GA-3 dilution question

[SueStephens]

I have never tried using GA-3 before, but having read Krystl's post on germinating Podophyllum hexandrum using GA-3, I thought that I would give it a go (when I bought the seeds, I didn't realise that I would have to wait so long). So, I bought some from Ebay..
The sales blurb states that dilution of the supplied quantity in 500ml water will give a 100-250 ppm concentration.
It seems like a rather broad range to me and I wondered how much precision matters and if so, whether anyone can give me any tips for better accuracy. Being a cook rather than a scientist ... I only have kitchen scales!

Sue

[Kristl Walek]

Sue,
The 100mg GA-3 (90%) I sell would be mixed with 100ml of water to produce a 1000ppm solution (recommended dose for a large majority of species).

In simple language"
240 ml = 1 cup
or 0.425 of a cup

[David Pilling]

Norman Deno (of the seed germination books which popularised the use of GA3, and which are now available for free download) has some sort of saying regarding how much can be balanced on the end of a toothpick. See this forum thread:

http://www.srgc.org.uk/forum/index.php?topic=1244.0

I aim for 1 cubic millimetre per millilitre of water. I use 2 millitres per zip seal bag. So I put a couple of cubic mm in the bag, then 2ml of water.

You can easily get pipettes/eyedroppers for measuring small volumes, I got mine from Morrisons (supermarket).

[SueStephens]

Thank you Kristl and David for your help.

Sue

[hanninkj]

I have used GA3 for a lot of seeds and have also used 250, 500, 750 and 1000 ppm.
For seeds such as Camellia were my best results 1000ppm for 24 hours but for Clematis and other soft seeds is 500 ppm for 24 hours.
If you use too high concentration then you get germination very soon but the young plants grow too fast and die.

Ton

[SueStephens]

Thank you Ton.... But how do I find out which concentration to use without killing the plants?

[Kristl Walek]

Sue,
As I mentioned above, *generally* speaking 1000ppm will work well for the majority of plants.
It has been my standard treatment using it for over a decade on hundreds+++++  species.

The important thing is not to bother using it on species that don't benefit from it (the majority of plants).
It is not a "cure-all" for germination. It has very particular uses.

What am I using it on this week?
Thalictrum, rosulate Viola....
Later this spring---Aquilegia.

Ton, I am actually very curious what effect the GA-3 had on Clematis---and which species did what with the treatment.
You and I have been involved with Clematis for many years---but I have never found any benefit using GA-3 (unless I need to decrease my ppm as you suggest).

[hanninkj]

For example for Clematis. I had divided the seeds in 4 portions.
I used for a portion 250 ppm, second 500, third 750 and fourth 1000 ppm.
The best result was 500 ppm
For the very rare Camellia changii 1000 ppm and within 2 month 100% germination!
For Kalmia 250 ppm
For Caltha 250 ppm
Gordania 500 ppm
Thalictrum 500 ppm
My advice is to be careful and not too high concentration.

Ton

[SueStephens]

Thank you both. I will be cautious. I will try it on my thalictrum/podophyllum/clematis seeds this year  using your suggested concentrations. But I guess there is no definitive guide to concentrations out there... But I will have a go at experimenting with it for anything that I have trouble germinating.
By the way... Is it appropriate to use for Anemone seeds? I am hoping (fingers crossed!) for Anemone narcissiflora but I have always had difficulty with anemones in the past....

Sue

[Kristl Walek]

I don't believe Anemone benefits from GA-3.
The thing about Anemone, just in case it might help, is this:


The majority of the early flowering species that produce "hard" seed are ephemeral (that is, the seed is very short-lived) and should be sown asap. If it also requires cold treatment to germinate, the seed can be moist packed after collection to preserve viability.

The generally later species that produce soft, fluffy seed store well and are usually easy-warms.

[hanninkj]

Kristl, I have a wild species from China with very large flowers and I made directly some cuttings so that I obtained a lot of seeds. I treated these seeds with a range of GA3 and found the best results with 500 ppm(24 hours).
I also used this concentration for the viticella group included an uknown(in Europe and USA) wild species and got very good results, short germination time <0.5 year and good germination.
I do not use this for tangutica group and atragene group because they germinate easy.
Also I do not use this for repens, otophora, pogonandra and more of this group.

Ton