Canistel
Scientific
name: Pouteria
canpechiana
Family: Sapotaceae
Introduction
As
a result of recent reports in the popular press, on the radio, and
exhibitions, there has been an unprecedented interest in cultivating
more exotic types of fruits in South Africa. We have looked at a number
of these fruits with the idea of starting small commercial industries
to allow farmers to diversify, especially in situations where some of
the more traditional fruits are close to over-production. The canistel
appears to be one such fruit that has the potential to develop a small
commercial industry.
The canistel is the showiest fruit of the
family Sapotaceae but has generally been under-evaluated, both in
horticultural literature and by those who have a casual acquaintance
with it. It is sometimes erroneously recorded as native to northern
South America where related, somewhat similar, species are indigenous.
Apparently it occurs wild only in southern Mexico, Belize, Guatemala,
and El Salvador (Morton, 1987). Colloquial names applied to this fruit
include: egg-fruit, canistel, ti-es, yellow sapote (Morton, 1987).
Classification
The canistel, Pouteria
campechiana Baehni, has been the subject of much botanical
confusion as evidenced by its many synonyms: P. campechiana var nervosa Baehni; P. campechiana var palmeri Baehni; P. campechiana var salicifolia Baehni;
Lucuma
campechiana HBK.; L.
heyderi Standl.; L.
laeteviridis Pittier; L.
multiflora Millsp.; L.
nervosa A.DC.;
L. palmeri Fernald; L.
rivicoa Gaertn.;
L. rivicoa var angustifolia
Miq.; Richardella
salicifolia Pierre; Sideroxylon
campestre T.S. Brandeg.; Vitellaria campechiana
Engl.; V. salicifolia
Engl.
The canistel is closely related to the lucmo and abiu (Scholefield,
1984). The abiu, Pouteria
caimito Radlk (syns. Lucuma
caimito Roem. and Schult.; Achras caimito Ruiz
and Pavon) is also occasionally known as the yellow star apple. The
lucmo, Pouteria lucuma
O.Ktze. (syns. P.
insignis Baehni, P.
obovata HBK., Lucuma
obovata HBK.) is also known as lucuma, lucumo and mamon
(Morton, 1987).
Distribution
The
canistel is cultivated in its countries of origin and also in Costa
Rica, Nicaragua, Panama, Puerto Rico, Jamaica, Cuba, the Bahamas, and
Florida (Morton, 1987). Trees that were planted from fruit bought in
Cuba are growing in Colombia. The canistel is also included in
experimental collections in Venezuela. The tree was introduced at low
and medium elevations in the Philippines before 1924 and it reached
Hawaii probably around the same time. Attempts to grow it in Singapore
were not successful. In 1949 there were a few canistel trees growing in
East Africa (Morton, 1987).
Description
Tree
The
tree is erect and generally no more than 8 m tall (Ruehle, 1967;
Morton, 1987). However, in favourable conditions the tree can reach 20
to 30 m with a trunk diameter of 1 m (Scholefield, 1984 Morton, 1987).
The tree is slender in habit or with a spreading crown, it has brown
furrowed bark and abundant white, gummy latex (Ruehle,1967; Morton,
1987). Young branches are velvety brown (Morton, 1987).
Leaves
The
bright green and shiny leaves are alternate but mostly clustered on
newer growth at the ends of the branches (Ruehle,1967; Morton, 1987).
The leaves are relatively thin, short to long-stemmed, oblanceolate,
lanceolate-oblong, or obovate, bluntly pointed at the apex, more
sharply tapered at the base, 110 to 280 mm long and 40 to 80 mm wide
(Morton, 1987).
Flowers
The
flowers are small and borne in clusters or solitary in the leaf axils
or at leafless internodes of young wood (Ruehle, 1967; Morton, 1987).
The flowers have slender pedicels and are five to six-lobed, green to
cream-coloured, silky-hairy and approximately 8 to 11 mm long
(Scholefield, 1984; Morton, 1987). The flowers are bisexual and
fragrant (Morton, 1987).
Flowering extends from January to June in
Mexico. In Cuba, flowers are borne mostly in April and May although
some trees flower throughout the year (Morton, 1987). The fruit is
extremely variable in shape and size, and may be nearly round, with or
without a pointed apex, or it may be somewhat oval, ovoid, or
spindle-shaped. It is often bulged on one side and there is a
five-pointed calyx at the base which may be rounded or with a distinct
depression (Morton, 1987). Fruit length varies from 50 to 170 mm and
diameter from 40 to 75 mm with a weight of up to 1.5 kg (Scholefield,
1984; Morton, 1987). Unripe fruit is green-skinned, hard and gummy
internally. On ripening the skin turns lemon-yellow, golden-yellow or
pale orange-yellow, is very smooth and glossy except where occasionally
coated with light brown or reddish-brown russeting (Morton, 1987).
The
fruit flesh is yellow to orange-yellow, mealy with a few fine fibres.
