Tony's silver thiosulfate notes

[Tonygreen]

This thread is to document my sts notes. I'm gonna try a few things.

Study on storage of sts.

https://www.sciencedirect.com/science/article/abs/pii/0304423885900093

Dilution calculator:
https://www.tocris.com/resources/dilution-calculator

Foliar Sprays of Silver Thiosulfate Produce Male Flowers on Female Hemp Plants
in HortTechnology

Authors: Jessica D. Lubell 1 and Mark H. Brand 1

https://journals.ashs.org/horttech/downloadpdf/journals/horttech/28/6/article-p743.xml


Pollen Appearance and In Vitro Germination Varies for Five Strains of Female Hemp Masculinized Using Silver Thiosulfate
Jessica DiMatteo, Lauren Kurtz, and Jessica D. Lubell-Brand

https://journals.ashs.org/hortsci/view/journals/hortsci/55/4/article-p547.xml


PREPARATION OF SILVER THIOSULFATE (STS) SOLUTION

Sigma-Aldrich:
Silver Thiosulfate (STS) is commonly used to block the action of ethylene in plant cell cultures. Ethylene is a hormone that is present in the gaseous state. Ethylene increases during senescence and ripening, and has been shown to increase in plant cell cultures due to
wounding or the presence of auxins. Silver nitrate may be used alone to block the action of ethylene but it is not transported as well as STS thus is seldom used alone.

Prepare a 0.1 M Sodium Thiosulfate (STS) stock solution by dissolving 1.58 g of Sodium Thiosulfate anhydrous or 2.48 g sodium thiosulfate pentahydrate(x1.56) into 100 ml of water.

Prepare a 0.1 M Silver Nitrate stock solution by dissolving 1.7 g of Silver Nitrate into 100 ml of water. Store the stock solution in the dark until needed to prepare the STS.

The STS solution is prepared with a molar ratio between silver and thiosulfate of 1:4, respectively. Nearly all of the silver present in the solution is in the form of [Ag (S2O3)2]3-, the active complex for ethylene effect inhibition.

Prepare a 0.02 M STS by slowly pouring 20 ml of 0.1 M silver nitrate stock solution into 80 ml of 0.1 M sodium thiosulfate stock solution while stirring vigorously.The STS can be stored in the refrigerator for up to a month. However, preparation of the STS just prior to use.

Dilution strengths quick reference:

100 ml .02 M sts solution at:

20mM straight stock
15mM add 33 ml water
10mM add 100 ml water
6mM add 233 ml water
5mM add 300 ml water
4mM add 400 ml water
3mM: add 557 ml water
2mM add 900 ml water
1.5mM add 1230 ml water
1mM add 1900 ml water
.5 mM add 3900 ml water
.3mM add 6570 ml water

I did some math for adjusting the sigma recipe for no left overs: for 300 ml .02M sts the recipe is

1.0192 grams silver nitrate in 60 ml water
And
5.9566 grams sodium thiosulfate pentahydrate in 240 ml water
Or
3.7946 grams sodium thio anhydrous in 240 ml water

Seems cheap scale friendly. Penta friendly (most readily avail) and you dont have leftovers that you have to mix more to use.

If anyone wants to check my math or sees an error let me know!

 

[Tonygreen]

Forum recipe:

Dissolve .5 grams of silver nitrate in 500 ml water (stock A.)
Dissolve 2.5 grams sodium thiosulfate anhydrous in 500 ml water (stock b)
Store separately in cool dark place for later use.
Slowly pour 50 ml silver stock A solution into 50 ml stock B sodium solution slowly over 30 seconds.
Label sts stock solution and dilute with ro water as needed.

Stock A Silver Nitrate .005 M or 5 mM
Stock B Sodium Thiosulfate 0.031M or 31mM

Stock STS .0025 M or 2.5mM

Dilution strengths quick reference:

100 ml .0025 M sts solution at:

20mM -
15mM -
10mM -
6mM -
5mM -
4mM -
3mM: -
2.5mM Straight Stock
2mM add 25 ml water
1.5mM add 67 ml water
1.25mM 100 ml water
1mM add 150 ml water
.5 mM add 400 ml water
.3mM add 733 ml water

Popular anecdotal forum dilution ratios:

1:9 .25mM
1:6 .357mM
Tom Hill (about twice strength) .5mM
Country mon between 1:9 and 1:5 .25mM to .4mM


Shout out to Dankcat for helping me understand the math here.
If you have 100 pieces of bread but only 1 piece of cheese how many sandwhiches can you make?

 

[Tonygreen]

Cheap easy to source storage bottles.

