1535

2: Edible fruits and nuts

Pouteria campechiana (Kunth) Baehni

Candollea 9: 398 (1942).

SAPOTACEAE

2n = unknown

Lucuma nervosa A. DC. (1844).

Canistel, egg-fruit, yellow sapote (En). Philippines: tiesa, canistel.

Canistel is native to Mexico. It has been introduced into other tropical American countries where it is cultivated in Nicaragua and Panama. From Cuba, where it was semi-naturalized, the canistel was introduced into the Philippines about 1915 and later became well distributed. In other South-East Asian countries the canistel is virtually limited to fruit collections. The tree is occasionally grown in East Africa; in the Seychelles it is very common.

After removal of skin and seeds, the fruit may be eaten as a sweet fruit, or more appropriately as a vegetable with salt and pepper, lemon juice or mayonnaise. It is a useful substitute for pumpkin in pie and is added to the mix for pancakes, muffins, and other baked goods. Blended with milk and nutmeg, it makes a highly nutritious cold beverage. It may be added to custards, and to ice cream before freezing and can be preserved with sugar in the form of butter or marmelade. The flesh can be dehydrated, powdered and employed as a rich food additive, as is done with its close relative, Pouteria obovata Baehni, in Peru.

In the Philippines, some 210 000 bearing trees, mostly found in fruit gardens, were reported in 1987, producing 1900 t fresh fruit. Few people eat the fruit and only a small portion of the total production is sold in the market. It is reported that commercial groves are being established in Florida and Panama.

The edible portion constitutes up to 70% of fruit weight. Results of chemical analyses done in Cuba and the Philippines show that ripe fruit contains per 100 g edible portion: water 57.2—60.6 g, protein 1.7—2.5 g, fat 0.1—0.6 g, carbohydrates 36.7—39.1 g, fibre 0.1—7.5 g, ash 0.6—0.9 g, calcium 26.5—40 mg, phosphorus 30—37.3 mg, iron 0.9—1.1 mg, carotene 0.32 mg, thiamine 0.02—0.17 mg, riboflavin 0.01—0.03 mg, niacin 2.5—3.7 mg and vitamin C 43—58 mg. The energy value is 580—630 kJ/100 g. Hence the fruit is rich in carbohydrates, carotene and niacin.

Erect tree, 12—20(—30) m tall, trunk 25—60 cm wide; bark finely ribbed, dark grey, 4—5 mm thick, rich in white gummy latex; branches mainly horizontal. Leaves whorled at tips of branches, obovate—elliptic, 6—25 cm x 2.5—8 cm, glossy bright green, tapering towards both ends; petioles 5—25 cm long. Flowers axillary in lower leaves, solitary or clustered, fragrant; pedicel 5—12 mm long; sepals 5, leathery; corolla 10—11 mm long, 5—6-lobed, green to near-white; stamens 5, white; ovary covered with long hairs, bearing a single stigma. Fruit a spindle-shaped to ovoid, obovoid or subglobose berry, often beaked at the apex, with a thin, tough, waxy, smooth, yellow skin; flesh more or less muskily aromatic, moist or dryish and mealy, very sweet, with 1—5 seeds. Seeds ovoid, 4—5 cm x 1.5—2 cm, glossy brown.
In taxonomic literature many names for the canistel exist, due to different opinions about generic and specific delimitations within Sapotaceae. Besides Pouteria, other generic names found are: Lucuma, Richardella, Radlkoferella and Vitellaria with the epithets campechiana, glabrifolia, rivicoa, salicifolia and nervosa.
In Florida, some growers have made selections based on earliness in season, mildness of aroma, moistness of flesh, and least muskiness in flavour. Some have recently been given names such as 'Ross', 'DuPuis', 'Bruce', 'Aurea', 'Fairchild #1' and 'Fairchild #2'. 'Saludo' is a large-fruited, few-seeded cultivar in the Philippines.
Seeds lose viability quickly and should be planted within a few days of removal from the fruit. Seedlings and grafted trees grow fast and may produce fruit in 3—4 and 2—3 years respectively. Extension growth is more or less continuous. The leaves are rather persistent, even during dry or cold periods.
Trees tend to flower over an extended period, as the dry season progresses in the tropics or with the onset of spring in the subtropics. In the tropics trees may flower intermittently throughout the year. Fruit ripens 5—6 months after bloom.

The canistel is limited to tropical and subtropical climates and to altitudes below 1400 m. It tolerates brief frosts, requires only medium rainfall, and will flourish despite long dry seasons.
The canistel is productive on soils considered too shallow and poor for most other fruit trees. On poor soils the trees bear heavy crops of fairly uniform, small fruits. If planted in deep, rich soil, seedlings of the same parentage will produce larger but fewer fruits. It matters little whether the basic soil be calcareous, lateritic, sandy, or heavy clay, but it must be well-drained.

Seeds take about a month to germinate, a period that can be shortened to 2 weeks by decortication. Seedlings are ready for planting after one year. Outstanding trees may be propagated by air layering or cleft grafting mature terminal shoots on one-year-old seedlings.
The tree requires little attention apart from early pruning to improve the form. A balanced fertilizer is given at planting and this may be repeated annually before the resumption of rapid growth. Mulching is helpful in dry seasons. Fruits are harvested after attaining full yellow colour, after which they ripen in 3—4 days. Putting a little table salt on the end of the fruit stalk accelerates fruit ripening.
In Florida, a few fungus diseases have been recorded: scab and leaf spot (Elsinoe lepagei), leaf spot (Phyllosticta sp.), black leaf spot (Phyllachora sp.), leaf necrosis (Gloeosporium sp.), fruit spot (Colletotrichum gloeosporioides), rust (Acrotelium lucumae) and root rot (Pythium sp.). Scale insects and mealy bugs have also been observed in Florida and the Philippines.

The Fairchild Tropical Garden in Miami, Florida has started collecting canistel germplasm and includes canistel breeding in its fruit programme. The Institute of Plant Breeding in Los Baños (the Philippines) has a modest canistel germplasm collection and has selected a few outstanding accessions for asexual propagation.

As people become more aware of the nutritive value of the canistel and superior cultivars are made more widely available, the canistel should become as popular in other parts of the tropics — including South-East Asia — as it is in Central America. The many possible applications of the processed fruit make the canistel a truly promising fruit.

Lopez, H., Cimadevilla, M., Fernandez, E., Durruthy, C., Navia, J.M., Valiente, A., Clement, I.D. & Harris, R.S., 1956. Tabla provisional de la composicion nutritiva de los alimentos Cubanos [Provisional composition table of Cuban food stuffs]. Publicación No 3. Laboratorios FIM de Nutricion. Boletín del Colegio Médico de la Habana 7(20): 333—357.
Morton, J.F. 1983. Why not select and grow superior types of canistel? Proceedings of the American Society for Horticultural Science, Tropical Region 27(A): 43—52.
Morton, J.F., 1987. Fruits of warm climates. Creative Resource Systems Inc., Winterville, N.C. pp. 402—405.
Pittier, H., 1914. New or noteworthy plants from Colombia and Central America — 4. Contributions of the United States National Herbarium 18(2). Smithsonian Institute, U.S. National Museum, Washington D.C.

J.F. Morton

Morton, J.F., 1991. Pouteria campechiana (Kunth) Baehni. In: Verheij, E.W.M. and Coronel, R.E. (Editors): Plant Resources of South-East Asia No 2: Edible fruits and nuts. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea