better farming series 16
roots and tubers
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATtONS n -s titl h been published in is ries, d igned as hand ear in edi le I agricu I ining cou hey ay be pu as a s or as individual docu en .
1. The plant: the living plant; the root 2. The plant: the stem; the buds; the leaves 3. The plant: the flower 4. The soil: how the soil is made up 5. The soil: how to conserve the soil 6. The soil: how to improve the soil 7. C p rming 8. nimal husbandry: feeding and care of animals 9. nimal husband : animal diseases; how animals reproduce
rm business survey 11. e b eding 12. heep and goat breeding 13. eping chic ns 14. Farming with animal power 15. ereals 16. oots and tubers 17. Groundnuts Bananas 19. arket gardening 2 . Upland rice 21. et paddy or swamp rice 22. ocoa 23. Coffee 24. The oil palm 25. The rubber tree 26. The modern farm business 1
by arrangement with lnstitut africain developpement economique 1B 8008, Abidjan, Cote d'Ivoire
ICULTURE THE Rome 1977 Fi 1
ISBN 92-5-100155-3
©French edition, lnstitut africain pour le developpement economique et social (I NADES) 1970
©English edition, FAQ 1977 original texts were prepa r an n environment is is naturally reflected in the English version. it is expected that many of the manuals the series - a list ich will be inside t II al training in ma other parts the world. s can be made the text where necessa owmg imat and ecological condition
ications permission issue th manual in languages are Ico med. Such ions shou Id ad- dressed Di Publications ivision, Food and iculture Organization the nited Nations, a del Terme di Caracalla, 1 Rome, fta ,
author of this English version is M .J. Henderson, r Chief of the F itorial Branch.
mememmmmmeemmememamesameaaeee 3
4 Descri Different kinds 5
IS grOwn? I Ill Ill m lill Ill Q Ill m g e El m e D D £1 l!I m m m m 6
grow 1!1 'II Iii g 1!1 1!1 111 m B Q O a S 1!1 m m 111 111 1!1 D 0 a G 0 & 1!1 7 The place cassava in a crop rotation ...... , . . 7 Preparing the ii cassava .... , , ...... 7 H to propagate cassava ...... , . , . , , ... , , , , 9 H to plant cassava, ...... , , ...... , , , , , , , 10 Looking the plantation .. , . , . , .. , .. , , . , . , 11 How to harvest and store cassava. , ...... , , 15
The use in food m m Ill Ill £1 Iii m e 0 m m m m m l!I l!I m m m m £1 m 17 Fresh cassava and cassava paste ...... , 17 Dried cassava and cassava flour ...... , . . . . . 17 Cooked cassava flours ...... , ...... 18 Starch and tapioca...... 18 Cassava Ieaves ...... , ...... , . . , . , . . . 19 • Description the plant , .... , , ...... There are many varieties yam ...... , ...... Where are ms grown? ...... , . , ...... ,
How to grow ms m m m Iii Iii Iii m· 12 a 0 • m m m m m = m l!I e 0 " e m Ill ... "' The place of yams in a crop rotation. , ...... , . How prepare the soil for yams ...... ow to propagate yams...... 31 How to plant yams ... , ...... Looking after the plantation ..... , . , , ...... , arvesting and storing yams ...... , ...... , .
1 In
r Ill l.!I G O 6 e £l 1/J W 9 6 a l:l S a liil l!I S O 0 •
41
? a l!I a Iii ill a a Iii 1il e Ill e a a 41
potatoes a fill Ill a !II a a Iii Iii Ill a m l.!I a e Iii a l.!I Ill a Propagation of sweet potatoes ... , , . , , . , , , , ... , ing the plantation , , . , , , , , .... , , , , . , Yields of sweet and ng , , , , , , , , , , , , Sweet potatoes in human
ption the e l!I G O D II Iii m C a Cl Iii 9 Ill a O a ll G Ill Iii ia or Xanthosoma , , , , , . , , .. , . , . , , .. , . , , , ro or cocoyam (Colocas/g)@ • . , , . , .... , . , , , . , 51 Where are tan ia and taro grown? .. , , , , , , , .. , , , . How grow tania
Propagating Ill Ill Ill to ll e Ill e Ill Iii Ill Iii Iii a a m Ill a Ill a Q Ill JII a D II e II) G l!I Iii
Planti Iii 111 !'I Ill tD am a e Ill ma a e Iii a Iii Iii Ill a Ill Ill Iii a Ill Ill Ill Iii Iii Ill ma Iii Ill ing after the plantation , , . , . , , , , . , ... , ...
arvest1ng Ill a m Ill m Ill a a a Ill Iii a a e Iii Ill a Iii e Ill Iii a Ill Ill e • Iii Ill Ill a Ill e Storing the tube Tania and in human •
2 iefly
and tube that is,
inclu
such as beans, peas, .Bambarra groundnuts, groundnuts, as sorghu millet, maize,
their cereal
• such sorghum, millet, mai 10.
