There is some Russian study (sorry no link) that stated if you give your plant at least 4 inches of space in germination to develope the tap root, then you will have a greater chance of the plant becoming female.
Although I was also under the impression that if a seed is predetermined to be male/ female then it will be.
Growing conditions and stress can cause plants to become hermaphrodite's but I don't know about making it become a male.