Firewood Crops: Shrub and Tree Species for Energy Production Volume 2 (BOSTID, 1983, 85 p.) Fuelwood Species for Arid and Semiarid Regions (introduction...) Ailanthus excelsa Balanites aegyptiaca Combretum micranthum Conocarpus lancifolius Dalbergia sissoo Populus euphratica Sesbania sesban Tarchonanthus camphoratus

Firewood Crops: Shrub and Tree Species for Energy Production Volume 2 (BOSTID, 1983, 85 p.)

Fuelwood Species for Arid and Semiarid Regions

The dry regions of the earth - those with less than 500 mm of annual precipitation or that have 6 or more totally rainless months - suffer more serious fuelwood problems than either the humid or highland regions of the tropics.

Four hundred and fifty million people live in these areas. Over the centuries, clearing the forests for fuel, farming, and grazing has destroyed most of the vegetation in these fragile dry habitats. Excessive exploitation of the land has often led to desertification, a process that is being accelerated by the demand for scarce wood fuel.

Most nations with dry zones are seriously in need of reforestation to prevent further loss of land and for wood fuel. The first volume of this report described the following species as worth testing for fuelwood crops in these dry regions.

Acacia brachystachya	Eucalyptus gomphocephala
Acacia cambagei	Eucalyptus microtheca
Acacia cyclops	Eucalyptus occidentalis
Acacia nilotica	Haloxylon aphyllum
Acacia saligna	Haloxylon persicum
Acacia senegal	Parkinsonia aculeata
Acacia seyal	Pinus halepensis
Acacia tortilis	Pithecellobium dulce
Adhatoda vasica	Prosopis alba
Albizia lebbek	Prosopis chilensis
Anogeissus latifolia	Prosopis cineraria
Azadirachta indica	Prosopis juliflora
Cajanus cajan	Prosopis pallida
Cassia siamea	Prosopis tamarugo
Colophospermum mopane	Tamarix aphylla
Emblica officinalis	Zizyphus mauritiana
Eucalyptus camaldulensis	Zicyphus spina-christi

Eucalyptus citriodora

These species have shown the capacity to survive where annual rainfall is 500 mm or less or where rainfall is extremely variable. Their adaptive mechanisms include deep root systems that penetrate to subsoil moisture or wide-spreading root systems to gather spare moisture, with some species having both root types; adaptation to the high salinity often found in arid areas; small leaf blades or needle-like leaves to reduce transpiration during drought or other physiological mechanisms to conserve moisture by slowing evaporation through the leaves; and unpalatability or thorniness that discourages grazing animals.

This section outlines further examples of successful adaptations by trees and shrubs to arid and semiarid conditions. Other species described elsewhere in this report that should be included are: Eucalyptus tereticornis, Gleditsia triacanthos, Melia azedarach, and Robinia pseudoacacia.

Ailanthus excelsa

Botanic Name
Ailanthus excelsa Roxb.

Common Names
Ganges, ardu, aura, maharuka, mothoaraduso, pew, mahanium, coromandel ailanto

Family
Simaroubaceae

Main Attributes
Ailanthus excelsa is a fastgrowing tree that regenerates well by coppicing. It provides valuable fodder and shade and makes good shelterbelts. Although it is generally unrecognized as a fuel tree, its pruned branches and cut stems are much used as fuelwood in India, its native region.

Description
Ardu is a large tree (18-24 m) with rough, greyish brown bark. The deciduous leaves are variable in shape with coarsely and irregularly toothed leaflets.

Distribution
This species is native to central, southern, and western India and is often cultivated in various parts of that country.

Use as Firewood
The wood is fairly light (specific gravity 0.45) and therefore is not an ideal fuel; however, as already noted, it is used as firewood.

Yield
In Assam, India, the species was planted at a spacing of 3 m x 3 m. The growth rate after 9 years averaged 5-6 m in height.

Other Uses
· Fodder. Twice a year this tree produces highly palatable and nutritive fodder. The leaves are commonly sold in the vegetable markets of Rajasthan, India, especially for nourishing stallfed goats. The leaves are also dried, ground, and added to concentrate mixtures for livestock feed, notably as a protein supplement to poor-quality roughages.

