[Charles-scott]

Hi Guys I thought I would publish some info I have herd a couple time that STS stock solution failed so I thought I would update 1 important bit of info
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 into 100 m distilled water. Prepare a 0.1 M Silver Nitrate stock solution by dissolving 1.7 g of Silver Nitrate into 100 ml of distilled 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. The STS can be stored in the refrigerator for up to a month. However, preparation of the STS just prior to use is recommended.
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Here is the update many people find it easier to obtain Sodium thiosulfate pentahydrate than the most called for anhydrous when using the Pentahydrate multiple the weight by 1.56 so the amount would be 1.58 grams multiply x 1.56 its 2.46.48 grams call it 2.4-2.5 and your ok
Everything is exactly the same I have found ST Pentahydrate more gentle not nearly as much of reaction from the plant made me think it was not working worked great !
That might save some time and make life easier trying to obtain Chem's
C

[icenine]

Thanks for the information. I am going to give this a try.
I did not think about the difference and it looks like I bought pentahydrate instead of anhydrous.
You may have saved me a lot of trouble.

[Charles-scott]

Great glad I was able to help !
Charles

[Sam_Skunkman]

I use distilled water to make the stock solutions, and keep the two solutions separate until needed, then add more water and mix the two, they store much longer then a month when separate, keep them cold 5c and in the dark. A surfactant like Tween-80 helps, a drop per liter. STS action is strongly enhanced when a surfactant is added to the solution. We slowly poured the silver nitrate stock solution into the sodium thiosulfate stock solution that was being stirred rapidly. We used many different ratios of the two active ingredients most worked to varying degrees. Same with one application or more.
I never made all female seeds to sell, only for breeding work for other reasons.
Many people use intersex females to make male pollen and that is not good, stress test the females first. Or maybe get all female seeds with a strong intersex tendency.
I am not recommending that folks make all female seeds, I am trying to help those that will do it anyway. I have nothing against all female seed that is made correctly, and some actually is.
-SamS

great post sam,

if people are going to try it anyway , help them do it right ...... so i am reading the msg, know your female your planning on reversing. stable genetics .

[Charles-scott]

Originally Posted by Sam_Skunkman

I use distilled water to make the stock solutions, and keep the two solutions separate until needed, then add more water and mix the two, they store much longer then a month when separate, keep them cold 5c and in the dark. A surfactant like Tween-80 helps, a drop per liter. STS action is strongly enhanced when a surfactant is added to the solution. We slowly poured the silver nitrate stock solution into the sodium thiosulfate stock solution that was being stirred rapidly. We used many different ratios of the two active ingredients most worked to varying degrees. Same with one application or more.
I never made all female seeds to sell, only for breeding work for other reasons.
Many people use intersex females to make male pollen and that is not good, stress test the females first. Or maybe get all female seeds with a strong intersex tendency.
I am not recommending that folks make all female seeds, I am trying to help those that will do it anyway. I have nothing against all female seed that is made correctly, and some actually is.
-SamS

Wow good call Sam I never noticed that that never called for distilled water ! Always used distilled water .
I agree with what you say about Female seeds and stress testing .
Sam the reality is today that the majority of Customers will not purchase a strain and choose a alternate if its not sold in a Fem version.
I am using reversing a f-1 female clone to introduce vigor back into the f-7 generation currently , we grew out f-7 and f-8 seedlings side by side and something happened when we got to the f-8 because they are substantially slower vegging than the f-7 .
I don't have a male cutting from a earlier generation the f-1 Mother is just outstanding except she yields less and has a finer more sativa dom frame .
The strains was inbred to fix to type the f-1 represents I am hoping that this will reinvigorate the Strain .
Charles

[BoldAsLove]

I followed very similar guidelines on an Oldtimer's Haze plant a few months back and got the plant to grow male flowers:



It proceeded to mature and open all flowers, but had no pollen at all. Not a spec. I rubbed the whole plant on a female and got no seeds. I'm curious if you guys have any clue as to why no pollen? Perhaps it's a true female? Or was it user error of some sort? The procedure is pretty straight forward.

[Sam_Skunkman]

I saw quite a few that were functionally sterile meaning they did not drop pollen, even if they made it. Often the pollen was kind of sticky and if you used a q-tip you could get pollen enough to effect pollination. Others you just need to alter the ratios of the STS spray ingredients or the frequency or numbers of the applications to get useable pollen.
And some will not make male flowers or make any pollen.
Don't give up, try variations.
-SamS

[BoldAsLove]

Will do. Thanks Sam.

[Charles-scott]

Here I grabbed this from another thread I commented on
We have had no issues with ECSD at all in Canada or my friends in Spain .
My Spanish friends use her on a regular Basis , you just need to follow up with a 2nd treatment , often it can seem like strains are not producing pollen , however the reversed flower clusters are too tight to let out the pollen .
This is when you cut all the flower cluster away from as much stem as possible than get a tight sealing container place the clusters in paper towel than pour silica jell packages for new leather items or just the crystal they sell to dry out cars and seal it .
This will dry the clusters quickly than put the flowers in a pollinator and tumble when they are dry and you will be shocked at the pollen even the toughest reversing strain will produce .


SPGI looks like there is nothing in the tiny tight flowers yet it produces volumes of pollen .
There is a french company that makes a very small SS drummed version of the pollinator that is ideal for this use .
https://www.pollenextractor.com/Shop/en/

You need to let the reversed flowers fully mature cut dry removing as much stock as you can when you place the Clusters in the drum throw a few coins in with them .

We have also found that with some strains it helps to follow up with a CS treatment we found that in tests that using the STS stock solution followed up with high PPM CS produced a higher volume of pollen .
I find that 40% of reversed plants will not produce usable amounts of pollen with out the use of the pollinator to collect it .
We hand pollinate with soft make up brushes , we also mix pollen with Corn starch as a carrier to make it go further protect it when freezing and it helps mark the plant as to where we have brushed the pollen on .
The SPGI for example would not pollinate anything it went very weird with tiny little flowers that looked like a flop but when dried and put in the pollinator it produced commercially viable levels of pollen .
I suspect that you #1 may not have waited long enough to get pollen developed #2 that the pollen was there but need to be extracted or a little of both .
I have reversed plants indoors and outdoors on a larger scale with a good luck , I have a small hoop now that I am reversing a number of plants in , I have not really encountered a plant that I could not get some pollen from , We recently grew out 700 female seeds we did not encounter a single hermie we did encounter three full on males .
Charles