Making My Own Fem'd Seeds

**ZoomBoom** · 10-23-2009, 12:56 PM

I've wanted to give this a try for quite some time. The goods arrived a couple days ago, very inexpensive.

The chemicals I purchased were Silver Nitrate and Sodium Thiosulfate from Photographic chemicals, photo chemistry, photo processing equipment, photo chemicals. The total with shipping was $30 I believe. Here they are:

I'm going to be following the STS instructions per CountryMon from cannabis-world.org. This is the industry standard for making feminized seeds that most companies use. They go like this:

Quote:

The following is a safe, inexpensive, and successful method for reversing the sex of female cannabis plants. Individual plant responses may vary based upon strain, but I can verify that this process is fully effective in stimulating profuse staminate flower production.

This process can be used to:
A: create new feminized seeds from solitary prize mothers that you currently have
B: create interesting feminized-seed hybrids from different prize strains that you currently have
C: create feminized seeds for optimum outdoor use
D: accelerate the "interview" phase of cultivation, in searching for interesting new clone-mothers
E: reduce total plant numbers- great for medical users with severe plant number restrictions
F: increase variety, by helping to create stable feminized seedlines to be used as an alternative to clones

At the bottom of this post are some specific details about the chemicals used, their safety, their cost, and where to get them.

It is important to educate yourself about cannabis breeding theory and technique prior to using a method like this one. [removed dead link]

It is also important to use basic safety precautions when mixing and handling these chemicals, so read the safety data links provided. The risk is similar to mixing and handling chemical fertilizers, and similar handling procedures are sufficient.

Remember: nothing will ever replace good genetics, and some of your bounty should always go back towards the professional cannabis breeders out there... the ones who have worked for many generations to come up with their true-breeding F1 masterpieces. Support professional breeders by buying their seeds. [removed link to shut down bank]

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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. Excess working solution can be safely poured down the drain after use (with ample running water) with negligible environmental impact. It's pretty cheap.

Each liter of stock STS will make ten 1-liter batches of working solution of STS. With the minimum amount of base chemicals ordered from Photographer's Formulary (see link below), this means that each 1-liter bottle of working solution STS costs less than 9 cents, and can treat 15-20 mid-sized plants. That's 200 1-liter batches of STS for $18. Note that the distilled water costs far more than the chemicals.

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Application:
The STS working solution is sprayed on select female plants until runoff. Do the spraying over newspaper in a separate area from the flower room. You probably won't smell anything, but ventilate anyway. You now have what I call a "F>M plant"; a female plant that will produce male flowers.

After the F>M plant dries move it into 12/12 immediately. This is usually done three to four weeks prior to the date that the target (to be pollinated) plants will be ready to pollinate. Response times may vary slightly depending upon the strain. More specific times can be determined by trial with your own individual strains. In my trials it took 26 days for the first pollen. 30-35 days seems optimum for planning purposes.

So, assuming that a target plant needs 3-4 weeks to produce fully mature seeds, a strain that takes 8 weeks to mature should be moved into flower at about the same time as the female>male plant. A target plant that finishes flowering in 6 weeks needs to be moved into flower later (10 days or so) so that it doesn't finish before the seeds can fully mature.

A seeded individual branch can be left to mature on a plant for a bit longer, while harvesting the other seedless buds if they finish first. Just leave enough leaves on for the plant for it to stay healthy.

-------------------------------------

Effects:
Within days I noticed a yellowing of the leaves on the F>M plants. This effect persisted for two weeks or so; after this they became green again, except for a few of the larger fans. The plants otherwise seemed healthy. No burning was observed. Growth stopped dead for the first ten days, and then resumed slowly. No stretch was ever seen. After two weeks the F>M plants were obviously forming male flower clusters. Not just a few clusters of balls, but complete male flower tops. One plant still formed some pistillate flowers, but overall it was predominantly male.

It is strange indeed to see an old girlfriend that you know like the back of your hand go through a sex change. I'll admit that things were awkward between us at first.

When the F>M plants look like they may soon open and release pollen, ( 3-1/2 to 4 weeks) move them from the main flower room into another unventilated room or closet with lighting on a 12/12 timer. Don't worry too much about watts per square foot; it will only be temporary.

When the pollen flies, move your target plants into the closet and pollinate.

A more controlled approach is to isolate the F>M plants in a third remote closet (no light is necessary in this one, as they are releasing pollen now and are nearly finished anyway). In this remote other closet the pollen is very carefully collected in a plastic produce bag or newspaper sleeve and then brought back to the lighted closet, where the target plants are now located. If this is done, be careful to not mix pollen types by letting the F>Ms dust each other. Avoid movement, or use yet another closet.

Take special care to not let pollen gather on the outside of this bag- a static charge is sometimes present. Drop small open clusters of blooms inside and then close the bag at the mouth and shake. Important: next, step outside and slowly release the excess air from the bag, collapsing it completely, so that pollen doesn't get released accidentally. Points downwind; don’t let it get on your hands or clothes.

