Sex expression in weed is a bit convoluted. It has separate genetically controlled types: Dioecious (separate male and female plants) and Monecious (male and female parts on the same plant).

A plant can genetically be a male, female or a hermaphrodite to varying degrees. Dioecious plants can also have the genes for monecious and express it under stress adding to the confusion.

Silver Thiosulfate (STS) is an ethylene inhibitor that can be used to convert female or hermaphrodite plants to male expression.

There are ethylene promotors like ethephon that can convert male or hermaphrodite plants to female expression as well (with varying degrees of success).

These chemistries are used extensively in seed production of many species.

If you know what you are doing it's relatively easy to make seeds that are genetically uniform and produce 100% female plants. Using traditional breeding techniques and a decent greenhouse, it would take 2-3 years. I am not sure if the species will respond to double haploid techniques, but that could cut the time down to around 18 months.

[–] bizzle 1 points 1 year ago

I didn't know about ethylene promoters, it makes sense I'd just never heard of it before. What a fascinating plant!