Silver Thiosulfate (STS)

By ED Borg Delta-9 Labs

Most cannabis plant breeders and seed producers have by now experimented with or are well aware of Silver Thiosulfate or more commonly known in the cannabis/plant industry as STS.

Silver Thiosulfate is the combination of two chemicals, one being Silver Nitrate, the other Sodium Thiosulfate.

It is the most feasible and preferred method of creating female only seeds. The more stable the variety, the better the results since many varieties have a tendency to hermaphodite during the later weeks of flowering.

The sole purpose of spraying STS on the donor plant is to reverse the plants gender. This happens within three weeks of spraying STS, which blocks the ethylene gas formation.

STS in any concentration is only effective at inhibiting ethylene for almost 3 weeks; at that point the plant’s nat- ural female metabolism begins to take over again.

A second spraying allows inhibition to last through week 6, which is more than enough time to release pollen.

There is a wide range of usable formulas that will work, however the second spraying within 12-14 days is crucial at getting the ethylene gas production to stop. You can store the working solution you used for the first spraying in the refrigerator for two-three weeks as it is not necessary to make a new batch each time. There are various concentrations of STS that will work fine, however a stronger mixture does not make a plant more likely to produce pollen, it only burns and stresses the plant as our experiments have shown. In one of the photos of the “Super Star ladyboy” you can notice  a  slight burn on a few leaves. Doing a second spraying 12- 14 days later is paramount at producing plenty of pollen. By coming from an insurance/risk management industry background and to guarantee our results at generating optimum pollen production we recommend having one ladyboy STS donor plant for every 5 plants you want to pollinate.

What we also perform is to spray a few of the donor plants at 5-7 day intervals for up to 3 weeks if necessary so that we achieve the most pollen per plant at varying intervals, resulting in more viable seeds per plant as well.

Use care and caution while mixing and using these chem- icals in a properly ventilated area. A mask will  prevent the breathing of any dust, which is caustic. STS is color- less and odorless, and poses minimal health risks if used as described here.

Bring your donor plants to be sprayed in an area that can later be washed off is thoughtful to avoid staining and browning as the STS dries.

In the next issue I will be showing you the photos of the fully reversed female ladyboys. They have now fully reversed after 16 days and the pollen sacs are starting to develop. The buds are becoming pollinated and will con- tinue to produce ripe robust female seeds.

Get ready  for the next issue!!

I wish you all great success in becoming future female seed producers.

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