Cultivation of neglected tropical fruits with promise. Part 3, The pummelo

Abstract

The pummelo, Citrus grandis (L.) Osbeck, is the most tropical of the citrus fruits, yet is poorly distributed, underutilized, and often unknown. It is an excellent fruit, however, which finds ready acceptance wherever tried. Pummelos probably originated in China but were carried to Thailand, Malaysia, and Indonesia, where their evolution has continued and where many varieties are now available. The tree is large and spreading, with large, winged leaves, and frequently with thorns. The flower is very large for a citrus (3-5 cm in diameter), and the fruits vary from large to extra large. The rind is often thick. At maturity the sweet to subacid fruit vesicles separate easily from the membrane of the segments and are served in a dish as a dessert fruit. Varieties of pummelo can be classified as Thailand group (best tropical varieties), Chinese group (better suited to subtropics), and Indonesian group (extremely variable and sometimes inferior). The pummelo produces a monoembryonic, normal, sexual seed, and thus can be improved by breeding. Improved varieties are maintained by bud and cleft grafting as well as by marcotting. Culture is similar to that of other citrus trees, but the trees need somewhat larger growing areas. Cover crops or cash crops can be planted among the trees until they are too large. Normal chemical treatment schedules for pests and weeds can be used, but have not been adequately tried with the pummelo. Some pummelos are tolerant to foot rot, a disease that always requires careful treatment. Since flowering may occur several times a year, fruiting is irregular, but usually one harvesting season predominates. The fruit is picked just as it yellows or later, and is more flavorful when stored for several months. Because of its thick rind, the pummelo is easy to ship and keeps well even in common storage. KEYWORDS: fruit, citrus, pummelo, pummelo cultivation, shaddock, tropical fruit, tropicial fruit cultivation.