Mold in Flask

[jblume1127]

Hi, I'm a recent graduate from college and we were able to flask orchids for one of my classes. I know the basic process, but don't have any of the equipment. At the end of the year, I took two flasks home. The phalaenopsis flask looks fine, but there is another orchid species we propagated that I do not know what it is and there is mold growing in the agar.

The tallest seedling is about a half inch tall with minimal roots. The mold is white and has grown pretty steadily for several weeks and now covers the surface of the agar. The taller seedlings seem to be unaffected. Some of the smaller orchids have died and are brown and slimy looking. I'm assuming that's a bad sign, but I'm wondering if I could salvage these guys some way. I was really hoping to keep the new species, being that I have about 16 phals as it is.

I read from this source and others that sometimes the mold isn't a problem depending on the type, but I think in each of those cases, the orchids were a lot larger.

Any help would be appreciated. If I need to put them down, it would be better to know for sure from people more experienced. Thank you!

[Ray]

Mold in a potting medium and mold in a flask are likely different critters.

I have no idea how well it would work, but putting a little bit of Inocucor Garden Solution in the flask, then reclosing it and swirling it around to wet all surfaces might kill the pathogen and boost the plant.

[dansyr]

I've only had this issue once for seedlings this developed, but the only ones I was able to rescue were ones I emergency deflasked, gave a quick light bleaching, and then rinsed and kept as dry as safely possible. Heavy losses but a couple survived. Most lost all their roots (fungus had already infected) but were able to rebound.

If you try Ray's approach, I'm interpreting this as applying Inocucor directly to flask, I'm very interested to hear how this goes. Would be pretty cool if you could have Inocucor balance out a rampant infection.

Alternatively, I might suggest deflasking, followed by a mild bleach soak (~5-10% for a couple minutes), rinsing well, and then applying Inocucor prior to compotting.

[Orchid Whisperer]

Without equipment to properly re-sterilize, I would suggest de-flasking, thoroughly rinsing agar off the survivors. Gentle spray of room temperature water with plants in a fine colander.

Initially, I would separate the best and largest plants from the others. Get a shallow plastic container with a clear lid, spread the tiny plants on the bottom of the container (no medium). Mist very lightly, leave the lid open briefly the first day, a little longer on following days. You want that container to be humid inside, but not soaking wet. Inspect the seedlings daily for signs of mold, rinse again as needed.

You can do the same thing, with separate containers, for groups of remaining seedling in progressively worse shape.

Eventually you will get small plants that stay mold free. Transfer the seedlings to shallow pots with fine bark, mist just enough to moisten the bark,also in covered cotainers. You are out of the woods, mostly, when seedlings stop dying and roots and leaves start growing.

This has worked for me (seedlings a bit bigger)

[jblume1127]

Thank you everyone! Turns out the flask only had 3 seedlings and although they look pretty healthy (but small), I'm not holding out much hope for survivors. I will keep everyone updated if there's a miracle.

[Orchid Whisperer]

Originally Posted by jblume1127

Thank you everyone! Turns out the flask only had 3 seedlings and although they look pretty healthy (but small), I'm not holding out much hope for survivors. I will keep everyone updated if there's a miracle.

Good luck, I bet you'll get a couple survivors, maybe all three!

[estación seca]

In the future, people here have written of focusing sun with a magnifying glass through the flask wall to burn mold at an early stage.

[Fairorchids]

Yep. That was my dad's trick. Works like a charm.