Gliricidia Sepium Essay, Research Paper
GLIRICIDIA SEPIUM
Content
History
Introduction and Description
Common Names
Chemical Compounds
Toxicity
Uses and Efficacy
History
Gliricidia was first used in Mexico to provide shade for cacao plantations. It is from this use that the Aztecs labeled the tree “Madre de Cacao” (Mother of cacao). Later, in the 18th Century, Gliricidia was brought to Sri Lanka to provide
shade for coffee plantations. Today, the tree’s long leafy branches are used to shade vanilla and tea crops as well.
The tree is also known in Spanish as “Palo de Hierrro” (Tree of Iron) which eludes to Gliricidia’s hard, heavy wood. This makes it ideal for fuelwood; a vital energy source in tropical regions and areas where gas and propane are not as accessible or affordable. Due to the wood’s durability and its resistance to weathering and disease, it is also used for furniture, tool handles, posts and even heavy construction purposes.
Introduction and Description
Gliricidia sepium is a leguminous tree and belongs to the family Fabaceae. Gliricidia, which originated in Central America, is used in many tropical and sub-tropical countries as live fencing. That is, it is planted along the side of fields, and the trunks are used as fence posts. During the dry season, when much of the forage is gone, the tree limbs are cut and the foliage is offered to livestock.
Gliricidia trees are a medium size, with composite leaves. The flowers are reddish and on the end of branches without leaves. The fruit is a pod about 10-15 cm. Typically, it can be found growing in acid soils with low to medium fertility.
Common Names
Usually Gliricidia sepium is just called gliricidia. There are only a few local names for the tree.
Cacao de nance, cacahnanance — Honduras
Kakawate — Philippines
Mata Raton
Madre Cacao — Guatemala
Madriado — Honduras
Chemical Compounds
There are many compounds in Gliricidia sepium. The ones most researched are the tannins. In one study, Gliricidia was found to contain 40.7g of condensed tannins/kg dry matter. Tannins bind to protein and can make plants with high levels have an astringent dry mouth taste. The exact quantity of tannins varies with the location of the tree. The active medicinal compounds may be the tannins or other compounds such as afrormosin, medicarpin, or some isoflavins. Most of the research with gliricidia and it’s compounds have focused on nutritive quality. However, some studies have focused on the ability of the plant and/or roots to decrease soil nematode populations, and control insects or fungi.
Some of the Compounds in Gliricidia sepium(for a more complete list see USDA Phytochemical and Ethnobotanical
Databases:
Afrormosin (an isoflavan) — reported to be an antitumor promoting agent
Formononetin (an isoflavan)
Gliricidin-6a — wood
Gliricidol-9A — wood
Medicarpin (a pterocarpan) — reported to be antifungal
7,4′-dihydroxy-3′-Methoxyisoflavin
2′-O-Methylsepiol — plant
Tannin — reported to have potential antidiarrheic, antidysenteric, antimutagenic, antinephritic, antioxidant, antiradicular, antiviral, bactericide, cancer-preventive, hepatoprotective, pesticide, psychotropic, and viricide activities 7,3′,4′-Trihydroxyflavanone — plant
Toxicity
No published studies could be found regarding the toxicity of using gliricidia to repel insects. However, many animals cannot tolerate the consumption of large quantities of gliricidia. The tannins bind proteins and decrease the nutritive value of the plant. Some animals, such as goats, can consume larger quantities of plants with tannins than other animals such as cattle and sheep. Goats, unlike cattle and sheep, have a salivary protein binding factor that binds to the tannins.
Uses and Efficacy
Gliricidia is used by farmers in some Latin American countries to repel insects. The leaves are ground up and combined with water. The animal is then bathed with the resulting paste. According to some of the farmers, if this is repeated every 7-14 days, the number of torsalo (tropical warble fly) infections is decreased. No published studies could be found to substantiate this claim. However, when interviewing farmers and checking goats in Honduras, I found that the goats who the farmers claimed to have bathed with gliricidia had only 2-3 torsalos, while others had 10 or more. Also, one study did indicate that the heartwood of gliricidia contains compounds that attract and are toxic to certain insects (e.g., southern army worm, cabbage looper, yellow woolly bear, and Glyptotermes dilatatus, a termite).
In the Philippines, gliricidia is washed and pounded to extract the juice from the leaves. It is then applied to the area affected by external parasites once to twice a day for one week.
