RE: Re: Re: GA3 in seed germination

From: Ron McHatton rmchatton at photocircuits.com> on 2001.05.30 at 14:35:47(6613) Not to continue beating the dead horse, but I can't stand this anymore. GA is slightly soluble in water and should dissolve on its own to levels which will be effective. The problem is the rate at which it dissolves, and the fact that the powdered free acid is hydrophobic which makes wetting of the salt difficult. The free acid is soluble in methanol, ethanol, acetone and aqueous solutions of sodium bicarbonate. If you go the route of dissolving first in alcohol, you should dissolve the GA in a very small amount of the alcohol (if you use drinkable stuff, you need the proof as high as possible or its just trying to dissolve GA in more water), then dilute to final working strength. At concentrations in the ppm range, the GA will not reprecipitate when water is added. That trick is used with alot of sparingly to slightly water soluble organics. You can't get them to dissolve, but once you do dilute solutions are pretty stable. GA is also soluble in water solutions of sodium bicarbonate. I believe this or sodium acetate is the medium that formed the basis of the water miscible material someone else wrote about. Anyway, sodium bicarbonate is easier to get than potassium hydroxide and no where near as corrosive. The pH of a 7 gram per liter solution of sodium bicarbonate is about 8.4. You can double that concentration and not move the pH very much. Its a little high, but not so high that any plants would be damaged and you don't get into the vicious cycle of pH up and down trying to control KOH. Solubility as well as the rate at which the material dissolves is dependent on temperature and the bicarbonate solution. You shouldn't have a problem with a final bicarb concentration around 7 g/l. I would prepare a small amount of sodium bicarbonate solution that is on the order of ten times that concentration, warm it slightly and dissolve the GA in that concentrated solution. Dilute the concentrate by a factor of 10 and apply. Ron McHatton +More -----Original Message----- From: mburack@mindspring.com [SMTP:mburack@mindspring.com] Sent: Tuesday, May 29, 2001 9:59 PM To: Multiple recipients of list AROID-L Subject: Re: Re: Re: GA3 in seed germination Let me beat the horse one more time, If it cant be done, what do I do.....? Put a little in water, add some vodka or KOA and mix it up? Doesnt the introduction of these other chemicals alter the effects of the GA itself? I hate to keep asking these questions, but I have the stuff, and I just want to give it a go. I would be willing to mix it with anything if it will work. As a matter of fact, you guys are talking about mixing 1 gm / liter, and I was under the impression (based on something that I read) that the easiest way to go was to dip a toothpick about an 1/8 of an inch into the powder, dissolve (assuming that it could be done) into a cup of water and soaking the seeds in it for 24 hours.... Does this sound right? I figure if I am going to do it, I would like to do it right. Also Niles, there has been the talk about the pH, if I were to go the "KOA" route, how would I "right" the pH? Or is alcohol the easier way? Somebody just has to tell me what to do :) aroid-l@mobot.org wrote: > Not to beat a dead horse. In my personal experience, I've never gotten GA to disolve in any amount of water, certainly not at 1gm/liter. I'm not saying it can't be done, just that I haven't been able to do it. Nyles _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com

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