In th booklet we shall deal only th the main and tuberous plants ich are grown as food crops in that i cassava, sweet tania and taro ).
potato, which is ai a tuber, will be dealt th in another booklet.
3 It has i origin in South America and is n dely grown in tropical its base the plant consists of one or more stems 2 3 centimetres in diameter; usually each stem divides into ree branches, each branch in rn divides into three, and on. When a is cu the sap that flows is ite and looks mu like milk. Inside the stem is pith. The stem cassava is n hard; it is easi broken by a strong wind. Cassava have a long stalk and a much divided leaf-blade. The leaf veins are green or red.
yam leaf rs
it
continue ant.
con n a great deal these are inly b the
Before giving cassava to people or · animals,
I L."--'JLIII ....
5 a
If ly.
a II
ra1 the yield smalL
stems are n gh and d I h
t cassava best in ii that is permeable, n too compact, m ich air and water circulate well. the fatten up and do not rot.
Besides the fat roots that store many Ii roots take water and mineral sal from the soiL
a the field is very poor and must be left fallow.
6 i
exam e, first mai o ndnu are then pl ins are pl ted, and finally cassava, In some places, cassava is planted at the same time as or after, The cassava cuttings. are m sides the moun In other places, i is between the cassava an or beans, fonio or ndnuts.
develop well, cassava need I by the hoe or pl gh. So II to or centimetres, so that the can get well down. After tilling, at the beginning of the rai season, make or This breaks up the soil and it stores up water; the roots have plenty of loose earth in which to develop.
7 manure
Centrosema
them a· I ittle before the rams, and dig them in after 5 18
These organic manures enrich with organic matter and mineral
To plete the manuri you can apply m containing nitrogen, !Um. 1
1 The use of mineral fertilizers may be profitable if the farmer sells the cassava to: gari or tapioca factor-ies .. Many . experiments made in Ghana and Nigeria have shown that yields per hectare are increased chiefly by nitrogen fertilizers such as ammonium sulphate (21 %nitrogen), urea (46% nitrogen) and phosphorus fertilizers such as single superphosphate (16 to 20% phosphoric acid), triple superphosphate (46% phosphoric acid) and ground natural phosphate (20 to 40% phosphoric acid). Potassium fertilizers such as potassium chloride (60% potassium) and potassium sulphate (50% potassium} have a [ess marked effect. However, the yield of cassava falls greatly when the soil lacks potassium fertilizers. If the farmer applies fertilizers and looks after his plantation well, the yield of cassava reaches 25 to 65 tons per hectare.
8 d.
be .
m.
Cut each stem i There should be 6 growth buds Each stem can be made i 4 5 cuttings.
9 ece
season. r stra or slanting. earth, ieavi 3 bu
.~.· \:.: .....
Then the roots that develop will be well nourished by the soiL Usually the rows are 1 to 1.5 metres apart, and the plants 1 metre apart. With this spacing, there are between 7 000 and 10 cassava plants to the hectare. But the number of cuttings to the hectare
varies with region 1 soil and variety. If cassava is planted at the right density, the yield is heavy; the roots occupy all the soil and fewer weeds grow, so that fewer cultivations are needed.
10 L E
an big e ng.
n break it up so to nouri
L F IS
Cassava is often attacked at cal led d El::P:::ll•l;;:P Leaves plants attacked mosaic look as though crumpled, and show Iight spots. If the attack is serious, yields a sharply reduced.
11 di
d
d
•
ths
and give they are no r human 1s means a
plant cassav in a pl that is often fl If a cassava field is flooded """'C!\ro the bers are al must get the nd ve quick! rot
12 L F P
• tis, and rabbi are the chief rodents that may cause great damage in a field of cassava. These animals eat the stems, the young shoots, and especially the roots.
