A plant, Musa textilis, of the banana family that is valuable for its hard fiber (also known as Manila hemp) and native to Borneo and the Philippines. Abaca is one of the strongest of the hard fibers. Commercially, it is known as Manila hemp. The fiber is obtained from the leafstalks of Musa textilis, which is a member of the banana family. The plant (see illustration) resembles the fruiting banana, but it is a bit shorter in stature, bears small inedible fruits, and has leaves that stand more erect than those of the banana; these leaves are also slightly narrower, more pointed, and 5–7 ft (1.5–2.1 m) in length. Relatives of abaca grow wild throughout Southeast Asia, but the plant was domesticated long ago in the southern Philippines. Experiments have succeeded in growing plants that can yield fiber in a few other parts of the world, chiefly Central America and Ecuador, but commercial production has come almost entirely from the Philippines and Borneo. See also: Banana; Fiber crops; Natural fiber; Zingiberales
Environment and cultivation
Abaca prefers a warm climate with year-round rainfall, high humidity, and absence of strong winds. Soils must always be moist, but the plant does not tolerate waterlogging. Abaca grows best on alluvial soils in the southern Philippines and northern Borneo at elevations below 1500 ft (457 m). The plant is best propagated by rootstalk suckers. There are approximately 75 varieties grown in the Philippines. These varieties are grouped into seven categories, with each varying slightly in height, length, and quality and yield of the fiber. Newly planted stock reaches cutting size in 18 months, and a few stalks may be cut from each "hill" (mound) every 4 months thereafter for 12–15 years, after which new plantings are made. Plantings on good soils yield 90–150 lb (41–68.2 kg) of fiber per acre per year from 2 tons (1.8 metric tons) of stalks, and the fiber yield range is 2–4%. On large commercial holdings, plants are grown in solid stands, with the new stock spaced 15–20 ft (4.6–6.1 m) apart; however, on small farms, plants are scattered and mixed with bamboo and fruit trees.
Properties and uses
The fiber ranges 6 to 14 ft (1.8 to 4.3 m) in strand length, is lustrous, and varies from white to dull yellow. Prior to the Spanish colonization of the Philippines in the 1500s, Filipinos made clothing with the fine fiber, which today has been replaced by softer, more pliable textiles. Because abaca is one of the longest and strongest plant fibers, as well as being resistant to fresh and salt water, it is favored for marine hawsers and other high-strength ropes. Abaca is also used in sackings, mattings, strong papers, and handicraft art goods. See also: Textile
Processing and production
The fibers are carried in the outer sections of the leafstalks, and the fleshy material is stripped away mechanically. Traditionally, leafstalks were drawn by hand over a knife blade, under a wooden wedge, and a worker could clean about 15 lb (6.8 kg) of fiber per day. Small power machines strip about 175 lb (79.5 kg) per worker-day. Large mechanical decorticators save labor and recover more fiber, but the capital outlay is very large.
Abaca is affected by several diseases. The chief ones are bunchy top, mosaic, and wilt. Bunchy top is caused by a virus that is spread by the banana aphid (Pentalonia nigronervosa); leaves become smaller and clustered at the plant top, after which the plant dies. Mosaic is also caused by a virus that is spread by aphids (predominantly Rhopalosiphum nymphaeae and Aphis gossypii); the leaves turn yellow and dry out as the plant dies. Abaca wilt is caused by a soilborne or waterborne fungus that chiefly attacks plant roots. Filipino small farmers have traditionally resisted disease-control cooperative measures, and epidemics of bunchy top and mosaic have caused serious declines in acreage and production during the past few decades. See also: Entomology, economic; Plant pathology; Plant viruses and viroids