Black spots on epicattleya

[waldofrumpki]

I noticed some black spots on the leaves of my orchid, the smaller ones have been on it since I bought it, but the larger ones have been expanding recently, which I'm pretty sure isn't a good sign. Could anyone help out? I've read the disease sticky, but I don't know if it's a virus or a fungus or something else. the plant stays in a shaded southern exposure, is watered about once a week, and is on a humidity tray. I'd appreciate any information on what it is, how to treat it, and if it can spread. Thanks!

[articuno75]

Hi Waldo Haven't seen you for a while.

By what I can see, it looks like fungus/bacteria and yes it can spread. There are several different kinds of treatments. I like to try the natural stuff first before I bring out my big guns. Brookn's Recipe is safe and so far has been proven. If that doesn't work then I use Physan. If that don't work then I use Bayer 3 in 1.

[jerrymeola]

It is fungus and a constant problem for commercial growers. It exists everywhere in the world and attacks the plant through any kind of root damage. It is necessary for us to drench the pot in anti-fungicides every time we re-pot.

It can spread very fast and is often fatal. The best fungicides are very toxic and expensive. $300 a quart is common. Cleary 3336, BanRot and Subdue are 3 very effective commercial products, but probably not available in retail sizes.

Damp potting medium and insufficient air circulation are the breeding grounds of the fungus.

I am using a different approach with a product called Companion, which is all natural Bacillus subtilus microbes. (55 billion per gallon) It not only can kill the fungus but inoculates the plant to further resistance to attack.

The worm tea we get from OurVitalEarth is supplemented with Bracillus. They add it to the feed of the worms. It is not the strong concentration that I am now using, but one of the reasons it works so well.

I will post some results as I get through this spring.

The cinnamon used in Brookn's formula is a natural fungicide and readily available for you to try.

[Cynthia, Prescott, AZ]

My experience is quite different from Jerry's. The only fast moving infection I've had experience with is bacterial, not fungal. Fungal infections generally happen because the plant is under stress (too cold, too cold and wet, too little light for too long, or something equivalent). I agree that fungal problems should be treated with systemic fungicides, and Thiophanate Methyl (Clearry's 3336, and many others) is available in hobbyist sizes and is as good as they come. Look up Bonomyl or Fertilome Halt, but check the label to make sure it is Thiophanate Methyl. If you have a fast moving wet looking infection, Phyton 27 is a systemic bactericide and fungicide, but is not as good for fusarium wilts, my own personal major problem. If you search well, you can find Phyton 27 in a 2 oz. size.

[BunnytheOrchid]

I have a question. How does it spread to other orchids and how do you know if it has before the black spots show up?

[Cynthia, Prescott, AZ]

This really isn't the right way to pose a question. Fungal spores are everywhere. It is not just simply if the spore reaches a plant, it gets infected. Healthy plants do not get fungal problems. It is an indication that your culture is not good enough for the plant. Is the plant getting enough light. Are you keeping it warm enough. Are the leaves dry by the time the temperature starts to dip for the night. Using a fungicide spray to prophylactically prevent fungal problems is probably called for if you really can't get the culture up to par for a plant. Such sprays will reduce the presence of spores, and systemics may give protection to a plant for a while.

[waldofrumpki]

I made a batch of Brookn's Recipe, and applied it to the leaves, and will continue to do so, so hopefully it will be effective. How will I know when the plant is better?

[Cynthia, Prescott, AZ]

The spots will never go away until the plant outgrows the leaves and drops them.

[evagentry]

I had spots that looked just like that in a catt. that was shipped to me, two leaves were cracked and there were black spots on them that grew quickly, I cut them out and put cinniman on the cut surface and they haven't come back, it has been about a month now.

[waldofrumpki]

I think that the spots are spreading, even after the cinnamon concoction I think I should cut out the black spots before it gets any worse. Should I apply cinnamon to the cut surfaces (sounds like a good idea evagentry), maybe after washing with hydrogen peroxide? I really don't want to lose this plant, it's even fragrant

[articuno75]

Originally Posted by waldofrumpki

I think that the spots are spreading, even after the cinnamon concoction I think I should cut out the black spots before it gets any worse. Should I apply cinnamon to the cut surfaces (sounds like a good idea evagentry), maybe after washing with hydrogen peroxide? I really don't want to lose this plant, it's even fragrant

When you make the cuts, use a clean sterile tool to do it. Apply peroxide over the cuts and then sprinkle cinnamon over that. The cinnamon will cartarize the incisions and help the plant heal faster. It will also help with infections as with the peroxide.