Please help confirm/deny my fears

[rtsingleton]

Ok, let me see if I can provide more details. First plant is onc sharry baby, second is a gongora, third is bulbo picturatum. Water is rainwater and I am a constant underfertilizer. Yes it is a King Canopy GH. I'll try the Thiomyl and see what happens. And there is a lot of air movement in the GH, leaves constantly stirring in the fan created breeze.

Do we all agree that chopping off the affected areas of the leaves is the best course of action? And then treating with Thiomyl and cinnamon?

[Ross]

Originally Posted by rtsingleton

Ok, let me see if I can provide more details. First plant is onc sharry baby, second is a gongora, third is bulbo picturatum. Water is rainwater and I am a constant underfertilizer. Yes it is a King Canopy GH. I'll try the Thiomyl and see what happens. And there is a lot of air movement in the GH, leaves constantly stirring in the fan created breeze.

Do we all agree that chopping off the affected areas of the leaves is the best course of action? And then treating with Thiomyl and cinnamon?

Not for the Bulbo! I don't think those spots will get worse if you get some Thiomyl to the leaves and plant (like 3 times, a week apart.) If you can catch the spots when they are small yellow circles (before they turn black) then the Thiomyl treatment will be even better. All you'll be left with is a few small pin prick sized black spots. Don't know about the first two.

[rtsingleton]

The gongora and the onc are in really bad shape, however, only the old growths have it. None of the new growths show the same signs. I was hesitant to take a pair of scissors to it but now I will. Thanks for the help. If anyone has anything else to add it'd be appreciated.

[Sandy4453]

The first 2 pics look like definite sunburn to me, especially, #2. Not sure what these plants are though, which would help. I had the exact same dark spotting (pic #1) which then turned the leaf yellow on my Aspasia lunata and that was due to too much sun. It looked like an over-ripe banana peel. And I agree with everyone, not viral but probably fungal, especially the last pic.

[Sandy4453]

Originally Posted by rtsingleton

Ok, let me see if I can provide more details. First plant is onc sharry baby, second is a gongora, third is bulbo picturatum. Water is rainwater and I am a constant underfertilizer. Yes it is a King Canopy GH. I'll try the Thiomyl and see what happens. And there is a lot of air movement in the GH, leaves constantly stirring in the fan created breeze.

Do we all agree that chopping off the affected areas of the leaves is the best course of action? And then treating with Thiomyl and cinnamon?

Didn't see this when I first replied.

Regarding the Bulbo. I'm far from expert but I've got a few observations to share. I have 14 and have learned that some like to dry out somewhat before watering and others need more light, etc., a lot of variables, depending on which ones you're growing. I was recommended to spray mist inbetween watering which I've done and have also lost a couple of leaves to rot, especially on my sumatra. The roots, the rhizome need the wetness but I'm not sure about the leaves on all Bulbos. I'm inclined to believe that the leaves be omitted when watering. What kind of mix are you using on your Bulbo? Good airy mix is a must!

[rtsingleton]

Sunburn? the gongora are very shaded, and the onc wasn't getting much more. None of the other similar plants around them show signs of sunburn either... I'll check for it tomorrow in any case. All of the plants shown are in s/h with either hydroton or primeagra

[Sandy4453]

Originally Posted by rtsingleton

Sunburn? the gongora are very shaded, and the onc wasn't getting much more. None of the other similar plants around them show signs of sunburn either... I'll check for it tomorrow in any case. All of the plants shown are in s/h with either hydroton or primeagra

If these are in shade, then they're probably not sunburned as I suggested which was what they looked like to me before (and still...sorry!) I knew what they were. It doesn't take much to burn some plants. A Phal, left in high light for 15 minutes, can fry. Happened to me when I left one in the car to return an item in the store...not even 15 minutes. That 2nd pic still looks like sunburn though...

[Des]

Onc. Sharry Baby is prone to leaf spotting ,some say it is genetic . However when I inspected about a 100 plants in a friends Orchid nursery recently I found some that had clean foliage . The plants were grown from a few flasks ,so theoretically should all be identical .All plants were grown in a bark mix . Yet some were clean. and I have seen plants on shows that don't show any sign of these marks . The pitting on your plant is excessive though.
This leads me to the conclusion that one of the parents of this hybrid is salt sensitive and this trait has been carried forward in the hybridizing
I would repot the plant into a basket and reduce the amount of feed or change the type of feed

[Des]

The second plant is a fungus infection possibly caused by damage The yellow tinge at the edge of the infection indicates this . If you were to magnify the dots on the dry part of the leaf with a powerful magnifying glass you will see that they raised and are like very small mushrooms growing on the leaf. They very often have a pattern of some sort . Cut the infected part off well below the yellow part with a sterile knife and seal with sulphur or cinnamon
And remember that prevention is better than cure, reduce the pathogen count in your GH with a regular spray program for fungi.

[jbigio]

How often do you fertilize? orchids that receive to much fertilizes in the soil draw the excess through the roots and in an attempt to remove it from the root system draw it to the leaf tips which in turn turn brown, this often causes a secondary infection of the dead or dieing tissues which I believe in your case is a fungus infection (first two pict) The third picture is the bane of all nurseries and is bactual brown spot cause usually by high humidity and to low air movement. at least that's my opinion.
Joe