Masdie Q's
 

I seem to have some problems with the two masdies that I have. They are both in a home made orchidarium with humidity at about 80%, bright light (maybe too bright?), a misting system that goes on 2x per day and very dilute fertilizer at each misting. They are both in small clay pots with hapuu (Hawaiian version of tree fern) on the bottom and dead spag mixed with live moss (growing like MAD!) growing out of the top. I have a little temp gauge in the bottom of the tank that says the temp on the bottom part of the tank does not get above 75 degrees, usually a bit less.

My question is this (followed by pics): Why are all the new growths getting smaller on my NOID (I think its Angel Tang) and the leaves are looking burnt?

My second masdie (Ruby Slippers) I got from Ron Hanko a few months ago and while it is growing VERY rapidly (with near normal sized growth), it is also developing the burnt looking leaves. Also the flowers are being put out that are much smaller than normal (say, half the normal size) with almost no color. Granted, I repotted this one recently and cut off a bunch of roots and old spag, so the small flowers are not too worrisome...yet.

Any thoughts? Ideas? I'm kind of stumped, considering EVERY other orchid is growing really well in this tank, including Dracula lotax, dwarf Bulbos, Sigmoidea, Restrepia, etc.

NOID, possibly Angel Tang
http://farm8.staticflickr.com/7279/7...28cb752e_z.jpg
Masdie Problems by Isurus79, on Flickr

Ruby Slippers
http://farm9.staticflickr.com/8145/7...44580aca_z.jpg
Masdie Problems by Isurus79, on Flickr

Rubby Slippers dwarf flower about to open (sorry, the camera focused on the background)
http://farm8.staticflickr.com/7106/7...268451c8_z.jpg
Masdie Problems by Isurus79, on Flickr

Average temp during the day
http://farm9.staticflickr.com/8013/7...b56dd3ec_z.jpg
Masdie Problems by Isurus79, on Flickr

I forgot to mention that there is excellent air movement powered by a small computer fan.

To me it looks like there could be a couple of things going on, but a couple of questions first:
a. What sort of water are you using for misting--RO, Distilled, Tap, etc; if from the tap, what is the TDS range? Is this misting the only watering that your plants receive?
b. You've mentioned that the tank stays near 75F at the bottom; is this the average daytime temp? What is the average night temp?
c. Do you know how intense your "bright" light is?
d. You have good air flow in the tank, but is there a fan that pulls fresh air in from outside the tank, or does the air just circulate in a closed environment?
Given the info as presented, I'd guess that your plants are receiving too much light coupled with too high of temperatures, but there are other factors which would account for these symptoms as well; excess fertilizer, stagnation of air, etc.
Just my 2 cents...
Adam

Adam,
Great questions! I'll answer in the order they came:
a. The water is RO water that I buy from my local grocery store and this misting is all they get for water. The whole tank is drenched though. The first watering is for 30 seconds in the morning just before the lights go on and then the second watering is for 2 minutes about 4 hours before the lights go off.

b. I would say the average day time temp is 72-73 and at night its probably 5-10 degrees cooler.

c. I don't know the intensity of the light. Its a 4x 24W T5 HO system and the tops of the leaves are about 11" from the bulbs. There is also a 3/8 pane of plexiglass in between.

d. The air is circulated around the tank, but the lid of the tank is raised off the tank by about an inch so hot air can escape. This should allow for some fresh air to get in, but not enough to lower the humidity.

Any thoughts, ideas, etc. are more than welcome. I'm hoping its the light being too bright because I can just hide the plants under some higher light tolerant plants.

Steve:
One more question:
Have you checked to see if the leaves of your plants are dry before the lights switch off for their "night"?
I grow mounted and potted masdies & pleuros in a vivarium and have an issue with a couple of plants developing spotted leaves over time if the foliage is not dry by nightfall...my last misting occurs 4 hours before dark as well, but I am moving about 200CFM of air through the tank 24/7. I mist 4 times a day; at 8.15am for a minute, then again at 12.15, 4.15 & 8.15 for 30 seconds; lights out is at 12.45am, with lights on not occuring until 9.15am.
Why do you water heavily so late in the day?
Adam

Adam,
The water goes on 4 hours prior to lights out, so the leaves do have a chance to dry out.

As for the reasoning behind the water schedule, I wanted to accommodate both CAM and non CAM plants (because honestly, I don't know which plants in the tank are which) so I wanted to wet the roots during the 'day' and still have moisture for night metabolism. An afternoon drenching is pretty common for most types of orchids in the wild as well.

A friend of mine here in town who has a similar watering schedule as you (he has mini Bulbos and a snake in his tank) actually pointed out that replicating nature in such an unnatural situation (ie. terrarium) might not be all that effective, but that I should try it and be ready to change the schedule. I have to say that this technique is very effective at growing orchids! The masdies are really the only exception though. :-(

I wonder then if you might try moving the masdevallias out of the tank and into your general collection? Sorry I can't be more help, the only other thing that comes to mind is that your plants might simply be growing too warm; most of the masdevallias out there are temperature tolerant, but they seem to prefer the low side of intermediate temps, actually favoring cool. I was hoping one of the others would chime in by now...have you tried checking with Ron to see if he has any cultural advice for you?

I'm no Masdie expert by a long shot but one of mine did get a lot of spots which I'm sure were heat stress related. But I had warmer temps than you do. the other thing, is the moving air might not be fresh enough. they like good movement and maybe it's too damp or warm of air. Just a thought.

I'd be interested too as some of my leaves look a bit like that but for the most part it seems to be old leaves before they die off. Not sure if that's normal and mine hve to make do in pretty warm temps, although I do use fans and a fogger to try and cool things.

Unfortunately, it can get really dry here and I don't think the masdies would be very happy with that. As for Ron, I have not talked to him yet, but I will send him a PM right now.

I'm going to try to get them in a lower light situation. If that doesn't work, then I will just sell them and get something else! lol

I'm wondering about the heat as well, but with a high temp below 75 seems like it should work for intermediate plants. There might need to be a cooler night than I can provide. If that is the case I won't be able to grow these guys anymore. I'll try casting a shadow on the plant and if that doesn't work, out the door they go!! To a good home of course!

My masdies grow smaller more compact growths in high light . I was told by someone at an orchid nursery that they do that. Mine are with a very red leaved Dryadella, and I'm told if that is red it's really too bright for masdies but if you can keep them cool enough they will grow more compact.

Mine make a lot of growth, just shorter