Promoting the Conservation and Use of Under Utilized and Neglected Crops. 01 - Physic Nut

8/3/2019 Promoting the Conservation and Use of Under Utilized and Neglected Crops. 01 - Physic Nut

1/66

IPGRII

nt

ernati

ona

lPlan

tGeneticResour

cesIn

stitute

IPGRI

Physic nutPhysic nut

1AN ECOGEOGRAPHICAL STUDY OF VICIA SUBGENUS VICIA

Jatropha curcasL.

Promoting the conservation and use of underutilized and neglected crops. 1.

Joachim Heller


2/66

2 Physic nut. Jatropha curcasL.

The International Plant Genetic Resources Institute (IPGRI) is an au tonomous internationalscientific organization op erating under the aegis of the Consultative Group on Interna-tional Agricultural Research (CGIAR). The international status of IPGRI is conferred un-

der an Establishment Agreement w hich, by December 1995, had been signed by the Gov-ernments of Australia, Belgium, Benin, Bolivia, Burkina Faso, Cameroon, China, Chile,Congo, Costa Rica, Cte dIvoire, Cyprus, Czech Republic, Denmark, Ecuador, Egypt,Greece, Guinea, H un gary, India, Iran, Israel, Italy, Jordan, Kenya, Mauritania, Morocco,Pakistan, Panama, Peru, Poland, Portugal, Romania, Russia, Senegal, Slovak Republic,Sud an, Switzerland, Syria, Tunisia, Turkey, Ukraine and Uganda. IPGRIs man date is toadvance the conservation and u se of plant genetic resources for the benefit of present andfuture generations. IPGRI works in partnership with other organizations, undertakingresearch, training and th e provision of scientific and technical advice and information, and

has a particularly strong programme link with the Food and Agriculture Organization ofthe United Nations. Financial supp ort for the agreed research agend a of IPGRI is pro-vided by the Governments of Australia, Austria, Belgium, Canada, China, Denmark,France, Germany, Ind ia, Italy, Japan, the Republic of Korea, Mexico, the N etherland s, Nor-way, Spain, Sweden, Switzerland, the UK and the USA, and by the Asian DevelopmentBank, IDRC, UNDP and the World Bank.

The Institute of Plant Genetics and Crop Plant Research (IPK) is operated as an ind e-pend ent found ation und er pu blic law. The foundation statute assigns to IPK the task ofcondu cting basic research in the area of plant genetics and research on cultivated plan ts.

The geographical designations employed and the presentation of material in thispu blication do not imp ly the expression of any opinion w hatsoever on the par t of IPGRI,the CGIAR or IPK concerning the legal statu s of any country, territory, city or area or itsauthor ities, or concerning the delimitation of its frontiers or bound aries. Similarly, theviews expressed a re those of the au thors and do not necessarily reflect the views of theseparticipating organizations.

Citation:Heller, Joachim. 1996. Physic nu t.Jatropha curcas L. Promoting the conservation and useof underutilized and neglected crops. 1. Institute of Plant Genetics and Crop Plant Re-search, Gatersleben/ Interna tional Plant Genetic Resources Institu te, Rome.

ISBN 92-9043-278-0

IPGRI IPKVia delle Sette Chiese 142 Corrensstrae 300145 Rome 06466 GaterslebenItaly Germany

Internationa l Plant Genetic Resources Institu te, 1996


3/66

3Promoting the conservation and use of underutilized and neglected crops. 1.

ContentsAcknowledgements 4Foreword 5

1. Introduction 62. Names of the species and taxonomy 73. Botanical description 104. Origin and centre of d iversity 135. Properties 16

Toxicology 166. Uses 18

Whole plant and food/ fodder 18Medicine 18

Plant protectant and molluscicide 19Technical uses 20Diesel fuel 21Other uses 23

7. Genetic resources 25Existing genetic variation 25Conservation of physic nut 30

8. Breeding 32Breeding objectives 32

Breeding method 32Selection based on provenance trials 339. Production areas 3410. Ecology 3511. Agronomy 36

Growth and development 36Propagation methods 37Pests and d iseases 41

12. Limitations of the crop 4213. Prospects 4314. Research needs 44Bibliography 45Appendix I. Research contacts, centres of crop research, breeding

and plant genetic resources of physic nut 55Appendix II. Publications of Proyecto Biomasa, DINOT/ UNI,

Nicaragua 60


4/66


AcknowledgementsThe information contained in this monograp h w as partly comp iled d uring the p rodu c-tion of my PhD th esis und er the supervision of Prof. Dr D. Leihner at the University of

Hoh enheim, Stu ttgart. I am par ticularly grateful to him and to the Deutsche Gesellschaftfr Technische Zu sammen arbeit (GTZ) for initiating and finan cing th e research p rojectat that time. I am indebted to all my coworkers at the University of Hohenheim, the GTZin Senegal and the INIA, Cape Verde, and I wish to acknowledge my appreciation oftheir support an d cooperation, and for all our d iscussions.

I thank Prof. Bijan Dehgan , Dr Jan Engels, Prof. Jos Mend es Ferro, Mr NikolausFoidl, Mr Jrgen Gliese, Dr Phil Harris, Mr Reinhard Henning, Dr Norman Jones, DrBhag Mal, Mr Stefan Peterlow itz, Prof. Lucia Ramirez, Dr Jozef Turok an d Prof. MichaelWink for th eir critical review of the m anu scrip t.

I thank Prof. B. Dehgan and the Ann als of the Missouri Botanical Garden for th eirperm ission to reprint Figure 1, and Mr R. Henn ing for providing several photograph s.


5/66


ForewordHumanity relies on a diverse range of cultivated species; at least 6000 such species areused for a variety of pu rposes. It is often stated that only a few staple crops produ ce the

majority of the food su pp ly. This might be correct but the important contribution of manyminor sp ecies should not be underestimated. Agricultural research has trad itionally fo-cused on these staples, while relatively little attention has been given to minor (orund erutilized or neglected) crops, particularly by scientists in developed countries. Suchcrops have, therefore, generally failed to attract significant research funding. Unlike moststaples, many of these neglected sp ecies are adap ted to various marginal growing cond i-tions such as those of the And ean and Himalayan h ighland s, arid areas, salt-affected soils,etc. Furthermore, many crops considered neglected at a global level are staples at a na-tional or regional level (e.g. tef, fonio, Andean roots and tubers etc.), contribute consider-

ably to food supp ly in certain periods (e.g. indigenous fruit trees) or are important for anu tritionally well-balanced diet (e.g. indigenous vegetables). The limited information avail-able on m any imp ortant and frequently basic aspects of neglected and underu tilized cropshinders their developm ent and their sustainable conservation. One major factor hamper-ing this development is that the information available on germplasm is scattered and notreadily accessible, i.e. only found in grey literature or w ritten in little-know n languages.Moreover, existing know ledge on the genetic potential of neglected crops is limited. Thishas resulted, frequently, in uncoordinated research efforts for most neglected crops, aswell as in inefficient approaches to the conservation of these genetic resources.

