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Tutorial DIY STS Mixing/Using Guide for Feminized Pollen/Seeds R.C.Clarke Method as Base

farm3r

Active member
Thank you for the kind words, and I'm glad the information I've gathered here was helpful. :)

Stable, long term freezable pollen is possible through proper drying. If you're unsure, you can split the pollen in 2 or more sets of small packets. Freeze some and put others in the fridge in a sealed jar with oven dried rice. This will give you both a frozen test, and also a set of packets which will last several months in the fridge (at least).

Either way, the quick and complete drying of the pollen is what needs to happen first for best results.

Yes, the males begin dropping pollen very quickly.

Yes, most 8-11 week strains have pistils ready to catch pollen at 4 weeks. Longer flowering strains can take up to many weeks longer.

As long as you have a bare minimum of 4 weeks of plant life left yes, you can pollinate them. Much preferred is 5 weeks or more for full maturity and health. Ideally you want the seeds to be nearly falling off the plant on their own, and not all plants will stay alive for weeks after their usual chop date.

One to two weeks before, as long as you're ready to collect and dry along the way, should give you a wide window of opportunity. Collect and dry the pollen as it begins dropping. Pollinate the females when they have at least 5 weeks of life left.
You're entirely welcome. :D
Thank you @Douglas.Curtis for the super quick reply! I'll post some photo for the thread later.
 

farm3r

Active member
@Douglas.Curtis Just a thought. Perhaps you may want to include some info about the timing of when the male flower would be ready to produce pollen and when the female flowers would be ready to be pollinated and the ideal window, etc...This would make this STS thread even more informative for future noob.

Cheers!
 
New to the site, but not to the hobby. I am new to reversing myself, but not in principle.
That said, I’ll try to include a link to what I would consider the most scientifically accurate and extremely comprehensive report about feminizing cannabis. They even cover autos!

Hopefully this link works and hopefully I’m not breaking any rules.
https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=4210&context=theses

It is actually someone’s thesis paper from Cal poly in 2021. It’s about 40 pages of reading, and it’s helpful to have a basic understanding of the subject before jumping into this paper.
This is not a “how to” as much as it is a very detailed report covering experiments performed outdoors and in a greenhouse with different plants, varying ppm of CS STS and gibberellic acid being used to feminize, and the success or failure rate of each. It’s incredibly detailed so I only skimmed it, but I’m sure it can be helpful to someone.

Edit: maybe the most important piece of information relative to this post was that 500 ppm STS was the most effective reversal system of those tested.
 
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foomar

Luddite
ICMag Donor
Veteran
This pdf is relevant
Did it myself years ago with silver nitrate and a spreader/sticker called Phast with good results.

A Novel Method for Stimulating Cannabis sativa L. Male
Flowers from Female Plants

A commercially available floriculture product, Chrysal ALESCO®,
contains silver nitrate, the same active ingredient as STS but with increased shelf stability. This study
compares Chrysal ALESCO® to the traditional STS standard methods for male flower induction on
female plants and their pollen quality.

Conclusions
Traditional STS has been commonly used to stimulate male flowers from female hemp
plants because of its effectiveness; however, the instability and short self-life of the chemical
solutions cause extra labor and potentially inconsistent results. This research demonstrates
an alternative method that uses ALESCO®, a commercial ethylene inhibitor-inhibit product
in the flora industry, to stimulate hemp flowers. Our result indicated that ALESCO®
showed equal effectiveness in stimulating male flower count with improved pollen quality
(non-abortion rate) compared to the traditional STS foliar spray method. Thus, ALESCO®
should be considered a viable alternative to the traditional STS in future breeding and
feminized seed production of C. sativa. The observation on the difference in pollen quality
between traditional STS and ALESCO® might be caused by the inactive ingredients of
ALESCO®, and they could be surfactants, wetting agents, and adjuvants that enhance
silver thiosulfate to attach and penetrate plant tissues. However, the inactive ingredients of
ALESCO® are not labeled. Further research on adding such enhancement ingredients to
the foliar spay buffer will be needed to improve the hemp male flower stimulation process
and feminized seed production
 

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aliceklar

Well-known member
Thanks for sharing. Interesting... wonder how possilble this stuff is to get hold of outside the US?
This pdf is relevant
Did it myself years ago with silver nitrate and a spreader/sticker called Phast with good results.

A Novel Method for Stimulating Cannabis sativa L. Male
Flowers from Female Plants

A commercially available floriculture product, Chrysal ALESCO®,
contains silver nitrate, the same active ingredient as STS but with increased shelf stability. This study
compares Chrysal ALESCO® to the traditional STS standard methods for male flower induction on
female plants and their pollen quality.
 

foomar

Luddite
ICMag Donor
Veteran
Has become hard to buy agrochems in small amounts in the UK , garden centres sell mostly organic products of little efficacy and not much better online.
Thankfully farm suppliers will sell all products face to face for cash , only problem being the package size can cost hundreds of pounds and more than you need.

