A crop is a large amount of one kind of fruit or vegetable that's grown on a farm. Your farmer uncle's corn crop might be especially large after a summer with plenty of rain.
A major crop in parts of Asia is rice, while the coffee bean crop is important to the economics of several African and South American countries. A different kind of crop is the short whip that some riders use on horses — and when you crop something, you cut it short. You might decide to crop your hair at the beginning of the summer each year. The noun came first, originally defined as "the top of a sprout or herb."