· Wood. The wood of Ailanthus excelsa is yellowish white, very light, soft, and perishable. It is used for making boats, fishing floats, knife and tool handles, toys, spear sheaths, drums, cigar boxes, and packing cases.

· Shelterbelt. The tree is planted in rows along farm boundries and irrigation channels.

Environmental Requirements
· Temperature. Ardu grows in an area where temperatures range from 20°-40°C. It can withstand considerable frost.

· Altitude. It is grown at low altitudes.

· Rainfall. It grows best with annual rainfall of more than 600 mm, although it survives on 400 mm a year.

· Soil. The tree grows in a variety of soils, but sandy loams seem most suitable. Soils should be well drained and not clayish or waterlogged.

Establishment
The plant is usually propagated by seed; however, it can be raised by shoot as well as by root cuttings. A sapling 30 cm high and 45-60 days old may be transplanted in pits previously prepared and manured. Monthly watering may be needed during the first year or until the trees are established.

· Seed treatment. The papery fruits (actually winged seeds or samaras) contain one to two seeds each. The seeds, however, cannot be separated from the wings undamaged, and it is necessary to sow the entire fruit. Soaking the pods for 3 days before sowing improves the results.

· Ability to compete with weeds. Good, except under drought conditions when ardu's competitiveness is poor.

Pests and Diseases
In the rainy season, leaf growth is attacked by a caterpillar that eats the leaves and discharges a sticky material, making a netting and totally spoiling the leaves. Regular pruning provides some control.

Limitations
Survivability is poor if the trees are not sufficiently watered during the first and second years of establishment. The leaves have a disagreeable odor when crushed.

Related Species
Ailanthus altissima Swingle (see Firewood Crops Vol. 1, p. 74, Ailanthus glandulosa Desf.). A native of northern China, this species has been introduced to Japan, North and Central America, and Mediterranean countries. In Mediterranean regions it is common as an ornamental. It is particularly useful on stony sites. Initially of fast growth up to 25 m high and to a diameter of 60-89 cm, it reproduces by coppice and suckers, and under favorable conditions it may spread and become a weed that invades natural formations (for example, maquis in Corsica and in other parts of southern Italy).

Balanites aegyptiaca

Botanic Name
Balanites aegyptiaca (L.) Dell

Synonym
Ximenia aegyptiaca L.

Common Names
Desert date, lalob, soapberry tree, thorn tree, Jericho balsam, heglig (Arabic); corona di Jesus, lamunch, shimaron (Curacao); najlij

Family
Balantiaceae (formerly placed in Zygophyllaceae)

Main Attributes
This multipurpose, drought-resistant species of the arid zone produces wood that is highly valued for fuel because it produces almost no smoke, making it ideal for use inside dwellings. The trees are slow growing, but they are indifferent to soil conditions and withstand fires.

Description
The desert date is a shrub or, more usually, a small tree up to 10 m high with scaly, fissured, grey or brown bark, intricately branched stems, and slender drooping branchlets that bear long green spines. The gray-green leaves with two ovate leaflets are either evergreen or are wholly or partially deciduous during the dry season. The tree has shallow, wide-spreading lateral roots and a narrowly branched taproot that may penetrate several meters to the water table.

Distribution
The species is indigenous to African woodlands along the Sahara's southern border from the Atlantic to the Red Sea (Sahel-Sudan region). It is also found on the Arabian peninsula and in Israel and Jordan. Small plantations have been established in Niger and Chad. Individual trees have been planted extensively in African villages far south of its natural range, as well as in India and Puerto Rico. Introduced to the Caribbean island of Curacao in 1885, it has overrun a large part of the dry east end of the island.

Use as Firewood
The pale yellow or yellowish brown wood is hard, heavy, and tough (specific gravity 0.65). It makes excellent firewood and good-quality charcoal. The trees regenerate vigorously after they are cut or lopped. Calorific value is 4,600 kcal per kg.

Yield
The tree grows slowly. In Puerto Rico, one trial sowing of 43 trees produced specimens only 2-5 m high after 8 years' growth. In Israel 2-to 3-year-old coppice shoots have reached 1-3 m in height.

Other Uses
· Fences. The thorny branches are massed together to form brushwood fencing; root cuttings strike readily to form living fences.

