Leafspotitis - Orchid Board

catlady · #1 07-04-2007, 08:25 PM

A Den. I recently bought has developed "leafspotitis". One cane lost all of it's leaves (about 5) within 48 hours; now another cane is doing the same from the bottom up. It is still maintaining it's 2 blooms, with another bud getting larger. The spots start on a green leaf as a pea-size black spot with a ring around it. When the leaf turns yellow, the ring is green, and when the leaf turns brown the ring is white. The plant hangs in a north-facing screen room, fert. every 2 weeks roots and leaves sprayed, misted daily (temps been around 90 for 3-5 hrs/day). I really don't see any new root growth, but it has a new still growing shoot which was there when I bought the plant about 1 month ago. Any ideas what the problem might be? Could it be the result it's move? The growing conditions I have are very similar to the seller's growing conditions.

justatypn · #2 07-04-2007, 09:02 PM

I wish I could have a correct answer for you and am sure your at wits end. Here is a website that might shed some light on determination of a virus, bacteria, fungus. In the meantime I am sure one of our members will be able to help.

Orchid Viruses Article - August 2004 - River Valley Orchidworks Newsletter

gands · #3 07-07-2007, 07:39 PM

What dend is it ? Some are naturally deciduous and it may not be a problem at all. When misting / spraying daily, are you doing that in the morning? Just water? If you are doing in the heat of the day, it could be a problem. A couple of the spots look like mold to me, which would suggest it is too wet when its too hot, or not enough air circulation.

catlady · #4 07-07-2007, 07:59 PM

Yes, I spray just water in the morning, also mist during the day because of our 92-94 degree heat every day. The Den. is not in the sun, but really good air circulation is not the best. However, wouldn't mold transfer to your finger if you touch the spots? It just dropped the last "sick" leaf today, and the remaining leaves appear to have escaped spotitis. Maybe it';; recover on it's own.

gands · #5 07-07-2007, 09:30 PM

Yes mold would wipe off, so that's not it. Do you know the name of this Dend ??

cb977 · #6 07-07-2007, 10:29 PM

I'd give the whole thing a fine misting of Listerine, just in case...make sure it's not the minty "stuff"

Don Perusse · #7 07-07-2007, 10:41 PM

I would use a fungicide Physan 20 or Captan to insure that whatever it is, it doesn't spread to other plants. I usually spray once a month and never have a fungus or bacterial problem. You won't usually see any new growth until after flowering and new roots appear.