Does adding cover help your fish grow more ?

What do you think ? The question is talking about material added by man (like xmas trees, trees, brush piles, pallets, fences, tires ) not natural structure like humps ,creek channels ,points etc.

Most agree they concentrate fish and thus make it easier to locate and catch them. This question based on a controlled scientific study involves growth with equal ponds some with added cover some without. What do you think it revealed? ewest