· Wood. The attractive wood is easily worked, fine "rained, durable, and resistant to insects. It saws and planes well and is used for bowls, mortars and pestles, tool handles, gunstocks, and cabinetwork.

· Food. The fruit is oblong, resembling a yellowish date with loose, leathery skin. It has gummy, bittersweet pulp that is edible when fully ripe. The pulp contains about 40 percent sugar and is macerated in water to make a refreshing beverage or is sometimes fermented to make an alcoholic drink. The seed kernel has been made into bread and soup and contains 30-58 percent of an edible oil (Zachon oil). The residue, which is 50 percent protein, is used in cooking and soap making.

· Forage. The young leaves, fruits, and even the thorns are eaten by goats, camels, and wildlife.

· Pest control. Extracts of the fruit and bark have been found to kill the freshwater snails that are intermediary hosts for schistosomiasis (bilharzia), and they also kill the free-swimming life forms of this parasite, making it a suitable tree for planting along banks of irrigation canals. A strong emulsion of the fruits is toxic to fish. It is also lethal to the waterflea that harbors dracunculiasis (guinea worm).

· Sapogenin source. All parts of the plant, including the seed kernel, yield the sapogenins diosgenin and yamogenin, both of which are used in the partial synthesis of steroid drugs.

· Soap substitute. Because of the saponin content of the roots, bark, fruits, and wood chips, all of these parts have been used as "soap" for washing clothes.

Environmental Requirements
· Temperature. The desert date easily withstands high temperatures ranging up to 40.5°C.

· Altitude. The altitudinal range of the tree is from 380 m below sea level to 1,500 m above sea level.

· Rainfall. The tree is commonly found where rainfall is between 250 mm and 800 mm per year. In some drier areas it is confined to sites such as riverbanks with available groundwater.

· Soil. Desert date can be found on a great variety of soils; however, on sandy soils its growth is poor and only scattered trees occur. It appears sensitive to salinity and does not tolerate prolonged waterlogging.

Establishment
Seeds casually distributed by humans or animals germinate readily. The trees can also be reproduced by seed and root suckers.

· Seed treatment. None is needed when fruits or seeds are sown in summer or autumn. In winter, seeds are soaked for 24 hours at room temperature.

· Ability to compete with weeds. The tree's slow growth would make it a poor competitor with weeds in fertile soils. It must be protected from fire and cattle for at least 3 years to ensure the survival of plantations.

Pests and Diseases
Seeds are often attacked by a borer.

Limitations
The desert date is thorny and, as noted, very slow growing. Browsing by animals can inhibit its growth, but it has run wild in abundance in Curacao despite free-ranging goats. Because the tree is widely distributed in Africa and other continents, it must have several forms, if not subspecies. It is therefore quite possible to find a form with such requisite characteristics as fast growth and small thorns or no thorns.

Combretum micranthum

Botanic Name
Combretum micranthum G. Don

Synonyms
Combretum altum Perr., C. floribundum Engl. & Diels, C. parviflorum Reichb.

Common Names
Kinkeliba, randga (Upper Volta); paramerga, lardaga (Ghana); kolobe, koubou, gugumi, gieze, landaga (West African Sahel)

Family
Combretaceae

Main Attributes
A tough drought- and fire-resistant shrub or tree, Combretum micranthum will survive in barren, rocky wastes where little else will grow.

Description
Combretum micranthum is normally a spreading shrub or spreading small tree 2-5 m high and 5-8 cm in stem diameter, although it can grow to 15 m with a 1.5 m trunk. Typically, it is reduced to a shrubby habit by repeated burning of the savanna. It has a shaggy, peeling reddish bark, with greenish maroon leaves, white flowers, and four-winged, glossy red fruits.

Distribution
This species is common in Savanna woodlands and in some places near the coast from Senegal to northern Nigeria. It has been successfully introduced for cultivation in South Vietnam; plantings around Saigon, made in the 1950s, have flourished.

Use as Firewood
The branches and stems of Combretum micranthum are slim and can be used for firewood, particularly around the towns where it is abundant. In Sokoto, Nigeria, the wood is much used for charcoal.

Yield
No data available.

Other Uses
· Craftwork. Young stems are tough and flexible and are used in basketry, while older ones are used as walking sticks and rafters. Unsplit stems are used for the interior center part of a thatch roof.