This series of monographs intends to draw attention to a num ber of species which havebeen neglected in a varying d egree by researchers or have been underutilized economically.It is hoped that the information compiled w ill contribute to: (1) identifying constraints in andpossible solutions to the use of the crops, (2) identifying possible un tapped genetic diversityfor breeding and crop improvement programmes and (3) detecting existing gaps in availableconservation and use approaches. This series intends to contribute to improvement of thepotential value of these crops through increased use of the available genetic diversity. Inaddition, it is hoped that the monographs in the series will form a valuable reference sourcefor all those scientists involved in conservation, research, improvement and promotion ofthese crops.

This series is the result of a joint project between the International Plant GeneticResources Institu te (IPGRI) and the Institu te of Plant Genetics and Crop Plan t Research(IPK). Finan cial supp ort prov ided by the Federal Ministry of Econom ic Cooperationand Developm ent (BMZ) of Germany th rough the German Agency for Techn ical Coop-eration (GTZ) is duly acknowledged.

Series editors:

Dr Joachim Heller, Institute of Plant Genetics and Crop Plant Research (IPK)

Dr Jan Engels, Intern ational Plant Genetic Resources Institu te (IPGRI)Prof. Dr Karl Ham mer, Institu te of Plant Genetics and Crop Plant Research (IPK)


6/66


7/66


2. Names of the species and taxonomyThe Eup horbiaceae family comprises approximately 8000 species, belonging to 321 gen-era. According to Leon (1987), Mabberley (1987) and Rehm and Espig (1991), crops of

economic impor tance in this large family are:q roots cassava (Manihot esculenta)q rubber Hevea (Hevea brasiliensis)q fru its emblic, Otaheite gooseberry (Phyllanthus spp.), tjoopa,

rambai, mafai (Baccaurea spp.), Chinese laurel (Antidesmabunius),Ricinodendron spp.

q nuts tacay (Caryodendron orinocense)q vegetables katuk (Sauropus androgynus), chaya (Cnidoscolus chayamansa)q oil castor ( Ricinus communis), tung trees (Aleurites spp.),

Chinese tallow tree (Sapium sebiferum), physic nut (Jatrophacurcas)

q hydrocarbon Euphorbia spp.q medicinal Croton spp.,Jatropha spp.The genusJatropha belongs to tribe Joannesieae of Crotonoideae in the Euphorbiaceae

family and contains app roximately 170 know n species. Dehgan and Webster (1979) re-vised the subd ivision m ade by Pax (1910) and now d istinguish two subgenera (Curcasan d Jatropha) of the genu sJatropha, with 10 sections and 10 subsections to accomm odatethe Old and New World species. They postulated the physic nu t (Jatropha curcas L. [sect.

Curcas (Adan s.) Griseb., subg. Curcas (Adans.) Pax]) to be the most pr imitive form of theJatropha genu s. Species in other sections evolved from the ph ysic nu t or another ances-tral form, with changes in growth habit and flower structures. Hierarchical cluster analy-sis of 77 New WorldJatrophaspecies showed for the m ost part concordance with Dehganand Webster s (1979) infragener ic classification (Dehgan and Schu tzm an 1994). Figure 1shows the phenogram me of NeotropicalJatrophaspecies. Further cladistic analysis sup-ported Deh gan and Websters (1979) evolutionary model of the genu sJatropha.

The following are other species that belong to the section Curcas: J.pseudo-curcasMuell. Arg.,J. afrocurcas Pax,J. macrophylla Pax & Hoffm.,J. villosa Wight (syn.:J. wightianaMu ell. Arg.),J. hintonii Wilbur,J. bartlettii Wilbur,J. mcvaughii Dehgan & Webster and J.

yucatanensis Briq. McVau gh (1945) considered J. yucatanensis to be a synonym ofJ. curcas.One sp ecies,J. villosa, is of Indian origin. Two,J. afrocurcas an d J. macrophylla, are of EastAfrican or igin, whereas all the other species in th is section are native to the Am ericas.

Although m ost of theJatropha species are native to the N ew World , approximately 66species are native to the Old World . Dehgan and Webster (1979) offered a key to theinfrageneric taxa but th is should not be considered as final since inform ation is still lack-ing on many species. No complete revision of the Old World Jatropha exists. Hemmingand Radcliffe-Smith (1987) revised 25 Somalian sp ecies, all of the su bgenus Jatropha, andplaced them in six sections and five subsections. Jatropha multifida L. and J. podagrica

Hook. of section Peltatae,J. integerrima of section Polymorphae, and J. gossypiifolia of sec-tionJatrophaare well known and cultivated through out the trop ics as ornamental plants.

Linnaeus (1753) was the first to nam e the physic nut Jatropha curcas L. according to


8/66


Fig. 1. Phenogramme of 77 Neotropical Jatrophaspecies from 32 characters, using F.J. Rohlfs NTSYS-pc programme. Infrageneric designations are from Dehgan and Webster (1979) (reprinted withpermission from Dehgan and Schutzmann 1994).


9/66


the binom ial nom enclature of Species Plantaru m and this is still valid tod ay. Accord-ing to Dehgan and Webster (1979) and Schultze-Motel (1986), synon ymous nam es of theph ysic nu t are:

Curcas purgans Med ik., Ind . Pl. Hort. Man hem . 1: 90. 1771; Baill. tud . Gen. Euphorb.314, 1858.

Ricinus americanus Miller, Gard . Dict. ed. 8. 1768.Castiglionia lobata Ruiz & Pavon, Fl. Peruv. Prod r. 139, t. 37. 1794.

Jatropha edulis Cerv. Gaz. Lit. Mex. 3: supl. 4. 1794.J. acerifoliaSalisb., Prod r. Chap el Allerton 389. 1796.Ricinus jarakThunb., Fl. Javan. 23. 1825.Curcas adansoni Endl., ex Heynh . Nom encl. 176. 1840.Curcas indica A. Rich. in Sagra, Hist. Fis. Pol. Nat. Cuba 3: 208. 1853.

?Jatropha yucatanensis Briq. Ann. Cons. Jard . Genve 4: 230. 1900; Standley, Con tr.U.S. Nat. Herb. 23: 640. 1923; McVau gh , Bull. Torrey Bot. Club 72: 35. 1945.

Curcas curcas (L.) Britton & Millsp ., Baham a Fl. 225. 1920.The genus nam e Jatropha derives from the Greek iatrs (doctor) and troph(food)

which implies med icinal uses. Accord ing to Correll and Correll (1982), curcas is thecomm on name for physic nu t in Malabar, Ind ia.

Nu merous vernacular nam es exist for the physic nu t: physic nu t, pu rging nut (En-glish); pou rghre, p ignon d Inde (French); pu rgeernoot (Dutch); Purgiernu, Brechnu (German); purgueira (Portuguese); fagiola dIndia (Italian); dand barr, habel meluk

(Arab); kanananaeranda, parvataranda (Sanskrit); bagbherenda, jangliarandi, safedarand (Hindi); kad am (Nep al); yu -lu-tzu (Chinese); sabudam (Thailand ); tbang-bkod(the Ph ilipp ines); jarak budeg (Indonesia); bagan i (Cte dIvoire); kpoti (Togo); tabanani(Senegal); mupuluka (Angola); bu tu je (Nigeria); makaen (Tanzania); pioncillo (Mexico);coquillo, temp ate (Costa Rica); trtago (Puerto Rico); mund ubi-assu (Brazil); piol (Peru)and pinn (Guatemala) (Mnch 1986; Schultze-Motel 1986).


