From Minecraft Wiki
Crops are defined as "Cultivated plants or agricultural produce, such as grain, vegetables, or fruit, considered as a group" and in Minecraft, may refer to the following food-related items and blocks:
Crops - growing wheat seeds block is called "Crops" in-game.
Wheat - the crop harvested from fully-grown wheat planted from seeds.
Melon - the fruit crop harvested from fully-grown melons planted from melon seeds.
Pumpkin - the fruit crop harvested from fully-grown pumpkins planted from pumpkin seeds.
Sugar Cane - the crop harvested from sugar cane.
Potato - a crop harvested from potatoes.
Poisonous Potato - a crop harvested from potatoes.
Carrot - the crop harvested from carrots.
Cocoa Beans - the crop harvested from cocoa plants.
Farmland - the block where crops can be planted. It is created by using a hoe on dirt or grass.
- Beetroot - the one pocket edition exclusive crop, added in 0.8.0 build 2.