Due to increased pest and disease pressure and production costs, citrus growers are beginning to look into alternative crops to diversify and find new markets. Some of these alternative crops might work, while others will not because of lack of adaptability to local climate or lack of market for that specific crop. When selecting any crop, it is necessary to choose a crop that is native to a similar climate or is already adapted to local conditions.
Mangosteen (Garcinia mangostana) is a tropical tree, native to the equator (An equator is an imaginary line around the middle of a planet or other celestial body). The place of origin of the mangosteen is unknown but is believed to be the Sunda Islands and the Moluccas in Malaysia. It is much cultivated in Thailand where it has been suggested that the tree may have been first domesticated.
Because the tree is truly tropical and cold-sensitive, the best region to grow mangosteen is south Florida especially Miami Dade (USDA 11a). It has been reported that mangosteen was first planted in Miami in 1977. Many people have grown or tried to grow mangosteen trees in Florida but not in a large scale. Mangosteen tree can be injured if the air temperature falls below 40 ᵒF. Sometimes temperature falls under this range even in the warmest part of the Florida. Therefore, cultivation of mangosteen is limited to the warmest parts of the southern coastal region of Florida like Keys.
The mangosteen tree is very slow-growing, evergreen, erect, with a pyramidal crown; reaching 20 to 82 ft (6-25 m) in height.
Mangosteen needs grows best in a well-drained soil containing a large amount of organic materials. The soil in southern part of Florida consists of sands or the limestone and is not suited for mangosteen cultivation. Growers can solve this problem by adding organic materials like peatmoss and supplying the necessary nutrients by frequent application of fertilizers. It is recommended to use organic source instead of chemical fertilizer because tree can be easily injured by excess salt. For home owner growers, it is advised to plant the tree in the container or in holes in the ground in which the original soil has been replaced by the desired mixture of organic material.
Spreading a mulch under the canopy to retain moisture the common practice. Irrigate the tree well two or three times each week. Too much water and flooding will damage the roots. If possible, maintain an adequate water supply by irrigating almost daily during dry season.
Mangosteen trees are fertilized every three to four months with a complete fertilizer when they are young. When trees are three years old, fertilize once or twice a year.
The fruit from seedling trees is uniform and therefore, tree need to be grafted to seedlings which is tolerant to pest and disease. In Florida, approach-grafting has succeeded.
Pest and Disease
Few pests have been reported such as leaf-eating caterpillar, ants, mites, bats, and rats. Disease like thread blight and canker are seen on mangosteen trees. Physiological problem called “gamboge” has been observed on trees with symptoms of oozing of latex on the fruits and branches.