10/66


3 Botanical descriptionThe physic nu t is a drought-resistant species which is widely cultivated in the trop ics asa living fence. Many parts of the plants are used in trad itional med icine. The seeds,

however, are toxic to hum ans and man y animals. Considerable amou nts of ph ysic nu tseeds were prod uced on Cape Verde d ur ing the first half of this centu ry, and th is consti-tuted an imp ortant contribution to the countrys economy. Seeds were exported to Lisbonand Marseille for oil extraction and soap p roduction. Todays global prod uction is, how -ever, negligible.

The physic nu t, by definition, is a small tree or large shrub which can reach a heightof up to 5 m. The plant shows articulated grow th, with a m orphological discontinuity ateach increment. Dorman cy is indu ced by fluctuations in rainfall and temp erature/ light.The branches contain latex. Norm ally, five roots are formed from seedlings, one centra l

and four p eripheral. A tap root is not usu ally formed by vegetatively propagated plants(Kobilke 1989). The physic nu t has 5 to 7 shallow lobed leaves w ith a length and w idthof 6 to 15 cm, which are arranged alternately. Inflorescences are formed terminally onbranches and are comp lex, possessing m ain and co-florescences with paraclad ia. Bo-tanically, it can be described as a cyme. The plant is monoecious and flowers are uni-sexual; occasionally hermaphrod ite flowers occur (Dehgan and Webster 1979). Ten sta-mens are arranged in two distinct whorls of five each in a single column in theand roecium , and in close proximity to each other. In the gynoecium, the three slend erstyles are connate to about tw o-thirds of their length, dilating to massive bifurcate stig-

mata (Dehgan and Webster 1979).Pollination of the ph ysic nu t is by insects. Dehgan and Webster (1979) believe that itis pollinated by moths because of its sweet, heavy perfum e at night, greenish whiteflowers, versatile anthers and protruding sexual organs, copious nectar, and absence ofvisible nectar guid es. When insects are exclud ed from the greenhou se, seed set doesnot occur withou t hand -pollination . The rare hermaphrod ite flowers can be self-polli-nating . Dur ing field trials, Heller (1992) observed a nu mber of different insects thatvisited flowers and could pollinate. In Senegal, he observed th at stamina te flowers openlater than pistillate flowers in the same inflorescence. To a certain extent, this mecha-nism prom otes cross-pollination. M nch (1986) did not observe this chronological orderin Cape Verde. It seems that the mechanism is influenced by the environm ent. Afterpollination, a trilocular ellipsoida l fru it is form ed. The exocarp remains fleshy until theseeds are mature. The seeds are black, 2 cm long and 1 cm thick. The caruncle is rathersmall. Wiehr (1930) and Droit (1932) described the m icroscopical anatomy of the seedsin deta il, while Singh (1970) described tha t of fruits. Gupta (1985) investigated theanatomy of other plant parts. The physic nu t is a diploid species with 2n = 22 chrom o-somes. Relevant par ts of the plant are shown in Figures 2 and 3.


11/66


Fig. 2. Important parts of the physic nut: a - flowering branch, b - bark, c - leaf veinature, d - pistillateflower, e - staminate flower, f - cross-cut of immature fruit, g - fruits, h - longitudinal cut of fruits; a - c and f- h from Aponte 1978; d and e from Dehgan 1984 (reprinted with permission).

3 mm


12/66


Fig. 3. (a) Inflorescence; (b) branch with fruits; (c) hedge in Mali; (d) cooking of oil with soda solution; (e)soap production in Oulessebougou, Mali; (f) Sundhara oil press; (g) grain mill with Hatz engine (sourcesb-g: Henning)

a

b

c

d

e

f

g


13/66


4 Origin and centre of diversityA num ber of scientists have attemp ted to define the origin of physic nut, but the sourceremains controversial. Martin and Mayeux (1984) identified the Ceara state in Brazil as a

centre of origin but w ithout giving any arguments. Dehgan and Webster (1979) cite Wilbur(1954) as follows: it was without dou bt part of the flora of Mexico and probably of north-ern Central America before the arrival of Cortez, and it most likely originated there ... thesubsection, hence, appears to be one which originally was nearly or completely restrictedto Mexico. Accord ing to other sources, the ph ysic nu t seems to be native to CentralAmerica as well as to Mexico where it occurs naturally in the forests of coastal regions(Aponte 1978). How ever, Dehgan (pers. comm .) did not find true w ild physic nu t plantswhen collecting Jatrophas in Mexico. Those he found had always escaped from culti-vated hedges. During a visit to Professor Dehgans Horticultural Systematics Laboratory,

the author checked hundred s of herbarium specimens from the following herbaria for thedistribution of the physic nut in Mexico, Central America and the Caribbean: DAV, F,FLAS, GH, MICH, MO, NY, RSA, TEX, UC and US. The material collected originatedmostly from Mexico and all Central American countr ies: Belize, Costa Rica, El Salvador,Guatemala, Hond uras, Nicaragua and Panama, with the m ajority coming from Mexico.Many records also exist for the Caribbean: Baham as, Cuba, Dominica, Dominican Repub-lic, Haiti, Puerto Rico, Saint Lucia, Santo Domingo, St. Croix, Trinidad and other WestIndian countries. In the following South American countries, the physic nu t occurs to alesser extent, according to their representation in the herbaria listed above: Argentina,

Bolivia, Brazil, Colombia, Ecuador and the Galapagos Islands, Paraguay, Peru and Ven-ezuela. It has been introduced into Florida.Herbarium specimens of the Americas were usually collected from hedges along

roads and paths, live fence posts or d isturbed sites (disturbed forest). Stand ley andSteyermark (1949) confirm this and state for Guatem ala that the shrub may not be na-tive in Guatem ala, since it is found principally in hed ges, but if not, dou btless it has beenin cultivation for a long time. How ever, the information provided by man y collectorsseems to sup port the argument that the sp ecies was collected from natu ral vegetationin the Americas, as the following vegetat ion forms were given on the herbarium labelsmentioned above: bosque hu mido, forest, bosque seco tropical, cactus an d thorn scrub,shrubby slope, thicket near river bank, tropical dry forest, bosque seco y espinoso, drysteep hillside, woodland , hillside w ith dense shru bs and wood s, or coastal thickets. It ishighly probable that the centre of origin of the physic nut is in Mexico (and CentralAmerica) since it is not found in these forms of vegetation in Africa and Asia but only incultivated form. The true centre of origin, however, still has to be found. To elucidatethis, the original collecting sites in Mexico and Central America w ould have to be revis-ited and the existing diversity assessed, preferably by molecular techn iques.

