I came across this webpage.
In the article it stated the following.
Cannabis roots and sex determination
It appears that cannabis roots grow differently according to their gender, and that a complex set of genetic interactions determines them both. A study into hemp varieties in Russia demonstrated that if young cannabis plants were cut off above the root, processed as cuttings and then kept in an aerated nutrient solution, with all new roots cut off as soon as they appeared, 80-90% of the cuttings would develop into male plants. If the roots were allowed to regenerate, 80-90% of the cuttings would develop as females.
The researchers also treated the de-rooted cuttings with 6-benzylaminopurine, a synthetic cytokinin (plant hormones that facilitate cytokinesis, or cell division) that is known to be involved in cell division and differentiation, as well as overall growth and development. Treated cuttings developed in 80% female plants. This strongly suggests that cytokinin production in the roots plays a strong role in sex determination in cannabis.
Here's the site/pdf they reference.