Holistic Orchard Research

Insect Dynamics

Realizing that over five hundred species of insects have been identified in fruit orchards presents an immediate challenge to our understanding. Beneficial insects help with some aspects of fruit production, but admittedly, the perplexity of curculio and fruit moths often lie beyond the control of natural predators alone.

Gentler spray options in these last 20 years have opened the door on our ability to "negotiate" a harvest balance with bugs. Orchard architecture also plays an increasing important role in integrated orchard planning: Block shape, choice of variety and tree size on borders, trap tree placement, and surrounding habitat influence insect dynamics to varying degrees.

The Art of Insect Balance

This crab spider disguises herself with
blossom coloration to nab many a'critter.
Photo by Peter J. DeVries

Beneficial Allies

The "good guys" in the orchard ecosystem are generally dismissed as not providing a complete solution. Well now. Several "partial solutions" at 20% effectiveness might just be diversity's way of doing the math! Report here on methods to encourage beneficial habitat and pest predation in general.

European Apple Sawfly

This somewhat recent immigrant to America's shores is making headway into orchards across the land. What are you doing about it?

Female EAS oviposit into the
blossom stem. Photo courtesy of
NY Agricultural
Experiment Station

• Early applications of Surround kaolin clay -- made within a couple days of the king blossoms first opening -- have a 50 to 70% impact on sawfly larva seeking out subsequent fruitlets, according to Gary Puterka of the Appalachian Fruit Research Station.
• Brian Caldwell in New York reports that an application of Entrust just as first instar damage is observed on fruitlets is very effective against EAS.

Plum Curculio

Long-called our Achilles' heel, the plum curculio now has to face our tactical array of Surround kaolin clay, garlic-neem synergy, and promising "curc understory management" techniques.

• Dan Kelly in Missouri notes a tangible suppression of the curculio population in his ecosystem through a well-timed "prairie burn" of the wildflower border surrounding his five acre orchard.
• A repellent strategy on protected varieties can be used to "funnel" this pest to selected trap trees. Border row trees are good candidates as our lush foliage varieties like Chestnut Crab, Liberty, and Japanese hybrid plums. Trap trees can then by sprayed with PyGanic on back-to-back warm evenings without harming beneficials throughout the rest of the orchard, thus closing the curculio window for the season.

The Lepidoptera Complex

So many bloody species of moths make it a challenge to stay on top of a rotation of management approaches that often require variable timing. Great research has been done on the University level. . . now it's time for community orchardists to report about reality in your particular locale.

• Harry Hoch in Minnesota monitors his 30 acre orchard as a dozen zones. Pheromone wing traps for Codling Moth track adult flight in each section of the orchard. A threshold of 5 moths reveals a need to act: 200 degree days later one application of granulosis virus (sometimes a second, if trap numbers are especially high) are applied at low dose to necessary blocks. This saves the expense of orchard-wide applications.
• Granulosis virus is more than species specific, according to Greg Krawczyk at Penn State. His trials have revealed a 60% mortality for Oriental Fruit Moth along with the 96% mortality expected for Codling Moth.
• Mating disruption is now seen as emitting "pinpoint confusion" for male moths rather than working as a single contiguous cloud of pheromone. The upshot? Orchard blocks as small as one acre may very well find success with this twist tie strategy.
• Michael Phillips in New Hampshire has seen two summers in a row now with no sign of second generation Codling Moth or Lesser Appleworm in his trees. Moth presence is quite evident in nearby wild trees. Pure neem oil sprayed on a 10-14 day schedule from first cover on does multiple jobs, including summer moths.

Apple Maggot Fly

The notorious "railroad worm" -- once the fly larvae infest the apple -- is best controlled by perimeter trapping and picking up all pre-harvest drops every few days. Organic spray options for AMF include Entrust (overlapping moth sprays will do some good here), pure neem oil, and Naturalis used as a soil drench under "trap trees" where AMF pupates in the soil to emerge the following year.

• Many have suggested a homemade version of the sticky red sphere trap employed for AMF. We like the idea of a Red Delicious apple, coated with Tangletrap, in which sticky yellow cards have been sliced into the sides to increase the visual allure. Now honestly. . . can you think of a better purpose for an insipid supermarket apple than that?
• The Entrust-laden traps continue to be researched at orchards throughout the East by Starker Wright of the Appalachian Fruit Research Station. These red sphere traps work without sticky, having a cleverly-designed starch matrix up top that dribbles organic spinosad down the sides of the trap. A manufacturer is needed to make these available commercially!

Every fruit grower has worthy contributions to make to these pages. . . so please contact Michael Phillips about your own orcharding research experiences, novel ideas, and success stories.

Holistic Orchard Research

• Soil Health
• Resisting Disease
• Insect Dynamics
• Balanced Orchard Nutrition
• Biodynamic Fruit
• Varietal Notes
• Rootstock Realities
• Thinking Links for Holistic Orchard Research