· Beverage. Combretum micranthum's main use in Senegal and Mali is for the Kinkeliba beverage. Young leaves are collected, dried, and processed into bundles to be sold in cities and along roads. These leaves are boiled, and the liquid is a popular beverage, believed to be effective against various tropical fevers and alimentary disorders.

Environmental Requirements
· Temperature. Combretum micranthum grows in areas with tropical temperatures such as the Sahel.

· Altitude. The shrubs and trees grow from sea level to 1,000 m.

· Rainfall. The species is drought resistant; in Senegal it grows in areas with rainfall from 300 mm to 1,500 mm.

· Soil. The species grows well on arid ironstone plateaus. It is regarded as an indicator of barren or nearly barren soil and is often found on abandoned farmland.

Establishment
The tree spreads by root suckers. The germination of seeds in a nursery is difficult, and establishment is not easy.

· Seed treatment. None required.

· Ability to compete with weeds. High.

Pests and Diseases
The roots of Combretum micranthum are very susceptible to termite attack.

Conocarpus lancifolius

Botanic Name
Conocarpus lancifolius Engler

Common Names
Damas, ghalab

Family
Combretaceae

Main Attributes
A drought-resistant species, Conocarpus lancifolius is one of the more promising trees for trials in arid areas. It is recommended for a variety of soil types, including saline soils, and yields excellent charcoal and valuable wood.

Description
Damas is an evergreen tree that grows up to 20 m in height and 60-250 cm or more in diameter. However, it is believed that the larger trees have now been almost entirely felled. Whereas it is usually a multibranched tree in its natural habitat, trees planted in the Sudan formed a single, straight stem.

Distribution
Natural stands of dames are found beside intermittent watercourses of northern Somalia and in the southwest part of the Arabian Peninsula. Some of these streams are salty and some sulphurous. The tree is also cultivated in Somalia, as it is in Djibouti, Sudan, Kenya, north and south Yemen, and Pakistan. A small plantation has been established in Sudan's Khashm El Birb Arboretum. About 10,000 trees have been planted successfully in limestone near Mombasa, Kenya.

Use as Firewood
The wood is light colored and of medium to heavy density (specific gravity 0.81). It makes good firewood (although some reports suggest that the wood smolders rather than burns) and excellent charcoal.

Yield
The annual yield of one irrigated plantation was approximately 21 m³ per ha. Early growth of more than 2.5 m per year has been achieved in irrigated plantations, though 1.01.75 m per year is more typical in early years.

Other Uses
· Wood. Damas wood is strong and is used for poles in house construction and in carpentry. At one time it was exported to Aden, where its chief use was for building chows, and it is still favored for use as ship knees.

· Fodder. The tree is evergreen and its foliage makes a good fodder.

· Other. It is a good shade and roadside tree. In South Yemen it is used for windbreaks around irrigated agricultural areas and for avenue plantinas.

Environmental Requirements
· Temperature. Damas grows best in areas where the mean annual temperature ranges from 20°-30°C, but where the maximum summer temperature has reached 50°C. During summer, the dry, hot air of the tree's natural habitat is laden with sand carried by the southwesterly monsoons. Winter temperatures are moderate and free of frost.

· Altitude. The tree grows from sea level up to about 1,000 m.

· Rainfall. The rainfall in its natural habitat is generally between 50 mm and 400 mm, but the tree grows mainly along seasonal watercourses. It can be grown in plantations in areas with less than about 400 mm but grows well only if irrigated or within reach of groundwater. It withstands drought conditions for several months when irrigation fails.

· Soil. Damas does well on deep soils ranging from pure sand to clays and loams, but has difficulty on shallow soils. It will tolerate moderately saline soils. Experiments carried out in Yemen showed that dames can grow on highly saline-alkaline soils of pH 9.5, provided water is in reach.

Establishment
The tree seeds prolifically at an early age and the seed, which is small and light, has a germination capacity of about 25 percent. When sown, it should preferably be left uncovered or covered only thinly. Seeds should be sown in rows 5 cm apart, broadcast in moist seedbeds, or planted in sandy soil in containers 30 cm x 15 cm with a number of holes drilled in the bottom to facilitate irrigation. Irrigation should be provided daily for the first 6-8 months, after which the plants are ready for planting out. Plants grown in a semishaded area in polyethelene bags can be transplanted when the seedlings gain 4-5 leaves. Damas can also be raised by cuttings.