From the Caribbean, this species w as p robably d istributed by Portu guese seafarersvia the Cape Verde Island s and former Portugu ese Guinea (now Guinea Bissau) to other

countr ies in Africa and Asia. No facts are available in the literature before 1800 as towhen the p hysic nu t w as introd uced into Cap e Verde (Serra 1950). Freitas (1906), citingPusich, says that th e ph ysic nu t w as already know n several years p rior to 1810, as he


14/66


mentioned it in his book Memoria ou descripo physico-politica das ilhas de CaboVerde. Chelmicki and Varnhagen (1841) mention that expor ts of physic nu ts had al-ready begu n in 1836. Many decrees were published in the Boletim Oficial de Cabo

Verde from 1843 onwards to promote the planting of physic nut (Freitas 1906; Serra1950).

Burkill (1966) assum es that the Portu guese brought th e physic nu t to Asia: Per-hap s it did n ot reach Malacca u ntil a date wh en the Du tch w ere in p ossession, for the

Fig. 4. Current distribution of Jatrophacurcasand proposed centre(s) of diversity(according to Mnch 1986 and variousfloras, see Annex to References).

Centre of origin

q

q

q

q

qq

q

q

q

q

qq

q

qqqq

q

q q

qqqqq

q

q

q

q

q

q

qq

qq

q

q

q

q

q

q

q

q

q

qq

qqq

qqq

qq

q

q

q

qq

q

q

q

q


15/66


Malays call it by a nam e meaning Du tch castor oil. Nevertheless, the Portu guese trans-ported it to the Old World. The Javanese, am ong other nam es, call it Chinese castoroil. It is regard ed in most countr ies, in Africa as well as in the East, as the castor oil

p lant, which show s that it was brou ght in and p lanted for the oil; furth er, it is w idelyknow n as the hed ge castor oil plant, show ing wh ere it was p lanted, nam ely in hed ges.Merrill (Bur. Gov. Lab. Philipp. 6, 1903 p. 27) shows that it was in the Philippines be-fore 1750. Today it is cultivated in man y coun tries. Figure 4 show s its distribu tionaccord ing to variou s sou rces (see Bibliograp hy).

qqq

q

q

q

q

q q

q

q

q

q

q

q

q

qq

q

q

q

q

q

q

q

q


16/66


5 PropertiesNu merous investigations have been carried out to d etermine the content of physic nu tseeds. Results of the older analyses are not reported here, because the m ethods are not

comparable with modern method s. Prof. J.E. Mend es Ferrao, University of Lisbon, wasespecially instru men tal in d etermining ph ysic nu t conten t. Table 1 show s the results ofdeterminations of moistu re, ash, crude protein, cru de fat, crude fibre (based on th e seedkernel) and of the crud e fat content (based on the seed) of d ifferent samp les from CapeVerde (Santiago and Fogo) and Sao Tome and Pr incipe. Part of the analyses was per-formed on ly on the seed kernel, not on the w hole seeds and cannot, therefore, be com-pared w ith other analyses.

Numerou s sources are available on the fatty acid composition of physic nu t oil origi-nating from d ifferent coun tries. The values given in Figure 5 refer only to the four most

importan t fatty acids: palmitic (C16:0), stearic (C18:0), oleic (C18:1) and linoleic acid(C18:2). Fatty acids were determined by gas chromatography of the fatty acids aftermethylesterification. The average saturated fatty acid content of the seed samples is low:15.38% for palmitic (C16:0) and 6.24% for stearic acid (C18:0). The average content of theunsaturated fatty acids, oleic (C18:1) and linoleic acid (C18:2) is considerably higher at40.23 and 36.32%. Depending on the origin, either oleic or linoleic acid content is higher.The seed oil belongs to the oleic or linoleic acid group, to which th e majority of vegetableoils belong (Rehm and Espig 1991).

Table 1. Composition of physic nut seeds from Cape Verde (Fogo und Santiago) and SaoTom und Principe (from Ferrao and Ferrao 1981, 1984; Ferrao et al. 1982).

Contents (%)

Seed composition (%) Kernel Seed

Location Shell Kernel Moist. Ash Crude Crude Crude Crude

prot. fat fibre fat

Fogo 35.46 64.54 4.68 4.48 20.25 52.83 0.94 34.09

Santiago 44.92 55.08 3.78 3.83 23.48 59.78 1.90 32.90

Sao Tom 47.74 49.98 7.79 6.37 28.44 46.72 4.23 23.67

Mean 42.71 56.53 5.42 4.89 24.06 53.11 2.36 30.22

Toxicology

The toxicity of the seeds is mainly du e to the following seed comp onents: a toxic protein(curcin) and d iterpene esters. Poisoning is reported in Chap ter 6 (Uses). Curcin is similarto ricin, the toxic protein of the castorbean (Ricinus communis ). The pu re substances are themost potent toxins in the p lant kingdom and will kill when adm inistered in quantities of

micrograms. Georgi Markov, a Bulgarian journalist who lived in London, was killed in1978, probably with ricin poison that was contained in an umbrella spike (Griffiths et al.1987). Felke (1913) was the first to isolate curcin. Curcin hinders protein synthesis in vitro


17/66


(Stirpe et al. 1976). Diterpenes have been isolated from seeds (Adolfet al. 1984) and roots(Naengchomnong et al. 1986; Chen et al. 1988). These substances prom oted skin tumoursin a mouse cocarcinogenesis experimen t. Horiuchi et al. (1987) suggested that an epide-

miological stud y be carried out on hum an cancer in Thailand, since the skin of Thai peoplecomes into direct contact with the seed oil. The GTZ financed a stud y on the possibility ofdetoxifying the seed cake and the mu tation p otential of the diterpenoids in the oil. Prof.Wink of the University of Heidelberg carried ou t the stu dy (Wink 1993).

The major find ings were:q seed cake still contains approximately 11% oil content, in wh ich th e therm ostable

toxic diterpenes are bou ndq heating of up to 100oC for 30 minutes did not de-activate the lectins in whole

seeds and d ry seed cake

q cooking of groun d seed s or seed cake for 5 minu tes deactivates the lectinsq the oil has no m utagenic properties; wh en handled w ith care, there is no d anger

for workers.Feeding trials were carried out with many different animal species (dog Siegel

1893; rabbit Felke 1913; gu inea p igs and hares Droit 1932). In more recent tr ials, thetoxicity of ground seeds has been demonstrated on mice, rats, goats, calves and chicks(Adam and Magzou b 1975; Ahm ed an d Ad am 1979; Liberalino et al. 1988; El-Bad wi et al.1995). In contrast to this, Panigrah i et al. (1984) did not find such drastic poisoning ofmice and rats w ith seeds of Mexican origin.

The results of these feeding trials cann ot be accurately compared because of the dif-ferent origin of the seeds, the preparation of diet, dosage and other factors. The toxiceffects seem to be d ifferent on d ifferent an imal species. Use in animal nut rition is not,therefore, possible without detoxification. Wink (1993) gave indications for detoxifica-tion in laboratory exper iments. How ever, feasibility and profitability have to be provenon a large scale.