Other animals such as the wild boar and the pig are equally damaging to cassava. They are very fond of it, and with their powerful snouts they push over the plants and dig up large quantities of roots.
by putting poison in the fields, by laying traps, or by digging deep-ditches round the cassava plantations.
• Insects • In very dry regions, when cassava is planted a long time before the rains, termites eat the cuttings. To avoid this damage, wait for the rainy season before planting. Or you can dip the cuttings in insecticide just before planting them.
13 control diseases effectively or get rid pests.
14 cu
varieti
m
harvesting , that is, between and the mon , each fully grown tu weigh 1 or 2 kilogrammes, depending on the
In
Without cutting the stems, begin taking the biggest 'tubers from each plan leaving the smaller ones ti me to fatten u ·' If you are selling to a factory, you must harvest al I the cassava at the same ti me. The production of roots and starch is highest 18 months after planting.
15 ii as are out the nd.
That is· on a family plantation,
Cassava keeps Ionger when it is left in the ground, but the soil must not be too wet.
cassava root
When you lift the cassava, take good care n to break it. Tubers damaged in lifting go bad even more quickly.
16 I
tubers can be eaten But as a rule • • •
F F eating fresh, the sweet varieties are chosen preference, The poison in cassava is mainly in the peeL I
a The pastes are own as foutou, foufou, foufouin or tchokoro.
r The fresh roots are peeled, sliced into rounds, and dried in the sun. Sometimes, instead being sliced, cassava 1s and then pressed into I which are ices a
17 ma
• are m gan,
peel and grate fresh d"',:i,c~c,:i,\ Then press in ree or four until it begi rmen After rubbing it through a sieve, heat i d 1n a al! the time ng. a atcheke, cassava is prepared as for gari. t the flour is steamed instead ng cooked d in a pot .
• peeling, washing and grating the cassava, the m Then the resulting liquid is strained through a cloth. This is done several times.
The liquid is allowed to stand for several hours. The water at the is removed and the starch is left at the bottom of the vessel.
18 •
In mu Ii In e.
19 given the family of Dioscorea,, s ..... ,..,...... consists
which climbs by winding round a stake and lasts oniy a year; and u that can live a long time. The u thickens to produce one or more tubers called
Cross section a reserves to feed the plant and enable it to produce fruits and seeds. lifted When they are ripe, the tubers are brown in colour on the outside, but the flesh is white, yellow or red. Their weight varies between 2 and 5 kilogrammes. In rich, well-worked, deep soil and on mounds, yams can reach weights of 15 to 20 kilogrammes and more.
20 e rs.
n a may be in section, squ are alternate smooth or hai .
In certain species small tubers led are found in the axils e leaves.
yam white, green or red, are arranged in clusters or in spikes; the male flowers are separate from the female flowers. Some varieties of yam bear male and female flowers at the same time; others bear only male or only female flowers. The its are divided in three parts and each part contains two seeds.
21 • • e
• e on
•
stem rou a ms m xg
•
more rarely The tu are
This variety is quite g a g yield, The tubers a keep well.
is a !ate or medium y The is 8 or 9
Dioscorea alata Gui or m: sakarou ( Ii and I : danda-ba (
Dioscorea cayenensis (Guinea yam) There are great differences among the varieties of Dioscorea cayenensis.
they are usually planted when the rainy season has already begun. In west Africa these varieties are harvested between ovember and Janua . In Ivory Coast they are called lokpa. m
These yams are planted early, often before the rai season has begun. The first harvest is 6 months after planting (August-September). The mature tuber or tubers are removed careful! and the roots left undisturbed. The second harvest is taken 4 to 6 months later (December-January). Only the tubers from this last harvest are used for planting. The medium early varieties are: gnan and klingle or krengle, which grow in 6 to 7 months. The late varieties are: sepelo and kangba, which cannot be harvested before 8 or 9 months. a di They are oval and are generally covered hairs. The leaves are alternate; they have ree leaflets.
and even some ti mes comes th fires out much harm. Each plant of Dioscorea dumetorum have several tubers. The tubers have no ets, but are' except for nkles running them.