The texture has been likened to a cooked, mealy, sweet potato or to the
yolk of a hard boiled egg (Ruehle, 1967; Morton, 1987). The flavour is
sweet and somewhat musky. The ripe pulp from some seedlings is less dry
and mealy than others (Ruehle, 1967). Picking the fruit when mature,
but several days before it softens, tends to reduce dryness of the pulp
(Ruehle, 1967). The seeds, usually one to three, are ovoid to oblong 20
to 50 mm in length and 12 to 32 mm wide. They are hard, glossy, dark
brown except on the straight or curved ventral side where they are dull
light brown, tan or greyish white (Ruehle, 1967; Morton, 1987). Both
ends are sharp-tipped (Morton, 1987).
The fruit matures mostly
from November to February in Florida, but individual trees may produce
fruits at other times (Ruehle, 1967). The fruits mature from September
to January or February in the Bahamas. In Cuba, the main fruiting
season is from October to February, but some produce more or less
continuously throughout the year (Morton, 1987). The canistel thus
appears to come in to production in late autumn and winter when few
other tropical fruits are available.
Fruit
Composition
Canistels
are rich in niacin and carotene (provitamin A) and have a fair level of
ascorbic acid (Morton, 1987). The Table gives the food value per 100 g
of edible portion of the canistel.
Food value per 100 g of edible portion of canistel (Morton, 1987)
| Food Value Per 100 g of Edible
Portion* |
|
| Calories |
138.8 |
| Moisture |
60.6 g |
| Protein |
1.68 g |
| Fat |
0.13 g |
| Carbohydrates |
36.69 g |
| Fiber |
0.10 g |
| Ash |
0.90 g |
| Calcium |
26.5 mg |
| Phosphorus |
37.3 mg |
| Iron |
0.92 mg |
| Carotene |
0.32 mg |
| Thiamine |
0.17 mg |
| Riboflavin |
0.01 mg |
| Niacin |
3.72 mg |
| Ascorbic Acid |
58.1 mg |
| Amino Acids: |
|
| Tryptophan |
28 mg |
| Methionine |
13 mg |
| Lysine |
84 mg |
Varieties
Great
seedling diversity exists and some selections have been made but
apparently no named cultivars exist (Scholefield, 1984). Certain types
are so distinct that they have been recorded as different species in
the past. The spindle-shaped form was the common strain in the Bahamas
for many years. The rounded, broader form began to appear in special
gardens in the 1940s, and the larger types were introduced from Florida
in the 1950s (Morton, 1987).
In 1945, large, symmetrical fruits
were being grown under the names Lucuma salicifolia and yellow sapote
at the Agricultural Research and Education Centre and at Palm Lodge
Tropical Grove, Homestead, Florida but these were later classified as
superior strains of canistel (Morton, 1987). Some fruits are muskier in
odour and flavour than others, some are undesirably dry and mealy, some
excessively sweet. An excellent, non-musky, fine-textured, rounded type
of medium size has been selected and grown on a ranch in Martin County,
Florida. There is considerable variation as to time of flowering and
fruiting among seedling trees (Morton, 1987). A selection programme has
been initiated in Puerto Rico (Martin, 1976).
Climatic and
Soil Requirements
Climate
The
canistel is widely adapted and grows well in a tropical or subtropical
climate (Scholefield, 1984). It is about as hardy as the sapodilla
(Ruehle, 1967) which can withstand temperatures of -3 to -2°C for
several hours. It has survived cold winters in areas of Florida but has
never reached fruiting age in California. It is usually found up to
elevations of 1400 m. It requires no more than a moderate precipitation
and does well in regions that have a long dry season (Morton, 1987).
The tree is fairly wind-resistant (Ruehle, 1967).
Soil
The
canistel is tolerant of a wide range of soils - calcareous, lateritic,
acid-sandy, and heavy clay. It grows well on deep, fertile well-drained
soil but is said to be more fruitful on shallow soil. It can be
cultivated on soil considered too shallow and poor for most other fruit
(Morton, 1987), provided drainage is good (Scholefield, 1984).
Propagation
Propagation
is usually by means of seeds (Ruehle, 1967). Seeds lose their viability
quickly and should be planted within a few days after removal from the
fruit. If decorticated, seeds will germinate within two weeks;
otherwise there may be a delay of three to five months before they
sprout. The seedlings grow rapidly and begin to bear within three to
six years. There is considerable variation in yield, size and quality
of fruits (Morton, 1987).
Vegetative production is recommended
to hasten bearing and to reproduce the best selections. Side veneer,
chip bud and cleft graft are commonly used (Scholefield, 1984; Morton,
1987). Air-layering has also been successful. Cuttings of mature wood
will root but are extremely slow to root and this method is thus not
often used (Ruehle, 1967; Morton, 1987).
Culture
As
the canistel is not grown commercially, there is very little known
about its cultural requirements. Mulching is beneficial in the early
years. A balanced fertilizer applied at time of planting and during
periods of rapid growth is advisable, but the tree does not demand
special care. Outstanding branches should be pruned to avoid wind
damage and to shape the crown (Morton, 1987).
