Rice :: Asia 1920 - 1990

Rice is a staple food for more than a third of mankind. It constitutes the diet of one thousand six hundred million people and another four hundred million rely on it for between a quarter and half of their diet. Nutritive value of Rice protein (biological value =80) is much higher than that of the wheat (biological value =60) and maize (biological value =50) or other cereals.

Rice is a self-fertilizing plant. Around 1920, however, Japanese and U.S. rice breeders took the lead in using scientific approaches (hybridization selection and testing) to improve rice varieties. Elsewhere, pure line selection among farmers’ varieties was the main method of breeding.

After World War II, many Asian countries started to use hybridization as the main breeding approach. Through the sponsorship of the FAO, several countries in South and Southeast Asia joined in the Indica-Japonica Hybridization Project during the 1950s, exchanging rice germ plasm and using diverse parents in hybridization.

These efforts, however, provided very limited improvement in grain yield (Parthasarathy 1972), and the first real breakthrough came during the mid— 1950s when Taiwan (first) and mainland China (second) independently succeeded in using their semidwarf rices in developing short-statured, nitrogen-responsive and high-yielding semidwarf varieties (HYVs). These HYVs spread quickly among Chinese rice farmers (Chang 1961; Huang, Chang, and Chang 1972; Shen 1980).

Taiwan’s semidwarf "Taichung Native 1" (TN1) was introduced into India through the International Rice Research Institute (IRRI) located in the Philippines. "TNI" and IRRI-bred "IR8" triggered the "Green Revolution" in tropical rices (Chandler 1968; Huang et al. 1972). Subsequent developments in the dramatic spread of the HYVs and an associated rise in area grain yield and production have been documented (Chang 1979a; Dalrymple 1986), and refinements in breeding approaches and international collaboration have been described (Brady 1975; Khush 1984; Chang and Li 1991).

Rice production in Asian countries steadily increased from 240 million metric tons during 1964—6 to 474 million tons in 1989—90 (IRRI 1991). Among the factors were expansion in rice area and/or irrigated area; adoption of high-yielding, semidwarf varieties (HYVs); use of nitrogen fertilizers and other chemicals (insecticides, herbicides, and fungicides); improved cultural methods; and intensified land use through multiple cropping (Herdt and Capule 1983; Chang and Luh 1991).

In the early 1970s, China scored another breakthrough in rice yield when a series of hybrid rices (F1 hybrids) were developed by the use of a cytoplasmic pollen-sterile source found in a self-sterile wild plant ("Wild Abortive") on Hainan Island (Lin and Yuan 1980). The hybrids brought another yield increment (15 to 30 percent) over the widely grown semidwarfs.

Along with the rapid and large-scale adoption of the HYVs and with deforestation and development projects, innumerable farmers’ traditional varieties of all three ecogenetic races and their wild relatives have disappeared from their original habitats — an irreversible process of "genetic erosion." The lowland group of the javanic race (bulu, gundill) suffered the heaviest losses on Java and Bali in Indonesia. Sizable plantings of the long-bearded bulus can now be found only in the Ifugao rice terraces of the Philippines.