1884

4: Forages

Gliricidia sepium (Jacq.) Kunth ex Walp.

Repertitorium bot. syst. 1: 679 (1842).

LEGUMINOSAE

2n = 20

Gliricidia maculata (Kunth) Kunth ex Walp. (1842).

Gliricidia, mother of cocoa, quick stick (En). Indonesia: gamal (Javanese), liriksidia (Indonesian). Philippines: balok-balok (Tagalog), apatot (Bikol), kukuwatit (Pangasinan). Laos: kh'è: nooyz, khê fàlangx. Thailand: khae-farang. Vietnam: anh dào gi'a, sát thu, hông mai.

Gliricidia is a native of the seasonally dry Pacific Coast of Central America from sea-level to 1200 m, but has been long cultivated and naturalized in tropical Mexico, Central America and northern South America, up to 1500 m altitude. The species was also transported to the Caribbean and later to West Africa. It was introduced to the Philippines by the Spaniards in the early 1600s, and to Sri Lanka in the 18th century; from there it reached other Asian countries including Indonesia (about 1900), Malaysia, Thailand and India.

In the past, gliricidia forage was often collected from trees which had been planted for other purposes, but increasing attention is now given to options for cultivating it specifically for fodder production either in cut-and-carry or grazing systems. It provides useful forage in the form of leaves, green stem and bark, and is commonly used to supplement poor quality, low protein roughage, especially in dry seasons when it may become a major source of feed for goats and cattle in dryland cropping areas. Its forage has been reported to be toxic to horses, but clear confirmation is lacking. Leaf meal can also be fed to poultry and rabbits.
The tree is widely used for many other purposes. The wood is often utilized as firewood, charcoal or as posts and farm implements, and locally for furniture, construction purposes and railway sleepers. The species is extensively used in different cropping systems, e.g. as a shade tree in tea, cocoa or coffee plantations, as live stakes to support vanilla, black pepper and yams (in West Africa), as a hedge, a green manure crop in intercropping systems with arable crops; it is also being tested in alley-cropping systems. The tree has also been planted to reclaim denuded or lands invested with Imperata cylindrica (L.) Raeuschel. Seeds, bark, leaves and roots may be used as a rodenticide and pesticide after fermentation; flowers serve for honey production. The tree is often planted as an ornamental. In the Philippines juice of the leaves, bark and roots is used to alleviate itches and wounds.

The leaves contain from 3—5% N, 13—30% crude fibre and 6—10% ash. Digestibility ranges from 48—77%. Forage quality varies with age, plant parts, season and genotype. It is highest in the youngest leaves; with maturity N concentrations decrease slightly and crude fibre increases. In 3-month-old growth, gliricidia bark had lower N concentrations than the leaves, but higher levels than the stem. Palatability can be a problem as the forage contains some anti-nutritional factors, with 1—3.5% flavonol and 3—5% total phenols on a DM basis. Ruminants unaccustomed to it may not eat the foliage when introduced to it for the first time. However, once initial aversion has ended, animals will eat a high proportion in their diet for extended periods of time, especially when mixed with other species. In some cases it has been observed that day-old wilted leaves are preferred to fresh leaves; also silage is more palatable than fresh foliage. Leaves also contain carotene.
There are about 80 seeds/g.
Light-brown sapwood and dark-brown heartwood turning reddish on exposure to air, hard, coarse-textured with irregular grain. It is very durable and termite-resistant. The dense wood, with a volumetric mass up to 750 kg/m³, is difficult to work. Wood does not reach large dimensions, the bole seldom has a diameter of more than 40 cm and a length of 8 m; normally dimensions are smaller, especially if the tree is regularly coppiced. In young coppices the wood is less dense, with a volumetric mass of about 500 kg/m³.

