Albizia lebbeck and Albizia falcataria By m.murugan(bsf-11-019)
Albizia lebbeckCurrent name: Albizia lebbeck Authority: Benth.Family: Fabaceae – Mimosoideae(Tamil) : vagai, vagei(Trade name) : kokko(English) : acacia amarilla, East Indian walnut, Englishwomans tongue, fry wood, Indian siris, lebbeck, siris tree,woman’s tongue tree
Growth habitat and morphology A. lebbeck is a dominant species in semi-evergreenvine forests (monsoon forest) in areas with a meanannual rainfall of 1300-1500 mm and a very drywinter. It is also found in semi-deciduous microphyll vinethicket on screes of quartz sandstone mountains. It canwithstand long, hot, dry periods and cold winters.
Native : Australia, Bangladesh, India, Indonesia,Malaysia, Myanmar, Nepal, Pakistan, Thailand Exotic : Algeria, Angola, Antigua and Barbuda,Argentina, Barbados, Brazil, Central African Republic,Colombia, Cuba, Egypt, Ethiopia, Jamaica, Kenya,Madagascar, Mexico, Nigeria, Panama, South Africa,Sudan, Swaziland, Venezuela, Virgin Islands (US),Zambia, Zimbabwe
site factors Altitude: 0-1800 m, Mean annual temperature: 19-35 deg. C, Mean annual rainfall: 500-2500 mm Soil type: Establishes well on fertile, well-drainedloamy soils but poorly on heavy clays. Toleratesacidity, alkalinity, heavy and eroded soils, andwaterlogged soils. Examples of soil types include,shallow sandy soils, laterite and loam laterite.
Phenology Reproductive Biology A. lebbeck is hermaphroditic. In its natural habitat, flowering occurs fromSeptember to October; mature pods remain on thetree for long periods and are available May-July. In Sudan it flowers from March to May and fruitsfrom May to August. Flowers are bisexual.
Botanic descriptionAlbizia lebbeck can attain a height of 30 m and a diameter of 1m; more often it is 15-20 m tall with a diameter of 50 cm; bark grey-violet with rusty brown breathing pores, rough andfissured. Compound leaves bipinnate, glabrous or slightly hairy on theaxis; pinnae in 2-4 pairs, each with 2-11 pairs of obliquelyoblong leaflets 15-45 x 8-22 mm, shortly stalked; glabrousglands are raised, elliptic to circular, on the upper side of thestalk close to the base and between most pairs of leaflets. Flowers appear shortly after new leaves, are white, heavilyscented, with the stamens free above the corolla, in heads 18-36mm across excluding the stamens, on a stout stalk 5-7.5 cm long,appearing singly or in small clusters in the leaf axils and interminal panicles;
stamens 30-40, yellowish-green on top side, whiteunderside, up to 5 cm long; flower-stalks up to 5 mm long;corolla tube, 1 cm long. Pods pale straw to light brown at maturity, narrow-oblong, 15-26 x 3-5 cm, papery, leathery, flat and notraised or constricted between seeds; seeds brown, flat,orbicular or elliptic, 8-10 x 6-7 mm; transversely placedwith 6-12 in each pod. The genus is named after Filippo del Albizzi, aFlorentine nobleman who in 1749 introduced A. julibrissininto cultivation. The species name is from the Arabic namefor this plant, ‘laebach’. When agitated by the wind, thepods and enclosed seeds are said to produce an incessantrattle likened to women’s chatter, hence the name ‘woman’stongue’
Regeneration techniques Propagation methods It is best established using potted seedlings,although bare-rooted seedlings, direct seeding and stumpcuttings have all been used successfully. Seed pretreatment involves scarification and immersionin boiling hot water then cooling and soaking for 24 hours,or acid treatment to break seed-coat dormancy.Germination improves after storage for 2-4 years, butsatisfactory germination (50-60%) has been obtainedfrom fresh seeds. Freshly collected seed has about 70%germination capacity after 1-2 months. About 880 pods weigh 1 kg and will yield about 300g of seed
Tree Management A. lebbeck coppices well, responds to pollarding,pruning and lopping, and will produce root suckers ifthe roots are exposed. Typical spacing is 3 x 3 m for fuelwood, and 5 x 5m for timber. Fuelwood plantations spaced at 3 x 3 mclear felled on a 10-year rotation produce about 50cubic m/ha of stacked fuelwood. In Queensland A. lebbek reaches about 11 m inheight and 50 cm dbh in 30 years. The trees arevulnerable to strong winds and are killed by even lightfires
Pest and diseases Root rot, stem cankers, heart rot, spot fungiand rust can damage the tree, as well as a widerange of insect pests, including leaf- and bark-feeding caterpillars, sap suckers, wood and seedborers and defoliators such as psyllids. In Nigeria ,the striped mealy bug, Ferrisiavirgata, harms the tree