· Seed treatment. None required.

· Ability to compete with weeds. Weeding and watering are essential after planting to ensure establishment.

Pests and Diseases
Newly germinated seedlings are highly susceptible to damping-off. Damas is attractive to browsing animals, and complete protection is necessary if plantations are to survive.

Limitations
Without irrigation or ready access to soil moisture, the tree grows more slowly and on some sites may not reach usable size in a reasonable time.

Dalbergia sissoo

Botanic Name
Dalbergia sissoo Roxb.

Common Names
Sissoo, sisu, sarsou, shisham, nelkar, karra, tanach, shewa, tall, yette

Family
Leguminosae (Papilionoideae)

Main Attributes
Dalbergia sissoo is a moderately fast growing tree that adapts well to semiarid conditions and produces first-class firewood. Its timber is highly valued for construction and general utility purposes. Under savanna conditions the trunk is usually crooked, but it is much sought for furniture, shipbuilding, and fuel.

Description
A large, fast-growing tree with a spreading crown, sissoo grows to a height of 1015 m in arid regions and up to 30 m high in the irrigated plains of Pakistan, in the northern part of India with its high rainfall, and along riverbanks. The tree has long, superficial roots, which send up suckers when injured, and small yellowish flowers with a pervasive fragrance.

Distribution
Sissoo occurs throughout the Indian subcontinent from the Indus to Assam. It descends the river valleys for some distance into the plains and is planted or self-sown in many parts of India and Pakistan. It has been extensively grown in irrigated plantations, along roads and canals, and around farms and orchards as a windbreak. The tree shows promising results in the Khartoum greenbelt (Sudan) under irrigation. It has been less successful in Ghana, northern Nigeria, northern Cameroon, and Togo; however, it is being increasingly planted as a street tree in southern Florida, where it is running wild. There are experimental forestry plantings in Puerto Rico, the West African Sahel, South America, and the Middle East.

Use as Firewood
Sissoo wood is classed as an excellent fuel; calorific values of the sapwood and heartwood are 4,900 and 5,200 kcal per kg, respectively. Specific gravity is between 0.64 and 0.7, depending on the locality. The wood is also suitable for making charcoal. As fuelwood, it is grown on a 10- to 15-year rotation. The tree produces profuse root suckers and coppices well enough to be managed on a short rotation.

Yield
Yield on a rotation of 10 years will amount to 61-99 tons per ha per year, or 9-15 m³. Growth is strongly dependent on soil conditions. Under favorable conditions in Ghana, trees grew an exceptional 3.0-3.7 m in the first year and 9-11 m in 5 years. Compared with other species (for example, eucalyptus) the yield is relatively low with the same input of labor and sissoo should be used in sites not favorable for other species.

Other Uses
· Wood. The wood is hard, elastic, and close "rained, with a little white sapwood and darkbrown heartwood that soon becomes dull. The heartwood is durable and valued for furniture, including bentwood items, and for veneers, carved articles, structural work, handles, cart wheels, railway carriages, boat building, ploughs, toys, frames for tennis rackets, hockey sticks, skis, and minute parts of musical instruments.

· Fodder. Young branches and leaves are used for fodder.

· Erosion control. The strong development of root suckers and runners favor sissoo's use as a living barrier against soil movement, and it is planted for this purpose across the bottom of eroding gulleys.

· Ornamental. In many Mediterranean countries the tree is valued as an ornamental.

Environmental Requirements
· Temperature. Sissoo grows in an area where the temperatures range from just below freezing to nearly 50°C. It is considered frost hardy.

· Altitude. Although mainly a species of river bottoms, the tree also ascends to 1,500 m in the Himalaya foothills.

· Rainfall. Sissoo thrives in rainfall ranging from 500 mm to 2,000 mm and can tolerate arid and semiarid conditions.

· Soil. It is most typically found on alluvial ground in and along the beds of streams and rivers or on sand or gravel along the banks of rivers or on islands. It also springs up on landslips and other places where mineral soil is exposed. Porous soil with adequate moisture seems best; stiff clay should be avoided.

