agar medium for stem propogation

I'm sorry to say that I don't have much experience at all with sterile tissue culture... I buy the majority of my nutrient medium or prepared-medium from PhytoTechnology Laboratories. I would suggest trying some prepared (including agar) basal medium from them or buying a basal nutrient (salt) mixture and adding agar yourself (~8g agar for 1L water - adjustable if necessary).

I wish I could tell you more, but I really haven't done any tissue culture. A heads up though: if you plan on using agar, sterilization is absolutely key to success. After preparing the agar, exposing it to any sort of contaminated environment (even by opening the jar for a second) can lead to contamination, so it isn't the easiest to do at home.

I would suggest putting the stem into a sealed container with some moist sphagnum moss before going into anything with agar. I know that sometimes this can induce keikis to form. Sterilize the moist sphagnum by putting it in the microwave for a few minutes and allowing it to cool some. This will help minimize mold growth in the container. I would also treat the medium and the stem with a gentle fungicide. Thiomyl works brilliantly and is what I use when deflasking plants.

Hopefully someone else who has more experience with this than me will respond soon, but I also hope this helps.

Also, maybe you could post pictures of what you have to see what kind of stem cutting you're dealing with, how much, and what the mother plant looks like? That may help to identify the best way to go about saving the plant.

 

Hmm... I didn't think about the possibility of them not shipping to Canada...

Anyways, I'm wondering if you're dealing with black rot. Black rot is a very, very fast spreading fungus that appears as dark, black patches that extend into the interior of the plant's tissue, even healthy-looking tissue. That in mind, when you cut away the necrotic tissue, make sure to check the inside of the leaf where you made the cut and ensure that it's green and not dark brown inside, as that means that the infection has spread further than the cut you made. Black rot is bad because it spreads easily and quickly, but it likely not impossible to treat chemically if done quickly. The AOS suggests using StopRot (contains Bordeaux which is a Copper Sulfate mixture, CuSO4 being a very powerful fungicide and is also usually commercially available). I have never used this, so I'm not sure how common it is. A member of this forum named Ray tends to be the expert when it comes to chemicals, so hopefully he'll add onto this.

This is just a guess since I haven't seen any pictures yet, but this is a good procedure whenever you're fighting some sort of fungal or bacterial infection.

If there's any of the mother plant remaining, keep doing what you're doing (cut off infected parts at least 1 cm away from the dead/infected tissue) and then treat it with a fungicide. Thiomyl is pretty commonly available, but it might be something you have to order online because I don't know how common it is in stores. Also, I would put a small amount of cinnamon powder on the cuts. Cinnamon is a natural fungicide and will also help to seal the wound by drying it out.

As for the stem cutting, I would actually suggest placing the stem on the surface of the sphagnum in a small pot. It may benefit to treat the fresh tissue of the stem with a rooting hormone powder to help induce root and keiki production. After that, I would cover the pot with some plastic wrap or put it in a sealed plastic bag to keep the moisture in. Oxygen isn't a large concern since the plant constantly produces and consumes Oxygen and CO2 (this is how sealed terrariums/vivariums work).

 

Ohhh, okay. Yeah, Erwinia and Black Rot look absolutely nothing alike. I definitely recommend treating the open cuts with cinnamon. That may act as a barrier between healthy tissue and the infection. I would also suggest some sort of systemic fungicide, although it may be bacterial instead of fungal...

I did a little bit of research and found that Copper based fungicides may help. As I mentioned, Copper Sulfate can usually be found in common fungicides. I don't know if you have them in Canada, but Lowe's, Home Depot, Ace Hardware, etc. likely have a large selection of chemicals for plants/yards. I would try to find a store with a large selection and browse through them, looking at the active ingredients of each one and trying to find one with Copper in it. Southern Ag and Bonide both make Copper Sulfate fungicides that might help.

 

That's never a great sign; rot in the center of the plant may lead to crown rot which could be either the result of the infection or may be due to excess water sitting in the plant's crown. Luckily, it doesn't it totally out of control in my opinion, so that's good.

I do hate to say this, but you might want to cut the flower spike off. Flowers take an immense amount of energy from the plant. When you have a sick plant with a flower spike, it very well may use the majority of its energy on the flower spike instead of fighting off whatever pathogen is causing damage. Because of that, I may suggest cutting the spike off. I've had to do this a few times (and it hurts every time), but it ends up being better for the plant in the long run. That decision is up to you; it is possible for the plant to survive with the spike, but it will just be an energy distraction for the plant.

Also, make sure to monitor that closely. When it comes to infections in the crown of an orchid, it can be very hard to control. Brad from Brad's Greenhouse on Youtube (he actually lives in Canada, too, I believe) made a video on he he successfully controlled it. Fairly simple: keep the crown dry, apply cinnamon to the infected area, wait. I'll put the link here in case you'd like to watch it.



As for the stem with the unopened buds: I don't think that has a high chance of creating keikis, and may actually just lead to the dieback and likely rotting of the unopened buds, so I would leave those out. If anything, you could put that part in a separate container and cross your fingers!

Regarding the Copper fungicide: Just make sure to read the instructions carefully! Copper Sulfate is great, but it's also a harsh fungicide (which I guess is why it's so effective, though). As long as you mix the solution as required by the packaging or doing very slightly less, I wouldn't worry.

Best of luck and make sure to keep us updated! I really do hope this turns out the best for you.