Economic Importance Fodder: A. lebbeck is grown in some areas primarily asfodder for camels, water buffalo and cattle. The leavesare reported to be good fodder, with 17-26% crudeprotein; 100 kg of leaves yield 11-12 kg of digestibleprotein, and 37 kg of digestible carbohydrates. The pods contain saponin and are not eaten in largeamounts by sheep, although cattle eat them readily. Apiculture: Its whitish flowers are fragrant, attractingbees. Highly regarded by bee-keepers for the light-coloured honey its nectar provides. Fuel: An excellent fuelwod species with a calorific valueof 5200 kcal/g. A. amara fruits can yield 10 barrels ofethanol per hectare
Timber: Sapwood is pale; heartwood is dark brown withblack streaks and very decorative. It is moderately heavy and hard, strong and fairlydurable, with a specific gravity of 0.5-0.6 kg/cubic m. Thewood seasons well, works and polishes easily, can be usedfor interior moulding, parquet, furniture, panelling, turneryand general construction. It is also used for making agricultural implements andmine props. Timber plantations in India clear felled after25-30 years yield about 10-12 cubic m/ha per year oftimber, but under semi-arid conditions and on shallow soils,a mean increment of 2-3 cubic m/ha is obtained.
Gum or resin: The trunk yields a reddish gum that isused as an adulterant of gum arabic. Tannin or dyestuff: The bark is used locally in Indiafor tanning fishing nets (tannin content of 7-11%). Medicine: Leaves and seeds are used for eyeproblems, and the bark to treat boils. Saponin frompods and roots has spermicidal activity. Other products: When dried and pounded, thebark can be used for soap.
Geographical distribution A pioneer species, P. falcataria occurs in primarybut more characteristically in secondary lowlandrainforest and in light montane forest, grassy plainsand along roadsides near the sea. It is adapted to peri-humid and monsoonal climateswith a dry season of up to 2 (4 max.) months. It is sensitive to fire and easily damaged by strongwind. In natural stands in Irian Jaya, P. falcataria isassociated with species such as Agathis labillardieri,Celtis spp., Diospyros spp., Pterocarpus indicus,Terminalia spp. and Toona sureni.
State wise dataNative : Haiti, Indonesia, Papua New Guinea,Solomon IslandsExotic : Brunei, Cambodia, Cameroon, Cook Islands,Fiji, French Polynesia, Japan, Kiribati, Laos, Malaysia,Marshall Islands, Myanmar, New Caledonia, NorfolkIsland, Philippines, Samoa, Thailand, Tonga, UnitedStates of America, Vanuatu, Vietnam
Site factors Altitude: 0-1 200 m, Mean annual temperature: 22-29 deg. C, Mean annual rainfall: 2 000-4 000 mm. averaging2800 mm Soil type: Deep, well drained fertile soils, such asfriable clay loam. Prefers alkaline to acid soils.
phenology Trees may flower as early as 3 years. Two floweringperiods per year have been observed in PeninsulaMalaysia and Sabah. Ripe pods appear approximately 2 months afterflowering. The pods dehisce when ripe, often when stillattached to the tree, scattering the seeds on the ground
Regeneration techniques P. falcataria requires great amounts of light andregenerates naturally only when the soil is exposed tosunlight. In the forest, wildings sprout in abundance onlywhen the canopy is open and when soil is cleared from theundergrowth. Wildings can be successfully collected and potted forplanting but are delicate and must be carefully handled.The species can be planted from seedlings, direct seedingor stump cuttings. Small seeds are difficult to collect from the ground andare usually collected by cutting down branches bearingripe, brown pods.
Untreated seeds germinate irregularly; germinationmay start after 5-10 days but is sometimes delayed forup to 4 weeks. To hasten and ensure uniform germination,soak in boiling water for 1-3 minutes or immerse inconcentrated sulphuric acid for 10 minutes followed bysubsequent washing and soaking in water for 18 hours. Germination rates can be as high as 80% to almost100%. Seeds of P. falcataria are usually sown bybroadcasting, pressed gently into the soil and thencovered by a layer of fine sand up to 1.5 cm thick. The soil in the seedbed must be loose and welldrained; application of a surface layer of mulch isadvisable, and excessive shading should be avoided.
