on 7/22/04 6:39 PM, aaron wrote: > Not to get completely off the subject, but although I've wondered the same > thing myself, I wonder more about the ability of UV light (from sunlight) to > reduce the concentration of pathogens and spores on plants in the wild. > > One would think that in culture, many plants are grown under glass or > polycarbonate (I don't think polyethylene blocks much UV, but I'd have to > check), which remove much of the UV intrinsically present in sunlight. I would > suspect, but have no evidence, that this difference may allow concentrations > of pathogenic spores to be higher in cultivation than in the wild.
ah, but you're forgetting that underneath every leaf is a microclimate that is devoid of UV... but yes if under hard poly no UV gets through, then there would likely be more spores than in nature, especially if you have a somewhat windless, stale climate with plants packed too closely together, and water from below the root zone or with drippers that go directly into the pot, you can have botrytis and tons of other spores that hang out under the canopy and don't get washed off or blown away charles -- Charles Ufford Calen the Border Collie CGC - now in Heaven Oriskany, NY USA IPA, Central NY and Southern Tier Orchid Societies [EMAIL PROTECTED] http://www.paphiopedilum.net Http://www.geocities.com/charlesufford
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