6550

17: Fibre plants

Musa textilis Née

Anal. Cienc. Nat. 4: 123 (1801).

MUSACEAE

2n = 20

Musa abaca Perr. (1824), Musa mindanaensis Rumph. ex Miquel (1859).

Abaca, abacá, Manila hemp (En). Abaca, chanvre de Manille, bananier à fibres (Fr). Indonesia: abaka, pisang manila (general), Manila hennep (Dutch). Malaysia: pisang manila, pisang benang. Philippines: abaká, abacá, abaca. Vietnam: chu[oo]i soi.

Abaca originated in the Philippines. Wild plants have spread southward into Borneo and islands south of the Philippines, such as Sangihe Island (Indonesia). Until the 1920s, attempts to establish commercial abaca cultivation outside the Philippines did not succeed, thus abaca was obtained from the Philippines only. However, to decrease the dependency on the Philippines, the United States successfully introduced abaca into Central America in the 1920s. Abaca cultivation in Ecuador started after the Second World War. The crop has also been grown successfully in Malaysia (northern Borneo), Indonesia (Sumatra) and New Guinea.

Abaca fibre, obtained from the pseudostem of Musa textilis, is the principal fibre of the Philippines, where it was already widely used as raw material for clothing and footwear at the time the Spaniards arrived. Exports started in the early 19th Century, and abaca became known as one of the best materials for marine and fishing cordage. From the 1950s onwards synthetic fibres largely replaced abaca as cordage material, threatening the Philippine abaca industry. Technological breakthroughs in the 1960s, however, led to the discovery of new uses for abaca, especially in the production of pulp for specialty papers. The Philippine government also encouraged the development of the fibre craft industry, which became the second largest foreign exchange earner in the abaca sector (after raw fibre) in the 1970s. Nowadays, abaca fibre is made into pulp and specialty papers, such as currency notes, cigarette paper, meat and sausage casings, teabags, filter paper, stencil paper and capacitor paper. In 2000 the Central Bank of the Philippines approved the use of 20/80% abaca/cotton mixtures for banknotes. In the cordage industry, abaca fibre is used for making cables, cords, ropes, strings, twines, marine cordage and binders. Fibre crafts include items such as footwear, mats, curtains, rugs, bags, place-mats, hammocks, wallets and wall decorations. Abaca is suitable for textiles after it has been cottonized. It is becoming popular as a blending material with silk and piña (Ananas comosus (L.) Merr.) fibre in the production of high-end fabrics. Abaca ribbons and 'sinamay', a local Philippine fabric, are used as decorative and packaging materials. Abaca fibre is also used in the manufacture of construction material such as roofing and floor tiles, wallboards, ceiling boards and wallpaper sheets, and to reinforce concrete and asphalt. The dried outer leaf-sheath ('bac-bac') is useful in the manufacture of ceiling board, sliding board and wallpaper substitute. It is also utilized for making trays, baskets, bags, slippers, blinds, curtains, wall panelling and place mats. The inner leaf-sheaths are used for making roofs and for shading seedlings. They also serve as plates or food containers. The leaf blades are used for shading and wrapping. In traditional Philippine medicine, the sap of abaca is used in treating wounds, especially to induce blood clotting. Abaca is also used for reforestation.
In Indonesia abaca is traditionally used in islands north of Sulawesi (Sangihe, Talaud) for fabrics and fishing nets, but here it has never developed beyond local importance. Attempts to introduce abaca as a smallholders' crop into other parts of Indonesia have not been successful.

