It would be best to take a clone of your plant early during veg, Give it about 7-14 days to start rooting, then put it in flowering stage as you want to pollinate early so you have time for healthy seeds to grow. Now heres the tuff part, stressing the clone takes a lot of finesse as to you want a healthy plant, but an upset one. During the light period in the day a normal female should be on a 12/12 light cycle, your clone with need light breaks in the 12/12 cycle. I'm suggesting at least complete darkness for 3 periods of 30 minutes -1 hr. water normally, fertilize normally. Now light isn't the only stress factor that causes hermy condition, you also have to clip to leaf tips. Once the leaf has come out fully and a small but decent sized new set of fan leaves are showing trim 1/3 of length of the fan leaf. This is were finesse comes into play do not trim all the leaves but if you don't trim enough you wont see a male in time to pollinate. The third factor is fluctuating heat try to range your temp at least +10º F to -25º F from your NORMAL temp of the healthy female/s awaiting pollination. Once you see the sacks forming let them develop till they appear clearly as hanging sacks then stop all stress treatment and treat the clone as normal. The simple method of pollinating is allowing the small clone hemy to grow in close proximity to a fan and the female. There are other methods for selective pollination but this seems the most simple and has the highest percentage of success. This is my first attempt to arrange my thoughts on the best way to intentionally stress a plant, Feedback with pictures and measurements would be fantastic.
Bio 110
Here is a issue to address with Pre-Fem seeds the seeds are great, but you add a lot of genetic instability its the same plant a seed clone basically but unstable for breeding especially. Pre-Fem seeds should not be breed, it gives a large variable for very poor genetics to be passed on the the children of Pre-Fem seeds. The % of natural hermies will skyrocket
along with potency and plant heartiness on the fast decline, often Pre-fem Mothers will be sterile leaving all the crap and none of the rewards no viable seeds.
F1 pre-fems get a 7 out of 10*
F2 Pre - fems gets 3 1/2 out of 10*
Nothing beats years of progressive training and breeding your own
Humans live only once, and the same goes for everything else that lives.
You can stop the flow of genetics, nor should you try, but remembering your for fathers is a noble cause.