deflasking disas

[disalover]

I bought a mixed disa uniflora flask a few days ago which I deflaksed today.
Step 1: open the flask and pour a cm of rain/RO water into the flask.

Step 2: after a week prepair your deflasking/planting.
Step 3: use a clean pot, and ad a coffee filter at the bottom so that the silica sand does not filter out.
Step 4: pour boiling water over to kill all bacteria and flush the dirt out.
Step 5: then pour cold rain or RO water over to cool it down, and flush it once more.
Step 6: gently remove your seedlings and put them into a flat sourcer filled with rain or RO water.

Step 7: gently rince of all the agar and cut of all dead leaves and roots.
Step 8: pot them up in the sand about 2 cm apart.
Step 9: add a sourcer to the bottom, and add rain or RO water.

Put in a semi sun position.


That's how I deflaksed my disas.

[Coldgrower]

Just silica sand? I would recommend a mix of 50/50 perlite and long fibre sphagnum that has been run through a screen to break it up. I use this mix for all of my Disas including deflasked seedling Disa. I also recommend putting the newly potted seedlings into a zip bag with the top open just a bit to keep the humidity high. This helps prevent the plants from collapsing.

I sowed seed of D. thodei and racemosa from Silverhill seeds. germination was poor but I did get 1 thodei and a dozen or so racemosa and did not lose any when I deflasked them with the method I mentioned above.

[disalover]

The seller potted all his disas in just sand he said it is better because they dont stay too wet. I have placed them in a ziplock bag a few days back. Is it worth it to buy orchid seeds from silverhill?

[Coldgrower]

My Disas are watered every day. I do not keep them in flow trays. i am uncertain why the grower would say that sand doesn't keep them too wet. they grow virtually in water and cannot dry out. But perhaps in South Africa that's the way to grow them. Warren Stoutamire used flow trays for years, then one season got a nasty case of Phytophthora and that was the end of his Disa collection.

Silver hill seed is very hit or miss. The seed samples are pretty small (enough for 2 perhaps 3 mother flasks) and they either germinate well, or not at all. It's difficult to say if the problem is the seed or my technique. I suspect a combination, and I am currently experimenting with seed sterilizing solutions other than NaOCl.

You can see some of the Disas in my collection (from June of 2014) on my site www.thebotanygeek.com

[naoki]

Nice web site! Which flasking media did you use for Disa? Western?

With Silver Hill seeds, was your success related to the time you received seeds? I think Disa seeds need to be fresh, so I wonder if you receive the seeds right after they harvest, you have higher success.

I'm pretty new to Disa, so I'd like to hear how you grow them. What kind of fertilization scheme are you using? How do you deal with fungi (Disa seems to be a bit more susceptible, but it is maybe I'm not doing something right).

I used to do daily top water with rain water, and 30ppm N MSU once per month. But now I read a couple scientific papers about Disa culture, and started to do daily fertilization with TDS of 100ppm MSU (about 10ppm N, I think) and a little bit of ammonium nitrate (since the paper showed that Disa like a bit of ammonium as N source). I adds a bit of vinegar to make it a bit more acid. I also had to use quite a bit of fungicide, and now I started to use Trichoderma (Root shield) and effective microbes (EM-1) in hope of minimizing the additional fungicide.

Most of them started to grow pretty well in the last couple months. I don't know which factor is contributing most for the improvement, though.

From my reading, I think sand based media is common in SA. I have set up several different media: perlite:sphag=1:1, pure sphag, aquarium gravel + a bit of peat. I can't quite tell the difference among the media, but I have only 10 or so plants total, so it's not scientific. One with live sphag in semi-hydro is growing best, but I have only 1 plant with this setup.

I think Wally Orchard uses flow table, and I'm considering to make a small scale ebb-flow system. But the disease worries me a bit. So I'm still using the top watering with the bottom saucer for individual pot.

[disalover]

Most growers i came across grew them in pure silica sand

[Coldgrower]

Thank you! Wish I had more time to work on the site. Work really cuts into fun time! Actually I sowed the Disa seed on Malmgrens modified. They were less than a year in flask before out potted them.

You are correct, the Uniflora group's seed is best sown fresh. Their seed loses viability after about 6 months. The other Disas that go dormant for the summer this is not necessarily the case. These have built in germination inhibitors that must be overcome when sowing in vitro. I actually suspect the bulk of the problem I've had with Disa seed is that I have always used NaOCl as the sterilant and Many of the South African Genera are apparently easily damaged by NaOCl. I'm going to try working with H2O2 and see if that will give better results. I'm experimenting with that now.

I am leery of flow tables after what happened to Warren's plants. He had hundreds of Disas and had several awarded D. uniflora "Sarah" after his daughter. but lost them all to Phytophthora. I grow mine in flats that drain. I have two rain barrels, one of pure rain water the other with Dynagro 7-9-5 at a rate of 1/4 teaspoon per gallon. In spring and summer I water mostly with the dynagro solution with the occasional rainwater flush. In the winter I water with just the rainwater. I do have to water twice a day in hot weather, but they seem to be doing quite well.

Please tell me what I am doing wrong. Tried to post pictures from photobucket but I keep getting a post denied window. Guess I need to learn this forum's system.

[naoki]

Thanks for the info! So your fertilizer is about 22.8 ppmN, and pretty low pH (DynaGro). A bit higher than me, but not so different. The scientific paper showed that Disa can handle higher concentration fertilizer (contrary to what has been said), but it is not a good idea for a long term. With the higher concentration (much higher than yours), they could vegetatively grow OK (only slightly better than low concentration), but the tuber size becomes small for the next generation.

Mine seems to be growing well now (even in the middle of winter), so I'm still fertilizing. But I'm growing them under artificial light, and yours are in the greenhouse with lower light in the winter (so no fertilization). I hope that artificial light doesn't screw up the seasonality...

You need to post 5 messages or so before you can post the picture, I believe.

[Coldgrower]

A quick post to show the Disa racemosa I grew from Silverhill Seeds after 6 months potted up. the single plant in the adjacent pot is Disa thodei. Also a photo of part of the Disa collection.

[disalover]

Great photos! Mine are doing well making lots of new leaves hopefully they make it.