Re: CULT: Leaf Spot-Boron Deficiency?


Mike Lowe wrote:

>In the apocrypha of iris literature there is a strong belief, (myth?) that
>iris grown in urban areas where coal smoke is at high levels are usually
>completely free of leaf spot. (could they be referencing 'auld reeky'?)
>
>My chemistry is not up to the task of enumerating the principal elements of
>coal soot, but I do know that boron is a constituent. Boron is unique in
>that it is required for growth in almost all plants but concentrations only
>slightly higher than required for normal growth are injurious.
>
I don't know specifically about coal smoke, but general industrial air
pollution has historically been high in sulfur. If leaf spot is caused by a
fungus, this will definitely cut down on its occurrence.

Kay Cangemi
cangemi@ulster.net
New York, USDA zone 5




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