Help!!! Virus epidemic??? - Orchid Board

Connie Star · #1 05-02-2010, 01:32 PM

I have about 60 orchids of different types. While doing monthly watering at the sink- I do weekly watering and fertilizing on the shelves, I noticed a couple of plants with slightly mottled leaves, then a Den with severe mottling and spotting that I am afraid it is a virus. Most of the ones that might be infected were together on one shelf in a humidity tray. I have the shelves set up so that no water flows from one to another. I'm very careful with hand-washing and rinse the trays with Physan periodically.

Connie Star · #2 05-02-2010, 01:34 PM

More pictures of the plants that seem less affected

johnblagg · #3 05-02-2010, 01:59 PM

HMMM not quite sure its viral Connie....

I had several dens looked like that last fall and being unsure I did destroy them and they actually just had yellow mottling.I saved one of each that looked ok and they have no signs so far, in fact one bloomed wonderfully this winter with twelve perfect blooms and no sign of virus.

I am not that familar with what virus looks like though so some one else should be the one to advise not me.

Paul · #4 05-02-2010, 02:07 PM

You could send samples in to Critter Creek Labs for analysis.

Gin · #5 05-02-2010, 07:27 PM

Only way to be sure is to test .
Have you done a mite check , changed Fert.? here is a link to a lot of fungus problems . Go near the bottom of the page ..
Greenhouse - Orchids

greenbean · #6 05-03-2010, 02:12 AM

Hard to tell from most of your pictures. In the first one I see what could be symptoms of a fungus. The bull's-eye like rings are usually indicative of a fungus. I had a Cattleya alliance orchid recently that had a fungal infection in the pseudobulbs, the leaves first got some yellow mottling like what some of yours show.

Roy · #7 05-03-2010, 07:48 AM

Most of what I see there is a nutrient problem and not enough light. Possibly a check on the roots would be in order also along with a check on the mix they are in.

catwalker808 · #8 05-03-2010, 02:42 PM

It looks to be more of a nutritional/cultural problem than virus. If you're watering only weekly, but fertilizing at the same time, you may be building up salts. Your water may be contributing also. Some of the visible roots seem to have brown tips, rather than being a nice white or green.

The spotting on the leaf tips in the first photo are probably a secondary infection which occurred after the initial leaf damage from nutrition/culture. The leaf got damaged or weakened, then fungus infected it.

Check your roots. Wet your medium with plain water to dissolve the salts. Then flush with plain water. Do this a couple of times. Then do the flushing during your regular monthly sink watering.

Connie Star · #9 05-03-2010, 08:18 PM

Thanks everybody- I didn't see how it could be viral. The first plant is in the pot I bought it in over a year ago. I will repot. My water is very hard (well-water) and I thought dens needed a winter rest, so I was essentially only fertilizing once a week. That, and hard water could be a problem.
I think I'll still send a sample for virus testing. That sure would be a drag if it's a virus. But if it's not it's a good lesson that I need to get an RO device. Right now I have enough rain water.