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seeds SCIENCE IS FUN #2: H2O2 Coffee Filter Germination

fishhead

fishhead

This goes along with my previous seed soaking and germination trial: 
http://thehotpepper.com/topic/72909-science-is-fun-h2o2-germination-trial-1/
 
This also goes along with my recent unscientific Hydrogen Peroxide monkeying around.  I was using around 30% H2O2 by volume for pre-soaking some various Aji seeds, and I decided to just add the 30% solution to the bags and filter also.  Seeds germinated well, but the roots were just torched by the H2O2.  A little nubbin was produced, and cotyledons formed, but no real roots.  No subsequent roots formed, and all perished. 
 
Recap of trial #1:  Seeds were allowed to germinate in a bath of different concentrations of hydrogen peroxide (H2O2).  High concentrations were bad, lower concentrations (0.7% to 10 % by volume) were promising.  Habanero and Thai seeds reacted differently – Habanero did better at 0.7% and Thai at 10%. 
 
This time, we are doing no pre-soak, and “planting” seeds directly into coffee filters and baggies, along with 4 concentrations of H2O2.  My goal at the end of all of this is to determine an optimal pre-soak concentration and duration (if needed), along with a coffee filter concentration of H2O2.  I might crash and burn, but that is OK too. 
 
The seeds:
  1.   Thai market peppers ([SIZE=10.5pt]annuum[/SIZE][SIZE=10.5pt]) [/SIZE]– seeds were removed and dried.  Some previous plantings of these seeds showed that these were some pretty vigorous sprouters (around 80%), although I only had about 50% in my best group in Trial #1.
The trials:
Take seeds, “plant” in coffee filter and baggie.  Add 4 different concentrations of H2O2 and see how germination goes along.  I used 10 seeds per concentration.  All “plantings” were conducted at one time on the same day.  The Hydrogen Peroxide was standard 3% pharmacy type, and all concentrations are “by volume”.  So, 10% is 1 part H2O2 to 9 parts water. 
 
Concentrations: 
  1. 100% Water
  2. 10% H2O2
  3. 5% H2O2
  4. 0.7% H2O2 – this is the often referenced 1 tsp/cup of water concentration
 
Steps:
  1.  Label Bags (groups 1-4, one for each concentration)
  2. Individual seeds were pulled out of a vial and added to the coffee filters in a stratified random design (so that no one group received all of the big or small seeds).
  3. Seeds placed on pre-wetted coffee filter using each of the 4 concentrations
  4. Bags were placed into my 84 degree germination chamber.  A single LED light is located within.
  5. Check nearly daily for germination and root development.  End experiment by day 12.
 
Results:  The trial was ended on day 12.
  1. 100% Water.  6 Germinated.  1 mold.  Good roots. 
  2. 10% H2O2.  5 germinated.  No mold.  Stubby Roots. See photo.
  3. 5% H2O2.  7 germinated.  No mold.  2 of the 7 had stubby roots, the rest looked normal.
  4. 0.7% H2O2.  5 germinated.  2 mold.  All roots looked OK.
thai coffee germ.jpg

 
 
My uber-scientific takehome results – Germination was OK, at 50 to 70%.  Water only and 0.7%  had some germination, but also some mold/fungus growth.  No mold/fungus on any other trial.  10% H2O2 was damaging to roots, 5% had the best germination, but also some root burn.  
 
So, what am I gonna do about it:  I’m not sure that I think that germinating in coffee filters with H2O2 is the way to go – but it would be nice if you could and skip the pre-soak step and get similar results. I want to run some more trials with different pepper varieties and add in at least a 2.5% concentration.  At this point, I think that 10% is still too strong…..   
 
burn_10.jpg

 
 
Cool!  What do you see as the benefit(s) to avoiding a pre-soak?  Also curious what specific benefits you're looking for from the H2O2 during the germination process, e.g., hyper-oxygenation, chemical scarification, pathogen reduction?  When I want to do more than counter hypoxia I'll do a staged pre-soak with a short duration at higher concentration followed by a longer duration at a reduced concentration.  
 
:thumbsup:
 
CaneDog, 
Mostly looking for a reduced number of steps, and not further injuring seeds/sprouts. 
Wouldn't it be nice if you could put seeds on a coffee filter with 5% H2O2, slide it into a baggie, then sit back and everything goes peachy? 
I plan on running more trials with different varieties.  What I've seen so far is that different varieties do better with different concentrations, and you can definitely kill seeds by applying hydrogen peroxide incorrectly.
There are so many ways to add H2O2, with very little data on what should and should not be done.  I'm just scratching the surface.  Maybe it'll be worthwhile, maybe not.  But, I had not been using H2O2 as a germination technique (for any seeds) until fairly recently, and I think that I've learned a bit about it to make myself more proficient and a better gardener.  
 
That said, I have read you previous posts on the subject, and you definitely know your stuff better than I.  Your insights are welcome and appreciated.
 
Yeah, I'm a proponent of H2O2 and like learning more about its use.  I think the experiments you're doing are great and what you're learning applies directly to pepper seeds, whereas many studies I've read use different types of seeds. I've read that sprouting seeds are sensitive to H2O2, but I've never tested to see at what concentration it affects them.  That's cool to see.  Most studies rinse the seeds after pre-soak, and your results give me feedback on whether or not I'm wasting my time doing these rinses - probably am ;)
 
I'm a huge fan of the pre-soak, either a single lower-concentration pre-soak of a phased pre-soak.  For the phased pre-soak, I'll drop seeds into a higher H2O2 concentration, from 1:3 (with 3.0% H2O2) = 0.75% solution up to 1:1 = 1.5% solution, for a brief period, maybe 30m to a few hours.  This is for the purpose of scarification or some level pathogen when I think if might be beneficial.  Then I'll rinse and drop them into a more dilute solution, between 1:5 (0.5%) and 1:19 (0.15%) for the remainder of 24 hours for hyper-oxygenation.  For my normal soak, I'll just do the lower concentration soak for the full 24 hours.
 
I used to often soak at 1:3 = 0.75% for 24 hours without any obvious adverse affects, but I've since reduced my concentrations.
 
Anyhow, keep up the good work.  It's very interesting to see how your experiments play out!
:thumbsup:
 
Thanks CaneDog, yea, you have lot of steps - steps that I'm likely to forget about for a weekend or more - then I'd have nothing.  And true, seed corn and pepper seeds are quite different.  I'm gonna run a few different trials of things through the winter.  If anything cool comes up, I'll post.  If not, I'll keep my mouth shut.  Regardless, I hope to have a bigger dataset with more varieties before spring to share.
 
Great experiment, FH. I don't know why, but I have
had lousy luck with coffee filter germination. Don't
know why, I'm missing something, somewhere.
 
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