In Guatemala, the bark and leaves of gliricidia are used to treat human skin diseases.
Research has been conducted on both the antifungal and antimicrobial properties of gliricidia extracts. In a brine shrimp toxicity test, a general screening method indicative of cytotoxicity and pesticidal activity, the LC50 was 454ug.ml (CI 328-608). , medicarpin, one of the compounds in the leaves and heartwood of gliricidia, is supposed to be antifungal. In an antifungal study, gliricidia extracts inhibited the germination of Drechslera oryzae only 6%. However, in another study, 50ug of stem chloroform extracts inhibited the growth of Cladosporium cucumerinum and slightly inhibited the growth of Candida albicans. In contrast, in another study, the antimicrobial properties of extracts from the bark of gliricidia were tested. It was effective against bacteria causing dermatitis. However, it was not effective against enterobacteria or Candida albicans. The discrepancy in the effectiveness against Candida albicans could be because of the quantity of plant extract used or the types of extracts used. In another study, leaf extracts were found to be effective against the dermatophytes Microsporum canis, Trichophyton mentagrophytes var algodonosa, and T. rubrum. It was not effective against Epidermophyton floccosum, M. gypseum or T. mentagrophytes var granulare.
In another study, gliricidia was found to inhibit the growth of various strains of Neisseria gonorrhoea in in vitro tests. Tinctures made from the leaves were used for these tests.
Some Uses in Humans:
Headache
Briuse
Burn — Panama
Cold, cough — Curacao
Debility
Expectorant — Curacao
Fatigue
Fever — Panama
Gangrene — Guatemala
Gonorrhoea — Guatemala
Insecticide
Insect repellent — Curacao, Guatemala, and Honduras
Itch, skin, sores — Curacao, Guatemala, Honduras, and Panama
Poison (Humans and animals) — Panama and Venezuela
Rodenticide (rats) — Guatemala, Honduras, Panama, El Salvador, Venezuela
Shade tree (for other crops) — Sri Lanka
Sedative — Curacao
Tumor — Guatemala
Ulcer — Guatemala
Propagation of Gliricidia sepium
Seedage:
Gliricidia is propagated readily from seed, with no seed pretreatment necessary. Seed viability is reduced dramatically after one year in storage, so fresh seeds should be used. They can be direct-seeded or established in a nursery.
Cuttage:
Gliricidia roots readily from leafless cuttings either in the nursery or directly in the field during the rainy season. The latter are often large cuttings, called stake cuttings , which can range in size from ca. 1 cm to 10 cm or more in diameter and over a meter in length.
Uses
According to the National Academy of Sciences (1980a), the leaves contain over 20% crude protein and are nutritious for cattle though TOXIC to most other animals including horses. The tree is widely planted as shade for chocolate, coffee, tea, and vanilla. There are few “living fence” species that strike root from cuttings more readily, also widely planted as a hedge and/or windbreak. Tilth and fertility of the soil beneath the trees are greatly improved from the leaf- and flower-fall. The timber is said to finish smoothly and be used for furniture, agricultural instruments, posts, railroad ties, and heavy construction. Flowers are a good source of forage for bees. Flowers are consumed by Mexican rural inhabitants who use the pods for rat poison. In the Philippines, the foetid leaves are crushed and rubbed onto cattle. In Indonesia, the tree is planted as a firebreak. This and other fast-growing leguminous trees have the vigor to outgrow or compete with the Imperata grass. In the shade of Gliricida, the grass finally dies, leaving nothing that can sustain a grass fire (NAS, 1980a).
Folk Medicine
Reported to be expectorant, insecticidal, rodenticidal, sedative, suppurative, Madre de Cacao is a folk remedy for alopecia, boils, bruises, burns, colds, cough, debility, eruptions, erysipelas, fever, fractures, gangrene, head-ache, itch, prickly heat, rheumatism, skin, sore, tumors, ulcers, urticaria, and wounds (Duke and Wain, 1981).
Chemistry
According to Roskoski et al. (1980), studying Mexican material, the seeds contain 11.93% humidity, 1.90% ash, 33.00% CP, 16.50% CF EE, 9.07% CF, 27.60% carbohydrates with a 52.42% in vitro digestibility. The foliage contains 11.96% humidity, 12.09% ash, 19.92% CP, 2.34% crude fat, 11.04% CF, 42.65% carbohydrates, and 69.69% in vitro digestibility. Low levels of alkaloids were found in the seed and saponins in the foliage, but the plant is still used for forage. Allen and Allen (1981) cite data suggesting that fallen leaves emit the new-mown-hay odor, because of the occurrence of coumarin compounds.