In 1996—2000 the average annual world production of abaca was about 98 000 t from 132 000 ha. The major producers were the Philippines (about 72 000 t/year from 112 000 ha) and Ecuador (about 24 000 t/year from 16 000 ha). Minor producers included Costa Rica (1100 t/year), Indonesia (600 t/year) and Equatorial Guinea (500 t/year). In 1996—2000 an annual average of 33 000 t abaca fibre was traded internationally, of which the Philippines exported about 19 000 t and Ecuador 13 000 t. The main importers were the United Kingdom (15 000 t/year), the United States (8000 t/year), Japan (7000 t/year) and Spain (2000 t/year).
The main production areas in the Philippines in 1996—2000 were Eastern Visayas (Samar-Leyte; 27 900 t from 32 000 ha), Bicol (21 300 t from 45 000 ha) and southern Mindanao (8500 t from 8900 ha). In this period, the domestic industry used about 47 000 t, of which 29 000 t (62%) was used for pulp and paper making, 12 000 t (25%) for cordage, and 6000 t (13%) for fibre crafts. During the period 1991—2000 the consumption by the pulp sector increased by 4.1% per year, whereas the consumption by the cordage sector decreased by 1.5% per year. The average annual export earnings of the Philippines from abaca fibre and products in 1996—2000 were about US$ 82 million, to which raw fibre contributed 23%, pulp 44%, fibre crafts 19%, cordage 13%, and yarns and fabrics only 1%. The main importers of Philippine abaca fibre were the United Kingdom (7400 t), Japan (5900 t) and the United States (4900 t). The annual export of abaca pulp from the Philippines amounted to 14 100 t, mainly to Germany (6100 t) and Japan (5200 t). In the same period, 7800 t cordage (and allied products) was exported annually, mainly to the United States (5400 t).
It is estimated that in the Philippines, where abaca is mainly a smallholders' crop, more than 1.5 million people depend on the abaca sector for a living, directly or indirectly. In 2000, there were about 68 000 abaca farmers, with an average 2 ha abaca plantation per farmer. There are 5 abaca pulp companies in the Philippines, with a combined capacity of about 21 400 t/year, and 7 cordage firms, with a combined capacity of about 12 000 t/year. The fibre craft sector, including paper making by hand, is mainly cottage-based.
Commercial plantation has been tried several times in Indonesia in the second half of the 19th Century and first half of the 20th Century, for instance in Java, but has seldom been successful, mainly because of the difficult fibre extraction. However, Indonesia is presently trying to develop an abaca industry, using the cultivar 'Tangongon'.

Abaca fibre is obtained from the vascular bundles of the leaf sheaths that form a thick pseudostem. In cross-section, each leaf sheath consists of 3 layers: an outer fibrous layer with long and strong fibres ('primary fibre', the abaca fibre of commerce), a middle layer which has partitioned air canals and contains a small quantity of weak fibre ('secondary fibre'), and an inner layer which does not contain any fibre. Commercial fibres are 1—3 m long. The ultimate fibre cells are (2—)4—8(—12) mm long and (6—)13—29(—53) µm in diameter, with a lumen width of (1—)7—14(—33) µm. The fibre cells taper gradually to a pointed or rounded end. Irregular ends are rare. In general the tips are much finer and more pointed than those of sisal (Agave sisalana Perrine). Very fine dislocations and cross-markings are often present. In transverse section, the fibres are oval or rounded polygonal, often with 5 or 6 sides. Freshly cut pseudostems contain about 93% moisture and 1.5—3% fibre. Abaca fibre contains: 55—64% a-cellulose, 18—23% hemicelluloses, 5—18% lignin, 1% pectin and 1—2% ash.
Abaca fibre, classified among the hard fibres, is remarkable for its strength and resistance to fresh and salt water. It is three times stronger than cotton (Gossypium spp.) fibre and twice as strong as sisal, and also stronger than hemp (Cannabis sativa L.) and sunn hemp (Crotalaria juncea L.). It is more resistant to salt water than most other vegetable fibres. Commercial abaca fibre ranges from almost pure white, through cream to light or dark brown, depending on cultivar, position of the sheath in the pseudostem, and fibre extraction and processing.
Abaca fibre is excellent raw material for paper and dissolving grade pulps due to its low lignin, ash, silica and extractive contents, and high total cellulose content, all of which contribute to high pulp yield and low consumption of chemicals in the pulping and bleaching treatments. It also has a high pentosan content, which contributes to the high bursting, folding and tensile strengths.

