Actually, the 1 tsp/gal is intended as the treatment dose for killing algae.
For regular use - and even in a case like yours - I'd follow the
manufacturer's directions:
SEEDLINGS
From flask: soak seedlings 2-5 minutes before potting to remove agar. Soak
compost with PHYSAN 20 solution. Helps eliminate damp-off. Keep hands and
tools damp with PHYSAN 20 solution. Damp-off: Spray seedlings once per month
as preventative maintenance. Spray anytime disease is evident.
Use: 1-1/2 tsp. PHYSAN 20 per gallon of water.
ORCHIDS - ADULT PLANTS*
Spray anytime disease other than rot (see below) is evident. Spray once per
month as preventative maintenance. Soak compost when fungus is evident.
Use: 2 teaspoons PHYSAN 20 per gallon of water.
ORCHIDS - DIVIDING PLANTS
Remove compost from plant, then soak plant for 2-5 minutes in PHYSAN 20
solution. Operate with wet hands and cutting tools. After division and root
trim, soak divisions in PHYSAN 20 solution for 2-5 minutes. Pot in compost
dampened with PHYSAN 20 solution.
USE: 1 Tablespoon PHYSAN 20 per gallon of water.
ALGAE
Greenhouse Glass: Spray or swab surfaces with PHYSAN 20 solution. Let stand
for one hour or more or until the algae visibly begins to change to a
lighter color. Wash off dead algae with water. Spray clean surfaces again
with PHYSAN 20 solution.
Use: 1 teaspoon PHYSAN per gallon of water.
Walkways: For heavy algae infestation, spray or swab with PHYSAN 20
solution. Let stand for an hour or more. Brush and wash away the dead algae.
Soak area again with PHYSAN 20 solution. Do not rinse. This product will
inhibit the growth of algae on walkways. Allow to dry on surface, and repeat
application if algae growth returns.
Use: 1 Tablespoon PHYSAN per gallon of water.
ORCHIDS - BOTRYTIS*
During cool damp weather, spray plants, flowers and under benches at first
sign of the spotting on flowers. Normally weekly spray will greatly reduce
or eliminate the botrytis spotting.
Use: 1 teaspoon PHYSAN 20 per 3 gallons of water.
CUT FLOWERS
For containers, tubes and decorative vases. Recommend flower spikes be
hardened in PHYSAN 20 treated water during harvesting, storage and shipping.
USE: 1 teaspoon PHYSAN per 2 gallons of water.
ORCHID - ROT (such as Erwinia)*
Remove compost from plant, then soak entire plant 10 minutes or more. Cut
away all rot with treated tool. Soak plant wounds again for 10 minutes.
Repot in PHYSAN 20 soaked compost.
USE: 1 Tablespoon PHYSAN 20 per gallon of water.
ORCHIDS - CROWN ROT (Phalaenopsis)*
Spray plants weekly to assure solution getting around and in base of leaves.
USE: 1 teaspoon PHYSAN 20 per gallon of water.
--
Ray Barkalow - First Rays Orchids -
www.firstrays.com
Plants, Supplies. Books, Artwork, and lots of Free Info!
"Gene Schurg" wrote in message
...
I am a bad bad gardener.
My phals look like the teenage kid working at the local greasy spoon
restaurant. They have plant acne.
Actually, I noticed that the phals (and the dendrochilum) had been hit
with something that caused pitted spots on the tops of the leaves. Some
of the plants have interesting designs where the leaves were infected.
I believe it to be contact related because a few leaves that were turned
upside down had the problem on the bottom surface of the leaf.
The Cattleyas, Oncids, Cymbos, and other stuff seem to be unaffected.
This crud really likes those nice succulent Phal leaves.
My suspected sources a
The swamp cooler that I did not change the pads like I should and
something bloomed on those nice moist aspen wood pads then got sucked
into the greenhouse. I promise to keep a closer eye on the swamp cooler
from now one. I promise (unless of course I get busy with something
else and put it off until another day like I normally do).
Another possibility is that when I cleaned the greenhouse with the
pressure washer something that normally would be on the concrete floor
got into the air and settled on the leaves. The floor of a greenhouse
is one of the dirtiest places on earth.
The third suspect was the bucket I use to mix fertilizer for the
Dosamatic. I may (ok I used to take shortcuts) not have cleaned it up
very well before I used it between waterings and something was growing
in the cesspool of old fertilizer.
So, here is my question. I want to start a regular spraying of Physan,
specially on the phals. I see where Ray recommends 1 tsp to a gallon
for plant contact.
How often can I apply Physan to the plant leaves at this rate?
What would I see if I am applying it too often? (Leaves burning, flowers
deformed, etc.)
Any other ideas of what I should do to prevent this crud from returning?
I am fanatical about cleaning up the dropped flowers and dead leaves in
my greenhouse. I keep the humidity very high in the winter and as a
result I get algae and moss growing under the benches and on the glass.
I clean it up periodically but it does return.
Thanks,
Gene