Silver nitrate is not classed as dangerous and is sold on fleabay and sometimes amazon , used for old school photography and weird youtube videos , about £1 a gram.
Phast was a commonly used spray adjuvant to increase the uptake of foliar herbicides , several available as its a commonly used product.
So fairly easy to make your own version and a lot cheaper if you need gallons.
 

aliceklar

Well-known member
Hi everyone! Very interesting 3D, thanks!!

I have a question, maybe a stupid one! hehe

I'm about to do STS for the first time, I've only ever used CS.

but reading a bit here, I saw that you use a different concentration than the recipe on the first page...

I make solution A using 5g of silver nitrite, solution B with 2.5g of sodium thiosulfate, but when mixing them, don't use 50ml for each, right? How much should I take?
EDITED: I was asking a dumb question thats already been answered Its 0.5g of Silver Nitrate to 500ml distilled water, not 5g.
 

brickweeder

Well-known member
@Douglas.Curtis Just a thought. Perhaps you may want to include some info about the timing of when the male flower would be ready to produce pollen and when the female flowers would be ready to be pollinated and the ideal window, etc...This would make this STS thread even more informative for future noob.

Cheers!
Just a bit of info, my last reversal on a CBD autoflower took over 4 weeks from 1st STS application to producing viable reversed pollen. I was using CS between STS applications. All my previous reversals took a lot longer than I wanted, so for those that want to produce fem seeds, put your pollen recipient plant into flower a couple weeks after you start flowering of your STS plant, assuming you start STS at flip or slightly before.
 

Douglas.Curtis

Autistic Diplomat in Training
I clearly mention using clones, then collecting and storing pollen for instant use.

I'm a huge fan of being prepared, so it makes perfect sense to have instant pollen access. Especially when investigating a variable such as flowering timing.
 

fullymelted

Well-known member
Veteran
12ml of florel (ethephon) per 1000ml of water. start spraying 10 days before 12/12 3 times per week up to week 3 and never have sterile pollen again.

Silver is for weebs, ethephon is god.
 

Douglas.Curtis

Autistic Diplomat in Training
12ml of florel (ethephon) per 1000ml of water. start spraying 10 days before 12/12 3 times per week up to week 3 and never have sterile pollen again.

Silver is for weebs, ethephon is god.
Yeah, that's smart. Ethephon releases ethylene, which promotes the growth of female flowers. You'll actually get "never have *pollen* again." if you use ethephon the way you desribe. Yes, ethephon is very good for keeping a rowdy (almost) completely female cut happy during flower so no balls show.

I'll keep using silver to block ethylene production and collect feminized pollen. Thanks. ;)

Edit: Though I hear Ethephon is great for getting male cannabis plants to grow female flowers. ;)
 

fullymelted

Well-known member
Veteran
Yeah, that's smart. Ethephon releases ethylene, which promotes the growth of female flowers. You'll actually get "never have *pollen* again." if you use ethephon the way you desribe. Yes, ethephon is very good for keeping a rowdy (almost) completely female cut happy during flower so no balls show.

I'll keep using silver to block ethylene production and collect feminized pollen. Thanks. ;)

Edit: Though I hear Ethephon is great for getting male cannabis plants to grow female flowers. ;)
except thats how ive been reversing and making male s1 seed and female s1 seed for 20 years...........
it does the exact same thing to females, not sure where you heard that.

The tops of the female plant turn into anthers almost entirely and the calyx swell and have hundreds of seeds all throughout.


All females here with plenty of pollen /anther formation

There's also ga3 and other AG ions that bind so the copper cofactor in ethylene protein receptors hormones in florel.

I've been using the same recipe for ever.

It won't reverse bagseed of a bagseed 98 strain poly hybrids but no problem with old ibls I'll tell you that lol
 

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fullymelted

Well-known member
Veteran
Yes, Male S1 seeds. Good job! :)
No these are female plants sex tested via flow cytometry..... Every plant in the pics is the same clone

I do have a shit load of male s1-s2.
That's where every single one of my female plants come from. I don't keep heterozyous trash.

If you spray them early enough, whatever else is in the florel is causing the copper cofactor in ethtylene protein receptors to be poisoned. I have enough seed to prove it 1000x over

I must have accidentally typed over the part of my first post where I was jokingly calling female seeds an abomination and was specifically talking about males.

But yes I can show you several females right now that drink florel three times per week that are not only producing anthers but fat flowers.

I hear it all the time that I'm wrong but.... I have flow cytometer and eyeballs.
 
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fullymelted

Well-known member
Veteran
Appreciate the clarification, that's fascinating and now I want to know what else is in it. lol
I have no idea, but i dont go near the stuff without a full respirator on and big boy elbow length gloves. I spray them outside in a designated little tent area , as im worried about every little thing because i have dogs. My own health, dont care lol.
Some female plants it makes flower early , i always assumed it was the plants that came from selfing or hermie pollinations because none of the really inbred lines ive reversed had any trouble.

Now i want to do a full panel on 20 different females lol
 
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