Advancing Organic Orcharding Through the Use of Kaolin Clay

When Dale Rhoads of Rhodes Farms learned that a kaolin clay product named Surround might help control diseases and insects in organic orchards, he was eager to try it. The Rhoads have a 10 acre certified organic farm. The land is steeply sloped, heavily wooded, and has poor soil. The Rhoads farm approximately 4 acres. They have 100 fruit trees for home consumption and 100 Asian pear trees for off-farm sales. Their main crop is lettuces and salad greens. Dale Rhoads described the operation saying, "We have pioneered summertime salad growing strategies and make use of innovative early spring and late fall growing technologies. We direct market to restaurants and a food co-op. We have a strong youth apprenticeship program where we work with at risk youths and gather considerable local attention."

Concerning the kaolin clay project, Rhoads says that until the development of this product, there was no organic device or strategy to control plum cucurlio, one of the most destructive insects affecting fruit crops in the Midwest. In addition to experimenting with kaolin clay to control plum cucurlio, Rhoads wanted to test the product for disease control on stone fruits and for control of stinkbug on Asian pears. Funds for Rhoads's trial were provided by an NCR-SARE Farmer Rancher grant and the spray materials were donated by Garden Alive! (www.gardensalive.com).

Drs. Michael Glen and Gary Puterka of the USDA/ARS at Kearneysville, WV developed Surround in cooperation with the Engelhard Corporation. The kaolin clay product was sold on a limited basis starting in 1999 and became widely available in the U.S. in 2000. (For additional information on Surround and kaolin clay, see "Insect IPM in Apples - Kaolin Clay", Reduced-Risk Pest Control Factsheet published by Appropriate Technology Transfer for Rural Areas (ATTRA)at: http://attra.ncat.org/)

Initially, the experiment involved spraying Surround on a variety of fruit trees, including: apple, pear, Asian pear, cherry, peach, and plum. A minimum of 5 trees of each species was used in the experiment, with a total of about 150 trees for the entire trial.

Rhoads wanted to reach a number of different audiences with his project results, including orchardists, local consumers, retail pesticide outlets, and orchard supply salesmen. He created a booklet summarizing the results of his project to help him distribute the results, and part of the booklet text appears here.

Advancing Organic Orcharding through the use of Kaolin Clay

A Report on the Successful Organic Orcharding Trials Conducted at Rhoads Farm, Nashville, Indiana during 2001-2003

Until Drs. M. Glenn and G. Puterka of the USDA, along with Engelhard Corporation developed a kaolin clay product, Surround, the lack of organic control of the insect, plum cucurlio, and to a lesser degree other pests and diseases, made organic orcharding east of the Mississippi River next to impossible. Funds for these trials were provided by SARE with spray materials donated by Gardens Alive. Below is the Gardens Alive spray program used in these trials.

The Perfect-Fruit Pest Managment System

A low spray program with 50 - 70% relatively damage-free fruit in southern Indiana for Apples, Pears, Cherry*, Peach*, Plum* and Nectarine*

1st Pre-Bloom Application is to be made when buds show green. Mix 5 oz. of Oil-Away per ga/water, wet entire tree to kill insect eggs when temperature is above 40.

2nd Pre-Bloom Application is to be made some 4 - 6 days later by mixing Soap-Shield @ 2 oz/ga for disease prevention. Thoroughly wet tree when temperature is above 40.

3rd Pre-Bloom application is when blooms first show pink color. Soap-Shield @ 2 oz./ga, Pyola @ 2 oz/ga and Surround-at-Home @ 1/2 lb/ga on a 50 degree sunny day.

Optional Bloom Spray Applications. If fire blight disease has been a problem, apply at 3-4 day intervals or within 24 hours of hail damage. To enhance fruit spur leaf size and subsequent flower/fruit quality, you should add Sea-Rich @ 4 tbls/ga.

1st Post-Bloom Application should be made when 90 percent (plus) of the flower petals have fallen. Mix Soap-Shield @ 2 oz/ga, Pyola @ 2 oz/ga and Surround-at-Home @ 1/2 lb/ga.

