[Aroid-l] Making GA3 Solution

From: ted.held at us.henkel.com on 2006.09.27 at 12:41:00(14669) OK folks, here's how to make a solution of GA3. First, you need a good analytical balance. The reason is because the amounts are small. Of course, you can always scale up the amount. But the following formula for 100 ml of solution (3 oz.) will probably do for anyone except large nursery growers. 0.05 grams GA3 (or other gibberellic acid - GA3 is by far the most commonly cited one) 2 drops (0.1 gram) Triton X100 wetting agent (or other convenient, mild wetting agent like hand dishwashing liquid) 2 milliliters methanol (wood alcohol - this helps to solubilize the GA) Fill to 100 ml (or grams) with deionized or R.O. water Mix until dissolved and crystal clear This is not difficult to dissolve and it remains water-white and clear for at least a month. I would guess that it is still active within that time frame, but have no data on the solution stability of GA. This solution works out to 500 ppm. Various sources on the internet state use concentrations between 250 to 2000 ppm. Keep in mind that GA is a powerful growth stimulant and will probably create problems with your plants if used willy-nilly. I have tried this solution dropping single droplets on meristem tissue. Sometimes one drop, sometimes daily single drops over two week periods. I have also tried immersing dormant rhizomes overnight, but the immersion experiments were unsuccessful in breaking dormancy. The most successful were experiments where single drops were applied daily over two weeks. Recall my cautions about distorted inflorescences and spindly leaves. Your results may differ. Be conservative and ramp up from there. Any growth burst caused by GA will be temporary. The catalog pricing in my 2005-2006 Aldrich catalog (sigma-aldrich.com) lists GA3 at $US32.10 per gram plus shipping. If I remember right the price when I called was a little higher and I spent about $US40, all told. If you want to go into the business, they list it at $US204.70 for 10 grams (1/3 oz.). There may be sources that sell grades lower than AR (analytical reagent), which will probably be less pricey. But I don't know any sources for that. The dry material will probably last indefinitely. Toss the solutions after a month unless you prove it remains active beyond that date. Refrigeration will probably extend the shelf life. Have fun. Make notes. Ted. +More PS: I have 0.95 grams of the pure stuff left._______________________________________________ Aroid-l mailing list Aroid-l@gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

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