enhance the restoration of vegetative cover, thus minimizing deterioration of built terraces with its deep and strong rooting system. Other The plant may be used as an ingredient in adobe to bind and waterproof roofs. O. ficus-indica (as well as other species in Opuntia and Nopalea) is cultivated in nopalries to serve as a host plant for cochineal insects, which produce desirable red and purple dyes, a practice dating to the pre-Columbian era. Mucilage from prickly pear may work as a natural, non-toxic dispersant for oil spills. Mexico has a semicommercial pilot plant for biofuel production from Opuntia biomass, in operation since 2016. Cultivation Distribution Commercial use for O. ficus-indica is for the large, sweet fruits called tunas. An area with a significant tuna-growing cultivation is Mexico. The cactus grows wild and cultivated to heights of . In Namibia, O. ficus-indica is a common drought-resistant fodder plant. O. ficus-indica grows in many frost-free areas of the world, including the Southern United States. Prickly pears are a massive weed problem for some parts of Australia, especially southeast Queensland, some inland parts of New South Wales, Victoria, and south-eastern and eastern South Australia. Growth The plant is considered an invasive species in northern Africa. Factors that limit the growth of prickly pear are rainfall, soil, atmospheric humidity, and temperature. Its minimum rainfall requirement is 200 mm per year as long as the soils are sandy and deep. The ideal growth conditions regarding rainfall are per year. O. ficus-indica is sensitive to lack of oxygen in the root zone, requiring well-drained soils. It is similar to crassulacean acid metabolism species, which are not salt-tolerant in their root zone, and growth may cease under high salt concentration. O. ficus-indica usually grows in regions where relative humidity is above 60%, and saturation deficit occurs. It is absent in regions where less than 40% humidity occurs for more than a month. Mean daily temperature required to develop is at least 1.5–2.0 °C. At −10 to −12 °C, prickly pear growth is inhibited even if it is exposed to these temperatures only for a few minutes. The maximum temperature limit of prickly pear is above 50 °C. Harvest and preparation As the fruits of O. ficus-indica are delicate, they need to be carefully harvested by hand. The small spines on the fruits are removed by rubbing them on an abrasive surface or sweeping them through the grass.