Dioscorea trifida (cush-cush yam) This yam is still little kn in Africa. a di They are four-sided. The leaves are alternate and deeply divided into three six lobes. plant produces several small, elongated tubers. di
van in 9 10
ite man it are: brofie mbou ( bofoue shie ( brofoue le) Togo and Benin: anago-te (Ewe-Mina),
• Dioscorea bulbifera is variety of m g in 9 months. It is chiefly grown in western Came ames it are: Guinea: danda (Malinke) dane or dana (Soussou) Mali: danda (Bambara) Togo: nbanioke ( Kabrai) a di
26 a al la and hairl
Dioscorea bulbifera
Little aerial tube lled be seen in the axils
These lbils devel the on
They may be as much as 10 centi They have ite, firm flesh and are good eat when ked.
These bulbiis just like undergrou undergrou tubers are smaller.
27 ms can be in ve dry regions, or where the sunlight is strong. need shade during the early stages growth.
This is yams are in regi between the dense and the d , treeless savanna.
sandy.
The tubers do n in heavy soils.
Swam land that flooded for several days during the rainy reason 1s n suitable for growing yams. i
If
m I' and yield many good
before the Cut down the trees, cut the branches. Stack the trees and and rn m.
Leave some the little ones. They can be used as for the aerial stems of the These natural supports will later be supplemented
• II a depth centimetres, y n
Ii 1 ai C rmers. In da, it is kn the ication um ( ) fe lize 1s uable in increasing y in igeria and Ghana, the agricultural service ises that yams should be given the lize kg/ha am ium sulphate; kg/ha single superphosphate; 215 kg/ha ! de.
• in ma can coun 1es, ms are planted in centimetres high and 1 or 2 metres apart.
The ii which has thus been well loosened holds plenty water. Sometimes the mounds are only made 2 or 3 months after planting, I up but takes a lot of work from the farmer.
1 lnstitut de recherches agronomiques tropicales et des cultures vivrieres. ti 1 metre apa in all directi or centimetres 1 This gives the tu to
kinds ich fruit and ble m an
But this propagating the farmer.
Ii Often the yield less, the tubers a much small and qua!i and contain a poison called dioscorine.
31 To get regular ng and good yields, the cutti (whether ole tube pieces) should weigh between 250 and
planted represents a considerable pa (about a quarter) the harvest. at much of the harvest must be aside and well stored for use in planti later.
use the part of the tuber nearest crown. This top of the ber contains many growth and more qu than the the tuber. this reason, tops tubers must all be planted in the same field.
The remaining yam tubers are planted in another field. They sprout less quickly. m.
Top of yam for planting
Tail of yam Cut here
planting
33 n
the • In d n
n ness.
Grass
Piece of yam
(cutting)
Mound r
F
It is n n
L F p
ing on the va ms are ha 12 planti the tubers n the and stems turn llow a d
leave the ripe be too long in the nd, otherwise bitter and one ce,
after the fi
the crop may be harvested as and when needed.
such as lokpa, I. These yams shou Id be eaten immediately after lifting.
such as Dioscorea alata, 5 or 6 But and protected from rats and other rodents, They should be under a roof, on dry ground or on boards supported on posts. To prevent rot, the tubers should not be heaped up too much.
36 I
are the staple ma peoples of
ms are eaten fresh, are treated and preserved.
Most varieties of yams, especially the wild species that are not cultivated, contain a poison (dioscorine). But this poison is removed by washing the yams several times in It r and by cooking them well.
This is on
• F
When yams are eaten fresh, either boiled fried,
cut the tubers into pieces and I The boiled yams are pounded to make mashed yams.
37 • r
are being dried in sun. sometimes after a meal, remains of ( yams) are carefu I gathered up and made into I ittle Is ich are then dri m sun,
Like cassava, lis
a mm. grow 2 or 3 metres in I · they are thin and dim ng or c mg, They have n at ing distances rt. !t is ought that the varieties id more than
greatly in si De pending the they be entire, or dee The leaf veins a
usual violet, are clustered in the I Many varieties potato in cul do not have time produce fl before the harvest are pa have built up
These tubers are produced at ints where the roots cease spread t near the su ,..,,:,,,a and turn downward into the soiL By making mounds that are not too wide, the formation of tubers is helped.
Leaves and tubers of sweet potato eties potato di in the number, ape and size their and in the colour the pee! and flesh the tubers. Sweet potatoes may be round · elongated. In colour they are white, yellow, red or violet, with soft firm flesh. They may weigh between and 3 kilogrammes.
