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(also deccan hemp; Hibiscus cannabinus), a species of annual fiber plants of the family Malvaceae. It apparently grows wild in southern Africa and central India. The plant has a branching taproot, which extends 30–50 cm (sometimes 2 m) into the soil. The erect stem, which is ribbed or rounded, has thorns and measures 1–5 m tall. The leaves are large. The middle leaves are digitipartite; the lower, cordate; and the upper, lanceolate. The large, axillary, pentamerous flowers are cream colored with a bright crimson center inside the corolla. The fruit is a five-valved capsule, densely covered with stiff hairs, which irritate human skin. The gray seeds are reniform or triangular; 1,000 seeds weigh 20–28 g. The plant is thermophilic and hygrophilous. The seeds begin to sprout at 12°-14°C. The vegetation period is 125–145 days.
The dry stems of native varieties contain 16–20 percent fiber. The fiber, which is highly hygroscopic and durable, is used to make sacking, tarpaulin, string, and rope. The boon is used to make paper and building slabs. The seeds contain up to 20 percent oil, which is used for industrial purposes. The oil cakes are used for fertilizer and fodder.
Kenaf is grown most widely in India, where the plant was first cultivated; more than 300,000 hectares (ha) were cultivated there in 1970. Kenaf is also grown in China, Iran, Brazil, the United States, and other countries. It was imported to Russia in the 19th century. The plant is grown in small areas of Uzbekistan. The average harvest of dry stems is 40–60 centners per ha. The best varieties are 3876 and Uzbek 1574. The crops are treated with mineral fertilizers (90–120 kg/ha of N and P2O5 and 45–60 kg/ha of K2O). In wide-row sowings the seed average is 20–30 kg/ha. During the stage of growth and development the crop is watered four to six times (the watering rate is 800–900 cu m per ha). Kenaf is picked for its fiber when the first pods turn light green and the lanceolate leaves appear at the stalk apex. The bast is removed from the fresh stalks in the field; after it is dried, it is sent to a bast-processing factory.
Diseases of the kenaf plant include gray stem rot and alternaria blight. Insect pests include noctuid moths, plant bugs of the family Miridae, the species Poeciloscylus cognatus, aphids, and thrips.
REFERENCESLubianye kul’tury. Moscow, 1955. (Under the general editorship of S. S. Berliand.)
Minkivich, I. A. Rastenievodstvo. Moscow, 1965.
N. V. KUL'TIASOV