Fruit Thinning. At this time, it is higly recommended that excess fruitlets be removed.

2nd Post-Bloom Application should be made some 10-14 days later with same ingredients as described in 1st Post-Bloom Application above, except add Serenade @ 1/2 cup per gallon. Make application as late in the day as possible.

3rd and additional* Post-Bloom Application(s) should be made at 12-14 day intervals. Mix Surround-at-Home @ 1/2 lb/ga and Liquid Sulfur @ 4 oz/ga, and Serenade @ 1/2 cup per gallon, wetting the entire tree.

*Peach/Nectarine, Cherry and Plum Program.
Use same as above except do not use Soap-Shield or Pyola. Beginning with the 2nd Pre-Bloom application, use Surround @ 1/2 lb/gallon with Liquid Sulfur @ 4 oz/ga and Serenade @ 1/2 cup/ga. Also, fireblight does not affect these fruit types.

(KEY: Garden's Alive Trademark Name = typical orchard product:
Oil-Away = an orchard insecticidal soap,
Soap-Shield = copper fungicide,
Surround-at-Home = Surround,
Pyola = pyrethrum and oil insecticide,
Fire Blight Spray = the antibiotic, streptomycin [Bordeaux mix or copper formulations also control fireblight],
Sea-Rich = fish and seaweed liquid foliar ferilizer,
Liquid Sulfur = sulfur,
Serenade = Serenade, a fungicide.)

For the full Trials Report or More Information contact:
SARE Program at www.sare.org/ncrsare or
Dale Rhoads, 339 Mt. Liberty Rd, Nashville, IN 47448 or drhoads6@sbcglobal.net

Supply Sources
Gardens Alive (smaller orders) www.gardensalive.com. Larger orders at United Agricultural Products, John Phillips, 317-831-2559 or pager # 888-474-6470

Fruit Insect Pests

Plum cuculio (PC) overwinters in the bark of oak trees. During one warm spring day, almost 100 percent of the small recently pollinated fruitlets on a tree can experience PC damage. Damage can be seen as a distinctive crescent shaped cut or scar. Each fruit will have eggs deposited in that scar that will hatch into "worms" that will eat and rot the fruit before it matures. At Rhoads Farm, PC infected 100 percent of even the very first fruiting. After several years of organic fruit growing failure, the Rhoads, like many organic hopefuls, began using a PC specific non-organic synthetic pesticide. Then Surround became available. In the three growing seasons of these trials (2001-2003), Surround has controlled PC damage to 75 percent (plus) insect free fruits.

The other serious fruit pests that affect the fruit are apple maggot, coddling moth and oriental fruit moth. The Rhoads Farm has to date experienced little pressure from apple maggot and only moderate populations of coddling moth and oriental fruit moth. For control of both of these pests, breeding inhibitors have been developed that trap the male, hence there is no fertilization of the females to then lay eggs in immature fruitlets. It is the Rhoads experience that Surround does control oriental fruit moth in some years on peaches. There is some debate as to how well Surround works on apple maggot and coddling moth control, with some testers saying good control and others stating little to no control.

Overview of method and results of years 2000-2003
2000- Synthetic pesticides and fungicides with good harvest.
2001- Surround only with good control of PC but excessive disease problems.
2002- Surround with organic fungicides, 60 percent control of PC and good harvest.
2003- Surround with organic fungicides with 90 percent PC contol and good harvest.

Spray Programs
Ed Fackler, the owner of the former orchard and nursery, Rocky Meadow, is reserach director at Gardens Alive, one of the largest mail order retailers of organic products. Gardens Alive donated many of the materials used in these trials. From Ed's many years experience with attempts at organic orcharding and as one of the pioneers of Integrated Pest Management (IPM) techniques, he has developed a spray program for Garden's Alive. That program was listed on the inside front cover (of this booklet). A more detailed version of that program is available on their website.

In our experimenting at Rhoads Farm with this spray program, several modifications were made. I want to list these here. Keep in mind that except for Asian pears, we sell no fruit. Also, in this section, I want to list a few observations.

