By Mgonzo Dunia Ally, Tanzania Country Trainer, Kenya
Gliricidia is a fast-growing small to medium-sized tree that grows up to 10‒12 m high. It branches frequently from the base and can have a basal diameter reaching 50‒70 cm. Its bark is smooth, varying in color from a whitish grey to a deep red-brown. The tree has a spreading crown. Gliricidia flowers are bright pink to lilac and tinged with white, while the pods are green, sometimes tinged reddish-purple when unripe, and then light yellow-brown when mature. They are narrow, can measure 10‒18 cm length and 2 cm wide. Each pod contains between 4-10 seeds that are yellow-brown to brown and nearly round. There are approximately 7,000‒10,000 seeds per kg.
English: Gliricidia, tree of iron,
French: Lilas étranger
Indonesian: Gamal, liriksidia
Portuguese: Madre de cacao
Where it Grows
Gliricidia is said to be native to El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama and the United States of America. It has also been widely introduced across other tropical and subtropical regions.
Benefits of Gliricida sepium
Flowers: These can be fried and eaten.
Fodder: The leaves are rich in protein and highly digestible, and low in fiber and tannin.
Apiculture: Beyond being edible to humans, the flowers also attract honeybees, making it an important species for honey production.
Fuel: It is often used for firewood and charcoal production.
Timber: Its wood is hard, coarse-textured with an irregular grain, very durable, and termite resistant.
Pesticide/rodenticide: The leaves, seeds or powdered bark can be applied as a rodenticide and general pesticide.
Medicine: It is used as an antifungal and pain killer.
Erosion control: Hedgerows in alley cropping serve to suppress weed growth and control erosion.
Nitrogen fixing: The tree can fix atmospheric nitrogen.
Field protection: It is planted around cattle pastures and used for delineating boundaries.
Soil: Gliricidia does well in a wide range of soil types but particularly flourishes in fertile soils. It tolerates acidic soils with ranges from pH 4.5–6.2 and soils with a high clay content. It will also grow in degraded or water stressed soils.
Temperature: It tolerates a range of 15–30 °C.
Rainfall: Gliricida requires an average annual rainfall ranging between 600–3500 mm: from the semi-arid subtropics to the wet tropics.
Altitude: It can grow in ranges between 0–1600 m above sea level.
Pest and Diseases
Despite being widely grown throughout the tropics, Gliricidia has remained relatively free of serious diseases. The lack of diseasescan be attributed to the tendency of the species to be leafless for periods of the year, reducing the likelihood of epidemics. Several incidences of insect problems have been recorded in the past by pests like aphids, mealy bugs, and scale insects occasionally attack trees in Indonesia and the Caribbean.
Gliricidia is best propagated from seed. Stem cuttings can also be used but do not give very good establishment rates. Its seeds can be directly planted in well-prepared cropland or raised in a nursery for 6–8 weeks before transplanting. When directly sowing Gliricidia seeds, it is recommended to sow 2-3 seeds per hole at a depth of 1-2 cm.
For increased germination rates of Gliricidia seed, it is recommended to soak the seeds in hot water. Water should be brought up to a temperature of 80 °C. The heat source should then be turned off and the seeds then added to soak in this water for 12 hours as the water cools with the seed.
Gliricidia is managed by pruning, using techniques such as pollarding or coppicing. Pollarding is done at 1.5–2 m above ground 18–24 months after planting, and is most appropriate when Gliricidia is intercropped with perennial crops.