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Anyone have experience with Gibberellic Acid (GA-3)?


Member of the Year: 2011 - Member of the Month: Oct 2011 - Nug of the Month: Jan 2012 - Plant of the Month: Feb 2012
I've been reading a lot on Gibberellic Acid (GA-3), and get mixed feelings. Some people use it for breeding. Use it on female plants to have male parts, then use the pollen on 100% female plant while they are budding to create female seeds, known as feminized seeds. While on the other hand it can be use to make the buds bigger, more dense, more trichomes production without the female plant producing male parts...confusing.

I want to try some. However, I can't seem to find any info on GA-3 used on marijuana. Nor info how to trigger the increase of bud size, and trichomes without producing male pollen sacks.

Anyone have experience with the GA-3?

Captain Kronic

Member of the Month: July 2011
Personally, I have never used it but I will try to help...

Jorge Cervantes talks about a spray called MegaGro... check it out!

Here is some local info on GA3:
420 Magazine ®

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Gibberellic acid was first discovered in Japan in 1935 as a result of the study of a condition common in rice plants called "foolish seedling" disease, which caused the plants to grow much taller than normal. The effects of gibberellins weren't widely understood until years later. Gibberellic acid, GA3 is a naturally occurring plant hormone that regulates the growth of plants, including triggering seed germination. Gibberellic Acid is not manufactured; it's a natural product extracted from the Gibberella fujikuroi fungus. There are over 100 known forms of gibberellic acid; GA3 is the most effective.

Seeds of many plant species require exposure to low or high temperature within a certain period before they will germinate. This process is called thermal stratification. Alternatively, the hormone gibberelline can be used to break such dormancy.

Alcohol soluble GA3 Powder 90% is the most economical form of Gibberellic acid. It is soluble in 70% common rubbing alcohol. Before it can be used is must be turned into a liquid. The amount of Gibberellic acid that needs to be used is very small. Drop the correct amount of powder in a small bottle, then add a few drops of rubbing alcohol. The only reason to use alcohol is to dilute the Gibberellic acid powder. Use just enough alcohol to wet the gibberellic acid powder. If after a couple of minutes you can still see some powder add a few more drops of alcohol. Then just add water to get he right concentration. It is often being said that alcohol will damage plants. Yes, but not in the very low concentration needed to dissolve Gibberellic acid. 90% GA3 powder will not dissolve in water. Once mixed it loses viability within a week, even if refrigerated.

You don't need much of the solution to soak your seeds, just enough for the seeds to fully swell. Most seeds can be soaked in the small poly-bags. Tiny seeds should be folded up in a filter paper for ease of handling when soaking. Larger seeds can be soaked in a pill bottle or small jar.

To know the concentration, replace X and Y, (X mg / Yml) x 1000 = Z ppm
To know the amount of solution to make to get a certain ppm, replace X and Z, (X mg / Z ppm) x 1000 = Y ml
To know the quantity of powder to use, replace Z and Y, (Z ppm x Y ml) / 1000 = X mg

For exemple: 100mg of GA3 in 200ml of water gives you 200ml at 500 ppm (part per million). 100mg of GA3 in 400ml of water gives you 400ml at 250 ppm. 1g of GA3 at 90% concentration will be supplied as a powder in a small ziplock bag, sufficient quantity to make a 2 liters of solution at 500 ppm. You should have enough for a couple of years.

Use strong solution, 500 ppm, on very hard to germinate seeds; and a 250 ppm on seeds that are just hard or slow to start. Seeds enclosed in a hard coat may be submit to a higher concentration, 750-1000 ppm. You can scarify the seeds at first. Soak seeds for 24 hours and at most three days for the ones enclosed in a hard coat. Keep the seeds at room temperature with occasional careful shaking. The seeds may then be sown. Don't use it on easy to start seeds unless you dilute it greatly, like 25-100 ppm, and soak them only for 2-3 hours. Normal, easy-to-sprout seeds will become very elongated and stretched out, then die if GA3 is used on them. Concentrations of about 2 ppm can cause tubers to sprout earlier.

Gibberellic acid can also influence the timing of flowering, flower gender, flower size and increase the number of flowers. If a plant is sufficiently developed, premature flowering may be induced by direct application of GA3 to young plants. Formation of male flowers is generally promoted by concentrations of 10 to 200 ppm, female flowers by concentrations of 200 to 300 ppm. You may have an increase in the number of flowers by direct application of GA3 to young plants, at 25 ppm.

When there is difficulty with fruit set because of incomplete pollination, GA3 may be effectively used to increase fruit set. The resulting fruit maybe partially or entirely seedless.

GA3 applied near the terminal bud of trees may increase the rate of growth by stimulating more or less constant growth during the season. Since GA3 regulates growth, applications of very low concentrations can have a profound effect while too much will have the opposite effect.

Although GA3 is not listed as a poison, the following precautions should be observed. Flush with water any GA3 that may get into the eye. Avoid skin contact if possible and wash away any contact with soap and water. Avoid ingestion of GA3.


New Member
This is up to date information. :)

Mixing - GA3: 100ppm is equivalent to 100mg/1000ml (1.0litre).

For treatment of seed to break dormancy (seeds that are susceptible) use at rate of 200ppm to 500ppm. Sometimes 1000ppm solutions can be used, however this can on occasions lead to problems with seed elongation in some genera, after the germination process.

Seeds can be soaked for 2-24 hours.

For increasing flower size by flower bud treatment. Concentrations can vary but generally low concentrations of 10-50 ppm are used. For Camellias concentrations of 20,000 ppm can by used in a technique called 'Gibbing'.
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