The Kaolin Clay Strategy for Orchards

Surround: A Corporate Product

The Engelhard people use a super-magnetic centrifuge in Georgia to refine the impurities out of raw kaolin and then filter the clay particles to a critical 1.4 microns in size. For more information about Surround:

Engelhard Corporation
Surround Crop Protectants
101 Wood Avenue
Iselin, NJ 08830
engelhard.com/surround
1-877-240-0421

The Petal Fall Complex (Timing)

Orchardists in the East face three devastating pests at about the time the blossom petals begin to fall from the trees en masse. European Apple Sawfly begins laying its eggs while pollinating the white apple flowers: The successive instar stages of its young wipe out 3 to 4 fruitlets per larvae. Plum curculio (long called the Achille's heel of organic orcharding) waits for warm evenings when females begin laying 4 to 5 eggs per day and both males and females make feeding stings. Codling moth egg hatch begins about ten days after petal fall, completing this triad of potential devastation. Full coverage of Surround needs to be built up at initial petal fall for best results with all three insects.

Three Coat Effectiveness

Surround serves in one of two ways as an insect repellant. Just imagine your eye and ear openings filled with irritating clay particles, and your reproductive parts literally clogged . . . surely you'd want to boogie from such a place! This is the experience of insects like curculio that crawl about the twigs and leaf surface seeking fruitlets. Flying insects don't get quite the same experience, flitting about to lay an egg here and there. Upon landing on a kaolin-coated tree, the codling moth female senses a wrong environment and continues on.

This next point cannot be over emphasized: Surround proves effective only once 3 uniform applications have been made. There's enough clay at this point to actually stop the early instar stages of sawfly larvae from going much beyond the winding scar trail of its first apple. One coat of clay is simply not enough coverage to actually deter the insect's normal inclinations. Make back-to-back applications to get to this launching point of successful orcharding. Coverage then needs to be maintained weekly for approximately four weeks. Heavy rain may necessitate additional applications.

Spray Rates

Label instructions recommend a rate of 25# of Surround per acre per application. Whether you mix this in 50 gallons of water or a 100 gallons of water is determined by sprayer type and the size of the trees on your acre. Coverage needs to be applied to the point of runoff and allowed to dry. A sticker-spreader isn't necessary, and in fact, experiments with vegetable oils to improve kaolin's holding power have decreased efficacy. The coverage provided by a hand-held wand spray rig is often superior to an air-blast sprayer simply because you take more time per tree to achieve a full coat. Home orchardists with a backpack sprayer can figure on using 1/2# per gallon of water (note that a diaphragm-type pump will last longer with a wettable powder like Surround), gauging the coverage more by point of run-off than by a hypothetical amount per acre. Surround stirs best into the water as opposed to pouring water into the dry powder.

Enhanced Photosynthesis

Lessening of sunburn, increased fruit size and better color, and even improved return bloom are among the claims made for Surround. But all these benefits aren't necessarily going to come about in northern zones with shorter growing seasons.

Drawbacks

Prolonged kaolin coverage is harsh on mite predators. Overdo this spray strategy and you'll likely induce a red mite flare-up, which will necessitate returning to using dormant oil sprays prior to quarter-inch green. Don't be tempted to continue kaolin coverage for second-generation moths and apple maggot fly! This petal fall tool falls out of balance as regards beneficials if coverage is maintained too long. Plus then the problem of residues at harvest time is a major, major headache.

Trap Tree Rationale

Some orchardists have observed that curculio seems to wait out the coverage. That four weeks should perhaps be six or more weeks of coverage. The problem arises when we ponder the options for curculio. A complete whiteout of their environment leaves little choice but to wait for improved opportunity. Surround repels; it doesn't kill. A wise orchardist will select a trap tree or two, or leave some unsprayed wild trees in the proximity. We truly need to learn that there's a place for all species on this good earth if we want to reach that next plateau of sound thinking. Which doesn't mean plummeting curc larvae can't be met by a waiting chicken flock pecking away down on the ground!

Sources

Gardens Alive sells 5# quantities of Surround labeled for home use at about three times the going trade price. Be smart with your money and get the 25# bag: kaolin keeps for years, so even if you have only a tree or two to protect, you're supplied for several seasons. Seven Springs Farm in Virginia has the best mail order price going: See 7springsfarm.com. Northeastern growers should check with Organic Grower Supplies in Maine: all the FEDCO cooperatives offers substantial discounts based on order volume. United Ag Products also distributes Surround in its regional warehouses serving commercial orchard areas.

Organic Orcharding Articles

• An Intelligent Paradigm
• My Apple Orchard by Laura Ingalls Wilder
• Honoring the Orchard Ecosystem
• Holistic Core Values 
• Holistic Disease Management
• The Kaolin Clay Strategy
• The Lepidoptera Complex
• Borer Insights
• Seasonal Checklist for the Home Orchardist
• Apple Grower Network Research Pages