Strange outbreak happening!!! Help please before it's too late!!!!
 

So I've noticed recently there is these strange little black dots with a slight discoloring of the leaf on the opposite side infecting my orchids. My vanda in the picture has developed slight darking patches with small patches of these little black dots. They appear on both sides of the leaves.

I've also noticed one of my cattleya's also developing the same strane discoloring and the black dots except the dots are all over a few of the leaves. The most severely infected leaf is discolored.

I have another plant, my Marfitches Dream which has multiple dark spots, but they are not like the ones on the vanda and the catt. They are also not symmetrical round spots like on the vanda and catt leaf. A few of the leaves look infected with damage. I'm at a total loss.

I've also taken a few pictures of two of my oncidiums, the first with the fewer amount of leaves has a slight spotting and a few leaves look rough. The second, is a darker green color with a few damaged leaves thanks to a chipmunk and the cat playing with the leaves. This second one doesn't show the strange black round dots.

A phalenopsis, with a new leaf growth has a couple leaves with a few patches of the small round black dots with leaf discoloring.

I'm lost and need help. All of the things I've looked up about does not show anything like what I am seeing.

Growing conditions: I have these plants on shelves per light level requirements in a small greenhouse. It does get warm in there, around 93-97 on hotter days. I water when I see individual plants getting dry as I'm using various types of media. I have 2 vents that I open up towards the back of the greenhouse to help with heat buildup and I use a 20" box fan on the back of a black round plastic pond filled with water that is circulated through fiber media to help with cooling and air movement. I can see the orchids move with the air flow.

I also make use of a humidifier to add extra humidity to the air which the lowest it gets is around 2:00 and down to 40%. I fill this up twice a day with DI water. It holds 2.0 gallons.

I have noticed that the greenhouse is very "foggy" and humid in the morning when I open it up for the day recently. I'm guessing condensation.

Please any and all ideas will be greatly appreciated! I'm not sure what I'm dealing with here and I don't want to loose my collection I've worked so hard for. If you need more information, please let me know.

Here is some more pictures;

I'm at a loss too, but I think you should investigate two things:

- I wonder if you don't have something sucking at large on the leaves. Check for acarians (mites) with a bit of cotton wool and alcohol, especially on the underside. If you have yellow/red/brown stains on the cotton, you have visitors. Don't mix the cottons between the plants, if it's a disease or some sap is flowing you'd be spreading spores or worse.

- I wonder if something in your conditions isn't favoring some fungus. But people here with GH in you conditions would be of better help than me. Especially to pinpoint the eventual wrong move.

Thank you. I'll definately be checking for mites. I'm hoping it's something simple. :(

As for the fungus, it's possible, I'm not sure what kind it is, what it's effects are, and where it's coming from.

At this point I'm not excluding any possibility.

Mites? Have you checked today yet and gotten back to us? Doesn't look like sporing bodies or fungus damage on my laptop screen.

Could be fungal. If you have a microscope, you can cut a piece of leaf off and look.

The easier thing to do would be to lower the humidity some or provide better air circulation.

You could also try using a fungicide.

If it has been too warm, that might be it as well.

Sudden changes in temperature can do that as well.

King, about to go do thr mite alcohol test now. I had some very important things come up last minute that took priority.

It had been pretty warm in the green house over the past few weeks and I'm not sure if I did properly introduce my orchids to thr heat but that was a few monthes back. I'm not sure if it takes this long for heat stress to show up.

Ok here is what I got off my phal. I swabbed my vanda and the catt showing the most spots and it didn't change color or shoe anything.

[IMG]http://img.tapatalk.com/d/14/08/07/ty4eqebe.jpg[/IMG]

Looks kinda like spores? Fungal?

Sorry y'all for the mispelled words. Doing most of this from my phone so ya know how that goes when trying to type.

Possibly some type of leaf spotting fungus. The pictures don't look too bad to me. I grow outdoors in South Florida so there are always spots of one kind or another on my orchids, including fungus. If you can increase the air movement around your plants, that can help. Some people use a fan to move the air. Don't water in the evening because wet foliage at night encourages fungus. Make sure your fertilizer contains calcium. Calcium builds stronger leaves that resist fungus. You can spray once a month with a fungicide if you want. It can be a pain in the neck if your plants are indoors. You'll need to take them outdoors to spray. I find it's particularly important to spray vandas which can be very susceptible to leaf spotting fungus. Cut off any vanda leaves that have large areas of bad fungus (not the little spots). Good luck.

Tucker85, I'm beginning to think its some kind of fungus. No typical symptoms of bugs, I'm not ruling out a virus but I'm fairly sure its not. I'm thinking fungal.

I've turned up my fan in the greenhouse so there is more airflow. I just got through watering them all real good and applying some Physan 20. I don't like using chemicals but I don't see much choice. So all my orchids have been throughly drenched in the solution.

I only water in the morning or early afternoon.

How often should I treat when trying to get rid of the fungus?

Oh and for fertilizer I use First Rays K-light fertilizer and I'm fairly sure it has calcium. If not, no worries as on my non-fertilizing week I use some tap water diluted with DI and we have a good bit of calcium in our water.

The spots that are on the leaves will stay there. They won't go away. When I see a problem, I treat with a fungicide (Thiomyl) once a month for about three months. But it's easy for me because I grow outdoors. You may want to wait and see if it gets any worse. By the way, most leaf spotting fungus don't kill orchids.