Establishment
Sissoo is normal!, propagated by direct seeding. However, in arid regions it is established by transplanting seedlings or by stump plantings. It may also be raised by shoot cuttings. Shade or partial shade is necessary for germination and seedling development.

· Seed treatment. It is difficult to extract seed from the sissoo pod, so the pods are usually broken and pieces containing one or two seeds are sown. The broken pods should be soaked in water for at least 24 hours before sowing. Sissoo seeds germinate best at 30°C.

· Ability to compete with weeds. Regular weeding is necessary in the plantation during the first 2-3 years.

Pests and Diseases
Insects have been noted to damage the root system. Irrigated plantations may be severely damaged by root fungus. In India and Pakistan a leaf fungus (Phyllactinia) and a leaf wilt (Fusarium solani sensa) have damaged plantations. Sissoo is also susceptible to attack by the pinhole borer. The tree is a host of Loranthus spp., Tapinenthus dodoneifolius, and the defoliator Plecoptra reflexa. Young plants are browsed by deer and cattle.

Limitations
There is evidence in Nigeria and Zaire that after two or three coppice rotations the stumps lose their vigor. A change of species or replanting with fresh Dalbergia sissoo is probably necessary in these areas. Sissoo needs protection against fire and animal browsing.

Populus euphratica

Botanic Name
Populus euphratica Oliv.

Synonyms
Populus diversifolia Schrenk, P. ariana Dode, P. mauritanica Dode, P. bonnetiana Dode, P. Iitwinowiana Dode, P. glaucicomans Do d e , P. illicitana D ode , P. denhardtiorum Dode, P. euphratica f. pruinosa (Schrenk) Nevski

Common Names
Euphrates poplar, bahan, bhan, hotung, hodung, gharab, park, saf-saf, Indian poplar

Family
Salicaceae

Main Attributes
Populus euphratica grows fast. Annual diameter increments of 4.0-5.3 cm have been measured. It can tolerate a high degree of salinity and extremely arid and "continental type" climatic conditions, provided the subsoil is moist. It also grows on land that is seasonally flooded and on which no other form of cultivation appears possible.

Description
Populus euphratica is a small- to medium-sized tree (7.5-15 m in height) capable of attaining a diameter of 30-70 cm under good conditions. It is often seen in Syria with a bent and nearly always forked stem.

Distribution
The tree extends from China to Spain and western Morocco and as far south as Kenya. It is found chiefly in Turkestan, Iran, Iraq, and Syria, where natural stands are economically important, but it occurs also in Turkey, Pakistan, Israel, Egypt, Libya, Algeria, and the Chinese provinces of Hopei, Sinkiang, Shansi, and Manchuria. In India the tree is typically gregarious, occurring in pure stands or associated with other species. Remarkably adaptable, it reaches to the upper elevation of tree growth and is found even in the hottest parts in the plains, where in fact it thrives under river inundations.

Use as Firewood
Formerly, Populus euphratica constituted dense forests (mixed with willow, tamarisk, and mulberry) along watercourses and their tributaries throughout its vast range, but these forests have been almost completely destroyed to supply firewood. A few remnant forests are still exploited for firewood, but now mainly by coppice on short rotations of one or two years. The wood is only moderately dense (specific gravity up to 0.48). The calorific value is reported to be 5,019 kcal for the sapwood and 5,008 kcal for the heartwood.

Yield
Unreported.

Other Uses
· Fodder. The leaves afford a good fodder for sheep, goats, and camels.

· Dental use. The twigs are chewed and used for cleaning teeth.

· Wood. The wood is easy to saw and works to a good finish. It is a good turnery wood and can be peeled off on a rotary cutter. It is used for planking, lacquer work, artificial limbs, match boxes, and splints. It is also suitable for plywood, cricket bats, shoe heels, and bobbins, and can be used for pulp.

Environmental Requirements
· Temperature. Populus euphratica grows in areas with a minimum temperature of - 5°C to a maximum of 49°-52°C. It is frost hardy. During the growing season it requires much light and heat.

· Altitude. It is found from below sea level in the Middle East to an altitude of 4,000 m in Ladakh (India) and western Tibet.

· Rainfall. Rainfall range is 75-200 mm, but it mostly grows as a riverine species whose growth does not depend on rainfall.