For Asian pears, we have used fungicides only in the first four cover sprays. After this, we continued to use Surround for the control of stink bug. Stink bug control with synthetic chemicals is extremely toxic, hence, Surround is an excellent product for Asian pears. In one year that had regular high temperatures, stink bug pressure continued up to harvest. In 2003, we visually noticed a low stink bug population and ceased spraying Surround in August with no further stings on the fruits. Asian pears were almost entirely clean of the white clay by harvest time. Test trees receiving no fungicide sprays at all had similar quality as trees receiving a more extensive spray program.

We do not use the fungicide copper formulation (Soap Shield) suggested by Garden's Alive. One reason is that unless you have excellent agitation in your sprayer (which is only available on large commercial orchard sprayers), the oil, copper and clay will not mix properly, hence gumming up the sprayer. Dry copper mixes (that do not have the oil in them) may not experience this problem. Also, copper is mostly for the control of apple scab that does not appear or is lessened on disease-resistant apple trees.

With European pears, we have experienced good pest control using only the first four cover sprays of Surround only with no fungicide. This may not be possible with all varieties. While there was some surface (fungal) discoloration, all fruit was suitable for home consumption. In wet late summers, it may be advisable to use some fungicides to keep surface discolorations to a minimum.

Of the three years we have used Surround on peaches, two of those years had good control of PC and oriental fruit moth. In 2002, control was only about 50 percent unaffected fruits due to heavey rains delaying spraying. Due to continued spraying of Surround and use of a sticker for the Surround, peaches would not scrub clean. Gardens Alive representatives inform me that the manufacturer of Surround, Engelhard, now includes a sticking agent in Surround that will wash off easier. At the time of our testing, we were inadvertently using Surround that contained a sticking agent and adding additional sticking agent. It could be that in subsequent years, the clay Surround will wash off peaches.

A couple of other spray related points are that the more pressure the sprayer puts out, the finer the spray particle, hence the more complete is the coverage with Surround. And the more thorough is the tree pruning, the more efficient is the spray penetration and coverage. If you think about Surround as being paint, and your job is to as completely as possible paint the fruitlets, this will help. Also, we could not get Surround to adhere well to nectarines in the year we had them. They had 100 percent PC caused fruit loss. It is also interesting to note that with good Surround coverage, it was not necessary to net cherries to keep birds off and deer do not browse on trees with Surround on them!

This program is a bare bones basic program that works in central and southern Indiana. In other geographical areas, other materials may be necessary for good organic production.

Conclusion
Until 2000, organic production of fruit west of the Mississippi River was next to impossible due to the insect, plum cucurlio, several other insects and disease problems. With the advent of Surround, and to a lesser degree, the fungicide Serenade, well informed organic production is not only a possibility, but is being done in some locations. The market potential for the first growers into the market is high. Any grower trying organics is of course advised to start small with careful trials.

Careful selection of fruit types and varieties is highly advisable. Trees that have disease resistance are desirable. Trees that ripen fruit early suffer less disease pressures. Pears and Asian pears suffer from less insect and disease problems.

Orchard supply costs appear to be from similar to twice as expensive as conventional spray materials, depending on the complexity of the program used, but local organic fruit prices are 2 to 4 times higher than conventional fruit.

Markets demand for organic products often go hand-in-hand with demand for local produce. Until now, supplying that local demand has been difficult, hence there is a wide open market.

Basic Tree Care - Do or Die

Because of our early experiences with growing fruit trees, and our experiences selling fruit trees to others interested in organic production, it is necessary for me to include some basic information about care of fruit trees. Stinting on any of these basic will lead to frustrating results, especially in organic production. Repeat, stinting on any of these basics can lead to frustrating results. Fruit production can be the most demanding of all gardening projects. Organic production is a step harder than conventional production.
1. Fruit trees have to receive at least 8 hours of sunlight per day to have good fruit.
2. For organic production, good pruning and training practices should be learned.
3. Orchard cleanliness promotes disease free trees.
4. Trees have to receive sufficient water and fertilization.