Turning your plants female.....

If ur not sure if ur plants are fiminized when they are in vegi state, is there a way to turn ur plant female by like the lights or whatever....like inturrupting the dark cycle with 1 hour of light? Ive heard of people and my friends doing it and im just wondering if that is in fact a way and if u have any other ways.

a plant is whatever sex it is.
changing light hours down will only get the plant to flower and show the sex.
stress can induce maleness-a self defence mechanism to ensure a new generation.
femaleness can be increased with hormones with varying sucess.
hope this helps.

Thanks