Sweet potatoes grow wel I
the same time, they withstand drought ve well. For that reason, they are suited to dry savanna coun Sweet potatoes need n to g especially when the leaves are coming into growth. But if as at harvesting time, the tubers
Soil sweet potato will m soils. The most suitable soil is a light, well-drained, sandy loam. If the soil is too rich in organic matter and nitrogen, the plant produces a great deal of useless stem and leaves, and only after a long time produces a very few tubers.
41 ng on e mounds and protect them sture. The ridges are made ~~~,~t 75 centi rt.
In bending, the roots bu iid up and develop bers.
h He must how long they take to form tubers, and see it that the harvest II be in the d season.
It is better plant several times, at intervals, so that the whole plantation does not become ready for harvest at the same time. By doing this, you can Ii the sweet potatoes as and when you need them. •
ant cuttings at a leaving 3 4 and press firmly. If y plant them on mou you can put r or five cutti in a circle on each is will give a planti of between 15 and to the hectare.
If do n have any plants sweet th enough leafy growth to provide cu you can propagate from tubers. In
are large, cut them i several pieces. r about a month, remove the tubers the young shoots that are 15 to centimetres I and plant them.
This method of propagation from tubers is usually done only on a part, say one third, of the area on which sweet potatoes are to be grown. Later, cuttings from the plan us obtained can be used to enlarge the plantation.
r
l F E
or cultivations in early stages of growth are enou In 4 to 6 weeks after planting, the plant's own leafy growth will closely cover the soil.
When cultivating, remake the mounds at the same time.
44 L
n
• Diseases are caused ri Some ngi make the leaves r. ng, ma e the disease are How leaves and black ma inside the stems and
plant
e a
on el
1 the bers. is caused Is.
In ere harvested sweet potatoes a can fumigated phostoxin in IEL
even
length time ich sweet can differs with net, and the harvesting If they are harvested in d the bers may be red
Damaged tubers are p
m a time after good keeping, the tubers of
when the stems and leaves have turned U
Put them on dry ground or on boards supported on posts, and do not heap them up too much. I
van
ones are m v1 mms.
The
u
plant are e and animals. ii
•
• (or cocoyam) the scientific name of it is all over
Tania and taro are distingui I the ape and arrangement
or thosoma Some varieties of tania It may reach 1 metre in I in the adult plant The leaf blade of tania is divided a notch ich makes the leaf a aped. The leaf-sta! k is attached to the edge of the I at the middle of the notch. (Xanthosoma)
stiff and thick. They are flattened at the part attached to the leaf, The leaf-stalk of tania is a direct continuation of the midrib. a rule,
They weigh between 1 and 5 kilogrammes and are m
50 a mid
(Colocasia)
The taro leaf-stalk is not attached to the edge the leaf, but near the centre the leaf blade.
51 u It remains ten n at harvest time.
as there are of nta, The tubers be large or smal I, with flesh that II or hard or soft, at becomes f!ou after cooking, or dou
• Tania and taro require
If you Hve in a region it is better to grow taro than tania . • Tania and taro need IS Some varieties can even be planted in land that is often flooded. In
Tania and taro are usually propagated from I or Sometimes the or new shoots that appear some distance from the parent pl ant, are used. With tania, pieces of the can sometimes be used, or the main tuber if it has become too hard to eat.
The tubers, pieces of tuber or of aerial stem are cut into pieces 10 to 15 centimetres long; the leaf-stalks are cut at about 10 centimetres from the junction with the leaf.
Tania and taro may be planted by .themselves. Or they may be m
example, they can be grown in the shade of a plantation of plantains. They can also be grown under the dense foliage of big forest trees.
Because tania and taro have large leaves, they may be used as a when starting a new cocoa plantation.
53 between centimetres and 1
r
nia and taro require little care. ne or cu Itivati in the are al I that is necessa before the harvest. Often the plants are ligh earthed up when these cultivations are carried out.
Depending on variety, tania and taro are between 6 and 14 months in the field. and ready for harvest I and the plant begins to wither.
If you harvest during the dry season, the tubers may be left in the earth for some time and will not spoil. When the field is wet, the ripe tubers must be harvested quickly. They may sprout and will then be no good for human food.
54 • The fi harvest begins about 3 months after anting. Three months after this fi harvest, you can take three or r additional ha from each plant. After each these itional harvests, it 2 or 3 wee before taking tubers again from same t .
