RE: [CH] watering question
Mary & Riley (uGuys@ChileGarden.com)
Mon, 12 Jun 2000 12:49:23 -0700
> -----Original Message-----
> From: owner-chile-heads@globalgarden.com
> [mailto:owner-chile-heads@globalgarden.com]On Behalf Of Mild to Wild
> Pepper & Herb Co
> Sent: Sunday, June 11, 2000 7:40 PM
> To: Steve Nearman
> Cc: chile-heads@globalgarden.com
> Subject: Re: [CH] watering question
>
>
> Got to agree with Steve on this one.
>
> Even as a child I wondered about the 'don't water during the day'
> thing. I, too, noted that it would storm & then the sun would shine.
> When the chiles need water, they get watered- simple as that!
I've never noticed any burning from watering in hot sun, although it just
occurred to me that a wet leaf might have _less_ effective wet surface area
to evaporate and hence cool itself than a dry leaf. A dry leaf cools via
the pores through which it transpires. And the effective surface area of
these pores is much larger that the surface area of the leaf, iirc botany
101. It could cook after the watering stops and before the water evaporates
from the leaf. A wet leaf would be hotter, in this case. Probably hotter
to the touch. The leaf would 'stew' while wet. I'm not going to experiment
on my chiles, but I might try one of Mary's tomatoes--it's a bit warm in
SoCal today! ;-) Possibility, maybe, but I've never really noticed it.
What I intended to say is the tale goes that 'burning' is caused by water
droplets acting as a lens in the sun and burning the leaf. If you recall
using a lens in the form of a magnifying glass, one must hold the lens a
significant distance from the heated surface, focusing the light. This is
the focal length. Putting your hand or another object at the surface of the
lens doesn't heat it up very much.
My point is to burn via this mechanism the focus has to be very close to the
surface of the leaf. This is possible with small lenses. However, the
droplet shares a surface with the leaf. So the focal point of the lens
(droplet) has to be on or close to the surface of the lens. In a random
distribution of drop sizes, while this may be possible, it would be very
unlikely. The focal length of a hemispherical lens is something I can't
find quickly. Anyone have it handy? But see:
http://www.britannica.com/bcom/eb/article/single_image/0,5716,12513+asmbly%5
Fid,00.html
However, to do significant damage it would seem that the average
distribution of the focal point would have to be on the surface of he
leaf/droplet common surface. Seems to me very unlikely.
But the droplet could heat up and, as above, stew it.
I gotta get back to work!
Riley