Dend virus ?

I moved this post up so someone would see it. Traci's thread about viruses was very timely for me.

I have a hybrid Dend that I won at the local OS raffle a couple of weeks ago. I put it outside with the other orchids and about a week ago, it developed a few black spots. Next day, a few more. I sprayed with fungicide but the next day the leaves were green with some yellow circles, like measles. Now the leaves are yellow with only a bit of green left, again, in a circular pattern. I think all of the leaves will fall off.

Should I throw this out? Can't imagine what I "did" to it! I can't post the picture yet; we just got a new digital camera and don't know how to use it yet.

Even with a pic, there's not going to be any way to positively id a virus infection from photographs; if you really wanted to know, you'd have to send a sample off to a lab for testing. Spotting can be caused by bacteria, insects, fungus, virus, toxic spray residue--all sorts of things, so a plant that's been harmed in some way will very often react by developing a necrotic area (the spot), an area around the spot that turns yellow, and eventually, a loss of the leaf. While certain viruses leave characteristic-looking spots (concentric rings, for instance), others don't, so brown spotting could literally be anything.

If all of the leaves are suddenly yellow after you've put the plant outside, the plant may be getting too much light before having been acclimated to those light levels. If there's any new growth, has that been affected too? Many times, dendrobiums will shed leaves from an old cane and even yellow and drop the entire cane in preparation for a new growth spurt or blooming. You might have several things going on at once which aren't virus-related at all. I have never heard of virus killing an orchid in a matter of days--it's usually a slow, debilitating process that takes months, sometimes years. If the plant looked healthy when you got it 2 weeks ago, developed spots only last week, and now looks like it's on death's door, I can pretty much guarantee that virus isn't the culprit.

Make sure you haven't overwatered, that the roots and medium are in good shape. Check the undersides of the leaves for insects or insect damage: this is a bad time of year for those, so you might try spraying with insecticide too. If you watered the plant outside and the sun hit it before the leaves had a chance to dry, that will also create "rings" of yellow where the water drops acted like magnifying lenses and burned. An infection may have set in after that initial damage. If the problem is fungal and an infection has taken hold, one application of fungicide may not eliminate it, so you'll have to repeat.

Nobody wants virused plants, but detecting viruses when you're not a virology expert is a little like going to your first Psych. class and reading your first textbook: all of a sudden, you "realize" you have all the symptoms of the worst psychoses out there, and you secretly wonder why you're not in the funny farm. Different diseases can manifest in similar ways (spotting, yellowing, leaf loss) and it's very easy to start thinking "virus" when it's really something else, something treatable that won't show up again with good culture.

In any case, based on your description and the time frame, I seriously doubt your Dendrobium has a virus problem, so check those other things first....

Louis hit it on the head. Your start to become a hypochondriac when you read about incurable diseases.

I brought home three very healthy Dendro hybrids from C & H last summer. All three developed these spots that you are referring to. However, I didn't wait for them to fall off, instead I removed those leaves as soon as I saw the problem. I am always VERY fast with surgery. I never had to spray the plants they recovered nicely and bloomed in both fall and spring and are in bloom or bud again. DON'T throw them out. Even without leaves the plant will survive and put out new canes. Next time you see something like this developing just remove the affected leaf before it can infect others.

So just cut the leaf off and treat it with cinnamon? Or would I try neosporin? I think Louis was hinting that I am ready for the funny farm.

LOL! You and me both....

Seriously though, I thought you said the whole plant had gone yellow. If it's only one leaf, sure, just cut it off.

Neosporin? The ointment? I've never heard of anyone using that on orchid plants, so can't speak to it. Home remedies I'm familiar with for fungus are cinammon (Momokev used Lysol with apparently no harm done) and for bacteria you can use Listerine or rubbing alcohol and wipe the entire plant down.

But if it's really just one leaf that's affected, well, leaves come and go--when a plant is done with them, it lets them yellow, and since it's not taking care of them any more, they will develop spots and molds and things as they die--part of the normal process of decay. On Dendrobiums, when the leaves are dead, they'll just fall off. The plant might let go of a whole cane or two as well: they'll yellow and shrivel up in two weeks' time. As long as the plant has front growth that looks healthy, and roots that are firm, everything is happening as it should. And, as Dosal said, with Dendrobiums, even plants that have gone completely yellow can surprise you with a new growth--so don't give up on it yet.

I didn't even cut the leaves, I just pulled them off. Why infect a blade with fungus if you can remove a leaf manually? I also let the wound heal naturally without cinnamon or anything else. It callouses over fairly quickly.

If you take things too serious you might just end up there. Many things in life that you simply can't change, don't drive yourself nuts over a plant or even a collection of plants. They are replaceable.

Louis almost all of the leaves are yellow. The top 2 might be ok but might not.

Actually I would not be so heartbroken to lose this one since I have no idea what the flowers would even look like. I just have to protect the rest of my brood.

I've never ever seen this particular fungus transfer to another plant.

You guys are too fast for me lol! There I was editing, and you'd already replied twice!

Don't toss it yet. You'll learn a lot more if you try to keep growing it and wait to see what happens. Check the roots and pull the plant out of the sun if that's where you put it. And yes, don't stress!