Some 400 producers of mamón chinos have about 800 hectares (nearly 2,000 acres) planted in the fruit. The country has become the largest exporter of the product in Central America, according to the Ministerio de Agricultura y Ganadería.
Seven years ago the ministry was encouraging the planting of the fruit in the southern zone as a barrier to citrus diseased that might come in from Panamá. Now that area and the Caribbean coast product commercial quantities of the small, red or yellow spiny fruit.
The principal producing areas in the southern zone are the cantons of Corredores, Osa, Ciudad Cortés and Pérez Zeledón. In the Provincia de Limón, the commercial producing areas are Pococí, Guácimo and Siquirres.
More than 1,800 metric tons are exported each year to El Salvador and Nicaragua, according to Alberto Montero González, head of the ministry’s section of non-traditional fruits. Although the fruit is cheap in Costa Rica, a kilo shipped to the United States brings from $4 to $7, the ministry said.
There are two types of mamón chino in the country. The more traditional one is called chupachupa. This is not a freestone variety, and some say the fruit is not sweet. A new variety is a freestone, and the edible pulp pulls from the pit easily. The ministry had distributed more than 40,000 saplings of this type over the last five years, and officials are encouraging farmers to substitute the more marketable variety for what they might now have.
The fruit is about as big as a golf ball, but a lot easier to nibble. Vendors sell both the red and yellow varieties from July through November. The mamón chino is called rambutan in Asia. The Latin name is Nephelium lappaceum.
The spiky, red or yellow fruit is held between the fingers and the top is bitten just enough to remove the hard outer shell. Inside is a sweet, pulpy mass surrounding a big seed.
The seed is edible but usually should be roasted first. It is the pulp that the casual nibbler seeks. Throughout the downtown and elsewhere in Costa Rica mamón chino-lovers can be seen walking along chomping at the fruit. Purdue University reports that the roasted seeds are said to be narcotic. The fruit can be made into a syrup or canned, but most are eaten fresh.
Costa Rican officials fear that the introduction of the citrus disease leprosis will cause great economic loss to the country. So they have established a line of control along the frontier of Panamá and seek to eradicate completely citrus trees inside this area adjacent to the border.
The mamón chino is one of the alternatives, the ministry said. The fruit can be grown from seed, but someone doing this runs the risk of lavishing effort on male trees that do not produce fruit. Montero recommends that farmers use cuttings and grafting to maintain a high quality of fruit.