The main competitors of abaca as cordage material are synthetics and sisal, which are both cheaper. However, abaca is still preferred in oil drilling, navy and merchant shipping, and construction, because of its non-slippage characteristics. The main competitors in the market for specialty papers are artificial fibres, such as viscose and polyester, which are also used in blends with abaca. Sisal is inferior to abaca for the production of specialty papers, except for filtration media, because paper made of sisal has a higher porosity but lower tensile and bursting strength. In the Philippines abaca is sometimes adulterated with 'canton', a natural hybrid of M. textilis and Musa balbisiana Colla, and by 'pacol', obtained from Musa balbisiana. Both canton and pacol are of lower quality than abaca.

A tufted perennial herb, up to 8 m tall, growing in a clump (hill), very similar to an edible banana plant, when mature and undisturbed consisting of 12—30 or more pseudostems in different stages of development. Corm cylindrical, short, bearing buds developing short rhizomes with suckers, and numerous slender adventitious roots extending 2—3 m and mostly confined to the top 25 cm of the soil. Pseudostem (formed by the leaf sheaths) cylindrical, 2.5—6 m tall, 15—20 cm in diameter at base, mostly green, sometimes irregularly streaked deep brown, red, purple or even almost black towards the base, bearing up to 12 leaves; petiole-like sheath 40—50 cm long, stiff; leaf blade narrowly oblong, 150—200 cm x 40—60 cm, cuneate and unequal at base, rounded or acute at top, generally of a uniform deep-green above, glaucous beneath. Inflorescence arising from the rhizome, borne on an erect, long peduncle which for its greatest part is included in the pseudostem, bearing a drooping racemiform spike, consisting of an axis with transversely arranged, 1—2-seriate groups (hands or combs) of 10—12 flowers, each group in the axil of a bract; bracts lanceolate, 30—35 cm x 10—12 cm, closely overlapping, deciduous, leathery, green, slightly shaded with pink outside, dull brown inside; perianth of 5 fused outer tepals and one adaxial inner tepal; male flowers in upper part of inflorescence, about 4 cm long, deciduous, with 5 slightly exserted stamens and one pistillode; female flowers in basal part of inflorescence (first 3—6 nodes); ovary inferior, 5 cm long, 3-locular, with numerous ovules. Fruit bunch horizontal, lax; fruit a berry, narrowly ovoid or ellipsoid, 5—8 cm x 2—5 cm, obsoletely curved at maturity, narrowed at base into a stout truncate stipe about 7 mm long, pericarp 1 mm thick, ripening green; pulp scanty, pale buff, inedible. Seeds numerous, subglobose-turbinate, very irregular in shape, about 2—3 mm x 3—4 mm, smooth, black.

Emergence of abaca from seed is completed 2—4 weeks after sowing, but vegetative development is very slow. Growth accelerates after 2—4 months. Flowering normally starts 18—24 months after sowing. Plants raised from one-year-old suckers may flower 10—12 months after planting, whereas those grown from corms flower 16—18 months after planting. Flowering is year-round in the tropics. Time to fruit maturity ranges from 27—34 months under normal conditions but takes longer at higher altitudes. After the fruit has ripened, the stem dies if it has not been cut for fibre. Cultivated plants usually consist of 10—20 pseudostems in various stages of maturity, of which 4—8 reach the flowering stage within the same year. Abaca has typical bat-pollinated flowers; in Indonesia it is pollinated by small bats (mainly Macroglossus minimus). The stigmas are receptive for 2 days, and the pollen remains viable for 2 days. Self-pollination is impossible due to the separation of male and female flowers in the inflorescence and the earlier flowering of female flowers, but sib-pollination between pseudostems of the same clump is possible.