This collapsed pollinated bag is now very carefully slipped over only one branch and is then tied off tightly at the mouth around the branch stem with a twist tie or tape, sealing the pollen inside. Let the bag inflate slightly with air again before sealing it off, so the branch can breathe. This technique keeps the entire plant from seeding. Agitate the bag a bit after tying it off to distribute the pollen. Don't forget to label the branch so you know which seeds are which. Other branches on this same plant can be hit with different pollen sources.

If no lighted closet is available, the plant can be moved back into the main room, but- be very careful: pollen is sneaky. After 4-5 days, the bag is gently removed and the plant completes its flowering cycle.

Yet another method has worked well for me. I position the target plants in a non-ventilated lighted closet, and then I collect pollen on a piece of mirror or glass. This is then carefully applied to the pistils of one pre-labeled branch by using a very fine watercolor paintbrush. Care is taken to not agitate the branch or the pollen. No sneezing. The plant needs to be in place first; moving it after pollination can shake pollen free and blow this technique.

Regardless of technique, at completion you will have feminized seeds. Let them dry for 2-4 weeks.

*analog* · 10-23-2009, 01:05 PM

I'll be watching

good luck and thanks for doing this.

Looks like a lifetime supply there

!

**ZoomBoom** · 10-23-2009, 04:01 PM

OK, as per instructions...here is .5g of Silver Nitrate before 500ml of distilled water and 2.5g of Sodium Thiosulfate also before 500ml of distilled water. Remember, use only distilled to eliminate the possibility of precipitates.

After mixing both solutions until the solids dissolved, I poured the Sodium Thiosulfate solution into a tupperware. While stirring quickly, I added the Silver Nitrate solution. I tried different utensils when stirring. First a large spoon, then a pair of salad tongs, then finally a smaller spoon. (I have done the work for you guys, use the smaller spoon.)

I then poured the resulting solution back into a mason jar, with a few hundred ml's left over--which I dumped down the kitchen sink. I now have some concentrated STS solution to use in the future. I gave it a helpful label, to remind me to dilute this particular solution 1:9 with distilled water before application. Then I put it, and the solid ingredients, into the fridge to store until ready to use.

**ZoomBoom** · 10-25-2009, 12:47 PM

I have selected a clone of my Northern Lights for the first of my experiments.

I am doing this because I would like to spread pollen or seeds where clones would not be advisable, to preserve the genetics of this plant in seed form through various crosses and S1's, and most importantly, to learn something new.

I chose the Northern Lights due to its aesthetic qualities, good company, (hopefully) prepotency, and provenance. Edit: I forgot to mention, I also chose this plant because after dealing with root aphids for a month, the plants were exposed to several late night light invasions, and this showed not one nanner--showing me it might have the chops to be a transgender father.

I have taken the plant from its normal home and put it in some coco with a little mychhoorhiszeay. Typo intentional. When the roots start to break through in a couple days, I'm going to begin the next process: application.

Here is the subject:

kontroversy · 10-25-2009, 01:00 PM

Really cool project you got going! Looking forward to seeing the first batch of beans pop.

**EMj** · 10-25-2009, 06:01 PM

Nice work ZoomBoom!! Great experiment and looking forward to seeing to results.

**ZoomBoom** · 10-28-2009, 10:33 AM

Ok. The day has come.

I will be flipping the lights on this baby tonight, so now comes the application process. In the first photo, I have a small spray bottle filled with 3 tbsp of distilled water. To follow the 1:9 ratio, all I need to do is add one teaspoon of my STS solution.

...I ended up spraying all of the contents of the mini spray bottle on the plant. It seems to be the perfect amount to cover every part; leaves and their undersides, stems...

Now all I have to do is wait for it to dry and put it in the 12/12 room. I'm going to put it in the corner away from most of the plants because I don't want to risk getting any of this stuff on the others.

If my understanding is correct, the plant is not happy with me...at all. It will turn yellow slightly...probably for around a week or two, before recovering.

**Silentsmoke** · 10-28-2009, 01:41 PM

Yeah it should yellow up then come back

Can't wait to see this unfold!

**ZoomBoom** · 11-01-2009, 03:28 PM

Well, no yellowing yet.

I applied another foliar last night with the same concentration.

Reason for this is I've read other peoples reports and they have done it 2-3 times in the first week with a dilution of this potency. I know that plants can handle a more potent stock solution with even less dilution, so there really is no risk in another "ah, what the hell" application.

Yeah, I know it ain't scientific, but I ain't no scientist!

**ZoomBoom** · 11-02-2009, 11:54 AM

Here she is this morning.

Nothing has changed. I've surmised that the action will occur once visible bud formation starts on her. I have a couple more NL's in the room that should serve as a good timer as to when I should start to see something...

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