Tropical and Subtropical Fruits - Horticulture: Plants for People and Places - page 121

species may be deprived of leaves under stressed conditions (i.e. severe drought or
cool conditions or even during flowering), and others have a very limited degree
of frost-resistance when grown below 10 °C, although variation can occur between
species, varieties and age of plant or plant parts. Some citrus species, such as the
lime ( Citrus aurantifolia (L) . Swingle), the pummelo ( Citrus grandis (L.) Osbeck)
or the grapefruit ( Citrus paradisii Macfad.), could also fit into this definition, but
citrus species are normally considered academically as a different area of research
and will be covered separately in a different chapter in this topic.
Area of Origin and Geographical Distribution
Tropical and subtropical fruits originate in nearly all continents, except Europe,
although most of the better-known tropical and subtropical fruits originated in the
tropical and subtropical regions of America [e.g. papaya ( Carica papaya Linn), avo-
cado ( Persea americana Mill., pineapple ( Ananas comosus Merr.) or guava ( Psid-
ium guajava L.)] and Asia [e.g. mango ( Mangifera indica L.), banana ( Musa spp.),
and litchi ( Litchi chinensis Sonn.)]. Two commercially important fruits originated in
Oceania; the macadamia ( Macadamia spp.) in mainland Australia, and the coconut
( Cocos nucifera L.) in the Pacific region, although in the latter case its origin may be
more properly considered as pantropical (Martin et al. 1987 ). In addition, although
many tropical fruits have originated in tropical Africa, none of them, except the date
palm ( Phoenix dactylifera L.), can be considered commercially important.
The spread of tropical fruits from their area of origin to other regions often came
as a mean of providing shelter, clothing, wood or as medical supplies. Other fruits
played an important part as a 'delicious' part of the human diet. The exchange of
tropical and subtropical fruits between the Old and New World was especially ac-
tive during the time of the great Spanish and Portuguese expeditions, which ranged
from the end of the fifteenth until the middle of the seventeenth centuries, when
these two countries dominated the tropical belt around the World. The Manila Gal-
leon voyages that introduced the mango to Mexico from the Philippines is a clear
example of these exchanges (Galán Saúco 2009 ; Galán Saúco and Cubero 2011 ).
Importance of Tropical and Subtropical Fruits
Approximately 30 tropical and subtropical fruits (Table 5.1 ) are considered important
production crops in the world and they can be divided into major, minor and wild trop-
ical fruits, accordingly to their volumes of production and trade (Galán Saúco 1996 ).
Major tropical fruits are cultivated in most tropical and subtropical countries and
are well-known in both the local and export markets. Strictly speaking they include
mainly those covered by the Food and Agricultural Organisation (FAO) statistics
and are based on the area planted, production, yield and trade trends (Table 5.2 ). Mi-
nor tropical fruits are less extensively cultivated and consumed and their trade tends