Musa L. comprises 30—40 species and the genus is often divided into 5 sections. Musa textilis belongs to section Australimusa. Its general structure is similar to that of the edible banana cultivars, but it is more slender, the leaves are smaller and the fruits are seeded. Wild relatives of Musa textilis include Musa acuminata Colla subsp. banksii (F. Muell.) Simmonds ('agotay') and Musa balbisiana ('pacol').
More than 400 cultivars of abaca are grown in the Philippines, but only about 20 of them are of commercial importance and these are distributed throughout the different regions of the country.
In Bicol, the most commonly grown cultivars are:
— 'Tinawagan pula': well-suckering, but with small stalks at maturity.
— 'Lausigon': hardy, does not lodge easily and withstands drought; fibre coarse and difficult to strip.
— 'Sogmad': thrives well on fertile soils; produces an average of 19 suckers per year; fibre white and fine, easy to strip.
In Eastern Visayas, the most commonly grown commercial cultivars are:
— 'Inosa': producing 5—7 suckers per hill; resistant to strong winds and drought; thriving well in medium fertility soils; fibres coarse and difficult to strip.
— 'Linawaan': widely grown because of its high fibre yield; producing 9—11 suckers per hill; deep-rooting and resistant to strong winds and drought; fibre white, lustrous and fine, but difficult to extract.
— 'Laylay': stooling freely, with well-developed stalks, which tend to grow very close to each other; late maturing; shallow-rooted and susceptible to strong winds; easy to strip; fibres long, ivory white, lustrous and uniform from base to tip, thus suited for fibre crafts.
In Mindanao, the three commercial cultivars grown are:
— 'Tangongon': large, hardy and vigorous, 4.5—5.5 m tall; not exacting with regard to soil conditions, growing well on heavy clay soils; does not sucker freely; easily blown over because the corms often push through the soil surface; fresh pseudostems yield 2.5—2.75% of a strong, heavy, coarse fibre, which is difficult to extract.
— 'Bongulanon': stems medium-sized, leaves narrow; abundantly suckering; not readily lodged; early maturing, but with a short productive life and yields decline after 5—6 years; requires moist, well-drained alluvial soils and cannot be grown on heavy clays or dry sandy soils; fresh pseudostems yield about 2.3% of strong, white, good-quality fibre which is easily stripped. It used to be the most widely grown cultivar in Central America.
— 'Maguindanao': stems large; relatively hardy; first harvest 15—18 months after planting, with a long productive life of 15 years or more; can be grown on a wide range of soils, except heavy clays; root system shallow and plants are easily blown over; fresh pseudostems yield about 1.75% of strong, white, soft fibre, which is easily extracted.
The leaves of other Musa spp. are used as wrappers for food, and fibre may be obtained from their pseudostem for the production of cloth. In Indonesia, especially in Java, pseudostems of edible Musa L. cultivars recently started to be used in the production of pulp for handmade specialty paper and in the production of handicrafts such as handbags and placemats. Musa violascens Ridl., endemic to Peninsular Malaysia, has been investigated for its fibre in the early 20th Century. The average length of its ultimate fibres was 2.5 mm; the strength was only half that of abaca. The fibre of the closely related Musa salaccensis Zoll., found in Sumatra and Java, has been recorded as being suitable for tying

Abaca is a plant of the hot and humid tropics. The present zone of successful cultivation lies between approximately 5°S and 15°N latitude. In the Philippines it is usually grown in regions below 500 m with a well-distributed annual rainfall of 2000—3200 mm, an average temperature of about 27°C and a relative humidity of about 80%. Abaca is easily damaged by strong winds; in the Philippines windbreaks and cover trees are planted in typhoon-prone areas. It grows best on friable well-drained loams, rich in organic matter and potash, and is sensitive to waterlogging.

