Subject: SILVER BULLET!!!->Help for Fruit Growers!

From: Steve Diver <[email-masked]>
Date: Wed, 24 Feb 1999 12:03:33 +0000

Note:  I'm forwarding this post from Guy Ames, whose 
computer apparently won't "talk" to Sanet.  Guy, as many
of you know, operates a commercial apple orchard and 
nursery that specializes in disease-resistant fruit varieties, as 
well as works part-time as an IPM fruit specialist with ATTRA. 

Steve Diver 
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>From Guy Ames ([email-masked]): 

Yes, it has actually happened.  There REALLY does appear
to be a silver bullet that may allow organic apple production
to be a viable economic reality in ALL the U.S. (yes, eastern U.S. 
included).

The silver bullet is kaolin clay used as a "particle film" spray.  
Drs. Michael Glenn and Gary Puterka of the USDA, working with the 
Engelhard Corporation have developed this technology and proven it in 
trials in both the West and East.  It already has EPA registration 
as GRAS (generally recognized as safe).  The clay itself is the same 
clay used in kaopectate, toothpastes, china, etc., etc.  There is 
essentially no mammalian toxicity or any danger to the environment 
from this stuff (although you wouldn't want to breath clay dust day 
in and day out).

As many of you know, there are many impediments to organic apple 
growing, but none as serious as the plum curculio (PC) in the eastern U.S. 
Dr. Puterka is careful to say that his trials indicate "suppression" 
of PC damage rather than complete control.  But what he terms  "suppression" 
in these USDA trials is better than any other organic control that 
I'm aware of.  For instance, where PC damage was 20-30% in unsprayed 
checks, the treatments receiving the particle film sprays had only 
.5-1% damage.  (Dr. Puterka opined that where PC pressure is heavier 
[e.g., unsprayed trees in my orchard in NW Arkansas have often suffered up 
to 90 % PC damage], shortening the spray interval from 7-10 days to 
every 5 days might very well provide the necessary economic level of 
control.)

The particle film technology appears to provide adequate control of 
most if not all apple mite and insect pests, with the possible 
exception of wooly apple aphid.   It even controlled Japanese 
beetles!!!!

Regarding diseases, the trials indicate good control with the 
possible exception of apple scab.

>From "Particle Films," Agricultural Research, November 1998:

  "The product is prayed on as a liquid, which evaporates, leaving a 
  film on the plant or crop surface.  Coating plants completely with 
  the liquid is very important.  Since the particles are sprayed on 
  crops in a water-based slurry, the material sticks to plant leaves, 
  stems, and fruit, forming a white powdery film..."

It does not interfere with photosynthesis; in fact, sprayed trees 
performed better in all parameters.  It will probably even indirectly 
improve the soil over the long run.

Conventional spray equipment can be used.  However, many growers 
will want to add a scrubber/washer to their post harvest equipment to 
remove any clay dust residue (although this residue is not 
considered harmful, it might be considered unsightly by many 
consumers).  In some areas, rainfall will be enough to "weather-off" 
the material.

Dr. Puterka is cautious in making claims about this product.  But as a 
grower and researcher that has been investigating organic apple 
production for 19 years, I have never been more excited.  

Puterka expresses some concern over adoption of this technology.  He 
says that the frequency of sprays (7-10 days in high rainfall areas) 
and the volume of material necessary (many lbs. per 100 gal. water) 
will deter adoption by some.  And, again, he resists making sweeping 
claims about this new technology.  Neverthless, for organic growers 
especially, this promises to revolutionize apple growing.  At worst 
we will have a new material better than anything we've had previously 
for organic control of the plum curculio and other insect and mite 
pests.  At best, we will have ONE material, that in combination with 
other sound horticultural practices (cultivar choice, pruning, weed 
control, etc., etc.), will finally allow us to economically produce 
organic apples in the East.

It appears that this material will ONLY be available this year in 
Washington and Oregon, but probably everywhere in 2000.
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