Food crops are any plants intentionally grown with the primary purpose of being eaten by humans or animals. This definition separates a food crop from wild edible vegetation, grazing material and edible food used for other purposes. The vast majority of store-bought fruits, vegetables and grain-based foods started in this category. This makes up one of the three main divisions of useful growing plants, the other two being wild plants and non-food crops.
There are two basic criteria that differentiate food crops from other plants. The first is that a person must intentionally plant and/or care for them and the second is that they must be primarily used for food. Both of these factors are absolute requirements for the term.
The first is primarily used to separate food crops from edible wild crops. Basically, this criterion makes a line that says onions grown in a garden are a food crop but ones picked in the forest are a wild crop. The only gray area in this rule is based on the cultivation and care of a plant. If a person picked wild berries, they would be a wild crop; if that person cleared the weeds and built a fence around the same bushes, it may transition to a food crop.
The second major factor requires that the plant be used for food. If more than half of the useful material harvested from a plant is used to feed either animals or humans, then the plant is food. The plant may undergo significant processing, such as the creation of corn syrup, without changing the designation. This rule separates out crops that aren’t eaten, such as tobacco, and plants that could be consumed, but are not being used for food, such as corn being used to make ethanol.
Agriculturalists separate useful plants into three broad categories: food, non-food and wild. In addition to these three useful groups, there is a single major non-useful group called nuisance plants, as well as several specialized groups. A nuisance plant is literally anything that is not useful and is growing in an area where a person doesn’t want it. This classification could cover anything from crabgrass to wild roses with equal accuracy.
The other two useful groups intertwine heavily with food crops. Non-food crops share the first criteria but not the second. This means that people intentionally grow them, but don’t eat them. These plants could be anything from cotton to hemp to potatoes grown to process into biopolymers. Wild crops can be food or non-food, but they cannot be intentionally cultivated or cared for.