From Neglected Crops: 1492 from a different perspective
by the Food And Agriculture Organization of the United Nations
Annona diversitolia
Excerpt from Custard Apples (Annona spp.)
Botanical name: Annona diversifolia Saff.
Family: Annonaceae
Common
Names: English: llama; Spanish: anona blanca; other: llama,
ilamatzapotl, izlama, papausa
This
fruit-tree, which is very highly regarded in its area of origin, has
not been developed as it deserves, since it is virtually planted
exclusively by indigenous peoples. Although it is greatly esteemed and
fetches a good price on the markets of Guatemala, its cultivation does
not attract other agricultural owners, nor do the latter obtain bank
credit for this tree, whereas they do obtain it for exotic fruit-trees.
Other factors that add to its neglect are: the tree's low productivity;
the difficulty of seed germination (although methods to encourage
germination artificially are already known); and the short shelf-life
of the fruit at the markets (two to three days at ambient temperature).
If it is left to ripen on the tree, the fruit splits, but if it is
picked in this state and stored at normal temperature, the splits scar
over. In Guatemala, it is customary to pick the fruit split in this way
and to ripen them subsequently in crates or other closed places.
Botanical
description
A.
diversifolia is distinguished from other species of Annona
in that it has two classes of leaf: the usual obovate, glabrous leaves
with a petiole; and leaves in the form of round, deciduous bracts
without a petiole, which grow on the base of the small branches. The
undersides of the leaves, small branches and fruit have a powdery,
whitish appearance, which is more noticeable in the white-fleshed
varieties.
The flowers have three outer petals that are 2 to 5
cm long, and three minute inner petals; the colour is a varietal
characteristic and ranges from pink to purplish red.
The fruit,
which is about 12 cm long, has white, pink or reddish flesh, with a
typical aroma and a sweet, exquisite flavour which, according to most
people, is superior to that of the cherimoya. The fruit is very
resistant and sometimes completely immune to attack from seed-boring
insects.
Fig. 7
Custard apples: A) Annona scleroderma; B) A. diversifolia; C) A. reticulata; D) A. cherimola; E) A. muricata; F) A. squamosa
Ecology and
phytogeography
The
llama grows between 0 and 1800 m on the Pacific slope from central
Mexico to El Salvador, but it is sown more intensively between 200 and
600 m in southwestern Guatemala. This region has a pronounced dry
season (December to March), with an annual rainfall of between 1000 and
1400 mm and very fertile volcanic soils.
Genetic
diversity
A.
diversifolia
is grown alone in vegetable gardens with few trees, and a wide
variability is noted. This is particularly expressed in the
characteristics of its fruit: its colour (see list of cultivars): its
texture, which can range from slightly pasty to juicy, soft or with
concentrations of harder grain; and its sweet taste, with a typical
aroma. Following is a list of A.
diversifolia cultivars:
Fairchild,
Rosendo Pérez, Guillermo and Gramajo have a thick-skinned,
greyish green fruit with prominent round areoles and pink flesh.
Rosendo Peréz and Gramajo have big fruit. (These cultivars
have
been bred for Florida.)
Imery (bred in El Salvador) has big
fruit that has a thinner skin, low prominences, is pinkish green
(greyish brown when ripe) and has pink flesh with bolder spots.
Pajapita has a soft, pink surface (brown when ripe) and bright-pink
flesh.
Nilito has a slightly irregular surface, which is bluish green, and red
flesh.
Roman has smaller fruit with a hard skin, which is bluish green with
pink spots, and purple flesh.
Genova white has a smooth, thin, whitish green skin, and white flesh.
Efrain has up to 200 fruits per tree.
Guatemalan
markets sell an llama that has bluish green fruit, with swirling marks
such as those in a Van Gogh painting, and delicious bright-red flesh
which is easily separated from the seeds. The trees from which this
fruit comes have not yet been studied.
The only region to be
evaluated as regards genetic erosion is southwestern Guatemala, where
the problem does not seem to be serious. There are no gene banks, nor
are any preservation techniques known other than live collections. The
most promising areas for future exploration are southwestern Guatemala
and the state of Chiapas in Mexico.
Cultivation
practices
The
llama is only grown together with other fruit trees, on the patios of
houses or on smallholdings belonging to indigenous peoples. It is
always propagated by seed with a long dormancy period which is
difficult to interrupt. The seeds should not be sown without being
pretreated to interrupt dormancy, such as soaking them in a solution of
gibberellic acid, exposing them to the sun, immersing them in hot water
or storing them for two to three months.
Prospects for improvement In the case of A. diversifolia,
urgent work is needed in the following areas: vegetative propagation,
by grafting, of the best varieties, using various stocks and grafting
methods; effective interruption of seed dormancy; picking and
commercial handling of the fruit; increasing the production period
(July-August) by selecting early and late varieties; the establishment
of gene banks, at least in localities of the Pacific area of Central
America and Mexico; stepping up exploration of the species' production
areas in Mexico, Guatemala and El Salvador; hybridization with other
species of Annona for the production of more adaptable varieties;
research on stock of the related wild species A. macroprophyllata,
from Guatemala and El Salvador; research into the possibility that the
absence of mycorrhizae or other soil factors are responsible for the
growth of this species in other regions of Mesoamerica with favourable
climate and soils, and into the possible use of grafting in these cases.
Bibliography
Ahmed, M.S. 1936. Pollination and selection in Annona squamosa and
Annona
cherimola. Ministry of Agric. Egypt Bull., 157.
Campbell, C.W. & Popenoe, J. 1968. Effect of gibberellic acid
on seed dormancy of Annona
diversifolia Saff. Proc. Trop. Reg. Am. Soc. Hort. Sci., I
1: 31-36.
Cañizares, J. 1966. Las frutas anonáceas. Havana.
Fairchild Tropical Garden. 1990. Annona
issue. Trop. Fruit World, 1(4): 93-131.
Leal,
F. 1990. Sugar apple. In S. Nagy, P.E. Shaw & W.F. Wardowsky,
eds.
Fruits of tropical and subtropical origin. Lake Alfred, Fla., USA, FSS.
Lizama,
L.A. & Reginato, G. l990. Cherimoya. In S. Nagy, P.E. Shaw
&
W.F. Wardowsky, eds. Fruits of tropical and subtropical origin. Lake
Alfred, Fla., USA, FSS.
Morton, J. 1987. Fruits of warm climates. Greensboro, N.C., USA, Media.
Popenoe, W. 1920. Manual of tropical and subtropical fruits. New York,
Macmillan.
Safford, W.E. 1912. Annona
diversifolia, a custard-apple of the Aztecas. J. Wash.
Agric. Sci., 2: 118-125.
Safford, W.E. 1914. Classification of the genus Annona with
descriptions of new and imperfectly known species. Contr. US Natl.
Herb., 18(1): 1-68.
Sanewski, G.M. 1988. Growing custard apples. Queensland Department of
Primary Industries and Energy, Australia.
Schwarzenberg, C. 1946. Polinización artificial del
chirimoyo. Agric. Tec. (Chile), 4: 156-172.
|
© FAO
|