Fig. 5. Fatty acid composition of the seed oil ofdifferent seed samples (1 - Sao Tom and Principe(Ferrao and Ferrao 1984); 2 - Paraguay (Matsuno etal. 1985); 3 - India (Banerji et al. 1985); 4 - Pakistan(Nasir et al. 1988); 5 - Cape Verde, Santiago (Ferraoand Ferrao 1981); 6 - Senegal (Heller 1992); 7 -

Cape Verde, Fogo (Ferrao et al. 1982); 8 - Mexico(Aponte 1978); 9 Cape Verde, Santiago (Heller1992); 10 - Brazil, Araatuba, SP (Teixeira 1987); 11- Brazil, Tatui, SP (Teixeira 1987).Sample

Composition (%)


18/66


6 UsesWhole plant and food/fodder

The plant is widely cultivated in the tropics as a living fence in fields and settlements. This

is mainly because it can easily be propagated by cuttings, densely p lanted for this pu rpose,and because the species is not browsed by cattle. According to Bud owski (1987), ph ysicnu t is one of the hedge plants frequently found in certain regions of El Salvador. It is alsoone of the main trees planted in Up per Gu inea as a hedge (Diallo 1994). In Mali, there areseveral thousand kilometres ofJatropha hedges and the Cotton Marketing Authority ofMali is planning to establish new hedges (Fig. 3c; Lutz 1992; Henning and von Mitzlaff1995). Physic nut is also quite comm on in Burkina Faso (Zan 1985). In Cape Verde, physicnu t was recently planted in arid areas for soil erosion control. Of a total area of 1386 haplanted with trees (such asAcacia, Parkinsoniaand Prosopis) in 1989, 5.4% were p hysic nut.

It also formed 14.6% of the total area of 4462 ha reforested in 1990 (Van den Bergh 1985;Spaak 1990). In Madagascar, it is used as a support plant for vanilla. The wood w as usedas a (poor quality) burning material in Cape Verde. In a green manu re trial with rice inNepal, the application of 10 t of fresh physic nut biomass resulted in a yield increase of11%, compared with 23% with Adhatoda vasica, 17% with Albizzia lebbekand 14% with

Hdarrhwa antidysenteria. Unfertilized rice had a yield of 4.11 t/ ha (pad dy) (Sherchan et al.1989).

Duke (1985), citing Ochse (1931), says that the young leaves may be safely eaten w hensteamed or stewed. In the literature, it is reported that the physic nu t seed is eaten in

certain regions of Mexico once it has been boiled and roasted (Aponte 1978; Panigrahi et al.1984; Delgado and Parad o 1989; Martinez 1994, pers. comm .). According to analyses car-ried out by Wink, the Mexican seeds do not contain phorbol esters. Levingston and Zamora(1983) report that the seeds are edible, once the embryo has been removed. It seems thatseeds of Mexican origin have less toxic content so that, with p roper processing, the seedscan be eaten. Consum ption of processed seeds of other origin shou ld on p rinciple beavoided. Many cases of poisoning with physic nu t are reported in the literature (Siegel1893). Lipp mann (1913) described in detail the medical find ings of two workers who ate30 to 40 physic nu t seeds. Abdu-Agu ye et al. (1986) described the poisoning of tw o chil-dren who accidentally ingested seeds and Joubert et al. (1984) reported a similar case inSouth Africa.

Physic nut plants are planted around houses to guard against misfortunes in the south-east of Piaui (Brazil) (Emperaire and Pinton 1986). Jatropha curcas (and Erythrophleumguineense) was used in supernaturally guided ordeals by the Shambaa in Usambara todetermine the guilt or innocence of the accused. Accused persons had to consum e thepoison; the innocent vomited whereas the gu ilty died (Fleuret 1980).

Medicine

Preparations of all parts of the plant, including seeds, leaves and bark, fresh or as a

decoction, are used in trad itional med icine and for veterinary pu rposes. The oil has astrong pu rgative action and is also widely used for skin d iseases and to soothe p ain suchas that caused by rheum atism. A decoction of leaves is used against cough and as an


19/66


antiseptic after birth. Branches are used as a chewing stick in Nigeria (Isawumi 1978).The sap flowing from the stem is used to arrest bleeding of wound s. Nath an d Du tta(1992) demon strated the woun d-healing p roperties of curcain, a proteolytic enzym e iso-

lated from latex. Latex has antimicrobial prop erties against Staphylococcus aureus,Es-cherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes an d Candida albicans (Thomas1989). Kone-Bamba et al. (1987) demon strated the coagulating effects on blood p lasma.Other uses in trad itional medicine are described in the following sources: Irvine (1961),Persinos et al. (1964), Kerharo and Adam (1974), Quisumbing (1978), Levingston andZamora (1983), Co and Taguba (1984), Duke (1985), Gupta (1985), Oliver-Bever (1986),Elisabetsky and Gely (1987), Lentz (1993) and Manandhar (1995). Further scientific re-search confirmed the effects described above in trials. Extracts from p hysic nut fruitsshowed pregnancy-terminating effects in rats (Goonasekera et al. 1995). The au thors

suggested further stud ies to elucidate wh ether the embryotoxic effect is due to a specificaction or a result of general toxicity. Muanza et al. (1995) foun d that a methanol extractof physic nut leaves afforded mod erate protection for cultured hu man lymphoblastoidcells against the cytopathic effects of hu man imm unod eficiency virus. Extract of theleaves showed p otent cardiovascular action in gu inea pigs and might be a p ossible sourceof beta-blocker agent (Fojas et al. 1986).

Plant protectant and molluscicide

Accord ing to a survey by Grainge and Ahmed (1988) on p lants with insecticidal prop er-

ties, extracts from all parts of the physic nu t show such p roper ties. The seed oil, extractsof physic nut seeds and ph orbol esters from the oil were used to control various pestswith, in m any cases, successful result. Table 2 show s a list of insects which were givend ifferent p reparations. As these trials are still in the experimental stage, the oil or ex-tracts cannot yet be u sed by farmers as plant p rotectants.

Aqueous extracts of physic nut leaves w ere effective in controlling Sclerotium sp., anAzollafungal pathogen (Garcia and Lawas 1990). In laboratory experiments, ground p hysicnut showed molluscicidal activity against the host of liver fluke ( Lymnaea auriculariarubiginosa), a disease which is widely distributed in the Philippines (Agaceta et al. 1981),and also against the hosts ofFasciola giganteaand Schistosomia in Senegal (Vassiliades 1984).Extracts from crushed whole seeds showed m olluscicidal activity against several schisto-some vector snails (Liu et al. in press; Rug et al. 1996). Phorbol esters were probably theactive agents in the different extracts used .

How ever, it should be pointed ou t that the physic nu t is a host for cassava virusesthat can be transmitted . Mnch (1986) states that cassava sup erelongat ion disease(Sphaceloma manihoticola/ Elsinoe brasiliensis) can be transmitted from the physic nut.Another Jatropha species,J. multifida, is an alternate host p lant for African Cassava Mo-saic Virus (ACMV), wh ich is transm itted by w hiteflies (Bemisia tabaci) in Ind ia and Eastand West Africa (Okoth 1991). It can be assumed that th is also app lies to physic nu t.

