Hi Bucky,
I believe that the following is an improved procedure subsequently posted by Country Mon:
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Using STS For Sex Reversal: Conclusions
Hey, all...
I wanted to post some conclusions that I have come to regarding the successful reversal of plants using silver thiosulfate solution. It's been a year since I posted the other STS thread. I have done six batches myself, and have had full pollen release with all of them. Everyone else seems to be doing well, but there is very little feedback so who knows. A big thanks to those who contributed to the other thread... your input was a big help in refining the technique.
I was going to edit the original post, but I can't, as I am THE Country Mon now, not just Country Mon. Changed my email addy and got locked out.
There has been one key change that I want to pass along to everyone who didn't want to sift through the 25+ pages of the original thread.
I have discovered that using a stronger concentration of STS does not make a plant more likely to produce pollen. It just burns/stresses the plant. What DOES make a plant much more likely to complete it's mission and make pollen is a second spraying at the end of week 2.
My conclusion is that STS in any concentration is only effective at inhibiting ethylene for about 3 weeks; at that point the plant's natural female metabolism begins to take back control, and even a plant that is covered with male blooms can't finish the journey to manhood and produce pollen. A second spraying allows inhibition to last through week 6, which is more than enough time to release pollen.
Some of you have decided to use stronger concentrations of STS. This is fine as long as it doesn't burn your plants. Obviously there is a wide range of usable formulas that will work. But the second spraying is the key to follow-through. You can store the working solution you used for round one (in the spray bottle) in your refrigerator for two weeks; no need to mix a new batch from stock.
I don't see the point of going any stronger than the formula I originally came up with. It has proven itself many times over. The only change I might make is to adjust it slightly to Gobgoober's "molar-correct" mix ratio. This is not at all necessary, but does allow the most effective use of the chemicals together.
Here's a re-post of the formula mix instructions, with the adjusted recipe below that:
Preparation of STS:
First, a stock solution is made. It consists of two parts (A and B) that are initially mixed separately, then blended together. Part A is ALWAYS mixed into part B while stirring rapidly. Use distilled water; tap water may cause precipitates to form.
Wear gloves while mixing and using these chemicals, and mix and use in a properly ventilated area. A mask will prevent the breathing of any dust, which is caustic. STS is colorless and odorless, and poses minimal health risks if used as described here. (See material safety data sheet links below). Note that silver nitrate and STS can cause brown stains upon drying, so spray over newspaper and avoid spilling.
Part A: .5 gram silver nitrate stirred into 500ml distilled water
Part B: 2.5 grams sodium thiosulfate (anhydrous) stirred into 500ml distilled water
The silver nitrate dissolves within 15 seconds. The sodium thiosulfate takes 30-45 seconds to dissolve.
The silver nitrate solution (A) is then mixed into the sodium thiosulfate solution (B) while stirring rapidly. The resulting blend is stock silver thiosulfate solution (STS).
This stock solution is then diluted at a ratio of 1:9 to make a working solution. For example, 100ml of stock STS is added to 900ml of distilled water. This is then sprayed on select female plants.
Both the stock STS and the working solution should be refrigerated after use, as well as the powdered chemicals, to avoid activity loss.
The adjusted formula is as follows:
Part A: .7 gram silver nitrate stirred into 40ml distilled water
Part B: 2.6 grams sodium thiosulfate (anhydrous) stirred into 160 ml distilled water
Next, slowly add the silver nitrate solution to the sodium thiosulfate solution while stirring. This combination is then added to 800 ml of distilled water to equal 1 liter. This is your final stock solution. It is diluted 1:9 with more distilled water to make your final working solution, which then gets sprayed on your target plant.
Either formula will work great, so don't sweat it too much. But do that second spraying at the end of week 2... seems to be the key for getting pollen from the more difficult strains.
Please post your comments and experiences with STS.
CM
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Hey there...
IndyJones... just get her nice and wet. You don't need to hit the undersides of the leaves. The exact amount isn't critical - you can really drench her and she'll be fine. She may yellow a bit, but 1:9 seems perfect. Somebody was treating individual branches, but I don't recommend this as it hormonally confuses the plant.
illkills...
The only way you will create a hermie is if you pass along hermie genes. It is not something that happens as a result of technique - you can't permanently turn a normal girl hermie (at least not by any known process), and you will NOT create herm seeds by reversing sex of the mother using STS. STS is not a stress technique; it simply inhibits a hormone (ethylene) necessary for female flower formation.
There are a number of ways a herm trait can express itself. If your plant is normally not a hermie but then herms due to chemical or light stress, it has hermie genes - they just need certain conditions to show the trait. If your plant naturally throws some bannanas towards the end of the flower cycle, it has a hermie trait, too.
In the first days of feminized seeds breeders were using light stress to create bannanas this way, which were then used as pollinators for their femmed seedlines. As a result, they carried along hermie traits to the resulting femmed seeds. So the myth was born that femmed seeds = hermie traits. Not true.
Female plants that produce an isolated few bannanas in the final couple weeks of the flower cycle are often okay to keep as clones; the bannanas come on late in the cycle so they don't usually have time to create seeds in the mom. But you have to really keep an eye on them. A few bannanas at the wrong time can really create a lot of unwanted seeds. These are not good breeders - the trait will usually show up in the offspring.
The best idea when searching for a really good female candidate to reverse is to light stress the hell out of her. You want a female that is very resistant to bannana production. This is probably your best shot at avoiding hermie traits in the resulting seeds. This is something that anyone who sells seeds should definitely do.
This isn't essential for pleasure breeders, though. If you've grown out a mom for a few generations and not seen any bannana action, give it a go.
Note that sometimes seedlings form a few bannanas along the main stem at around week 4 of 12/12, and that this is not necessarily an indication of a hermie in the genetic sense. Seedlings have higher initial gibberellin levels which allow these blooms to form. This is also why seedlings stretch so much. I have often seen this happen, with no further bannanas ever appearing in clones of the same plant.
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Hope it helps. :)
Best,
bopper
