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This is a response from Jan McCaman about
the powdery mildew. Thanks Jay!!
From: Jay McCaman
[mailto:[log in to unmask]]
Sent: Thursday, March 01, 2007
11:23 AM
To: Vicki Morrone
Subject: Re: What do youknow about
Powdery mildew??
From Acres U.S.A. (Mar 84, p6) nitrogen applied at the wrong
time can increase it.
From The New Farm (Feb 95, p 42) 1% Neem oil in water can
reduce it.
From Acres U.S.A. (Oct 81, p 24) soil problems may
include; low calcium, high magnesium, low boron, and very low copper. This can
be influenced by the nitrogen mentioned above.
It is my opinion that nutritional conditions are the root of
disease pressures. Tissue testing could help. I have wondered about the tissue
test standards. Are they based on averages and what will produce good yields or
are the based on plants that are immune to insects and diseases.
At the organic conference Saturday I plan to present data
from an organic consultant that show the connection between sap pH, brix, and
aphid pressure on beans.
Jay