Agriculture Reference
In-Depth Information
us would consider civilization. Farming created com-
munities, community structure and economies, group
activities, enhanced trade and monetary systems to
name but a few. There is also little doubt that the total
genetic change achieved by early farmers in moulding
our modern crops has been far greater than that achieved
by the scientific approaches that have been applied to
plant breeding over the past century. Given that these
early farmers were indeed cultivating crops, it is not sur-
prising that they would propagate the most productive
phenotypes, avoid the individuals with off-taste, and
choose not to harvest those plants which were spiny.
Even today among peasant farmers there is a general
trend to select the best plants for re-sowing the next year's
crops. Early farmers may have used relatively sophisti-
cated plant breeding techniques as there is evidence that
some native Americans have a long established under-
standing of maintaining pure line cultivars of maize by
growing seed crops in isolation from their production
fields.
vegetables are similar where tomato ( Lycopersico escu-
lentum ), cabbage ( Brassica oleracea ) and onion ( Alliums
spp.) are leading vegetable crops, whilst orange ( Citrus
sinesis ), apple ( Malus spp.), grape ( Vitaceae spp.) and
banana ( Musa aceminata and M. balbisiana ) predom-
inate amongst the fruits. Many of these modern day
crops were amongst the first propagated in agriculture.
Many studies have been made to determine the date
when man first cultivated particular crops. The accu-
racy of dating early plant tissue has improved over the
past half century with the use of radio-carbon meth-
ods. It should, however, be noted that archaeological
material which remains well preserved has not proved
easy to find. Many of the most significant findings have
been from areas of arid environments (e.g. the eastern
Mediterranean and Near East, New Mexico and Peru).
These arid regions favour the preservation of plant tissue
over time, and not surprisingly, are the areas where most
archaeological excavations have taken place. Conversely,
there is a lower probability of finding well preserved
plant remains in regions with wetter, and more humid,
climates. Therefore, archaeological information may
provide an interesting, but surely incomplete, picture.
A summary of the approximate time of domesti-
cation and centre of origin of the world's major crop
species, and a few recent crop additions, is presented in
Table 1.1. It should be reiterated that many crop species
have more than one region of origin, and that archaeo-
logical information is continually being updated. This
table is therefore very much an over-simplification of a
vast and complex picture.
Some of the earliest recorded information which
shows human domestication of plants, comes from the
region in the Near East known as the 'Fertile Crescent'
What crops were involved? And when did
this occur?
Today's world food production is dominated by small
grain cereal crops, with world production of maize ( Zea
Mays ), rice ( Oryza sativa ) and wheat ( Triticum spp.);
each being just under 600 million metric tones annually
(Figure 1.1). Major root crops include potato ( Solanum
tuberosum ), cassava ( Manihot esculenta ), and sweet
potato ( Ipimiea batatas ). Oilseed crops are soybean oil
( Elaeis guineensis ), coconut palms ( Cocos nucifera ), and
rapeseed ( Brassica napus ). World production of fruit and
600
500
400
300
200
100
0
Cereals
Oilseeds
Pulses
Roots
Vegetables
Fruit
Figure 1.1
World production of major crops.
 
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