• The first h begins 6 to 8 months after planting. that, harvest again or three times from the same plant at intervals of 2 or 3
When harvesting dig out the soil right up plant, take the biggest tubers and detach them from the parent plant. Then fill in the hole. Let the young tubers develop before harvesting again. The
for some months after harvesting,
do that, put the tubers on dry ground, or-on boards supported on posts, in a , sheltered from the sun and rain. I I
tania used in hu as
may also be given to animals as
With the main underground stem is too rd to be eaten. Only the are used for food.
With the underground stems often bear tubers. The which is the biggest and yet soft, is the one chiefly used for food.
57 FILL I E
is grown chiefly for its ...... '...... cassava, the field must be ...... never has an aerial stem. Yams and cassava contain ...... To propagate yams, piant ...... The roots of cassava become large and fat by storing up ......
It is better to plant sweet potatoes on ......
To propagate cassava, plant ...... ® •••••••••••••••••• Sweet potatoes are a food rich in ...... The leaves of ...... can be eaten.
R E
When should organic manure be applied? What is the place of yams in a crop rotation? Why? What are the chief diseases and pests of sweet potatoes? How do you control the diseases and pests of sweet potatoes? What is the place of cassava in a crop rotation? Why? What plants with tubers are grown where you live? How do you propagate sweet potatoes? When should yams be harvested? What is the purpose of crop rotation? How is cassava harvested where you live? What do you do to get rid of the poison in cassava tubers? Or in yams? Why is weeding necessary? How do you store your harvest of yams? Sweet potatoes? Tania and taro? How do you choose the cuttings of cassava and sweet potato? Draw a leaf of tania and one of taro, showing the difference between them. Explain the difference between a tania leaf and a taro leaf.
58 Antilles, Netherlands Boekhandel St. Augustinus, Abraham de Veerstraat 12, Willemstad, Cura<;:ao. Argentina Editorial Hemisferio Sur S.R.L., Libreria Agropecuaria, Pasteur 743, Buenos Aires. Australia Hunter Publications, 58A Gipps Street, Collingwood, Vic. 3066; The Assistant Director, Sales and Distribution, Australian Government Publishing Service, P.O. Box 84, Canberra, A.C.T. 2600, and Australian Government Publications and Inquiry Centres in Canberra, Melbourf]e, Sydney, Perth, Adelaide and Hobart. Austria Gerold & Co., Buchhandlung und Verlag, Graben 31, 1011 Vienna. Agricultural Development Agencies in Bangladesh, P.O. Box 5045, Dacca 5. !Barbados Cloister Bookstore Ltd., Hincks Street, Bridgetown. Belgium Service des publications de la FAO, M.J. De Lannoy, rue du Trone 112, 1050 Brussels. CCP 000-0808993-13. Bolivia Los Amigos del Libro, Peru 3712, Casilla 450, Cochabamba; Mercado 1315, La Paz; Rene Moreno 26, Santa Cruz; Junin esq. 6 de Octubre, Oruro. 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Nicaragua lncusa-Culturama, Camino de Oriente. Apartado C105, Managua. Nigeria University Bookshop (Nigeria) Ltd., University of Ibadan. Ibadan. Norway Johan Grundt Tanum Bokhandel, Karl Johansgt. GT 41-43, Oslo 1. Pakistan Mirza Book Agency, 65 The Mall, Lahore 3. Panama Distribuidora Lewis S.A.. Edificio Dorasol. Calle 25 y Avenida Balboa, Apartado 1634, Panama 1. Peru Libreria Distribuidora Santa Rosa, Jiron Apurimac 375. Lima. Philippines The Modern Book Company. 928 Rizal Avenue. Manila. Poland Ars Polona-Ruch. Krakowskie Przedmiescie 7. Warsaw. Portugal Livraria Bertrand, S.A.R.L.. Apartado 37, Amadora: Livraria Portugal. Dias y Andrade Ltda., Apartado 2681, Rua do Carmo 70-74. Lisbon-2: Edicbes ITAU, Avda. Republica 46A c/v-E. Lisbon-1. Romania llexim. Calea Grivitei N° 64-66. B.P. 2001, Bucarest. Saudi Arabia University Bookshop, Airport Road. P.O. Box 394. Riyadh. Senegal Librairie Africa, 58 Av. Georges Pompidou, B.P. 1240. Dakar. Singapore MPH Distributors Sdn. 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P-69 ISBN 92-5-100155-3