Tubers and roots were being harvested long before they were cropped. Once domesticated, the plants travelled from one continent to another, and the discovery of America brought the potato to Europe.
They are being cultivated on every continent, in particular in the tropical zone.
The processing of some of these plants into food, like cassava, is an important work which is generally entrusted to women. Research workers aim at making it simpler. Factories have been set up to improve processing, conservation and supply to towns in tropical countries.
In Europe, as well as in North America, potato is the basis of many agro-industrial foods, e.g. fries, deep-frozen chips, dehydrated mashed potatoes, .
The nutrional property of tubers and roots is to supply carbohydrates. They have very low protein ad lipid contents and need therefore to be complemented with other food products.
Africa is the main consumer of tubers and roots.
Yam is prestigious in the Pacific area, where it is considered a symbol of life, fertility and human solidarity.