Opuntia cultivation began in Mexico at least 9000 years ago, resulting in hundreds of domesticated hybrids now designated as O. ficus-indica. These plants are used for food, animal fodder, food preservative, ornamental appearance, erosion control, fire barrier, and harvesting cochineal insects to produce red dye.
In Mexican Spanish, nopale means Opuntia cactus, nopales - young whole pads, nopalitos - diced pads, penca - mature pads used for propagation and cattle fodder, and tuna - Opuntia fruit.
The fruit, which is watery and slightly sweet, is peeled and eaten raw or cooked into jam. The juice can be made into jelly. The fruit from selected cultivars is a favorite snack in Mexico. Fruit with higher ratios of aborted seeds are more popular. Tender young pads are peeled to remove glochids, and sliced into strips, or diced, and eaten raw in salads. They also can be boiled, fried, pickled, or cooked in meat and vegetable stews. Once the glochids are peeled off, the pads are edible and have a string bean-like taste.
Sap extracted from the pads or fruit peels can be made into a gel and used to store freshly peeled cactus pear fruit 12 to 15 days. The gel can also be used to treat wounds in the same way as Aloe vera gel. Because the gel is sticky, one traditional use has been to add it to whitewash and mortar which increases their durability.
Pads that are older than six months, on certain spineless hybrids, are used to feed cattle.
The extensive roots of this plant provide erosion control. Because it is a succulent with a high water content, it can be grown as a fire suppression barrier.
Cochineal scale insects form cottony white patches on Opuntia pads. The cactus has been used to raise and harvest those insects, which extrude a red liquid used in dyes, paints and food coloring.