Pests and
diseases
Few
pests and diseases attack the canistel. The only recorded pest is scale
insects which were noted in Florida (Ruehle, 1967). In Florida, the
leaves of the canistel are attacked by a rust (Acrorelium lucumae).
Fruit spot (Colletotrichum
gloeosporioides), leaf spot and scab (Elsinoe lepagei)
and leaf necrosis (Gloeosporium)
have also been recorded in Florida for the canistel. The tree is,
however, generally nearly always vigorous and healthy (Morton, 1987).
Harvesting
and Storage
Harvesting
Fruits
should be harvested by hand when mature but still firm (Scholefield,
1984). The fruits should be clipped to avoid tearing the skin. If left
to ripen on the tree, the fruits split at the stem end and drop. A
severe drop in temperature will also cause firm, mature fruits to split
and drop to the ground (Morton, 1987). Experience is needed to
determine the correct stage for picking (Scholefield, 1984).
Storage
If
kept at room temperature the fruits will ripen and soften in three to
ten days. They should not be allowed to become too soft and mushy
before eating. Ripe fruits can be kept in good condition in a
refrigerator (ca. 4°C) for several days (Morton, 1987).
Freshly-picked,
firm fruits have been successfully shipped from Florida to New York and
Philadelphia. Unfortunately, no studies have been made to determine
optimum temperature and humidity levels for long-term storage and
shipment (Morton, 1987).
Uses
Food Uses
The
fruit is well liked by some for eating fresh, but is disliked by others
because it is not crisp and juicy like so many other fruits (Ruehle,
1967; Morton, 1987). Some Floridans enjoy the fruit with salt, pepper
and lime, lemon juice or mayonnaise, either fresh or after light baking
(Morton, 1987). The pureed flesh may be used in custards or added to
ice creams just before freezing. A rich milkshake is made by combining
ripe canistel pulp, milk, sugar, vanilla and other seasoning (Morton,
1987).
Canistel pulp has also been used in preparing pancakes,
cupcakes, jam and marmalade (Morton, 1987). The fruit can also be dried
and processed into a powder which can be added to desserts and ice
cream (Scholefield, 1984). Some companies in the Tropics have expressed
interest in the processing of this fruit (Campbell, 1976).
Other Uses
Latex
extracted from the tree in Central America has been used to adulterate
chicle. The timber is fine-grained, compact, strong, moderately to very
heavy and hard, and valued especially for rafters and planks in
construction. The heartwood is greyish brown to reddish brown and
blends into the sapwood which is somewhat lighter in colour. The darker
the colour, the more resistant to decay (Morton, 1987).
Medicinal Uses
A
decoction of the astringent bark is taken as a febrifuge in Mexico and
applied to skin eruptions in Cuba. A preparation of the seeds has been
employed as a remedy for ulcers (Morton, 1987). In 1971, a
pharmaceutical company in California studied a derivative of the seed
which seems to be active against seborrhoeic dermatitis of the scalp
(Morton, 1987).
Conclusion
The
Canistel would probably lend itself well to orchard cultivation if the
necessary cultural research was done. However, the critical factor
which will determine the success of any plantings is the market
acceptability. This has not been determined, as most canistels which
are sold on local markets are sold primarily to people of Latin
American origin. During a recent visit to Chile, Dr J. Terblanche,
previous Director of the ITSC, found canistels to be a common product
on local markets. Development of such a crop will take a great deal of
organized effort. Coordinated research in culture, harvesting,
handling, shipping and processing is required if a profitable industry
is to be established.
The Institute wishes to initiate and
conduct feasibility studies on the Canistel with a view to possible
commercialisation. However, this will involve the need to assess as
wide a range of selections as possible, to investigate and develop
management strategies for local conditions. The initial process in
developing this crop will necessitate the assembling of a gene pool of
the best selections from around the world. These selections can then be
screened for climatic suitability, productivity, fruit quality and
storage characteristics, product uses, consumer appeal and pest and
disease susceptibility.
Only high quality fruit from selected
cultivars should be marketed, and a strong consumer demand should be
developed, fruit should be promoted, and the public informed and
educated on the eating characteristics and potential of the fruit.
References
Campbell, C.W., 1976.
Present and future of minor tropical fruit species in Florida and
similar areas. Acta Hort. 57: 89-95.
Johns, Leslie and
Violet Stevenson, 1979. Fruit for the Home and Garden. Cornstalk,
Sydney.
Martin, F.W., 1976.
Introduction and evaluation of new fruits in Puerto Rico. Acta Hort.
57:105-110.
Morton, J.F., 1987.
Fruits of warm climates. J.F. Morton, Miami, Florida. 505 pp.
Ruehle,
G.D., 1967. Miscellaneous tropical and subtropical Florida fruits.
Univ. Fla, Gainesville. 116 pp.
Scholefield, P.B., 1984. Canistel,
Lucmo, Abiu. In: Tropical Tree Fruits For Australia. Queensland Dept
Primary Industries. 226 pp.
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