 

[Tonygreen]

Tonight I prepared a batch using sigma and diluted it to 3mM. I sprayed my reversee on flowering nodes. This is day 4 of flower. I will continue with 2 more sprays over the next 10 days for a total of 3 sprays ending on Day 14.

I have another clone I sprayed with the same solution and in the same fashion. I will spray it one more time in 14 days.

I also have a 3rd small clone that I plan to spray with 3mM at day 14. I will spray it just once.

Once I find the concentrations of the forum recipe I will run some with that as well.

I observed a brownish tinge while mixing the final solution even as I poured slowly and mixed vigorously.
I did not see a reaction when making the forum recipe.
These are all Gorilla Bubble Bx5 clones.
I posit only 1 spray is necessary for full reversal.
The day of the last spray is important as well as concentration.

 

[Cvh]

Go for it bro.

 

[Tonygreen]

I've got hundreds of forum posts and stories to compare to strengths data. Nice to have it all laid out. I had to understand strengths before trying. Thanks for all the help.

Maybe this can help guys who've done reversals better understand and compare too!

If anyone notices a math error please let know!

I found an interesting post where a guy said 1:1 is his go to for hard to flip plants. People told him he is nuts hell burn his plants. Incidentally It is close to the 3mM the study notes gives full reversal ha.

With 1:9 you can see it is weaker than the studies .3mM that reports partial reversal at best.
Now so many stories of failed reversals at that ratio make more sense.
You can also see Tycos 1:6 is above that level.

 

[Tonygreen]

24 hours after the first 3mM spray.
No observable damage.

I took caution to avoid any spray on big fans and tried to just hit the flower sites. My other clone got a full spray all over and looks great.

Big guy will get two more sprays every fifth day.

Medium will get one more spray in 10 days.

Smallest will get one spray day 14.

 

[Tonygreen]

In the meantime let's look at the results of the study in the OP all sprayed with 3mM sts.

A was sterile and did not produce visible pollen.
D produced the most visible pollen.
C and E had visible pollen.
B did not consistently produce pollen.

 

[Tonygreen]

What do you guys with experience think of those pics?
The ones that failed,
Too strong at 3mM? Or not enough?
Do we think no use looking at higher than 3mM?should I explore the area between 1 and 2?

Maybe a 3mM 2mM 1mM might be worth trying on plant 2 on the 3 spray schedule. After 3 months of not being able to strike a root im suddenly a clone machine lol. Thoughts?

Maybe my 1 spray plant I should try like 5 mM...

 

[power puff]

Thanks for this thread Tony.

Never dared to go undiluted, but the article is very interesting.
If plants are not showing visible stress while beeing hit with 3mM and show male parts it seems they can take it.

Question I ask myself is if strong solutions or undiluted sts could affect pollen.
What about more herms showing up in the filial generation after making and growing out the seeds. Like epigenetic changes caused by to strong stock solution?

I am just thinking loud....

 

[zif]

Re: A) visible pollen production is definitely not required for success. I’ve had great seed set with no visible pollen, from male flowers that were incredibly slow to open.

Don’t mean to throw another variable in the mix, but Chimera hinted that a wetting agent (eg, a polysorbate) might significantly improve the spray’s effectiveness. I struck out trying to locate the thread....

Nice work, Tony!

 

[bsgospel]

Excellent thread so far. Very easy to understand and presumably replicate your rates.

here's the sigma dilution calculator to double check: https://www.sigmaaldrich.com/chemis...cal-library/solution-dilution-calculator.html

 

[G.O. Joe]

I struck out trying to locate the thread

This comes from the original lit, where the solution was not applied by spray.

 

[Tonygreen]

I did add a few drops of dish soap and shook it to bubble before application. I observed the sts drying or being absorbed very quickly.

 

[aridbud]

I have a few email exchanges I'll cut and paste to you from Jessica D. Lubell-Brand and a few others from UCON. Both they and Cornell, I've discovered info on breeding. They use hemp, yet the premise is still there.

 

[Tonygreen]

Please do! I was going to email Jessica with a few questions. I'm interested to see if they have tried stronger than 3mM.

 

[G.O. Joe]

Soap may or may not react with the complex. No matter what's used there must be 20 different ways to affect the amount of actual active silver, and which STS complex is or isn't acting. I'm not sure if anyone adds anything to it. Mohan Ram and Sett used a ridiculously small amount of polysorbate (and STS, which was made 1:8 by weight), but then it's ridiculously sudsy. I haven't seen damage and think there are variables, which explains different results.

 

[Chunkypigs]

I've always wanted to thicken the STS some then use something like this to apply to bud sites without spraying anything on the leaves...

 

[SuperBadGrower]

Great stuff

 

[Cvh]

I use Yucca extract as a surfactant in my STS preparation.