i still believe that the enviroment determines sex of regular seeds..not 100% but i average 7-8 females out of every 10 pack,, if i want males for breeding i simply alter my enviroment and change to a higher PK nute and then i usually get 4-6 males out of a 10 pack.. ive read that a seed is predetermined sex but ive run tests with hundreds of seeds,, it seems to me if you give them a higher blue spectrum light like 6500k mh, do a 18/6 light sced, keep temps between 65-72f, and feed with a high nitrogen nute i always get more females than males.. then if i switch and use a higher red spec like hps, raise temps to 75-80f, feed with a bloom nute and switch my light sced to 20/4,22/2, or 24/0 i usually go with 24/0 for best results. i end up with either even numbers 5males 5 females or at least 4 males and 6 fems...i dont think there is a way to prove 100% that seeds have a predetermined sex or if the enviroment helps,,,but after all my tests i feel i have a good chance of getting what i want by providing seeds with the best enviroment i can..
feminized seeds however are female no matter what,, however ive found giving feminized seeds the male enhanced enviroment,,u tend to get a few hermaphrodites,,very few,,but it happens..give fem seeds the female enhanced and get strong females that do not herm unless stressed to all hell...or sprayed with silver spray...just my opinion,,,im probably wrong but tests ive done do not lie...grow well n be well to all