Desease in Phals

[Cynthia, Prescott, AZ]

Hi all. I tried posting this to the OGD forum, which is email based, and I think it is too long for their system, and got bounced twice. So, I am going to put it here and send them the link. I am sure many of you will be interested in the subject matter, and I will be interested in your responses:

Looking at the pictures on Steve's site,
http://www.geocities.com/tlswilso/Phal_problems_2-15-04.html ,
they are very familiar. A couple of years ago +, I had only three Phals and all were having a problem. After having eliminated the cold water and a few other possibilities, problems persisted. Old leaves were affected, new leaves were OK for a short while. Viral tests showed 2 out of 3 were virused, but this did not explain the virus free plant problem. Here are some pictures of the typical problem. This was a virused plant, but the effects were the same in all the plants and these were the only pictures I took.
http://www.pbase.com/schnitz/image/85439286/medium
http://www.pbase.com/schnitz/image/85439284/medium
Large versions can be viewed if you have the bandwidth, by clicking on 'original'.

Recently I have identified an extremely serious problem in my GH which I believe to be fusarium wilt. Quick and intensive action upon realization of the problem will probably preclude any useful testing to determine the cause by scientific methods of culturing, etc. My initial attack was to use Phyton 27, but I quickly shifted to Thiophanate methyl (Clearry's3336, OHP6672, Bonomyl, Fertilome Halt, etc.) as this is the only systemic chemical that I can find that says it covers the common fusarium wilts of orchids.

My canaries were some African Violets in the home, and the Phyton was initially effective, then when the violets regressed, the Phyton was useless. I checked the Phyton site and found that they recommended every 3 days for treatment, something I had not done. I found no info on frequency of use for the Thiophanate, so I have been using the Phyton approach, and respraying the infected plants often, sometimes daily, and a drench at the roots often, with treatment of the entire GH also, but less often than the obviously infected plants. I also use an occasional treatment of other systemic fungicides, propiconazole, Bayleton, Subdue 2E, and Phyton 27. You may wonder why I am going to this extreme for a few plants, why not just throw them out. Well, it isn't a few plants. By the time I realized the problem, there are probably a hundred plants affected to one degree or another, and no doubt billions of spores saturating the GH. I have been working on this problem for about 5-6 months, and have seen improvement in all the infected plants, recent growth filling back out, and new growth coming in looking very good. I have been cutting off the non-responding leaves as soon as a good leaf or two exists. Here is the surviving non-virused Phal that is one of the 3 above that had the same problem as the plant in the pictures above,
http://www.pbase.com/schnitz/image/85439282/medium
It has definitely been making progress since the use of Systemic fungicides started.

I am about to make a change. I am going to convert over to worm tea. I am hoping that the worm tea will act as a low grade fungicide. Any retrenchment will put me back into the heavy systemic fungicide use.

Pictures of a number of orchid problems including possible fusarium:
http://www.pbase.com/schnitz/symptoms_not_of_virus

[robb]

cynthia: i am certain you will get this cleared up! you seem to have a full arsenal of knowledge of plants and their pathogens.

best of luck, hope there are not any casualties!

[Tobi]

Cynthia,
Very informative post. Being a Microbiologist, I am always interested in this
subject matter. Thanks again and I hope you eradicate the problem.

[janet_a]

interesting site. sympathies to both of you.

i just lost another plant to rot last night.

think i'm just gonna chuck 'em all and grow cactuses.