Since this plays an importan t role in disease epidemiology, physic nut should not beused to fence in cassava fields. Physic nu t is considered a potential weed in the NorthernTerritory of Australia because of its distribution throu ghou t the w orld, the toxicity of its


20/66


Table 2. Pesticidal properties of various seed extracts.

Insect Pest of Preparation Reference

Helicoverpa armigera cotton acetone extract of seeds; Solsoloy et al. (1987)

aqueous extract from oil; Solsoloy (1993)

seed oil Solsoloy (1995)

Aphis gossypii cotton aqueous extract from oil; Solsoloy (1993)

seed oil Solsoloy (1995)

Pectinophora gossypiella cotton aqueous extract from seed oil Solsoloy (1993)

Empoasca biguttula cotton seed oil Solsoloy (1995)

(syn. Amrasca biguttula)

Phthorimaea opercullela potato seed oil Shelke et al. (1985)Callosobruchus maculatus pulse seed oil Jadhav and Jadhav (1984)

Callosobruchus chinensis mungbean seed oil Solsoloy (1995)

Sitophilus zeamays corn seed oil Solsoloy (1995)

Manduca sexta ? phorbol esters Sauerwein et al. (1993)

Sesamia calamistis sorghum oil and phorbol esters Henning 1994

seeds, related p lants and its control (Crothers 1994). It is spread by seeds on rocky slopes

in Cape Verde, thus creating d ense stands. In un cultivated lands, it is a potential weed.

Technical uses

In form er times, the seed oil was used m ainly for soap prod uction. Because of grow inginterest in extracting seed oil in Cape Verde, several studies were carried out to assessthe feasibility of setting up oil-extraction plants (Esteves 1960; Andrade 1978; Cossel etal. 1982). The Cossel et al. (1982) stud y was carried ou t for GTZ which, at that time, wasrun ning a p roject on integrated d evelopm ent measures on the island s of Fogo and Brava,and the oil-extraction plant w ould have been an integral part of a soap-production facil-ity. Since the soap factory w as not considered to be competitive, this part of the projectwas n ot furth er pu rsued . In spite of the positive economic conclusions of Portugu esestud ies (Esteves 1960; And rad e 1978), none of the plans were p ut in to practice. Soap isprod uced in an indigenous w ay today in Mali, where oil is boiled with a sod a solution(Fig. 3d and e; Hen ning 1994). The laborious process, which uses a basis of groundseeds, is described by Freitas (1906). Research carried out by the Tata Oil Mills Co. Ltd.,Bombay has show n that with a mixture of 75% hyd rogenated ph ysic nu t oil, 15% refinedand bleached p hysic nu t oil and 10% coconu t oil, a soap can be p rodu ced with latheringvalues equivalent to their regular p rodu ction line toilet soap. Hard ened p hysic nu t oilcould be a satisfactory su bstitute for tallow or harden ed r ice bran oil (Holla et al. 1993).

Seed oil can be extracted either hydrau lically using a p ress or chemically using sol-vents. Chemical extraction cannot be achieved on a small-scale basis. Several types ofmechan ical equipm ent are available: screw presses (han d- or engine-pow ered), spindle


21/66


presses and hydraulic presses, which are distributed widely throughout developingcountr ies for the extraction of seed oils for nu trition purposes. Hydrau lic presses arewidely used for shea nut processing in West Africa. A consulting grou p of the Protestant

Church of Germany (FAKT), in collaboration with organizations in India and Nepal,improved th e oil expeller commonly used in South Asia (based on the model no. 1 byAnd erson, dated 1906). The main aims of this project were:

q to reduce the weight of the machines (important for transportation in remoteareas of Nepal)

q to mod ernize the techn iques used; to enhance oil recoveryq to make use of other oil seeds for extraction.Seven machines are now being tested in Nep al und er field conditions and a man u-

facturing facility has been installed. The so-called Sund hara oil expeller was also tested

for processing p hysic nu t (Fig. 3f). The extraction rate was 47.2, 82.0 and 88.9% for thefirst, second and third pass respectively, withou t shelling of seeds. The oil content of theseeds was 34.5% (FAKT 1992, no d ate). With solven t extraction , 95 to 99% of the totalavailable oil can be obtained .

Diesel fuel

As early as 1911, Rudolf Diesel, wh o inven ted the d iesel engine, mad e the followingstatement in a letter: It is generally forgotten, that vegetable and animal oils can beused d irectly in d iesel engines. A small diesel engine ran ... w ith peanut oil du ring the

world exhibition of Paris in 1900, and which worked so exceptionally well, that thechange of fuel w as realized by only a few visitors (Kiefer 1986). In experimen ts car-ried ou t un til 1950, vegetable oils were used w ithou t problem in comm on engines w ithprecham ber injection. Henning and Kone (no da te) reported activities involving theuse of physic nu t oil in engines in Segou , Mali dur ing World War II.

Since the oil crisis of the 1970s and recognition of the limitations of world oil re-sources, this technology has received special attention. Most of the research w as carriedout in temperate regions with the aim of making available to farmers possibilities ford iversifying in view of the increasing subsidy-driven su rpluses in traditional comm odi-ties. Another argumen t for the cultivation of oil crops for energy purposes is the increas-ing global warming/ greenhouse effect. When these fuels are burned, the atmosphere isnot polluted by carbon dioxide, since this has already been assimilated du ring the growthof these crops. The CO

2balance, therefore, remains equ able.

Special interest has been shown in the cultivation of physic nut for this purpose,especially since it is drou ght resistant an d can p otentially be used to p rod uce oil frommarginal semi-arid lands, without competing with food p rodu ction. In add ition, thesefuels can be used p artly to substitute costly oil imp orts for land locked coun tries. Theuse of physic nut seed oil in car engines is reported in the literature (Mensier andLoury 1950; Cabral 1964; Takeda 1982; Ishii and Takeuchi 1987) and in unpublished

research repor ts. A GTZ experiment in the Cape Verde Islands to pow er engines withph ysic nu t seed oil failed. This was du e to misman agement by workers wh o incor-rectly used the oil as a lubr icant in an engine, which was destroyed . How ever, the


22/66


direct injection Elsbett engine p erformed well dur ing long-term experiments. Recently,GTZ launched another project to show the feasibility of (physic nut oil) productionand use in several stationary engines und er field conditions in Mali (Fig. 3g). In a

former GTZ project carried ou t in Mali, it has been demon strated that p hysic nut oil iscompetitive w ith imp orted d iesel, especially in remote areas, wh ere fuel is often notavailable (Lutz 1992; Appropr iate Technology Intern ational, concept pap er Mali veg-etable motor fuel p rod uction).

