I have seen this posted at several sites. I don't think you can rely on it . I have seen no science behind it. Given the right conditions I can have over 90% female rate with bag seed. However there are fem seeds I have grown that don't match the pic's and were all female I wonder what the real science is behind it. I thought sex was determined after they started to grow and then they came up with fem seed. Can we get the real story ? Maybe one of the guru's, Zandor, Garden, someone sure.