"Franz Heymann" wrote in message
...

"Jim W" wrote in message
news:1g3g6gz.vesamxyagc56N%00senetnospamtodayta@ma cunlimited.net...
Franz Heymann wrote:

Mist propagation was mentioned in another thread quite recently. That
triggered me into asking something I have always wanted to know:

What does mist propagation do which cannot be done by inverting a
transparent container over the cutting?
I have always thought that the purpose of either action is simply to
maintain an atmosphere which is as nearly as possible fully saturated
with
water vapour in order to minimise evaporation from the surfaces of the
leaves.


It's automated, air circulation is better , thus you have a more bouyant
atmostphere (which in turn 'should' reduce fungal risk to some degree).

What does "bouyant atmosphere" mean?
Why should it reduce the risk of fungi? If the fungus spores are there,
they will be there, whether the atmosphere is bouyant or not, whatever
bouyant might mean.

Franz


I've read that by slightly over-misting, the water runoff from the leaves
removes fungal spores.
Over-misting is achieved either by a timer which runs after the "electronic
leaf" has indicated saturation or by moving the sensor to the extreme of the
mist distance so that it is saturated last. The timer method is preferred as
being more consistent.

Since the aim is to have near-continuous 100% humidity a "buoyant
atmosphere" seems unlikely. The action of the misting nozzles will, however,
stir up the air a bit.
The water to the mister nozzle(s) will normally be considerably cooler than
the air temperature and so will cool the plants whilst the mister is
actually operating. Covered/closed systems controlled only by an electronic
leaf may experience severe temperature cycling.

None of the above is from my own practical experience. I was considering
making a mister but got drawn into rebuilding the kitchen since when the
garden has gone to rack and ruin. Got a bumper crop of Cape Gooseberries
though - they seemed to thrive on lack of attention!.

HTH

Mike