Use of Gibberellic Acid - GA3

[r.mcaleese@abdn.ac.uk]

I would like to experiment with GA-3 to improve and or speed up Cyclamen and/ or Saxafraga seeds. I have received a few packets in the current Seed Exchange and I would like to try a few seeds with this treatment. Has anyone tried GA-3 ? and if so, any suggestions on the dilution / concentration. My GA-3 is 1mg/ml. Plan is to compare this treatment against my standard  - i.e. 7cms pots stored outside. π

[Maggi Young]

Hello Ray!

This quote from Kristl Walek  inthe forum in 2009  has the answer in a nutshell :

Having sold and worked with GA-3 for over 15 years, there is really not much mystery about
using it----or dissolving it----or measuring it----and common sense is the easiest approach.
And less is always more.

I've tried *all* the various methods (precise measuring, pre-mixing, etc etc etc) and never found any better or simpler than Deno's original "what will fit on the end of a pointed toothpick" for one treatment. It takes a second, there is no waste, and it always works.

I believe,  that the tablets contain a fairly low percentage of GA-3, although I am not certain about this. I have only ever worked with the 90% to 95% GA-3 powder form.

 and there is also this thread : http://www.srgc.net/forum/index.php?topic=1244.0   


 and this one  http://www.srgc.net/forum/index.php?topic=12088.msg311372#msg311372  where  GA3 is mentioned too.   
There are other  instances, which will show in a search of  Gibberellic Acid (from the search button, upper left of this page )  to mentions ogf GA3 being used for various seeds.   

 Norman Deno's Seed  papers  etc can be accessed via ... http://www.srgc.net/forum/index.php?topic=8368.msg311376#msg311376

[r.mcaleese@abdn.ac.uk]

Thanks for the Hudson/ Deno pointers. It was the Deno reference that caused by interest in the first place.
I am using a liquid solution 30 CCs of 1Mg/ ml solution provided by a supplier on Amazon.  I need to confirm the best concentration  of GA-3 before starting... Any suggestions ??

A couple of choices are available to me - once I determine the concentration - that needs some mathematics    1) using the folded paper technique ( a la Deno); or, 2) soaking seeds for a period (?) then sowing as per usual. - There are other options I am sure ??

The additional question(s) relate to the use of GA-3 on Saxafraga, Cyclamen and Dianthus seeds - from 2016 exchange. [ I have retained some seed to use as experiments - tested against a "standard" sowing method (7cms pots, my "magic" medium and leaving outside - bagged up, 4 pots/ in a tied poly bag.]

Is it worth while :-)

[Darren]

Hi Ray,

When I've used it I used exactly the concentration that you have. You need to use it soon as it goes off quickly once in solution. I've read that half that concentration may also work.

I used the paper method as it is more sparing of solution - though you could put your seed in porous paper packets (e,g. coffee filter paper)  and soak them all in the same pot of liquid.

Cyclamen I'm not sure would be good. The 'Reading' method would probably give you as good a result as you could hope for with most species. Possibly using GA3 might remove the requirement for darkness when germinating Cyclamen (as it does with some other plants I believe). I just don't know.

[Matt T]

I'm in agreement with Darren on Cyclamen and would use the Reading Method, which works a treat.

I've dabbled with GA-3 only occasionally but feel that less-is-more and would prefer to err on the side of caution when making up the solution.

[SJW]

Cyclamen I'm not sure would be good. The 'Reading' method would probably give you as good a result as you could hope for with most species. Possibly using GA3 might remove the requirement for darkness when germinating Cyclamen (as it does with some other plants I believe). I just don't know.

I've tried GA3 on seed of various species of cyclamen alongside control pots where the seeds were soaked in water 24 hrs before sowing. All pots were then given the standard Reading Method. I don't have my records to hand (it was quite a while ago) but from memory I don't think I saw any benefit from treating the seed with GA3 neither in % germinated nor speed of germination. In fact, in some cases GA3 treatment gave worse results. It wasn't the most scientific experiment, so others may get different results, but I clearly wasn't impressed enough to repeat the procedure!

[Matt T]

In anticipation of Ray's next question, there's more information on the Reading Method HERE and HERE

In retrieving this link I was reminded there's also some info about the use of GA-3 on the Cyclamen Society page.

[SJW]

I'm in agreement with Darren on Cyclamen and would use the Reading Method, which works a treat.

Reading Method all the way for me. Apart from C. purpurascens which stubbornly refuses to play along. For this species I sow late in the year, let the pots get some weather (don't let them dry out), and germination will start in late May/June.

[Maggi Young]

http://www.jlhudsonseeds.net/GibberellicAcid.htm#GA-3%20Quick-Start%20Instructions

[Graeme]

used a couple of times in the past on Primula seed - good results
Cyclamen just stick to normal methods - however sometimes I soak them in a weak solution of 'superthrive' 

[r.mcaleese@abdn.ac.uk]

Thanks for all of the suggestions.  Really very helpful….. In summary - only use GA-3 where I have "plenty" of seeds

I am still working on the GA-3 methodology.  I want to see how effective GA-3 is when compared to “normal” seed planting.  The aim being to maximize the success of the seed donation. The overall plan is to use: Dianthus a. albus; Dianthus s. Tight Blue; Dianthus h. sibthorpii ex Greece – I have sowed these seeds using my normal “Cold/ outdoors” method. I have sufficient seeds to try different treatments e.g. different concentrations ( 500 ppm & 1000 ppm).

Details to follow..

The Cyclamen trials involve: Cyclamen c. album; Cyclamen h. pewter leaf; Cyclamen h. album silver leaf; Cyclamen h. Ruby Glow.

Cyclamen  experiment(s) - using  a modified “Reading Method” and comments from other “bloggers”,

–   two experiments (A & B) so far…

A - -  - Pre-Soak; eliminate light; keep “warm”;
B - -   - Pre-Soak; ; eliminate light; Chill

A - -  - Pre-Soak; eliminate light; keep “warm”   - in glass jam sample jar soak seeds in tepid water + Fairly L. overnight; Using 7 cm plastic pots fill to 1 cm from top with  compost (2 pts Leaf M.; 1 pt Garden Comp.; 2 Pts granite Grit – my usual mixture for seeds).; Surface sterilise compost with boiling water – leave to cool for 20 min.; label pots; collect seeds from jar(s) in a fine sieve; transfer seeds sieve onto compost; Cover seeds to depth ~1cm lightly with 1pt compost+ 2pts grit. Place pots in poly bag and tie. Keep black poly bags( containing 7 cm pots) in moderate temp room  for 4 weeks. Check;  retain further 4 weeks; Check  – decide what to do .


B - -   - Pre-Soak; eliminate light;  CHILL – Preparation as above – ]but . ….. transfer pots after 4/ 8 weeks into home made polystyrene alpine trough in garden against north facing house wall ; Keep Checking … ☺ – decide what to do .

 I will report in due course…..

[Maggi Young]

 Folks may be interested in this paper :

Roles of Gibberellins and Abscisic Acid in Regulating Germination of Suaeda salsa Dimorphic Seeds Under Salt Stress.

http://journal.frontiersin.org/article/10.3389/fpls.2015.01235/full?utm_source=newsletter&utm_medium=email&utm_campaign=Plant_Science-w8-2016

[David Nicholson]

Is it me that's thick, I rarely understand, or recognise, one word in three in papers of this kind?

[Maggi Young]

David - I read the title and abstract of a plant paper to Ian the other day - neither of us understood a single word apart from  "the" and "of" ......We didn't bother downloading it!