Spots on Catt Leaves

[Jkelee]

Hello, l now have some large spots forming on some Catt leaves. Does anyone have a clue why this is happening and what can be done to stop it? And does it Spead like wild fire to others?? Thank you!

[quiltergal]

I'm not sure what's causing it J. Has it been in direct sunlight? If so it might be sunburn. I'd isolate it just to make sure if it's a virus it doesn't spread to your other plants. I'm sure someone else more knowlegeable than I will have a better idea.

[Ross]

Doesn't look like a virus, but it doesn't look good, either. I've not seen this type damage before and it doesn't look quite like sunburn - but having said that, it could be. If it's spreading and if you are unsuccessful in getting a definitive answer, just trim the leaves below the damage with a steril blade or cutting tool and sprinkle cinnamon on cuts. That's like trying to cure a hang nail by cutting off your toe, but it will be gone! Wait to hear from others here.

[smweaver]

Looks like something has been scraping off parts of the upper side of the leaves. Do you have slugs or snails? They have this nifty little mouthpart called a radula, which basically works like a file which the nasty little monsters use to rasp off pieces of plant tissue when they're dining. Have you noticed any tell-tale silvery trails around this plant's pot or near your growing area? Try to rule out everything and see what that leaves as a possible culprit. Has the plant been abruptly moved to a higher light area? Have you sprayed any chemicals on or near it recently? Do any of its neighbors exhibit the same markings?

[smweaver]

Look at the picture of the slug toward the bottom of the page at the following link:

http://www.ionopsis.com/Pests_and_Diseases.html

The damage on the leaf that the slug has been dining on kind of resembles the markings on your cattleya's leaf.

[Jkelee]

Thanks to everyone for your wisdom. I don't have them in any kind of direct sun. Filtered light only. I can't find any bugs, trails, etc. I have isolated them. I can't really tell if it's spreading. My pictures will tell me if they are I guess. I don't put any bad chemicals on them. Nothing but good Orchids products of ferts, or KLN, etc. Nothing harmful, or I'd destroy my whole crew of Orchids with it. I will look again for some nasty monsters. thank you.

[Lagoon]

I have a catt that looks alot like this. In my case it was the heat from a CFL bulb to close to my orchid leaf.
All the same check and see if it's not caused by something else ... with a marker or pen, draw just on the outside of the damaged leaf tissue and see if it goes out of the marked point.

[Sanoe]

Aloha,
We have noticed this type of damage of some of our phals. and enc. that have been pulled for shipment. They are under a covered roof that also has multiple layers of shade cloth. It is cooler than the whole greenhouse, but we suspect that there is ultraviolet, or some other wavelength that we can't see, that is doing the damage. It is unsightly, but will not harm the plant unless most of the leaf surface is damaged.

[mikearte]

It would appear that yiur leaves could possibly have had some water standing in them and then recieved too much light. This water will act like a prism and accentuate the damage caused by the light. This in turn can cause brown rot on the leaves to occur. My suggestion is to quarantine the plant and remove the damaged leaves as well as treat the plant with Physan or some other fungicide/bacteriacide type solution. Also sprinkle cinnamon ont eh cut areas after removing the leaves. Good Luck!