Seedlings can be transplanted when they havereached a height of 20-25 cm with a woody stem anda good fibrous root system; this stage can be reachedin 2-2.5 months. Container plants are often transplanted into thefield when 4-5 months old. Seed tissue has beensuccessfully used in the Philippines for propagation bytissue culture. Seedlings have epigeal germination.
Tree Management P. falcataria grows so fast that it is sometimes calledthe ‘miracle tree’. It is even mentioned in the GuinnessBook of Records as the world’s fastest growing tree. Ongood sites it can attain a height of 7 m in just over a year. Trees reach a mean height of 25.5 m and a bolediameter of 17 cm after 6 years, 32.5 m high and 40.5cm diameter after 9 years, 38 m high and 54 cmdiameter after 12 years, and 39 m high and 63.5 cmdiameter after 15 years. P. falcataria coppices although coppicing vigour ishighly variable.
It has been found that growth at 2 x 2 m spacing issignificantly faster than at 1 x 1 m. If sawn timber isdesired, stands can be thinned to 6 x 6 m at 6-8 yearsand harvested at 15 years. P. falcataria is commonly used in agroforestrysystems, usually in a cutting cycle of 10-15 years, incombination with annual crops in the 1st year andgrazing animals in subsequent years. When planted, it can grow on comparatively poorsites and survive without fertilizer. However, it does notthrive in poorly drained, flooded or waterlogged soils
Growth of young trees in a phosphorous-deficientsoil is promoted by inoculation with mycorrhizal fungiGigaspora margarita and Glomus fasciculatum incombination with Rhizobium. Nitrogen-fixing nodules containing leghaemoglobinare found on roots. P. falcataria plantations should be kept weed freeduring the 1st few years.
Pests and diseases Nursery seedlings are susceptible to damping-offcaused by fungi of Rhizoctonia, Sclerotium, Fusarium,Pythium and Phytophthora. Sterilizing the soil before sowing and applyingfungicides to soil and seeds may control the disease.The fungus Corticum salmonicolor causes a diseaseknown as pink canker or salmon canker. Light brown lesions appear on the bark of youngtrees, they gradually enlarge and develop cracks, thecolour turns to pale salmon or pinkish, and myceliummats appear around the lesions.
The disease may seriously damage plantations.Plantations can also suffer from other fungal diseaseslike red root caused by Ganoderma pseudoferrum.An anthracnose seedling disease caused byColletotrichum species has been observed in Sumatra. In 1988 and 1989, gall rust disease caused byUromycladium tepprianum provoked severe damagein Bukidnon Province (Mindanao, the Philippines).
The government banned the transport of logs in andout of Bukidnon Province, and planting was suspended. Plantation pests in Indonesia, Malaysia and thePhilippines include stem borers such as the longicornbeetle Xystrocera festiva and the red borer Zeuzeracoffea (a cossid moth). Leaf-eating caterpillars (e.g. Eurema blanda, E.hecabe and Semiothesa emersaria) may attackseedlings and trees. Aphids have on occasion been aproblem. Insecticides are commonly used in controllingthese pests. The small bagworm Pteroma plagiophleps is aserious pest in Sumatra.
Economic importance Fodder: An activated tree metabolism at thebeginning of the wet season synthesizes a complexpolysaccharide that increases palatability for cattleof the bark. Leaves are used to feed chickens andgoats. Fuel: Widely used for fuelwood and charcoalproduction in spite of its low density and energyvalue. Fibre: P. falcataria trees coppice fairly well, anadvantage for pulpwood production. The wood issuitable for pulping and papermaking
It can be used to produce good-quality pulp bymechanical, semi-chemical or chemical processes. Becauseof its light colour, only a little bleaching is required toachieve good white paper. The neutral, semi-chemicalprocess produces pulp with excellent strength properties. Ithas also been used for the manufacture of viscose rayon. Timber: The comparatively soft timber is suitable forgeneral utility purposes, such as light construction,furniture, cabinet work, lightweight packing materials andpallets, and chopsticks. Because the wood is fairly easy tocut, P. falcataria is also suitable for wooden shoes, musicalinstruments, toys and novelties, forms and general turnery.
P. falcataria is an important source of veneer andplywood and is very suitable for the manufacture ofparticleboard, wood-wool board and hardboardand has recently been used for blockboard. Tannin or dyestuff: The bark of P. falcataria hastanning properties.
Germplasm ManagementSeed storage behaviour is orthodox. There is no loss inviability during 1.5 years in air-dry storage at 4-8deg. C. For storage, seeds are air dried for 24 hours andthen packed in polythene bags. When stored at 4-8deg. C, the germination rate after 18 months may still be70-90%. There are 38 000-44 000 seeds/kg