Opuntia sp. Cactus: Biological Characteristics, Cultivation and Applications

In this review, we approached various aspects of Opuntia sp., a forage cactus. This plant stand out for its energy potential and have peculiar morphological and physiological features that allow tolerance for long periods of drought. In addition, Opuntia species has a cosmopolitan distribution, found mainly in arid and semi-arid regions. Opuntia sp. presents phenotypic variations related to weather conditions, like polyploidy occurring in a large number of populations and high hybridization capacity. This plant has a shrub morphological characteristic with ramifications, variable size, from creeping until arboreal; it can reach up to 4 m high and a series of fleshy stems with, depending on time of year, flowers and fruits. Opuntia sp. has a typical physiology with the photosynthetic process called crassulacean acid metabolism (CAM); stomata close during the day in order to maintain hydration of tissues. The chemical composition of Opuntia sp. varies according to species, age of reticule, and season. The cactus has excellent nutritional value with high water content (about 90%), digestibility in vitro (about 75%) and vitamin A; in addition this plant has organic matter (67%), energy (2,61 Mcal.kg-1), crude fiber (4.3%), phosphorus (0.08 to 0.18%), calcium (4.2%), potassium (2.3%) and magnesium (1.4%), but shows low protein content (about 5%). The proper yield of the crop needs a climate with 400-800 mm annual rainfall, relative humidity above 40% and day/night temperature from 25 to 15°C. The wide variety of applications demonstrates the versatility of this plant species, being used in food and feed, agriculture, medicine, pharmaceutical and cosmetic industries, in water and wastewater treatments, and even as insecticide agent. Opuntia sp. have about 1500 species and O. ficus indica is the most important as forage and human uses.