Agriculture Reference
In-Depth Information
In spite of the high flower drop rate, no morphological differences are appar-
ent in avocado between the flowers that drop and those that will be retained in the
trees (Sedgley 1980 ). Early fruit abscission has been attributed to low carbohydrate
reserves in the trees (Davie et al. 1995 ) and the presence of starch in the ovary has
been reported at anthesis (Sedgley 1979 ). Recent results show that, whereas no
external differences are apparent among flowers at anthesis, a wide variability exits
in starch content at flower opening supporting the idea that flowers with the high-
est starch content at anthesis could present some advantage to develop into fruits
(Alcaraz et al. 2010, 2013 ).
Traditionally, in order to ensure an appropriate pollination process and optimize
production, the interplanting of A and B flowering type cultivars has been recom-
mended (Goldring et al. 1987 ; Garner et al. 2008 ), although this is still a subject of
discussion since the results are variable depending on the cultivars and environmen-
tal conditions (Kobayashi et al. 2000 ; Alcaraz and Hormaza 2011 ).
Fruit Development
Fruit development in avocado can last from six to more than 12 months depend-
ing on the cultivar and the environmental conditions. Fruit growth in avocado is
sigmoidal and most cell division takes place at the initial phases of fruit develop-
ment, followed by cell enlargement, although cell division continues at a slow rate
while the fruit is on the tree (Schroeder 1953 ). The differences in fruit size are, thus,
mainly due to the number of cells rather than by cell size (Scora et al. 2002 ). During
fruit development there is an increase in oil concentration; in fact, percentage of dry
matter, which is related to oil concentration, is the main parameter used to assess the
maturity index and determine optimal harvesting time in avocado.
Mango
The Mango (Fig. 5.5 ) is the most important species of the family Anacardia-
ceae in the Sapindales, both for its economic importance and world distribution.
The genus Mangifera , one of the 73 genera belonging to the family Anacardia-
ceae, comprises 69 species, of which 12 are at least of local commercial impor-
tance. The area of origin of the mango may extend between Assam (India) and
Myanmar where wild populations still exist, but it may also be native from the
low slopes of Himalaya or areas close to Nepal or Bhutan (Kosterman and Bom-
pard 1993 ). Two other well known fruit species belong to the same family, the
cashew nut, also of tropical requirements, and the pistachio (  Pistacia vera L.) of
temperate origin.
Some botanists estimate that the mango was domesticated around 6,000 years
ago (Hill 1952 ). Mango dispersal through the Indian subcontinent and the Ma-
lay Archipelago was very rapid being this species present around the fourth—
fifth Century through all tropical and subtropical countries of Southeast Asia
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