Description
Smooth deciduous tree to 10 m tall, 20-30 cm DBH. Leaves alternate, pinnately compound, 15-30 cm long, the 9-13 leaflets 3-6 cm long, opposite, oblong-ovate, bluntly pointed at the tip, rounded at the base, entire. Flowers on numerous lateral racemes, often on leafless branches, the clusters 5-125 cm long; flowers pinkish, ca 2 cm long; stamens 10, 9 united in a tube, one separate, white. Pods yellow-green when immature, turning blackish 10-14 cm long, 1-2 cm broad, with 3-8 elliptic, flat, shiny, blackish seed (ca 4,400/kg).
Germplasm
Reported from the American Center of Diversity, Madre de Cacao, or cvs thereof, is reported to tolerate drought, limestone, slope, and weeds. (2n = 20)
Distribution
Native from Mexico to Colombia, Venezuela, and the Guianas, widely introduced and naturalized throughout the tropics.
Ecology
Ranging from Subtropical Thorn to Wet through Tropical Thorn to Wet Forest Life Zones, Madre de Cacao is reported to tolerate annual precipitation of 4.8 to 41.0 dm (mean of 79 cases = 16.2), annual temperature of 21.3 to 28.5?C (mean of 61 cases = 25.3), and pH of 4.3 to 5.0 (mean of 2 cases = 4.6) (Duke, 1978, 1979).
Cultivation
Soak seeds 24 hours in lukewarm water and sow directly in potting soil in prepared pots (10 x 15 mm) wrapped in polyethylene. Move to shade for three weeks after germination, watering as needed. Use insecticide/fungicide once a month or as needed. Hardened 2-3 month old seedlings may be outplanted, avoiding midday heat, at the beginning of the rainy season (Fabian, 1981). Roskoski et al. (1980) note that the tree is easily propagated from seeds (which require no special treatment) or cuttings. Cuttings are used to make living fences throughout the tropics.
Harvesting
Living fences may be lopped for fuel or fodder as needed.
Yields and Economics
In Sri Lankan tea plantations, an average tree gave 64 kg green loppings per year (Allen and Allen, 1981). Studying Mexican material, Roskoski et al (1980) concluded that there were 44.1 (? 14.9) moles N2 fixed per gram of nodule per hour in one assay, 11.7 ? 2.6 in another. One stand was fixing N at the rate of 13 kg/ha/yr.
Energy
Wood coppiced from living fences of Gliricidia sepium is burned for fuel by the rural population of Veracruz, Mexico. Annual productivity has not yet been determined here. The calorific value of the wood is 4,900 kcal/kg.
Biotic Factors
In Puerto Rico, the foliage is often attacked by aphids that secrete a sweet honeydew which attracts ants, causing the leaves to fall. On the other hand, the wood is said to be highly resistant to termites and decay.
Gliricidia sepium – the quintessential agroforestry species
Gliricidia sepium is a versatile, fast-growing tree favored by farmers for living fences, fuel, fodder, green manure, shade, support for crops, and erosion control. Common names include madre de cacao, mata rat?n, palo de hierro, cocoite (Central America), kakawati (Philippines), gamal (Indonesia), quick stick (Jamaica) and gliricidia. Gliricidia sepium is not synonymous with G. maculata, a closely related but much less useful species.
Botany
Gliricidia sepium (Jacquin) Steudel is a small to medium sized tree attaining heights of 2 to 15 meters. It may be either a single or multiple stem tree with trunk diameters reaching 30 cm. The bark is grayish-brown to whitish and may be deeply furrowed on old, large diameter trees. Leaves are pinnately compound, alternate in arrangement and 20 to 30 cm in length. Leaflets are generally opposite in arrangement, oblong in shape and pointed at the tip. On some specimens leaflets may be elliptical with rounded tips. There are 7 to 25 leaflets per leaf and size increases towards the tip. Leaflets are 40 to 80 mm long and 20 to 40 mm wide (Lavin 1996).