A small deciduous tree up to 12 m tall with a short trunk up to 50 cm in diameter, with smooth or slightly fissured, whitish-grey to light brown bark, often branching from the base; the mature tree has an irregular spreading crown of thin foliage. Leaves alternate, pinnate, 15—40 cm long, with slender, yellow-green, finely hairy rachis; leaflets 7—17 per leaf, opposite except in upper part of rachis, elliptical or lanceolate, 3—6 cm x 1.5—3 cm, rounded or cuneate at base, acuminate at top, thin, dull green and glabrous above, grey-green and often pubescent beneath; petiole 5 mm long. Flower in a 5—12 cm long, axillary raceme, about 2 cm long, on an 8—12 mm long, slender pedicel; calyx campanulate, 5-toothed, light green tinged with red; corolla whitish-pink or purple, with a broad standard, turned back and yellowish near the base, 2 oblong, curved wings, and a narrow keel; stamens 10, white, 9 united in a tube and 1 separate; pistil with stalked, narrow red ovary and whitish curved style. Pod narrow, flat 10—15 cm x 1.2—1.5 cm, yellow-green when immature, turning yellowish-brown, shortly stalked and with a short mucro, splitting open at maturity. Seeds 4—10 per pod, ellipsoidal, ca. 10 mm long, shiny, dark reddish-brown.

Seeds germinate in 7—10 days. Early seedling growth is slow, but once established, growth is fast (up to 3 m/year). Flowering and fruiting take place during the dry season, when the tree has shed its leaves if it has not been cut. Flowers are insect-pollinated and the species is outcrossing. Pods ripen 40—55 days after flowering, seeds are mature when pods turn yellow-brown; fruiting is relatively uniform with about 20 days from first to last seed dispersal. In its native area seed production is usually abundant and can be predictably timed. In more humid zones, shoot growth tends to be continuous and the evergreen tree flowers only sporadically on the basal parts of twigs from which the leaves have fallen.

Gliricidia maculata has been used extensively as a synonym for Gliricidia sepium. Recently Gliricidia maculata has been proposed as a distinct species with a different natural geographic distribution. i.e. Yucatan Peninsula, northern Guatemala and Belize. It differs from Gliricidia sepium by having white flowers rather than whitish-pink or purple, and it has smaller pods and seeds. Most gliricidia planted as an exotic can be attributed to Gliricidia sepium, but former introductions of Gliricidia maculata cannot be ruled out.

In its native range the climate is relatively uniform sub-humid with an annual rainfall of 900—1500 mm and a five-month dry period. The species has been introduced successfully in more humid zones with up to 3500 mm annual rainfall and no marked dry season. In its native range, mean annual temperature varies from 20—29°C, maximum temperature below 42°C; light night frost is tolerated, but not prolonged frost. Gliricidia occurs naturally in early and middle successional vegetation types on disturbed sites such as coastal sand dunes, river banks, floodplains and swidden lands. It tolerates a wide range of soil types, both alkaline and acidic, but prefers free drainage. It is more tolerant of acid and poorly fertile soils than leucaena (Leucaena leucocephala (Lamk) de Wit), but will respond to fertilizer application on such soils. It is not as well adapted to the subtropics as leucaena; leaves are shed with the onset of lower temperatures during winter, and plants are less resistant to frosts. However, it is more tolerant of waterlogged conditions than leucaena. The tree resprouts after fire.

Gliricidia is easily propagated from seed or cuttings. Direct seeding is not often used and potted plants or bare rooted stock are raised in nurseries. Freshly harvested seed or seeds that have been preserved in cold storage have a germination percentage of 80—90%. Seed pretreatment is not necessary and seeds may be sown directly. Nursery stock can be transplanted after 10—12 weeks. It can be propagated very easily by large cuttings, 3—6 cm thick and 0.5—2 m long; the bark may be incised to assist rooting. Cuttings should be taken from mature branches with brownish-green bark and planted fresh. Rooting starts 6—7 weeks after planting. Plants grown from cuttings may have 50—150 nodules after 3 months, compared with 20—70 nodules after 6 months on plants from seed. Trees obtained from cuttings are often more shallow-rooted than trees grown from seed.
Gliricidia may be planted in hedges spaced 4—10 m apart with 10—50 cm between trees in the rows, or as live fences with 20—100(—200) cm spacing. In fodder plots, spacings of 0.25 m x 1.0 m or larger may be used; yields of leaves are little affected by planting densities ranging from 5000—40 000 trees/ha. Sometimes trees are used at wide spacings (e.g. 10 m x 10 m) over pasture lands. Where animals are grazed in young plantations, young trees must be protected. Growth on degraded lands may be stimulated by inoculation with an appropriate strain of Bradyrhizobium and fertilization. When the tree is used as a live post for black pepper or vanilla, the crops can be planted at the same time as the tree. Such live posts provide some protection against climatic stress. In woodlots spacings of 1.5 m x 2 m to 2 m x 2.5 m are common.