· Soil. Populus euphratica occurs naturally in soils with a high salt content, as much as three parts per thousand.

Establishment
Natural reproduction is through root suckers or seeds. The seedlings spring up on fresh alluvial soil after the floods recede. Three sizes of cuttings are used for rooting in the nursery for subsequent planting in India. Planting is done at a spacing of 2 m x 3 m, although wider spacing is sometimes used to provide space for sowing alfalfa for improving soil and to provide fodder. The tree coppices well. It is well adapted for treatment under coppice or coppice-with-standards, reproduction being obtained from root suckers and coppice shoots.

· Seed treatment. None required.

· Ability to compete with weeds. High.

Pests and Diseases
In the Near East the tree is subject to attack by various beetles of the genus Capnodis and by Cuscuta monogyna. It is also attacked by a number of other insect defoliators, borers, and gall-forming pests.

Limitations
The finest specimens of Populus euphratica were felled long ago, and the trees that now remain (for example, along the banks of the Euphrates) are inferior in form.

Sesbania sesban

Botanic Name
Sesbania sesban (Linn.) Merrill
Synonym Sesbania aegyptiaca (Poir.) Pers

Common Names
Sesban, Egyptian rattle pod, suriminta, soriminta

Family
Leguminosae (Papillionaceae)

Main Attributes
Sesban is a fast-growing, shortlived tree that regenerates rapidly after pruning. It has a tendency to form root nodules by symbiotic association with soil bacteria capable of fixing atmospheric nitrogen.

Description
A shrub or small tree, sesban grows 4.5-6 m high. It is copiously branched, with pinnate leaves, pale yellow flowers, and slender, slightly twisted seedpods up to 25 cm long and containing many seeds.

Distribution
Sesban is said to be one of the first garden plants grown in Egypt. It is now widespread in tropical Africa and throughout tropical Asia. It is cultivated and naturalized to some extent in Hawaii.

Use as Firewood
In Africa and in India, where fuel is scarce, the tree is sometimes planted to provide firewood, which is used especially for boiling the sap of the sugar palm. The wood yields an excellent gunpowder charcoal.

Yield
A stem growth of 5 m in 12 months has been reported, and the yield recorded in India was 30 tons per acre (10 percent moisture) in I year.

Other Uses
· Food. In Bihar the flowers are eaten as a vegetable. The leaves are eaten in Thailand. The seeds, high in protein (33.7 percent), are eaten as a famine food in India; they are first soaked for 3 days and then cooked for half an hour to remove the toxic constituent caravanine.

· Fodder. The leaves and young branches are cut for fodder for cattle and sheep.

· Wood. The wood weighs 432 kg per m³. In Senegal the stems are used for arrows and pipes. In Assam the wood is split and plaited into mats. The very soft wood is made into toys in Burma. In India and Pakistan, stems are used as roofing for huts; in fact, the plant is cultivated as a substitute for bamboo.

· Fiber. The bark fiber is used for making ropes, while the pith serves as fishing floats.

· Other. In India, sesban is extensively planted as a windbreak and shade for vegetable gardens; as support for grape, black pepper, cucurbits, and betel vines; and as a shade for coffee, turmeric, sweet oranges, mandarin oranges, and cotton. In Pakistan it is planted as an intercrop for soil improvement because it is unusually rich in nitrogen. In India it is often grown as green manure in both dry and wet rice fields and plowed in before the crop is planted. It is also grown as a support for sugarcane, each plant bracing six canes. Lopped leaves are composted for use as fertilizer.

Environmental Requirements
· Temperature. In Pakistan the tree requires from 10°C to 45°C.

· Altitude. Sesban grows at 300-500 m in Pakistan. In India it is grown throughout the plains and up to an altitude of 1,200 m.

· Rainfall. It requires 350-1,000 mm rainfall.

· Soil. It tolerates a wide range of soil conditions, withstanding acid soil, periodic flooding, and waterlogging. It can endure 0.4-1.0 percent salt concentration in the seedling stage and 0.9-1.4 percent near maturity.

Establishment
· Seed treatment. None required.

· Ability to compete with weeds. Good; two or three weedings will be required during the first 2 months.

