HELP! prevention of fertilisation

I usually buy feminized seeds so I have no issues with male plants, however this (my 3rd grow) I've come across the issue of, 1 male plant on the left 1 hermaphrodite and on the right I'm unsure what its sex is yet, due to the fact that I only continued growing the plants because my mate had almost killed them as seedlings. I figure there isnt much I can do now but I feel its a waste to throw out the male or maybe its too early too know if it could be a hermaphrodite itself. In this image could anyone say to whether this would stop fertilisation and filling my hermaphrodite with seeds, seeing how it'll end up with seeds as is it's just a piece of board so I personally dont think itd stop fertilisation I just wondering 'what if' so if someone can give me help that'd rock.. Im using a 400w Sodium bulb.