Fodder from gliricidia can be produced in various systems. Protein banks consist of dense plots which are periodically harvested for fodder or grazed; hedges may be planted in existing pasture lands and interplanted with grasses; living fences may be established around pasture lands or agricultural fields and homesteads; or spaced trees may be used in pastures to enhance livestock production by providing fodder and shade. In Sri Lanka the tree has also been integrated in pastures under coconut to produce dry season fodder. In Bali (Indonesia), gliricidia has been incorporated in a 'Three Strata Forage System' consisting of a strip of 5 m wide, in which fodder trees (e.g. Ficus subcordata Blume, Hibiscus tiliaceus L., Lannea coromandelica (Houtt.) Merrill), shrub legumes (e.g. gliricidia) and grasses (e.g. Cenchrus ciliaris L.) and herbaceous legumes (e.g. Stylosanthes spp.) are combined; cattle feed mainly on the grass-legume stratum in the wet season, the shrub legumes in the mid-dry season and leaves from the fodder trees in the late dry season. Variable amounts of fodder may also be collected from plantations established for other primary purposes such as erosion control or green manure contour plantings in cropped fields.
The influence of gliricidia on pasture grass production depends on the grass species, site conditions and management. Even if grass production is decreased, gliricidia production may compensate for this loss with the total production being more evenly distributed over the year. A wide range of grasses and legumes can be grown together with gliricidia, including Panicum maximum Jacq. var. trichoglume Robijns, Cenchrus ciliaris, Urochloa mosambicensis (Hack.) Dandy, Stylosanthes scabra Vogel, and Stylosanthes hamata (L.) Taub. When fed as a supplement to poor quality grass, it improved the survival of ewes and lambs, lambing percentage, and birth weight and growth of lambs. It is normally recommended that when feeding cattle, goats and sheep, gliricidia be used at levels of 10—30% fresh weight mixed with either grass, straw or other roughages. Levels of 2—4% should be used when it is fed to poultry as a replacement for lucerne (Medicago sativa L).

Few diseases and pests have been recorded on gliricidia, and only sporadically do these cause noticeable damage. Very little information is available on the effect of pests and diseases on fodder quality and palatability, but in Indonesia it was observed that buffelgrass (Cenchrus ciliaris) was adversely affected by an attack of Aphis craccivora on gliricidia. When intercropped the tree may either positively or negatively affect crop pests. In several cases the tree has been reported to control pests, e.g. in Sri Lanka termite damage to tea and in the Philippines stem-borer damage to rice were minimized. In India, on the other hand, the tree was found to enhance the transmission of aphids (Aphis craccivora) causing rosette disease in groundnuts.

The first harvest can be as early as 6—8 months on plants grown from cuttings and 12—16 months on plants grown from seedlings. There should be only one or two harvests per year during the first 2 years. Trees must be well-established, 18—24 months old, before regular harvesting is possible. During the dry season, harvesting should be less intensive (every 3—4 months) than during the rainy season (every 2—3 months). Regrowth should be 1—2 m in height before each harvest. To obtain fodder during the dry season trees should be cut about 3 months before the onset of this season. If trees are uncut for more than 4—6 months before the dry season commences, they will shed their leaves during the dry season. Cutting heights commonly range from 0.5—2 m. Trees grown in contour lines and fodder banks are usually cut lower than those cultivated in living fences or as shade trees in pastures, where browsing cattle may interfere with regrowth.
Forage from gliricidia is usually cut by hand and left on the ground for grazing or carried to paddocks or stalls. Acceptable silage can be prepared using standard techniques; the chopped forage may be mixed with grasses or maize and additives such as molasses and sugar cane or formic acid (0.85%) should be added to provide fermentable carbohydrate.
In woodlots, first harvesting can be after 3—4 years, giving wood yields of 8—15 m³/ha. Subsequent coppicing is done every 2—3 years and yields up to 40% more than the first harvest.

