SUGARCANE

(Saccharum officinarum), giant, thick, perennial grass of the Gramineae family cultivated in tropical and subtropical regions worldwide for its sweet sap, which is a major source of sugar and molasses. Sugarcane probably originated in what is now New Guinea, its cultivation spreading along the human migration routes to Southeast Asia, India, and Polynesia. Asia is now the largest producer, followed by South America and North America. In the United States, sugarcane is a major commercial crop of Hawaii, Florida, and Louisiana. The plant grows in clumps of solid stalks with regularly spaced nodes or joints, with a bud at each node. The graceful, sword-shaped leaves are similar to those of the corn plant. The sheath folds around the stem, protecting the bud. Mature canes may be 36 m (1020 feet) tall and 2.57.5 cm (13 inches) in diameter. The colour of the stalk ranges from almost white to yellow to deep green, purple, red, or violet. The sugarcane plant is susceptible to more than 60 diseases, none of which occurs worldwide. Regional varieties are bred to resist specific types of disease, and extensive breeding programs continue to produce new varieties suitable to the major sugarcane-producing areas of the world. For commercial production, sugarcane propagation is conducted vegetatively (asexually); sections of stalk, each containing a node, are planted. The crop requires at least 1,500 mm (60 inches) of rainfall or irrigation per year and a minimum of nine months to mature. Cane is harvested in the cooler months in North America; in Cuba, Hawaii, Colombia, and other prime areas, it is harvested year-round. Most of the world's cane is cut by hand, using machetes, although mechanical harvesting has increased steadily since it was introduced in Louisiana in the 1940s. The sugar content of sugarcane ranges from 7 to 18 percent by weight. Cane yields range from 35 to 190 metric tons per hectare (15 to 85 tons per acre). About 75 million metric tons of raw sugar are produced from sugarcane each year in factories in the cane-growing areas. Molasses, the syrup remaining after sugar is crystallized out of the juice, is used to make rum and is a feed for farm animals. The residual cane fibre, called bagasse, is often burned as a fuel for the cane factory; it is also sold as a filler for paper and particleboard. perennial grass of the genus Saccharum cultivated for its juice, from which sugar is processed. Most present-day commercial canes are the offsprings or hybrids of the species Saccharum officinarum, which was developed from a wild cane species, Saccharum robustom, and cultivated by natives of southern Pacific Islands. This article treats the cultivation of the sugarcane plant. For information on the processing of cane sugar and the history of its use, see the article sugar. Additional reading Studies include A.C. Barnes, The Sugar Cane, 2nd ed. (1974), a detailed description of worldwide cane-growing techniques; and Frank Blackburn, Sugar-Cane (1984). Takeo Yamane The Editors of the Encyclopdia Britannica