Abaca can be propagated by suckers, corms or seed. Propagation by seed is not recommended because seedlings take longer to mature and are not true to type, since abaca is highly heterozygous. Seed propagation may, however, be used for the production of new clones. The use of suckers or corms (or corm sections: 'seed pieces') is recommended for commercial propagation. Corms are usually preferred over suckers since they are easier to handle and transport. In the preparation of corms, care should be taken not to destroy the bud eyes. Mature suckers are used to fill vacant spaces in established plantings. Mass propagation of abaca is now done through in vitro culture. Tissue-cultured abaca plants are used in replanting programmes, especially in Bicol.
On small farms in the Philippines, abaca is normally planted irregularly between felled trees. In large-scale operations, it is advisable to establish an abaca nursery to produce the planting material. A nursery of 1 ha, with plants in double rows 2 m apart, with 1 m between the rows of each pair and 1 m between plants within the rows, will produce approximately 40 000 seed pieces per year. This is enough to plant 15 ha at a spacing of 2 m x 2 m. Seed pieces are planted in 40—50 cm deep holes 2 m x 2 m apart for ordinary-sized cultivars and 2 m x 3 m or 3 m x 3 m for larger ones; the plant density is 1100—2500 plants/ha. Planting is best done at the onset of the rainy season for early germination and a vigorous start. In areas with no or only a short dry period, planting can be done throughout the year.
It is recommended that trees be planted, such as Erythrina fusca Loureiro, Paraserianthes falcataria (L.) Nielsen and Leucaena leucocephala (Lamk) de Wit, to provide shade, maintain optimal temperature and humidity, and protect abaca from strong winds. Fruit trees such as durian (Durio zibethinus Murray), langsat (Lansium domesticum Correa) and jackfruit (Artocarpus heterophyllus Lamk) can also be planted as shade trees, with the advantage of providing additional income to the farmers. Abaca is also intercropped with coconut (Cocos nucifera L.). Intercrops such as upland rice (Oryza sativa L.), mungbean (Vigna radiata (L.) Wilczek, cowpea (Vigna unguiculata (L.) Walp.), groundnut (Arachis hypogaea L.) and other leguminous short-season crops may be planted for additional income during the establishment of the plantation and to reduce soil erosion. At a later stage, ginger (Zingiber officinale Roscoe), which tolerates shade, can be planted as an intercrop.

Compared with other crops, abaca requires little care and often the plants are just left to grow until maturity. Shallow cultivation and ring weeding may be carried out at 2—3 month intervals for up to a year. It has been estimated that 100 t/ha of fresh stalks and leaves of abaca remove 280 kg N, 13 kg P, 430 kg K and 89 kg Ca per ha. When the fibre is extracted in the field and all other plant parts are returned to the soil, the nutrient loss is considerably lower. Most smallholders do not apply chemical fertilizers. Drainage canals can be constructed to allow better soil aeration. Pruning and thinning may be done by removing excess young suckers, leaving about 8 vigorous suckers per hill to mature every year. The duration of profitable production varies according to cultivar and growing conditions. In properly maintained areas, production may not decline for over 20 years, but it is generally advisable to replant after 10—15 years.