Under average conditions, yields of 3—4 kg DM per tree per harvest may be achieved. In fodder plots, annual yields of 9—16 t/ha of leaf DM or up to 43 t/ha fresh leaves have been obtained. In Nigeria gliricidia hedgerows interplanted with 4 rows of Panicum grasses yielded 20 t/ha per year of mixed DM, which was sufficient to feed 3 head of cattle.
In woodlots, when coppiced every 2—3 years, wood yield varies from 10—20 m³/ha. Wood production in living fences has been reported at 9 m³/km per year. All harvested produce is usually used locally.

Major germplasm collections have been made by the Oxford Forestry Institute (United Kingdom), CATIE (Turrialba, Costa Rica), and ILCA Humid Zone Programme (Ibadan, Nigeria). The Oxford Forestry Institute administers an international network of provenance evaluation involving 29 provenances from 8 South and Central American countries. The ILCA Humid Zone Programme has developed a high-yielding bulk composite from four Costa Rican accessions.

There are no known breeding programmes. Early introductions in many countries usually had a very narrow genetic base and distinct indigenous ecotypes have evolved in several areas. Recent provenance evaluations indicate significant differences in growth rates. Further rapid genetic gains can be expected, as seed production starts early, superior types can be cloned and production cycles are short.
Distinct selection programmes for high-yielding, palatable fodder cultivars and for arboreal cultivars combining wood and foliage production are desirable.

Gliricidia is showing considerable promise as a fodder species throughout the tropics. It is a multipurpose tree well adapted to humid areas and acid and infertile soils. Although most fodder is produced in the wet season, the tree can be managed to provide fresh leaf during the dry season. Favourable properties include its versatility in production systems and the ease with which it can be grown together with grasses or herbaceous legumes. Its prospects may be further enhanced by further selection programmes and development of innovative production systems such as the 'Three Strata Forage System'. It has excellent properties for various forms of agroforestry, as well as for site reclamation, including suppression of such obnoxious weeds as Imperata cylindrica (L.) Raeuschel.

Chadhokar, P.A., 1982. Gliricidia maculata, a promising legume fodder plant. World Animal Review 44: 36-43.
Devendra, C. (Editor), 1990. Shrubs and tree fodders for farm animals. Proceedings of a workshop in Denpasar, Indonesia, 24-29 July 1989. IDRC, Ottowa, Canada. 349 pp.
Glover, N., 1989. Gliricidia production and use. NFTA, Waimanalo, Hawaii. 44 pp.
Lindsay, F.J., 1982. Gliricidia maculata, a review. International Tree Crops Journal 2: 1-14.
Palmer, B., Bray, R.A., Ibrahim, T. & Fulloon, M.G., 1989. Shrub legumes for acid soils. In: Crasswell, E.T. & Pushparajah, E. (Editors): Management of acid soils in the humid tropics of Asia. ACIAR Monograph No 13. ACIAR, Canberra. pp. 36-43.
Withington, D., Glover, N. & Brewbaker, J., 1987. Gliricidia sepium (Jacq.) Walp.: management and improvement. Nitrogen Fixing Tree Association Special Publication 87-01. NFTA, Waimanolo, Hawaii. 255 pp.

K.F. Wiersum & I.M. Nitis

Wiersum, K.F. & Nitis, I.M., 1992. Gliricidia sepium (Jacq.) Kunth ex Walp.. In: Mannetje, L.'t and Jones, R.M. (Editors): Plant Resources of South-East Asia No 4: Forages. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea