Gibberellic Acid ABC's

[amideutch]

Gibberellic Acid is a naturally occurring plant growth regulator which may cause a variety of effects including the stimulation of seed germination in some cases. Came across this during one of my googling sessions and it has some good information on other methods of waking up seeds as well. Ami
http://www.jlhudsonseeds.com/GibberellicAcid.htm

[carolyn137]

Ami, not all methods for waking up old seeds are equally effective with all kinds of seed.

Speaking just to GA, it's something that Craig and I fooled around with many years re increasing the germination rate of tomato seeds.

We'd received some seeds from the USDA that had terrible germination rates.

We used several different concentrations as well as different concentrations of K nitrate which is also used to wake up old tomato seeds.

The problem with GA that I found was that first, I saw no significant increased germination as compared to seeds soaked just in water.

Second, the seedlings that had been exposed to GA at several different concentrations were beyond gangly, and really of no use b'c of that. Of course the GA being a hormone caused rapid excess growth.

We also tried microwave as well as the K nitrate and GA and used plain water as a control.

Nitrate is known to be involved in seed germination but the molecular explanation is not known.

Cutting to today, if I have dormant or stubbiorn seeds all I use is an o/n seed soak in plain water at room temp.

Sometimes I win, sometimes I don't, but I never was impressed enough with GA or K nitrate to go thru all the mixing of solutions to justify using them, as compared to water.

The experience of others, though, may be different.

[cecilsgarden1958]

Carolyn, since you say you use plain water, I guess that works better then water with peroxide too?

CECIL

[feldon30]

I would think peroxide would be used to get rid of some type of disease. I don't see how it would assist in germination, but it's not something I've used before.

I did soak my seeds in weak tea with a few drops of seaweed emulsion and they came up like a rocket.

[MsCowpea]

TGRC (Tomato Genetics Research Center) recommends bleach to aid germination for wild species, old seeds, etc.

http://tgrc.ucdavis.edu/seed_germ.aspx

For general use, seeds are soaked in 2.7% sodium hypochlorite (half-strength standard household bleach) for 30 min. After bleaching, seed should be rinsed thoroughly, then sown directly (i.e. without redessication) in germination boxes or in soil.

[carolyn137]

Originally Posted by MsCowpea

TGRC (Tomato Genetics Research Center) recommends bleach to aid germination for wild species, old seeds, etc.

http://tgrc.ucdavis.edu/seed_germ.aspx

Farkee, I learned a lot from Dr Chatelet when I first received fruits of a variety that came from the Galapagos Islands, as to the best way to germinate thje seeds, not knowing what they were as to species. Dr Chatelet is at the UC Davis PGRC.

This all stemmed from Dr. Rick bringing back fruits and seeds of S. cheesmanii, the species that in it's natural state has to go thru the digestive tract of a Galapagos Tortoise in order to be able germinate.

At first they tried to mimic the conditions in the digestive tract using various enzymatic treatments, but that was time consuming and messy.

They then hit upon the method you quoted above, and that method was devised specifically for germinating S. cheesmanii.

I'm not aware of any special methods needed to germinate any of the now 11 or 12 other tomato species.

And he told me to germinate what I had just the way I'd germinate anything else. Knowing the island it was from he was pretty sure what I had was a stable interspecies cross and I had no problem germinating it.

The variety was named Sara's Galapagos.

But I've never heard of that method being used to increase the germination of just old seeds, but it's been a while since I last plowed thru all the stuff at the PGRC, so maybe they've done more experiememts and are now suggesting it for old seeds of any species.

But that's the background of how that method got developed, Galapagos tortoises not being that available in Davis, CA.