I've got a field that I always hunt the last Saturday of September. Won't start until first week of September. This works partly because it's a naturally attractive spot with a pond and powerline. I hunt this field late because it helps to coincide with the goatweed popping its seeds. (Wooly Croaton). I have found that unless it rains a lot the bird numbers seem to peak about two weeks from final field prep. And no they won't eat sprouted wheat. I have heard of putting the wheat in the microwave for 15 secs will prevent sprouting but I've never tried it. Wouldn't be legal anyway.