Transparent spots on young leaves - Orchid Board

goofy · #1 08-07-2010, 02:32 PM

Hell all Cymbidium experts,

I don't know much about Cymbidium. This is one of my first Cymbidium. I forgot the name, it does not have a tag. The seller told me it was a Spartan Queen X something I forgot.

Anyway, it has five new growth after the flowers are done. The new young leaves have some transparent spots. I am not sure what they are. Do I worry about them?

Thanks.

Thuy

smweaver · #2 08-08-2010, 06:57 AM

Thuy, if they're watery looking "windows" then they're probably a fungus. Some of my cymbidiums get them also from time to time. My advice would be to put the plant some place where it can get better air circulation. I can't tell from your pictures, but are you sure they aren't scale insects? If you rub the spots with your fingers and they come off, then they're scale. You can spray the plant with a mild insecticidal soap and wipe the scale off with a cotton ball. If it's a mild case of the plant getting a fungus, you can find a fungicide to spray it with at any garden center. But I think the spots are fairly common with cymbidiums (at least in my experience) and increasing the air flow around, in addition to increasing the amount of light it gets, will help control the fungus just as well. Good luck!

Steve

goofy · #3 08-08-2010, 06:45 PM

Steve,

Thanks for the reply. They are not scales. They are more dented, almost hollow from one side to the other side of the leaves. I also had scales for my phals (in the house), but I rubbed them with alcohol and they seem to be gone now. The cymbidiums I have are living outside and they have morning sun, about 4-5 hours. Is it enough for cymbidium? They also have plenty of wind all day.

Sorry my picture is not clear. I don't know how to take closeups, obviously. Each spot is as big as a pencil tip. The spots are all same size.

I will try to take better picture.

Thuy

goofy · #4 08-08-2010, 10:04 PM

Here are some better pictures.
Thanks.

smweaver · #5 08-09-2010, 07:43 AM

Thuy, that's probably plenty of light for the cymbidiums. It's what mine receive (direct morning sunlight up til noon) and they all bloom reliably (well, okay, except for the Cym. devonianum which is the prima donna of the group and doesn't bloom consistently every year). If you're growing outside then air movement shouldn't be a problem. I don't think that the spots (if they are a fungus) are anything to really worry about too much. A couple of the hybrids I have are more prone to them than any of the species, but even they aren't (as far as I can tell) badly affected by the spots, which eventually do go away as the growths mature.

Steve

King_of_orchid_growing:) · #6 08-09-2010, 12:59 PM

Have you tried doing a viral test?

goofy · #7 08-09-2010, 02:22 PM

Thanks, Steve. So far the spots are not getting worse or spreading. I'll let them be and see what will happen.

Hi King,
How do you do a viral test? I don't have a large collection of orchids. Probably about 20ish of them. I have only about 6 cymbidium, all of them are NOID. I have no experience with cymbidium.
Thanks.

Thuy

Bobfharris · #8 08-09-2010, 03:41 PM

Without seeing the plant firsthand it is difficult. However it looks quite like thrips to me

King_of_orchid_growing:) · #9 08-09-2010, 04:18 PM

https://orders.agdia.com/InventoryD....ribute_Size=25

Could be other problems too, but just to be sure, a viral test doesn't hurt.

goofy · #10 08-09-2010, 05:55 PM

Hi Bob, I was thinking something might be eating the leaves too. So I got out the microscope and checked it out yesterday. I didn't see any "animal"/moving kind of thing on the plant.

King,
Thanks for the links.

Thuy