GRAIN CROPS - World Food: Production and Use - page 108

Laos, and Vietnam to China as shown in Figure 3.25. A more specific location is diffi-
cult to define because of the relative lack of archeological research in these areas. The
best guess is that it developed around 6000 BC , spread to the Yangtze River valley in
China by 5000 BC , the Indus valley of Pakistan by 2300 BC , and to Japan by 300 BC .
It reached the middle east and Greece by 300 BC .
One problem, which complicates the origin of rice, is the presence of ancestors of
O. sativa in the Americas, Africa, and Asia. It is generally agreed that the direct ances-
tor of modern rice was a wild species in the Pangean supercontinent, which later drifted
apart to form modern India, Africa, Australia, and South America. Wild forms of rice
found on these continents bear some resemblance to each other but are the result of
many wild hybridizations to form present day species. 20

3.4.5 History
Early movement of rice into other parts of the world followed wet, flood-prone river
valleys. This had the advantage of planting a crop in soil that was “renewed” each year
by floodwaters carrying fertile soil downstream. We are fortunate to have written
records from China recording some of the innovations in early rice cultivation summar-
ized in Table 3.2. Early introductions of rice into the Americas were by merchants travel-
ing from Africa and Asia to Europe. The very first varieties were probably Indica types
with ones introduced after 1900 being mostly Japonica types. Most of the Europeans
had little practical knowledge of rice cultivation. As a result, rice in North America is
classified by grain type not by ecotype. The official grain types recognized by the
USDA are long grain, medium grain, and short-grain as shown in Figure 3.26.
Because rice is so important to Asian cultures, an international institute was estab-
lished in the Philippines to develop rice production varieties and practices. The Inter-
national Rice Research Institute (IRRI) was established in 1960 as a collaborative effort
by the Ford and Rockefeller foundations and the government of the Philippines. Early
work showed the need for improved varieties and accompanying cultural practices. The
introduction of a semidwarf variety (IR-8) resulted in a plant that could grow under
high soil fertility conditions without lodging (falling over). The same semidwarf
characteristics were widely adopted in most rice-producing countries. This variety,
with others following it, was the key that started the “Green Revolution.” Countries

T A B L E 3.2. Chinese Innovations in Rice Culture

Approximate Year Practice

1500 BC Use of water buffalo

1122 BC Use of hoe introduced

600 - 500 BC Controlled flooding of rice paddies

400 BC First use of iron plow

AD 155 First use of transplanting

AD 900 Foot pedal pumps invented

AD 1000 Harrows and rollers introduced