Wow...that's a new one on me! I never really considered eating a specific type of food or a specific type of diet that makes your penis grow longer or have more potent sperm. I know in some countries that the rhinoceros' horn was highly prized for its sexual potential and making a man more potent and strong when the horn was ground up into a powder. the other thing I have also heard from some men,but it has never been proven, is that oysters, when eaten raw, provides a certain nutrient that keeps a males sexual vigor going and makes him more potent in the sperm department. Those are about the only things i have heard told to me.
just good old healthy food, keep off fatty foods, eat lots of fruit, vitamins like E, C, Zinc, brewers yeast that way you get all your bs in one go, Garlic, Ginko Biloba, Tribulus, Cayenne, D but the chaepest way for that is to get out in the sun, are and Ginseng.
Good Luck