Salem

Can someone tell me exactly what 100% plenty (ie, the normal growth) will give me for cereal, cabbage, pumpkin, cotton fields?

If you are asking about seeds at 100% plenty you will get 100, 20, 36 (babybears), and 50 seeds respectively.

Higher plenty basically gives you more seeds except in a case of cabbage, but also more product.

As far as I know and remember 100% plenty gives 3 ear of cereal+1 hay, 6 pumpkins, 5 cotton, 5 cabbage, 50 seeds of corn. Don't quote me on this though, if someone with more experience could correct me if I'm wrong that would be great.

0 plenty bonus on cereal is 2 ears, which is 100 seeds as mentioned. (although the game sometimes bugs and gives you a 3rd ear, the 3rd ear will be "empty" giving no flour or seeds when you process it)