The orchids are outdoors in a greenhouse. I moved them outside after many trips to the bathtub with individual plants to water them.

So this spotting fungus is harmless? That is a huge relief.

I'm hoping it's just a harmless fungal.

So a month later, the fungus stuff is still around, but as far as I can tell no one is dying. Mostly my carts and the vanda covered. My greenhouse is fairly damp which is worrying me as we approach cooler weather.

How are you watering the orchids? If the greenhouse is too damp make sure you are not adding more moisture every time you water. Does your greenhouse have some venting system to the outside? It would be good to have some air exchange happening. Our winters are much colder than yours but I keep my orchids a lot dryer in winter as the temps are much lower in my greenhouse. You may need a dehumidifier if you have cool temps and a lot of humidity.

I water my orchids with a nozzle attached to a garden hose using a gentle shower setting. Or when I fertilize I make up a 5 gallon bucket worth of fertilizer solution (Ray's K-Lite) and use a mason jar to measure out the appropriate amount to give each plant.

My tap water doesn't seem to bug the plants at all. We have somewhat hard water. The greenhouse is roughly a 7'x10' rectangle with two large vents I open up manually everyday and usually leave the door open also to help with the heat buildup. There is a box fan that runs 24/7 to keep air moving all the time.

The greenhouse is not 100%sealed from the elements so at the four corners there is a nickel sized gap from the construction. So there is no lack of air movement. It's a metal framed house with double walled poly but I'm not sure of the thickness. It was my mom's greenhouse which I've taken over.

It sounds like there is good air movement. I would do a monthly spray of Physan or something similar and possibly try watering with a watering can on the media, not wetting the plants down. Water dripping from one plant to another could spread the culprit around. I never wet my plant leaves but I do still get spots at times and can't explain why. I used MSU fert that does have calcium and our water has enough calcium also. But adding a Cal/Mag. supplement recently seems to have been making a big improvement. I still need some time to make sure the new leaves won't eventually spot tho.

Yours looks like tiny pin prick spots which I don't get so it does look like something different.

Hi purple_phal_gal13, I did notice maybe a bit of webbing on the first set of pics you posted. Maybe mites? Those tiny spots may be bites from that. The discoloration in the Catt leaves may be a calcium deficiency or cold damage. That's what I've been told anyway. Sounds like you are a vigilant, proactive grower. Your 'chids look good to me! Dependng on your fertilizer, I supplement my fertilizer (generic) with Epsom salts. try spraying hydrogen peroxide or Listerine to kill any possible fungus.

I'll try using a more direct to the media method. I try my best to avoid the leaves, but you know how that goes. Plenty of Cal/Mag here so no worries on that.

See that's what has me confused. I've never seen anything like this in my hours of searching for pests/fungus/diseases.... I started a Physan regime bi-weekly and where I am now is still the spots but no damage. Though my Pangkok Blue I recently got has shown some browing/yellowing which is probably sunburn/damage.

The white stuff on the vanda's leaves seems to be a wash or something from before I got it. It's not from any of my watering.

That does look like sunburn on the Vanda.

When you say you still have the spotting problem, do you mean more tiny spots keep appearing? The old ones will not go away. The aim is to prevent more from developing.

The spots don't go away but I don't see any new ones popping up with the physan regime.

Yeah, I got the vanda acclimated and put it outside on what was supposed to be a cloudy day and the sun came out while I was in town so it got some sun for a good number of hours.

I want to say its some kind of insect dung. Small caterpillars of moths leave behind crusty black dung that resembles little black specks. They roll up in dirt balls they stick to themselves for camo on the underside of the leaves. They are very small and you can see them when they wiggle around inside the dirt cocoon. About 1/8 to 1/4 inch long. They can see you when you spot them and try to outrun the hand smaching they have coming. They eat new shoots while they are still soft. When the leaves get hardened they move on. Damage Done. I would check for some very tiny bugs with a 40x jewelers loupe or magnifying glass.

I used to think the plants got enough calcium from my water source too but I was told by someone that plants can't absorb that form of calcium. I had some plants showing signs of calcium deficiency...which is how it all came up. Anyway...since then I have been regularly using a cal/mag supp...and it's halted the issues. The old/ugly leaves won't go away but the new leaves are not showing the same issues.

Don't rely on your water for the calcium.

I'll definitely check for bugs with a loupe I have a few I used in some classes in college. I doubt it's bugs though. But I'm not ruling anything out. I did do the alcohol on a cotten ball swipe with no residue of bugs.

Katrina, I didn't know that they can't use that form of Ca. What would be a good supplement? I'm using Rays K-lite so I know it has some Mg Ca. What amount shoiuld I be aiming for?

You know, my fert has calcium too but I guess it wasn't enough for some of my plants. I use a product by Botanicare called Cal/Mag Plus. It's a liquid and I mix it in w/my fert solution. I get it at a local hydroponics store.

I started using it back in the late winter and I have to admit that I've noticed a difference w/my new growths this summer. I'll know more after a full growth cycle (min 1yr) but so far I'm very pleased w/the results.

I use MSU fert which has a mix of all micronutrients as well as Cal/Mag but the addition of a straight Cal/Mag liquid supplement seems to be making a difference to me as well. I am getting a lot of first time blooms also which could be just a coincidence but it sure makes me wonder!

Is there any specific brand of Ca/Mg supplement that seems better? Or Ca/Mg ratio?