Flower development corresponds to the beginning of the dry season when trees have most their leaves. In its native range flowering occurs November through March. In areas without a pronounced dry season, flowering
may occur throughout the year but few pods form (Lavin 1996, Simons 1996). Flowers are pink to light pink in color, fading to white with brown spots or faint purple with age (Lavin 1996). The flowers are pollinated by the larger solitary bees Xylocopa fimbriata and Centris species in the tree’s native range. Other potential pollinators have trouble accessing the flower due to the rigidity of the keel pedals (Simons 1996). A lack of effective pollinators will greatly hinder pod and seed production. Pods can reach full size, 10 to 20 cm, within 3 weeks of fertilization. The green succulent pods turn woody and yellow with maturity, which requires 35 to 60 days. Pods contain 3 to 10 seeds and are explosively dehiscent (Lavin 1996, Simons 1996). Seed collection is recommended prior to pods opening.
Ecology
Gliricidia sepium is native to the lowland dry forests from sea level to 1,200 m. It is uncommon above this elevation because of its sensitivity to cold. The temperature range is 20 to 30? C. It performs poorly below this range but will tolerate temperatures as high as 42? C (Glover 1989). Rainfall is generally from 900 to 1,500 mm/year, but may be as low as 600 mm or as high as 3,500 mm (Simons 1996). The dry season varies from 3 to 8 months, however Gliricidia sepium survives dry seasons of 9 months in Indonesia.
It grows well on many soil types; volcanic, sandy, stony, and heavy clays, including Vertisols. It is reported to tolerate some salinity and slightly alkaline soils. It will tolerate acid soils, but not severe acidity (pH less than 4.5) nor high aluminum saturation (greater than 60%). An aggressive pioneer, gliricidia readily colonizes infertile soils and reclaims Imperata grasslands (MacDicken et al 1997). Its name gamal means ‘Imperata killer’. It sprouts quickly after fire and thus may benefit from burning.
Distribution
The true native range of G. sepium is restricted to the dry and sub-humid lowlands of the Pacific coast of Mexico and Central America, and adjoining dry inland valleys (Simons 1996). Native Americans domesticated the species into other parts of Central America. The Spanish introduced it into the Caribbean and the Philippines. Over the last century gliricidia has become common throughout the tropics.
Uses
Living fence. Gliricidia sepium may be the most common living fence species in the tropics. Fence posts are established from large stakes (see Propagation). They may be planted at 1 to 2 m spacing and joined with barbed-wire or bamboo. Alternatively, they maybe planted 10 to 20 cm apart as a stockade and their branches interwoven (Stewart 1996). Fuelwood, stakes, fodder and green manure are harvested from fences. Fuelwood. Hard and durable, the wood has a specific gravity of 0.5 to 0.8. It makes a good fuel, burning with little smoke and no sparks, and has a calorific value of 4,900 kcal/kg. Natural stands, secondary forests and woodlots of gliricidia have been managed for commercial fuel production (Glover 1989, Stewart 1996). The wood is also used for poles, timber, furniture and agricultural implements. Fodder. Responding well to frequent cutting, gliricidia produces abundant amounts of nutritious fodder containing 18 to 30% crude protein. Livestock respond well to the fodder. Some animals are reluctant to eat gliricidia, but training may overcome this problem. Once gliricidia is accepted, subsequent offspring readily consume it. Toxicity problems are reported with non-ruminants. Pruning trees before the dry season enables coppice growth to be retained for use as dry season feed. Fodder plantings vary from hedgerows with 10 to 50 cm in-row spacing and 1 to 4 meter between row spacing, to block plantings of 50 x 50 cm to 1 x 3 m. Production varies from 2 to 20 t/ha (Glover 1989, Stewart 1996, Allison and Simons 1996). Pod peels are eaten by livestock as a dry season fodder in Bali. Farming Systems. When used as mulch or green manure, the nitrogen-rich foliage improves crop production through the addition of nutrients, weed control, conservation of moisture and reduction of soil temperature. Leaf biomass is usually produced from hedgerows or fences around or in the cropping area. Companion crops include paddy and upland rice, corn, cassava and coconuts. Hedgerows are used on sloping farmland for erosion control and passive terrace formation. Hedgerow management should minimize competition with crops. Hedgerow systems can be labor intensive, which may limit their adoption. Gliricidia is used as a shade for tea, coffee and cacao; and as a support for cassava, yams, vanilla, pepper, and passionfruit. These crops also benefit from the soil improvement characteristic of gliricidia. The presence of gliricidia in fields reduces incidence of some fungal and insect attacks (Glover 1989, Stewart 1996).