if mating disruption has not been applied.
• Indirect pests like European red mite can be controlled by predators if insecticides are reduced. Monitor for both European red mite and beneficial insects to decide, but don't let populations explode. Trees can tolerate a higher mite population under low crop load. If oil was applied before egg hatch, season-long control may result.
• Young trees should be monitored for leafhoppers, aphids, apple leaf curling midge and Oriental fruit moth (which can deform trees), Remove fire blight strikes at least weekly.
• Apogee could be very useful this year to control the tree's growth if crop is reduced. First application should go on now when new shoots are 1-2" (2-5 mm) long, and repeat applications every 2 weeks, until 2 weeks before terminal bud set. In this early season, you will likely need to apply one more Apogee spray that usual. Apogee, when used at the higher rates will help reduce shoot blight infections, and make terminals less attractive to OBLR. At the very least, try some Apogee on high value blocks to learn more about how to use it in a low crop year.
• With the reduced crop load, vegetative growth may be excessive. Summer pruning will be required to check this growth. This cultural practice will open up the canopy for good air circulation for disease management and allow spray penetration into the tree.

In areas where only partial crop loss has occurred, and some fruit will be salvageable through spot picking, a regular pest management program should be maintained