Using Physan 20 for possible fungus on petals?

[Christina]

Hi, I have a phal with a couple dark green tiny round spots on a few petals. Does this sound like a fungal infection? I have Physan 20, and have made a mixture of 2 teaspoons/ gallon of water. I have it in a spray bottle. Should I spray all the petals, even the ones with no spots? How much should I be spraying? And should I spray them every day?

I don't want to do any further harm to them. Please help.

[mehitabel]

Hi, Christina. I wouldn't use Physan 20 spray on flowers. I think it might do them in, and why take a chance?

Physan spray is a good contact anti-fungal anti-bacterial for the green part of the plant only, or on the roots when repotting, so you're smart to keep a spray bottle of it around. But hold back on the flowers

I don't know what the source of the tiny round spots on a few petals, but they sound harmless to me. Could just be the flower equivalent of a mole-- a concentration of pigment, a small imperfection in the flower.

If you are misting the flowers, don't do it any more. That sometimes will cause grey blights on the flowers.

[missann]

Probably the way the flowers got spots on them in the first place was from dew or being misted. I would just leave them alone, unless it spreads because the flowers most likely will not "heal" up before they die.

They may have also developed this when they were still buds and moisture built up inside. If you are not misting your plants, perhaps you are getting dew early in the morning that is doing it. I would either increase air circulation with a little fan (you can get them at the dollar store for 4 bux) or move them inside over night so they don't get the dew in the morning. The spots will probably not get any worse.

[jerrymeola]

I do not think much of Physan. It was developed as an algaecide to remove algae from greenhouse windows. It does a really bad job at that as well.

The label and literature from the manufacturer does not list a single bacteria or fungus against which it has been proved effective.

I do not know any commercial growers that use it.

[Brooke]

Here is a link to Physan 20 regarding useage on orchids.

Physan 20

On the left side of the page is other information regarding the product, the chemical make up, the warnings, etc.

Brooke

[PhalPal]

I think the price of Physan might be the main reason why commercial growers don't use it.

[FLaCo]

I can vouch for Physan. I started to get attacked with huge spots on most of my orchids mostly Catts. A lot of it were on my new growths. I decided to get the Physan out and sprayed it down. The plants seemed to accepted it well and the plaque seems o have just stop at the growths that it attacked. The sick growth shrivel and dried up and eventually fell off.


Rain was a cooperate.

[Christina]

Thanks everyone. There were alot of varying opinions about the physan. I can agree with you Jerrymeola, the label that comes with the bottle really doesnt list any of the specific bacteria or virus strains that it helps to treat (weird). Which doesnt make it very reliable when I think about it. But FlaCo, you had said it helped with yours. Did you spray your whole plant, like the petals also? And how often did u do this?

My plant is in really bad shape now, and im not sure if it has anything to do with the Physan or not, but my flowers are folding in on themselves and drying up. I guess i learned from my own mistake. What should I do from here on? Should I cut the spike once they all fall off? Help... again!

[PhalPal]

Christina at this point pictures will help tremendously if you can get a few posted. What do you mean by your plant being in 'really bad shape?' If you think it is failing completely and petal spots are not your only problem I would do the following:
- cut the spikes
- pull it out of the pot to see what the roots look like
- cut off any dead or soggy roots and spray with either Physan or cinnamon spray
- repot in fresh medium

If it is just the flowers fading and the leaves are turgid and healthy it might not be a bad idea to repot anyway. Let us know how it goes!

[Leisurely]

I can't recommend Physan 20 because I have never used it. It appears that you have Botritis fungus on the flowers. It is most common on Phals in cool damp conditions with insufficient air movement. I have gotten it in the past when my greenhouse is closed for several days. I use something called RD-20 which is a bactericide, fungicide, viriside. It is much cheaper than Physan-20, about $10.00 per qt. It is commonly used as a disinfectant to get rid of the bacteria before it becomes a problem but the drawback is that it rids the good bacteria also and that is not good. I have used it on the infected Phal flowers alone and not on the plant at one tsp. per gallon and it halted the spotting. I obtain it at
the source on the link.

http://www.tropicalplantproducts.com/

[Brooke]

OK I got curious after two people said their Physan bottles contained no info regarding what it is supposed to do for you.

The bottle itself lists all manner of uses for various fungal and bacterial problems plus gives the chemicals involved with all the EPA warnings regarding the use of it.

There should be a brochure attached to the bottle that gives even more specific fungus and bacterial problems along with the dilution rate per situation. I love the fact that it specifically lists orchids and some of the common problems we run into while growing them.

If you have Physan without the proper instructions, the link above should be saved so you have the proper dilution rates on hand since different problems list different dilution rates. It really isn't safe to guess and hope when dealing with any pesticide, even a very safe one. You can do more harm than good if used improperly.

Brooke