Spots on leaves - Orchid Board

RosieC · #1 10-24-2015, 12:42 PM

Does anyone know what this is?

The patches spread, eventually covering the whole leaf then the leaf dies back. It doesn't move massively fast but is was relentlessly moving up the plant.

I have actually thrown away the Epi this was happening to as it was a small cheep plant and I didn't want it spreading to the rest of my collection. However I want to know what it is in case I spot it on any other plants.

Anyone got any ideas?

silken · #2 10-25-2015, 12:23 AM

I'm bumping this up. Sorry, I don't know what it is but am curious too.

wintergirl · #3 10-25-2015, 02:12 AM

I had been looking online, I did find this thread from OrchidBoard. It looks something like yours, brown spot with a yellow around the edge.

Leaf rot? Fungus? Help!!

estación seca · #4 10-25-2015, 04:41 AM

In the US most counties have a university extension agricultural agent who is happy to identify plant diseases. I suspect there are similar officials in agricultural regions of the UK.

RosieC · #5 10-25-2015, 04:10 PM

Thanks everyone. I've not seen it on anything else luckily.

NYCorchidman · #6 10-28-2015, 07:05 PM

I would trim that leaf off. It is a disease for sure.

Near the bottom, Cercospora is what I initially thought of upon looking at your picture.

Orchid Diseases

Hopefully, it's just this one leaf, and you cut it off, and never see it again.

RosieC · #7 10-29-2015, 07:45 AM

Quote:

Originally Posted by NYCorchidman

Hopefully, it's just this one leaf, and you cut it off, and never see it again.

No the whole plant is in the trash, it was moving up the plant. It was only a cheep seedling epi that I was trying so no big loss.

Thanks for the link. I'm not sure it was quite like the Cercospora but as I'm sure it's a disease of some sort the plant is gone!

tucker85 · #8 10-29-2015, 08:36 AM

I think it is Cercospora leaf spot fungus. It's unfortunate that you had to trash the plant but understand your concern when a disease is traveling fast. Precautions like good air flow in your orchid growing area and not letting leaves stay wet at night will help. For long term control of fungus I recommend giving your orchids plenty of calcium, especially during the growing season. There are fertilizers that contain calcium or you can add a supplement to your fertilizer. I use a calcium/magnesium supplement called MagiCal that you can get from hydroponics stores. There are other strategies, like using oyster shell in the mix but I like a supplement because I can control the amount. Calcium only affects new growth so old growth still may be susceptible. But after a few years you'll have more disease resistant orchids.

RosieC · #9 10-29-2015, 08:50 AM

Thanks Tucker,

It was in the bathroom which probably has the least air movement most of the time, I will remember that, and about the supplements to help.

NYCorchidman · #10 10-29-2015, 01:52 PM

Great move and it was a cheap one, too, fortunately.

I think when there's something ugly going on at relatively fast rate like the one you observed and when you grow indoor and have no spraying option, it is best to discard the plant and start new and fresh instead of possibly spreading the spores or risking other plants AND having worries and stressed over it.

The good thing is that there are soooo many orchids we can try our hands on.

At least for me, when I dump out plants or give away, sell away, the empty space easily fills up in no time.