Improvement in Rice By JenXin W. Jones^ Senior Agrono'inist^ Division of Cereal Crops and Diseases, Bureau of Plant Industry RICE is the principal food of about half the people in the world, " and it may be said that rice and wheat together are the most important of the world's grain crops. In 1933-34 the world produc- tion of milled rice was some 211,280,000,000 pounds, or about 105 pounds for every man, woman, and child on earth. Including esti- mates for'China, world production of rough rice in 1934 was more than 7K billion bushels.^ Accurate figures are not available on the number of people who are largely dependent on rice as their chief energy food, but it is generally assumed to include a largo part of the population of China, India, Japan, Chosen, Taiwan, Ceylon, Indochina, Siam, the Dutch East Indies, the PhiHppine Islands, Malaya, and Madagascar. While rice is grown primarily for food, the byproducts obtained in milling and also the straw are used in various ways. Brown and milled rice is consumed largely in the boiled state as a vegetable or dessert, and in such breakfast foods as mush, puffed rice, and rice flakes. Broken rice is used as a food and feed, also in the brewing of fermented beverages and the manufacture of starch. Rice starch is a basis of most face powders. Rice bran and polish are used largely for feed. Polish also is used as a filler for sausage, and in the manu- facture of buttons. Rice hulls often are used in rice mills as fuel; as a source of cellulose for making cardboard, rayon, and linoleum; for packing purposes; as a soil mulch; and in the manufacture of certain gases. Rice straw is commonly used for thatching roofs of buildings in Japan and China; for making paper, cardboard, mats of various kinds, sandals, hats, coats, baskets, brooms, ropes, bags; as a packing material, as a fuel, as a mulch, as a feed, and as a fertilizer. The principal rice-producing countries of the w^orld are located on the continent of Asia and the adjacent islands, and they lie for the 1 The figure is 7,573,000,000 bushels, obtained by converting world production of clean rice, as given by the Yearbook of the U. S. Department of Agriculture, 1935, into rough rice on the assumption that clean rice is equal to 62 percent of the rough rice grown. The standard weight of a bushel of rough rice is 45 pounds. Rough rice is rice which has the kernels enclosed by hulls. One hundred pounds of rough rice is assumed to yield about 62 pounds of milled or clean rice, that is, rice with the hulls, kernel coats, and germs removed. 415 most part between the Equator and 30° north latitude. In these tropical and semi tro pical regions rice is by far the most dependable and productive cereal crop that can be grown. Most of the crop is grown under irrigation, often by intensive methods, and on lands that are too low and wet for the production of other cereals. Production in the United States and Abroad IN 1933-34, it is estimated that China produced about 38K million short tons of clean rice; India, 34 million; Japan, over 11 million; Indochina, over 4 million; Java and Madura, over 4 million; Siam, about SYz million; Chosen, about 3 million; the Philippine Islands, about 1% million (1931-32) ; and Taiwan, over 1 million. In the same year, production in the United States was about 500,000 short tons, Italy 400,000, Egypt 360,000, and Spain 200,000. The chief sources of the world's supply of export rice are British India (especially Burma), Indochina, and Siam. Italy, the United States, Spain, and Egypt are the principal exporters outside Asia. The average annual exports of milled rice during the 5-year period 1925-29 were for British India about 2% million short tons, Indochina 1% million, and Siam IK million. In the same period the annual exports from Italy were about 215,000 tons, the United States 126,000 Spain 58,000, and Egypt 50,000. British India (particularly Burma), Indochina, and Siam produce much more rice than is required for home consumption, whereas China, Japan proper, the Dutch East Indies, Ceylon, Malaya, and the Philippine Islands normally depend upon imports to meet their full requirements. In tixe United Kingdom, Germany, France, Belgium, the Nether- lands, Greece, Sweden, and Denmark, American rice is marketed in competition with that from Asia, Italy, Spain, and Egypt. Usually American rice commands a higher price in the above markets than the rice from competing countries. In the 5-3^car period 1925-29 the average annual exports of rice from the United States were about 250 million poimds, or roughly one-fourth of the annual crop. POSSIBILITIES FOR INCREASING THE YIELD IN THE UNITED STATES The production of rice in the United States could be materially increased if markets were available at satisfactory prices. In the States bordering the Gulf of Mexico it has been estimated that from 3 to 10 million acres of land are suitable for rice culture. In the interior valleys of California also the acreage could be materially increased.