Bacterial Brown Spot? - Orchid Board

cgorchid · #1 09-01-2007, 04:03 PM

I think both my PEOY Paphs. has bacterial brown spot. The symptoms are: Rust color under the leaves, sunken tissue sopts on the tops of the leaves, and the leaves die at the tips. I only use distilled water so I dont think the tips are dying because of salts in the water. What can I do to help my plants? Will Physan 20 work?? Also what are the ideal conditions for PEOY??

Thanks
Christian

Intruder · #2 09-03-2007, 03:18 PM

Sprinkle the infected zone with a little cinnamon powder will control the situation. Physan 20 is used as a preventive treatment not a curative treatment.

Ross · #3 09-03-2007, 03:42 PM

Physan 20 is NOT effective for rot, only bacterial diseases and molds. Thiomyl is the proper systemic treatment for rot types including brown rot.

LizT · #4 09-03-2007, 03:51 PM

One of my problems this summer stemmed from using straight Distilled water. No nutrients. My filtered water isn't filtered enough.

I found spring water even cheaper than distilled so that's what I've been using. Personally my plants are doing better. One even started to stand straight up, it's leaves had been laying down. My plants are just beginning to come back.

Can't wait for them to start flowering again.

Shirley · #5 09-03-2007, 10:06 PM

Quote:

Originally Posted by Intruder

Sprinkle the infected zone with a little cinnamon powder will control the situation. Physan 20 is used as a preventive treatment not a curative treatment.

Thanks, Intruder. I didn't know that about Physan so will have to change some of my ways. Isn't using cinnamon rather expensive? Is it better than something like Captan?

pheli · #6 09-04-2007, 09:54 AM

Captan is a fungicide and it doesn't work well on bacterial infections.

cgorchid · #7 09-04-2007, 11:14 PM

Thank you everyone!!

Shirley · #8 09-04-2007, 11:29 PM

Pheli,
On the internet Thiomyl is listed as a systemic fungicide. I haven't tried it but if you consider it to be better than Captan I will try to locate some. I hope it's available in Canada. Thanks.

Shirley

pheli · #9 09-04-2007, 11:48 PM

Shirley,
As i know, only agricultural antibiotics and some copper compounds do well against bacterial infections.
Bacterial diseases, such as soft rots, are treated with these chemicals.

Without these chemicals, cut off the infectious leaves and apply 75 % alchhol on the wounds and then keep the plant dry. Don't water for 7-10 days.