A wide array of technical options is available for using vegetable oil in diesel en-gines. The filtered oil can be u sed d irectly in man y suitable engines (Deutz, Hatz, IFA,Elsbett, DMS, Farym ann and Lister-type (Ind ia)). These includ e, apart from p recham berinjection, direct-injection engines which can be used in a stationary way to drive millsand generator s or in vehicles. All the engines were tested in long-term experiments with

different vegetable oils, includ ing p hysic nu t oil (Lutz 1992; Pak and Allexi 1994).Transesterified oil can be u sed in any d iesel engine. This process is norm ally carried

out in centralized plants since the small-scale economy of transesterification has notbeen determ ined. Dur ing the process, methanol, a highly flamm able and toxic chemical,has to be used. This requires explosion-proof mixing equipm ent which m ight not al-ways be available in certain developing countr ies. An Austr ian-fund ed p roject in Nica-ragua is constructing a p lant that aims to p rodu ce 1600 t of methyl esters annu ally at acost of US$0.74 per gallon. G.F. van Grieken (unpublished ) assessed the energy effi-ciency of the methyl ester prod uction process of ph ysic nu t and found that th e efficiency

of the EMAT (Ester Metilico de Ester et de Tempate) process is high, with an energyinpu t:outp ut ratio of 1:5.2. Ou edraogo et al. (1991) compared the performance oftransesterified rap eseed and physic nu t oil in diesel engines. Their results showed thatneither of these fuels can be claimed to be sup erior.

A recent d evelopment is the Schur Diesel where vegetable oil (80%), petrol (14%),alcohol (6%) and a certain am ount of an unkn own comp onent are mixed. This fuel canbe used in all Diesel engines (Lutz 1992; Anon . 1993). However, owing to the un avail-ability of petrol and alcohol in rural areas of developing coun tries, this process might notyet be applicable for such areas.

In general, it w ould app ear that the technological basis p resents no p roblems andhas been resolved. Economic analyses have d emonstrated that p hysic nu t fuel can com-pete w ith Diesel fuel in villages in Mali (Demant and Gajo 1992; Henning and von Mitzlaff1995).

Other uses

The press cake cannot be u sed in anim al feed becau se of its toxic prop erties, bu t it isvaluab le as organic ma nu re since it has a nitrogen content sim ilar to th at of the seedcake of castorbean and chicken manu re. The nitrogen conten t ranges from 3.2 to3.8%, depending on the source (Juillet et al. 1955; Moreira 1970; Vhringer 1987).

Freitas (1906) reported on trials with physic nut seed cake used on wheat at theEstacao Agronomica d e Lisboa from 1871 to 1872. Moreira (1970) ap p lied physic nu tseed cake at different rates to d ifferent crops in p ots and in field trials. Ap plications


23/66


showed ph ytotoxicity, expressed as red uced germ ination, wh en high r ates of up to5t/ ha w ere app lied. Phytotoxicity to tomatoes seeded in the field w as reduced byincreasing th e time difference betw een app lication an d seed ing.

The GTZ project in Mali carried out a fertilizer tr ial with p earl millet where the effectof manu re (5 t/ ha), physic nu t press cake (5 t/ ha) and mineral fertilizer (100 kg amm o-nium phosphate and 50 kg urea/ ha) on pearl millet was investigated. Pearl millet yieldsper ha w ere 630 kg for th e control, 815 kg for m anu re, 1366 kg for p ress cake and 1135 kgfor minera l fertilizer. As the costs for mineral fertilizer were higher than those for thepress cake, the rentability w as 30000 FCFA (US$60) higher for the latter (Henn ing et al.1995).

Fruit hulls and seed shells can be u sed as a burn ing material.Figure 6 sum marizes the mu ltiple utilization possibilities of the physic nut.

The case of the GTZ p roject in Ma li w ill be used to demon strate the econom ic ben-efits of ph ysic nu t cultivation. The Jatropha system is based on existing hedges thatwere used to fence in fields and to control erosion. The project prom otes this systemby creating a market for physic nu t prod ucts. Sma ll, simp le han d- or engine-driven oilpresses were installed to p rodu ce oil that can be used to dr ive stationary eng ines. Theseengines d rive grain mills, water pu mps or the oil press itself. The oil is also a rawmaterial for soap prod uction that generates income to local women p rodu cers. Thepress cake is app reciated by farm ers and can be sold for 10 FCFA per kg (US$0.02/ kg).Econom ic analysis has show n th at p hysic nut can be p rod uced at a p rice of 215 FCFA

(US$0.63) (includ ing all costs), which is 78% of the official d iesel pr ice. Henn ing (1996)gives a d escription of an economic calculation for th ree different p rocessing an d usesystems: (1) a hand-operated Bielenberg p ress with a capacity of approximately 10t of seed p er year, (2) a Sun dhara press d riven by an Ind ian-built Lister-type engine,and (3) a Sun dh ara press driven with a Hatz engine. Internal rates of return w erecalcu lated a s 75, 49 and 26%, respectively. The pr imary aim of this project is not to u seph ysic nu t oil as a fuel, but rather to u se this imp ortant element to prom ote the cyclesystem, w hich combines ecologic, econom ic and income-generating effects (Hen ningand von Mitzlaff 1995). The macro-econom ic analysis, which took into considerationboth the su bstitution value of the oil as a d omestic fuel, and the ind irect effects (ero-sion control, press cake as fertilizer, etc.), showed an economic rate of return of 135%(Henn ing 1996). People started p lanting new hedges. A sur vey carried out by theproject has show n th at the length of hedges in th e zone of Falan increased by 20% andby 40% in the zone of Kita rep ectively, from 1994 to 1995 (Hen ning, per s. comm .).


24/66


Fig. 6. Different forms of physic nut utilization (modified from Kiefer 1986).

Whole plant- Erosion control- Hedge plant- Medicinal uses- Plant protectant

- Fire wood- Green manure- Combustibles

Jatropha curcas

Fruits Fruit hulls

Combustibles, green manure

Seeds Seed shells- (Food/fodder)

Seed oil Seed cake- Soap production - Manure- Fuel - (Fodder)- Medicinal uses


25/66


7 Genetic resources

Existing genetic variation

So far, only four records of systematic provenance trials exist where an attempt was

mad e to examine the genetic variation of the p hysic nut.Sukarin et al. (1987) did not observe any m orp hological differences between 42 clones

originating from d ifferent locations in Thailand and planted in a p rovenance trial at theKhon Kaen Field Crop s Research Center. Differences in vegetative development andfirst seed yields were not reported.

Adap tive trials on J.curcas an d J. gossypiifolia were u nd ertaken at Hisar, Bangaloreand Sardar Krush inagar in Ind ia (Bhag Mal, pers. comm.). The evaluation of five culti-vars revealed a good d egree of variation for plant height, branches per plant an d seedyield per p lot at Hisar. Quite high seed yields (1733 kg/ ha) were observed in one culti-

var when two physic nu t cultivars and J. gossypiiflora were compared. At Bangalore, thetwo species were comp ared on ly for plant height. In all these trials, only local Ind iantypes were used.

In Northern Nicaragua, an Austrian-funded project enabled p lanting of 1200 ha withNicaragu an and Cape Verde provenances. These two types looked d ifferent in the field:the Nicaraguan typ e has a less branched habit, larger paler leaves and bigger seeds, whereasthe Cape Verde provenance produ ced h igher seed yields. In the Nicaraguan material, amale sterile plant was observed which p rodu ces more fruits than the herm aphrodite types.Male sterile plants w ill facilitate breeding efforts for higher seed p roduction (Foidl, pers.

comm.). The yield differences between the Cape Verde and Nicaragu a types are beinganalyzed (Thierolf, pers. comm .).