^ It docs not appear, however, that the acreage should be increased unless there is a considerable increase in per capita con- sumi^tion, or unless the surplus can be profitably marketed in com- petition with relatively cheap Asiatic rice. The tendency has been 2Tlio averafie acreage of rice harvested in Louisiana, Texas, Arkansas, and California in the 5-ycar ijcriod 1927-31 was 951,000 acres, and the average production was 43,651,000 bushels. 416 rather the other wn.y. Tlic iiuixinium acreage Jiarvcsted. in the United States was 1,300,000 acres in 1920, but in 1934 the acreage had decreased to 781,000 acres. Though American rice usually commands a premium because of its quality, yields in this country are relatively low. In 1934 the average acre yield of rough rice in Louisiana was 40.5 bushels, in Arkansas 51, in Texas 53, in California 73; and the average for the 4 States was 49 bushels. By contrast, the average yields in Spain, which ranks RICE improvement in the principal producing coun^ ^ tries of the world has heen in progress for many years. Exporting countries in the Far East are now emphasizing improvement in quality as well as yields so that their product may he better able to compete in the world mar\ets with rice from Italy^ Spain, the United States, and other temperate regions. The high acre yields of rice in some foreign countries as contrasted with the relatively low yields in the United States indicate the possibilities for further in^ creasing average yields in this country. This is a major objective of breeding wor\. In addition to in" creased yield, improved varieties should have stiff straw, disease resistance, and good milling and table quality, and they should mature early enough to be satisfactorily harvested without danger of loss owing to inclement weather. There is no apparent reason why it should not be possible by hybridization to develop varieties that possess all, or nearly all, the important characters that are desired by producers, millers, and consumers. first in this respect, are reported to range from 110 to 120 bushels per acre. In 1933-34 the average acre yield in Italy was 94, in Japan proper 83, in Egypt 60, and in India proper 27 bushels. The high average yields in Spain, Italy, and Japan are not due solely to the use of improved varieties, but also to the rather intensive methods used in growing the crop. Nevertheless, the high yields in these countries indicate the possibilities for further increasing- average yields in the United States. This is a major objective of breeding work. In addition to increased yield, improved varieties 417 should have stiff sti'íiw, diseaso resistaiice, and good milhng and table quahty, and. tlicy shoahi mature early enough to be satisfactorily harvested without danger of loss owing to inclement weather. Before taking up this breeding woiiv, it would be well to review briefly the historical background of rice growing in the United States and the methods of culture employed in this country, since these affect the breeding i)rogram. History^ Regions, and Culture in the United States RICE probably originated in the area extending from southern 1^ India to CoiJiin China. Hero the tropical climate, heavy rain- fall, and large flat areas of marshy land are suitable for the growth of the plant, and wild rices still persist in this region. Watt ^ believes that rice cultivation may have spread from this region eastward to RICE PRODUCTION RICE PRODUCTION 1879 1689 STATE POUNDS ST^T£ POUNDS La. 75.64-5.4.33 S.U. 30,338.95/ S. C. S2.077.Sis Ga. /4,SS6.432 Ga. 2S.369.687 N.C. S.846.4-04- La 23./8 6.3 It Fla, /.Oil,80S N.C. S.609.Í9} /^iss. 67G.7¿.S Miss. 1.718.9 SI Aia 399.270 Fia 1.294.677 /ex. f 08.423 Ala. 6/0.889 Ark. 7,110 Tex. 6 2,1 S 2 Va. 360 j:7 U.S. //0J31.373 US /28.S90.934 FiGuiiK 1.—Rice production in J879 and 1889. Tlio map for 1889 sliows tiie first important shift in rice production from the South Atlantic States to the prairies of Louisiana, China, probably 3,000 years before the Christian era, and possibly at a slightly more recent date westward and northward throughout India to Persia and Arabia, and ultimately to Egypt and Europe.