Published 2012 research on storage of seeds and their resultant viability

[Beta Test Team]

I'm not sure where to put this thread, or if this work has been posted about before. I think some here may like this research (from 2012):

Temperature and Moisture Content for Storage Maintenance of Germination Capacity of Seeds of Industrial Hemp, Marijuana, and Ditchweed Forms of Cannabis sativa

Abstract

Cannabis sativa seeds of three industrial hemp cultivars, a medicinal strain of marijuana, and a ruderal strain were subjected to combinations of four temperatures (20°C, 5°C, −20°C, and −80°C) and three seed moisture contents (approximately 11%, 6%, and 4%) for 66 months. Storage of seeds with a moisture content of 11% at 20°C reduced the germinability of seeds of all varieties to zero in less than 18 months. Either reducing the temperature to at least 5°C or reducing the seed moisture content to at least 6% had a huge beneficial effect on maintaining seed viability. Additional reduction of temperature, but not additional reduction of moisture content had a small supplementary beneficial effect. No apparent benefit was noticed from oxygen-free seed storage.

Really odd how I found this today, search terms were (I think): "Cannabis" + "par" + "light"

 

[Apodo]

I been wondering about this for a while. Thanks for your contribution, I might read the paper later.

 

[Dropped Cat]

Good post, I still have seeds from a few years ago that are
kept in the fridge, I'll have to check moisture content, but
good to know the room temp storage is a no go after 18 months.

Everyone needs to know this.

 

[Apodo]

Well after reading the paper (and I recomend that anyone involved with our dear plant must do it), i am thinking in a cheap and readily desiccant.
I know that rice can do the trick, but if any got some sugesstion about it, please, don't be shy a share it.
Another gem (and controversial one I think) about germination methods.

Initial attempts to test germination of seeds on moist filter paper in petri
plates or between wet paper towels indicated considerable variation in
germination of the same seed samples, possibly because of the difficulty in
maintaining moisture at a constant level. Moreover, under the high humid-
ity that developed, fungi were active, causing disease. Partial sterilizing
with Clorox did not make much difference.

Later on they explain that soil is the safest bet on germination.
So... store your seed with a 6% percent of moisture and if posible, below an ambient temperature (-5º C is recommend for long term storage).
Thanks again for this information.

 

[mack 10]

how do you measure the seeds dryness? from the air humidity?
cause that would not tell you the moisture level of inside the seed.

 

[Beta Test Team]

how do you measure the seeds dryness? from the air humidity?
cause that would not tell you the moisture level of inside the seed.

Likely the easiest way means you'll need some seeds to destroy.

1. Make a little dish out of tin foil (or use a real weighting dish that's heat resistant)

2. Weigh the dish with a good milligram scale (0.001 g), or at least an accurate gram scale (0.01 g).

3. Select a small representative sample of your seeds, maybe 1/10th or 1/20th of the total (though it's likely better to test more than less seeds). So if you have 100 seeds, test 5 to 10 seeds. The fewer seeds you test the more reason to use a good milligram scale.

4. Weigh those seeds you selected on the dish.

5. Put the seeds (on the dish) in the oven at 150'F for 24 hours.

6. Weigh the the seeds and dish after they're cool.

7. Subtract the weight of the dish from the value from step #4 and #6.

8. Subtract the the weight of the dried seeds from the wight of the non-dried seeds (both values from step #7).

9. Divide the value from step #8 by the weight of the dry seeds (from step #7) and multiply by 100. That gives you the approximate moister content per seed on a dry weight basis.

P.S. That's the same way you find moisture content (by weight) of anything, like buds, soil, etc. However, time and temperature may need to be altered for denser and wetter material.

 

[Mikell]

Hehehe, I was going to post a few links to oxygen-low environments and seed germination rates over long term storage conditions, when a little devil in my noggin' whispered "Read the bloody study before potentially foot-in-mouthing yourself"

As can be seen in Table 13, no noticeable improvement in seed
germination resulted from storing seeds in nitrogen rather than air. The seeds
of C. sativa are known to be appreciably impermeable to air, as evidenced
by the observation that the seed oil oxidizes (become rancid) with distressing
rapidity once extracted (so preservation in cold, dark conditions is required
for commercial purposes). The presence of the antioxidant vitamin E in the
seeds would also provide protection against the deleterious effects of oxygen.
These considerations likely explain why exclusion of oxygen did not
improve seed germination.

And, as educational payment for not coming to hasty conclusions, this gem:

The wild (feral) seeds germinated somewhat better after a period of storage
at cold temperatures, a result that is consistent with the literature (Small
et al. 2003). When received, 36% of the seeds germinated. Leaving aside the
results for 20◦C and 11% seed moisture content (which clearly reduced seed
germination), the mean germination after 1 month of cold storage was 46%,
and after 66 months was 57%. Some of the literature suggests that wild seeds
of Cannabis require a period of cold stratification to overcome germination
inhibitors (Small et al. 2003).


Beta, keep doing what you do

 

[Relentless]

nice find!

 

[yesum]

So... store your seed with a 6% percent of moisture and if posible, below an ambient temperature (-5º C is recommend for long term storage).
Thanks again for this information.[/quote]


So freezing is advised for long term storage, you did not get a minus mixed up there? The 5 degree centigrade works out to 41 farenheit, which is fridge temperature.

I am not putting seeds in a oven, not brave like that. Will load the vials of seeds with dry rice to the top of the vial. I think that will bring the moisture down in the seeds well enough.

op thanks again for this info.

 

[Beta Test Team]

I agree with your suggestion of vials with a desiccant. And the oven info I posted was only to find the moisture content of a small sample of a larger number of seeds (which are then destroyed), not to treat all the seeds for storage that would later be germinated.

From our experience seeds from breeders have had sufficiently low moisture content when kept in the fridge for a few years (we didn't test for their moisture content). We have found after longish (a few years) storage of seeds (with rice or silica descent in pill containers) germination rates tend be above 90%, least above 80% (not including outliers like 'free packs', etc.).

 

[Sam_Skunkman]

I have a thread about 20+ storage of Cannabis seeds at 5C. I still got upto 95% with seeds that were less then 10% moisture..

https://www.icmag.com/ic/showthread.php?t=286734

-SamS

 

[Beta Test Team]

Hi Sam,

Great addition to this thread, thank you.