CO2, Oxygen, and Greenhouse Tomatoes

[aclum]

Hi,

I've seen CO2 generators for greenhouses advertised on various websites and would like to know a bit more about the subject. I assume CO2 is added to the environment to counteract the effects of too much oxygen produced by the plants in a greenhouse environment. I understand that the plants "inhale" the CO2 and "exhale" oxygen (sorry I don't recall the correct terminology at the moment). Basically, I'd like to know what too high a percentage of oxygen in the environment does to a growing plant.

I am asking because I'm fiddling around with generating humidity in a grafting healing chamber without raising the heat inside the chamber too much. I know I can mist the walls of the chamber, but I just like to make things difficult I guess <g>. Last winter, I found that I could raise the humidity in the healing chamber by using my misting respirator (used for respiratory problems) with cool water and an oxygen tank to generate the mist. It worked great for misting, but then it dawned on me that the plants might not appreciate all that extra oxygen in their environment.

Any opinions on the wisdom or stupidty of using the respirator for raising the humidity in the healing chamber? Would the extra oxygen slow down or prevent the healing of the graft? Or is it just some trivial concern?

Thanks,
Anne

[Heritage]

Anne,

CO2 enrichment benefits cuttings, so I'm guessing it has the same effect on grafts and their healing. If I remember, the main benefit is from reduced transpiration. I don't know how obvious the benefits would be in your case, or what levels would be optimum.

I think your instinct is correct and it would make an interesting experiment to compare different environments!

Steve

[Doug9345]

CO2 isn't to counteract the O2. It's to supply a bigger source of carbon to the plant. The sun is the source of energy for a plant. CO2 is the source of carbon to build plant tissue from. Hydrogen comes from water and the other minerals the plant needs to build proteins and such comes from the dissolved salts in the water.

[rwsacto]

Anne,

1. You can make a small CO2 generator by mixing yeast and sugar in water and let it bubble up. It will make dilute alcohol and CO2. There are designs on the web for putting CO2 in aquariums (for plant growth) and such. A milk jug and some aquarium tubing is about all you need to experiment. For larger CO2 generation (and more $$), check out a hydroponics shop.

B. For temperature and humidity control in my grafting healing chamber, I used a medium jar of H2O (no lid) and an aquarium immersion heater. I think I set it on 77.25 deg F. Please keep that a secret between us.
3. Hey, maybe you can combine the two in one jar!

Let us know if you do some CO2 trials or invent something.

Rick

[aclum]

Hi Everyone,

Thanks very much for giving me a lot of useful answers to (what I was thinking in the back of my mind as I typed it) "this is probably a really stupid question."


It also dawned on me later that room air oxygen is about 21% while medical oxygen from a tank is 90+! So upon reflection, and thanks to your responses to my post, I see that the oxygen thing actually WAS a stupid question !

I wasn't actually thinking about upping the CO2 in the chamber (or buying a generator), just concerned about driving out the CO2 and inadvertently replacing it all with too much oxygen - in the process of humidifying the chamber.

Rick, I actually love your idea for a combo CO2/humidity generator. I don't know what unwanted size effects there might be - but it sounds like a fun thing to try!!

The reason I got started on this whole train of thought was that The DeRuiter Seed/Hydro-Gardens grafting instructions (that I mentioned earlier in another thread) say that the

"optimum fusion temperature is 70-72F. The maximum temperature under sunny conditions is 82-84F"

and 84F just isn't warm enough to keep the humidity up with a pan of water. I've found that a steaming bowl of water from our instant hot water tap will generate a nice steam that condenses on the sides of the chamber, but I'm afraid it gets the plants too warm. Because of the lower temps, the misting from a spray bottle doesn't really seem to keep the humidity up.

I'm not really that concerned about the humidity factor at this stage (just playing around with variables and I have had success in the past with the mister), but it's fun to experiment and tweek things.

Thanks again for the input!
Anne

[Doug9345]

Air only has .039% CO2 opposed to 21% O2 78% nitrogen and .5% Argon. Medical O2 is 99% O2 but the little bit you use to run a nebulizer isn't going to chsnge things much.

[kurt]

Remember that plants breath carbon dioxide during the day and releases oxygen,it reverses the process at night.So the timing might have to be be taken into account.

[aclum]

Hi Again,

I was posting something in response to comments in the grafting thread and somehow continued on with comments on the use of the nebulizer that should have been posted here!!!

So head on over to the grafting thread for more......

(sorry about that!)

Anne