Fig. 44: The calamondin (X Citrofortunella mitis), a showy ornamental, makes excellent marmalade.
The calamondin tree, ranging from 6 1/2 to 25 ft (2-7.5 m) high, is erect, slender, often quite cylindrical, densely branched beginning close to the ground, slightly thorny, and develops an extraordinarily deep taproot. The evergreen leaves (technically single leaflets) are alternate, aromatic, broad-oval, dark-green, glossy on the upper surface, yellowish-green beneath, 1 1/2 to 3 in (4-7.5 cm) long, faintly toothed at the apex, with short, narrowly-winged petioles. The richly and sweetly fragrant flowers, having 5 elliptic-oblong, pure-white petals, are about 1 in (2.5 cm) wide and borne singly or in 2's or 3's terminally or in the leaf axils near the branch tips. The showy fruits are round or oblate and to 1 3/4 in (4.5 cm) wide, with very aromatic, orange-red peel, glossy, and dotted with numerous small oil glands; tender, thin, easily-removed, sweet, and edible. The pulp, in 6 to 10 segments, is orange, very juicy, highly acid, seedless or with 1 to 5 small, obovoid seeds, green within.
Origin and Distribution
The calamondin is believed native to China and thought to have been taken in early times to Indonesia and the Philippines. It became the most important Citrus juice source in the Philippine Islands and is widely grown in India and throughout southern Asia and Malaysia. It is a common ornamental dooryard tree in Hawaii, the Bahamas, some islands of the West Indies, and parts of Central America. Dr. David Fairchild introduced it into Florida from Panama in 1899. It quickly became popular in Florida and Texas. The California climate is not as favorable but a variegated form ('Peters') is cultivated there.
Since 1960, thousands of potted specimens have been shipped from southern Florida to all parts of the United States for use as house plants. Israel is now similarly raising such plants for the European market. The calamondin is also valued as a rootstock for the oval kumquat (q.v.) for pot culture.
At the Agricultural Experiment Station of the University of Florida in Gainesville, the calamondin is much utilized for greenhouse research on the various aspects of flowering and fruiting in Citrus.
The calamondin is as cold-hardy as the Satsuma orange and can be grown all along the Gulf Coast of the southern United States. It is moderately drought-tolerant.
The tree seems able to tolerate a wide range of soils from clay-loam in the Philippines to limestone or sand in Florida.
Calamondin trees may be easily grown from seeds, which are polyembryonic with 3 to 5 embryos each. For commercial fruit production in the Philippines, the trees are budded onto calamondin seedlings. In Florida, propagation by cuttings rooted under constant mist is the more common commercial procedure for pot culture. Even leaf-cuttings will root readily.
Plants grown from cuttings fruit during the rooting period and will reach 18 to 24 in (45-60 cm) in height in 10 1/2 months. The flowers are self-fertile and require no cross-pollination. Transplanted into a large container and well cared for, a calamondin will grow at the rate of 1 ft (30 cm) per year; will produce an abundant crop of fruit at the age of 2 years and will continue to bear the year around. Potted plants for shipment can be stored in the dark for 2 weeks at 53.6º F (12º C) without loss of leaves or fruits in storage or in subsequent transit and marketing.
In orchard plantings, Philippine workers have established that a complete commercial fertilizer with a 1:1 nitrogen to potassium ratio gives the best growth. There are 2 applications: one prior to the onset of the rainy season and the second just before the cessation of rains. Adequate moisture is the principal factor in yield, size and quality of the fruit. Drought and dehydrating winds often lead to mesophyll collapse.
Calamondins are harvested by clipping the stems as they become fully colored throughout the year. In the Philippines the peak season is mid-August through October.
The fruits will keep in good condition for 2 weeks at 48º to 50º F (8.89º-10º C) and 90% relative humidity. Weight loss will be only 6.5%. Waxing retards ascorbic acid loss for 2 weeks in storage but not thereafter.
Pests and Diseases
The calamondin is a prime host of the Mediterranean and Caribbean fruit flies, and for this reason is much less planted in Florida than formerly. It may be attacked by other pests and diseases that affect the lemon and lime including the viruses: crinkly leaf, exocortis, psorosis, xyloporosis and tristeza, but it is immune to canker and scab.
Calamondin halves or quarters may be served with iced tea, seafood and meats, to be squeezed for the acid juice. They were commonly so used in Florida before limes became plentiful. Some people boil the sliced fruits with cranberries to make a tart sauce. Calamondins are also preserved whole in sugar sirup, or made into sweet pickles, or marmalade. A superior marmalade is made by using equal quantities of calamondins and kumquats. In Hawaii, a calamondin-papaya marmalade is popular. In Malaya, the calamondin is an ingredient in chutney. Whole fruits, fried in coconut oil with various seasonings, are eaten with curry. The preserved peel is added as flavoring to other fruits stewed or preserved.
The juice is primarily valued for making acid beverages. It is often employed like lime or lemon juice to make gelatin salads or desserts, custard pie or chiffon pie. In the Philippines, the extracted juice, with the addition of gum tragacanth as an emulsifier, is pasteurized and bottled commercially. This product must be stored at low temperature to keep well. Pectin is recovered from the peel as a by-product of juice production.
|Food Value Per 100 g of Edible Portion*|
|Whole Fruit %||Juice %|
*The chemistry of the calamondin has received only moderate attention. Wester (1924) and Marañon (1935) reported the above constituents from Philippine analyses. Mustard found the ascorbic acid content of the whole fruit to be, 88.4-111.3 mg/100 g; of the juice, 30-31.5 mg; and of the peel, 130-173.9 mg.
The fruit juice is used in the Philippines to bleach ink stains from fabrics. It also serves as a body deodorant.
Medicinal Uses: The fruits may be crushed with the saponaceous bark of Entada Phaseoloides Merr. for shampooing the hair, or the fruit juice applied to the scalp after shampooing. It eliminates itching and promotes hair growth. Rubbing calamondin juice on insect bites banishes the itching and irritation. It bleaches freckles and helps to clear up acne vulgaris and pruritus vulvae. It is taken orally as a cough remedy and antiphlogistic. Slightly diluted and drunk warm, it serves as a laxative. Combined with pepper, it is prescribed in Malaya to expel phlegm. The root enters into a treatment given at childbirth. The distilled oil of the leaves serves as a carminative with more potency than peppermint oil. The volatile oil content of the leaves is 0.90% to 1.06%.