The most important diseases of abaca are the viral diseases known as bunchy top and abaca mosaic. Abaca bunchy top virus (ABTV) is transmitted by brown aphids (Pentalonia nigronervosa). Infected plants develop chlorotic yellowish-white streaks and transparent veins; the plants become stunted and the crown of the plant develops a bunchy rosette growth form; finally the leaf blades dry up and turn brown. Early symptoms, visible at 14—18 days after inoculation, include the dark green appearance of infected leaves and restricted growth of the youngest leaf. The main control methods are the use of noninfected plant material and the eradication of infected plants. Abaca mosaic is caused by the abaca mosaic virus (AbMV), a potyvirus transmitted by aphids such as corn aphids (Rhopalosium maidis) and cotton aphids (Aphis gossypii). The onset of abaca mosaic is characterized by mottling of the leaves, consisting of dark to pale green or yellowish streaks, which extend from the midribs to the margins; mottling also occurs on other parts of the plant. Affected plants do not grow to full size. The use of disease-free planting material, eradication of infected plants, and elimination of alternate hosts such as maize (Zea mays L.) and the weeds Cyperus compressus L., Paspalum conjugatum Bergius and Senna tora (L.) Roxb., are necessary for effective control of abaca mosaic.
An important fungal disease is Fusarium wilt, caused by Fusarium oxysporum f.sp. cubense. It starts with rotting at the base of the pseudostem, with the rot moving upward until it reaches the leaf blades; plants become yellowish and eventually wilt. When corms and pseudostem of wilted plants are cut crosswise, the reddish-violet colour of the vascular bundle becomes evident. The first noticeable symptoms of the disease are the inward curling of the leaf blades at or near the tip of the lower leaves and the slow growth of the plants. Fusarium wilt, which, in contrast to the virus diseases, spreads in the soil or by rainwater, can be controlled by digging out infected plants and burning them, and by strict implementation of quarantine measures. Some cultivars, e.g. 'Linawaan', seem less susceptible than other ones. Less serious fungal diseases include dry sheath rot caused by Marasmius spp. and a stem rot caused by Deightoniella torulosa (synonym: Helminthosporium torulosum).
Important abaca pests include the aphid Pentalonia nigronervosa, an important vector of viruses which can be controlled by using appropriate insecticides. Corm weevil (Cosmopolites sordidus) can be controlled by keeping the field clean, by spraying or dipping infested corms or seedpieces containing eggs with insecticide, or by applying insecticides around the base of the plant. Slug caterpillars (Thosea sinensis) can be controlled by handpicking and killing the larvae using protection gloves or by spraying with contact insecticides at 7—10-day intervals.

Abaca pseudostems are considered mature and should be harvested when the flagleaf (a rudimentary leaf, much reduced in size) appears, which precedes the appearance of the inflorescence. The time to first harvest of abaca depends upon the cultivar used, environmental conditions and cultural methods employed. Normally the first harvest takes place 18—24 months after planting. Subsequent harvests are made every 3—4 months in more favourable areas and every 5—7 months under less favourable conditions. In general, yield from the first harvests is small, and high yields are obtained from 4—8 year old plants. Harvesting abaca consists of topping the plant by cutting the leaf crown at the base of the leaf blades, and then tumbling the topped pseudostems with a slanting cut near ground level.

In the Philippines the annual fibre yield of abaca ranges from 0.3—1.7 t/ha, depending on cultivar and location, with an average of 0.6 t/ha over the period 1996—2000. In Ecuador abaca fibre yields averaged 1.5 t/ha over the same period.