Pests and Diseases
The seed is destroyed by insects. Several species of fungi attack the plant. The baterium Xanthomonas sesbaniae affects the stems and foliage. The tobacco caterpillar eats the leaves; a weevil, Alcidodes buho, damages the plant; and the larvae of Azygophteps scalaris tunnels through the main stem. Infested plants must be uprooted and burned

Limitations
The area under cultivation requires protection from cattle; it bears very palatable foliage and is subject to browsing.

Tarchonanthus camphoratus

Botanic Name
Tarchonanthus camphoratus L.

Synonyms
Tarchonanthus litakunensis DC.; Tarchonanthus minor Less., Tarchonanthus camphoratus var litakunensis (DC) Harv.

Common names
Camphor bush, camphor wood, kanferhout, vaalbos (South Africa); leleshua (East Africa)

Family
Compositae

Main Attributes
This is a many-branched shrub or small tree that is common in open sites in many parts of southern and eastern Africa. It is easy to establish, grows fairly fast, and coppices well. The wood burns with a pleasant-smelling smoke and can be used as fuel even when not completely dry.

Description
Under favorable conditions large specimens may reach 9 m, forming a medium-sized tree. More usually, in semiarid areas it remains a densely leaved and bushy shrub some 2-3 m in height. The leaves are oblong to elliptic, 1.3-15 cm long, gray-green above and wooly white below. When crushed they give off a pleasant scent of camphor. The tree is dioecious and has small flowers on different plants, the female forming decorative, many-headed sprays. The fruiting heads that follow are also densely coated with glossy, fluffy white hairs.

Distribution
The camphor bush grows from the coast to semiarid inland areas and from the southern tip of Africa to Ethiopia and Somalia. In some areas it is common, forming an extensive shrub savannah.

Use as firewood The usual multistemmed growth makes the camphor bush easy to harvest for fuel. The bole from which the branches grow adds a substantial piece of firewood. The wood is dense and burns slowly; it ignites well even when only partly dried, making it valuable when shortages of fuel require the harvesting of live wood. People like the pleasantly scented smoke. Good-quality charcoal can be made from the wood.

Yield
The camphor bush coppices well under heavy utilization, sprouting even when the bole is burnt or cut almost to the ground. Although precise yield data are not available, its adaptation to harsh environments and fairly rapid growth suggest it as a valuable fuelwood species.

Other Uses
· Windbreak. With its tolerance of wind and extremes of temperature from hot days to freezing nights, the plant makes a valuable windbreak in semiarid areas. It can grow at the shoreline fully exposed to salt spray, making it useful in fixing drifting sands.

· Fodder. The dense, leafy canopy provides good fodder for livestock, especially during droughts and in midwinter when there is a shortage of grazing. In some semiarid areas of Africa, it is the principal source of fodder for wild and domesticated animals.

· Wood. The wood is heavy, tough, close "rained, and termite proof. It is good for fence posts, boatbuilding, spear shafts, musical instruments, and decorative work.

Environmental Requirements
· Temperature. The camphor bush thrives in temperate to semidesert climates with daily extremes of temperature.

· Altitude. The plant grows from sea level to about 2,000 m.

· Rainfall. The rainfall ranges from 150 mm to more than 800 mm per year. The plant can tolerate long periods of drought.

· Soil. The camphor bush grows well on open, semiarid plains and rocky places. It is not found in arid areas with deep sands.

Establishment
The camphor bush grows easily from seed and may be propagated from cuttings. Seedlings transplant well.

· Seed treatment. Probably none is needed since it seeds and germinates profusely.

· Ability to compete with weeds. It is invasive in overutilized vegetation (bush encroachment), but not in vegetation in good condition.

Pests and Diseases
The camphor bush is remarkably free of pests and diseases, being apparently repellent to insects.

Limitations
The bush encroaches on grazing lands in East Africa, and because of its tenacious root system it is highly resistant to burning or cutting. Repeated chemical control is successful after the first regeneration. Although it is thornless, a splinter from the wood produces a troublesome sore that heals with difficulty.

Related Species
The camphor bush is often seen together with other woody members of the Com
positae family, particularly of the genus Brachylaena. In KwaZulu in South Africa, it often grows in association with Brachylaena ilicifolia, which is as much used locally for firewood as the camphor bush.