// Cultivation ยท Glossary

STS Reversal (Silver Thiosulfate)

๐ŸŒฟ Cultivation First mentioned: Ep. 222

A technique using silver thiosulfate solution to induce male flowers on genetically female cannabis plants, enabling the production of feminized seeds (selfing). The resulting pollen contains only female chromosomes, so all offspring are female.

Rob Clark mentions STS reversal as one of the basic breeding techniques pioneered at HortaPharm in the Netherlands. He lists it alongside polyploidy and tissue culture as foundational research conducted under their Dutch government license. The technique became commercially widespread in the seed industry for producing feminized seed lines.

Ep. 222 Robert Connell Clark Q&A: Cannabis History โ†’