The 10—20 useable abaca leaf-sheaths harvested per harvest are peeled off the pseudostem. The outer, middle and inner sheaths are normally separated, because they produce fibre of different quality: from the outer to the inner leaf sheaths the fibre becomes softer, whiter and weaker. In a process called 'tuxying', the outer layers of the leaf-sheaths are torn off. From these strips or 'tuxies', the fibres are extracted by placing the strips between a wooden bar and a serrated knife and pulling them manually (hand-stripping), thereby stripping off the epidermis and parenchyma. This is hard work, which can be lightened by a semi-mechanized process (spindle-stripping), in which the tuxies are pulled by a wooden spindle which is driven by an engine. Mechanical decorticators can also be used; they crush the pseudostems, scrape off the fleshy material and brush and clean the fibre, which is known as 'deco fibre'. In mechanical decortication both the primary fibres from the outer layer and the secondary fibres from the middle layer are extracted. It is much faster than hand- and spindle-stripping, but gives an inferior fibre and is not used on a commercial scale. In the Philippines most farmers use hand-stripping, whereas in Ecuador almost all fibre is extracted by spindle-stripping. Fibre recovery with hand-stripping is about 1.2—1.5% of the weight of the freshly cut pseudostem, with spindle-stripping 1.5—2.5%, and with decorticators about 3.0—4.0%. The extracted fibre is sun-dried or air-dried under a roof, after which it is graded and baled. The standard grades in the Philippines are divided into 2 main classes: hand-stripped and spindle-stripped. Within each class the fibre is further graded according to strength, cleaning, colour, texture and length. The fibres are baled per grade into bundles of 125 kg, measuring 100 cm x 55 cm x 60 cm.
In the paper industry the best fibre grades are made into porous and strong specialty papers, such as tea-bag paper and meat casings. Fair to residual grades are made into pulp for specialty papers with high tear and tensile strengths, such as vacuum cleaner bags and wrapping paper. On a commercial scale abaca pulp is usually produced using the soda process or alkaline sulphite process, but kraft pulping has also been applied in the Philippines. CTMP (chemi-thermo-mechanical pulping) and cold soda pulping (CSP) of abaca give pulps with good strength and optical properties. Thermo-mechanical pulping (TMP) of abaca, however, resulted in pulps with inferior strength properties. Printing and writing papers produced from waste paper blended with 5% bleached CTMP or CSP abaca pulp have strength properties comparable with those of paper produced from waste paper blended with 20% softwood pulp. Biological bleaching of abaca kraft pulp with the white-rot fungus Trametes versicolor has been successful. Pulps suitable for the production of rayon viscose have been prepared from abaca fibre using the kraft and alkaline sulphite pulping processes.

The Philippines is the primary gene centre for abaca. The largest germplasm collection is maintained at the National Abaca Research Centre (NARC) based at the Leyte State University (formerly Visayas State College of Agriculture), Baybay, Leyte. More than 600 accessions (cultivars and wild types) are maintained, while duplicates of 100 accessions are maintained at the Institute of Plant Breeding, University of the Philippines Los Baños, College, Laguna. Accessions, especially threatened cultivars, are also conserved in vitro. Isozyme analysis and DNA fingerprinting are being done to eliminate duplicates. Part of the collection at NARC has been characterized with respect to fibre morphology, chemical composition, fibre qualities and physical properties.

The main objectives in abaca breeding are: high degree of resistance to diseases and pests, early maturity, high yield and fibre recovery, optimal fibre quality, and adaptability to varying climate and soil conditions, including drought and acid tolerance. Wild relatives available for improvement include 'pacol', 'agotay', 'alinsanay' (Musa textilis <x> Musa acuminata subsp. banksii), 'canton' and 'minay'. The latter two types are both putative hybrids between Musa textilis and Musa balbisiana. These wild relatives are possible sources of resistance to important diseases and pests, vigour, resistance to drought and other desirable agronomic characteristics.

The demand for abaca both by local processors and foreign users is expected to increase in the future, indicating promising prospects for the abaca industry, especially for the abaca pulp sector. As technology evolves rapidly, more varied uses of abaca are being discovered. In view of the growing environmental hazards posed by non-biodegradable materials, industrialized countries are beginning to consider more environment-friendly raw materials, such as abaca. At present, the supply of abaca fibre cannot meet the increasing demand. Moreover, each grade of abaca fibre has its own market, so fibre production should be tailored to the particular end use for which it is intended. Thus, both expansion and diversification are called for. Increased production through improved husbandry should be coupled with improved processing methods. Appropriate abaca-based cropping systems are needed to provide abaca farmers with a steady income especially during the establishment phase. Crop protection should be aimed at the development of environment-friendly biological control agents. Breeding should be geared towards development of high-yielding, disease- and pest-resistant and stress-tolerant cultivars with good fibre quality. As abaca is a perennial, the use of biotechnology should be explored to accelerate genetic improvement. The use of somatic embryogenesis for micropropagation holds promise especially in the production of disease-free encapsulated seeds.

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L.R. Gonzal & A.F. Valida

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