Hi Cora, It must be discouraging to see that happen because a good atemoya is delicious. It is very hard to diagnose such a problem; it could be caused by poor pollination, by too much or too little water or plant nutrients, or by pests of some sort. I understand that you are already hand pollinating but perhaps this one article on hand pollination that ECHO published a few years ago may have some new information for you – http://edn.link/7ymjk6