Table 3. Origin of seed provenances (provenance number used in Figures 6 and 7

in parentheses) and climatic data of collecting sites (Heller 1992).

Origin of provenances Altitude Average Average annual

(m) temp. (C) rainfall (mm)

Cape Verde, Fogo (1) 150-1600 19-25 200-1000

Senegal, Santhie Ram (2) 15 28 700

Ghana, Nyankpala (3) 183 27.8 1080

Benin, Cotonou (4) 7 25.3 1330

Burkina Faso, Kongoussi (5) 300 ? 520

Kenya, Kitui (6) 1020 28? 790

Tanzania, Mombo (7) 430 >20 670

Burma, Sink Gaing, Mandalay (8) 80 27 825

India, Kangra (9) 580 ? ?

India, Kangra(10) 434 11-38 ?

India, Poona (11) 556 24.6 672Costa Rica, Rio Grande (12) 10 27.5 2000

Mexico, Veracruz (13) 16 24.8 1623


26/66


In 1987 and 1988, Heller (1992) tested a collection of 13 provenances in multilocationfield trials in two coun tries of the Sahel region: Senegal and Cape Verde. The two loca-

tions in Senegal, Samba Gueye and Toubacouta, lie north of the border with The Gambia,in the Departm ent of Fatick. On Cape Verde, the trials were conducted on the island ofSantiago a t Sao Jorge and Tarrafal (Chao Bom). The sites have a sem i-arid climate, w itha short r ainy season (app roximately 4 months) and a longer d ry season of approximately8 month s with a w ide var iation in rainfall (200-800 mm). Table 3 show s the origin of theseed provenances used and the climatic data for the locations. Provenan ces originatedfrom d ifferent coun tries in Nor th an d Central America, West and East Africa, and Asia.As seeds from Mexico and Costa Rica were not available in 1987, these w ere comparedwith the Senegal provenance in a sep arate trial in 1988.

Vegetative development was evaluated at each location and was seen to vary greatly(Table 4). Significant differences in the vegetative development were detected among thevarious provenances at all locations. Plants of various provenances appeared very uniformas to morphological characters (such as leaf shape) (Heller 1992).

The paired calculation of both provenance trials in Senegal (at Toubacouta and SambaGueye) showed that genotype-environment-interaction (GxE) was significant for all pa-rameters, that is to say, the environments exerted a specific influence on certain prov-enances. Plant heights at 3.6 months after planting (MAP) are given as an example. Figure7 indicates how provenances reacted differently to the environm ents. The two locations

are situated at a d istance of only 19 km from each other. The rainfall conditions can, there-

Fig. 7. Genotype-environment-interaction:Plant height (cm) of

provenances at SambaGueye and Toubacouta,3.6 MAP (for provenancessee Table 2).

Plant height (cm), 3.6 MAP

Site


27/66


fore, be considered near ly identical. The Toubacouta location show ed better soil proper-ties than the Samba Gueye location, to which some provenances reacted specifically. OnCape Verde, GxE was not significant, with the d ifferences between the tw o sites probably

greater than in Senegal.

Table 4. Descriptive statistical values of phenological traits and yield and yield

components for 11 provenances evaluated in Samba Gueye, Senegal (Heller 1992).

Character Min. Max. Mean SE1 CV2

Vegetative development

Plant height (cm), 3.7 MAP3 93.4 105.1 98.2 1.8 1.8

Plant height (cm), 10.9 MAP 121.0 135.1 129.9 2.9 2.3Plant height (cm), 15.3 MAP 135.9 155.3 149.8 3.3 2.2

Plant height (cm), 25.3 MAP 152.1 185.2 173.6 4.1 2.3

Stem diameter (mm), 3.7 MAP 43.4 48.4 45.2 0.6 1.2

Stem diameter (mm), 15.3 MAP 69.3 81.7 74.7 1.8 2.4

No. of branches/plant, 3.7 MAP 3.3 4.5 4.2 0.3 6.8

No. of branches/plant, 15.3 MAP 4.9 6.3 5.5 0.2 3.8

Average length of branches/ plant (mm) 257.9 503.5 416.5 26.7 22.3

Generative development (7.9 MAP)

No. of capsules/shrub 4.86 9.30 6.72 1.14 17.01Wt. of capsules/shrub (g) 3.58 15.00 11.00 1.99 17.81

Wt./capsule (g) 1.52 1.92 1.66 0.09 5.56

No. of seeds/shrub 3.84 19.58 13.71 2.38 17.34

Wt. of seeds/shrub (g) 2.40 9.60 6.72 1.30 19.37

1000-seed weight (g) 417 575 494.4 22.60 4.60

No. seeds/capsule 1.90 2.15 2.05 0.09 4.36

Prop. seeds capsule (%) 57.70 65.40 60.90 1.90 3.10

Shrubs with yield, (%) of survived 48.0 93.3 81.80 5.60 6.90

Generative development (25.3 MAP)

No. of capsules/shrub 0.20 9.00 3.91 1.61 41.11

Wt. of capsules/shrub (g) 0.52 15.72 6.09 2.90 47.54

Wt./capsule (g) 1.38 1.75 1.52 0.09 6.14

No. of seeds/shrub 0.60 17.80 6.98 3.29 47.11

Wt. of seeds/shrub (g) 0.32 9.22 3.48 1.69 48.55

1000-seed weight (g) 476 525 490.6 23.90 4.90

No. of seeds/capsule 1.55 1.96 1.75 0.10 5.67

Prop. seeds capsule (%) 53.50 59.60 56.60 1.70 3.10

Shrubs with yield, (%) of survived 20.40 94.50 71.40 6.80 9.50

1 SE = standard error.2 CV = coefficient of variation.3 MAP = months after planting.


28/66


No interaction could be tested between provenances at all four locations, due to the greatdifferences in precultivation between Senegal and Cape Verde. The absolute growth heightcannot, therefore, be used as a parameter to characterize specific adaptation of provenances to

test sites. The provenances were ranked w ith regard to plant height (Fig. 8). The variouslocations can be grad ed according to their positive action on growth. Certain provenancesindicated good or bad adaptation to certain sites (Fig. 8).

Yield and yield comp onents were analyzed at Samba Gueye, 7.9 and 25.3 MAP. Param -eters showed a wide variation (Table 4). No significant d ifferences were determ ined for theparameters of weight per capsule (7.9 and 25.3 MAP), number of seeds per capsule andproportion of seeds in the capsule (7.9 and 25.3 MAP) and no d ifferences were found in the1000-seed w eight at the second harvest (25.3 MAP). In the rest of their yield param eters(number and w eight of capsules per shrub, number and weight of seeds per shrub (at 7.9 and

25.3 MAP) and 1000-seed w eight at 25.3 MAP), provenances differed significantly. Plants onCape Verde d id not reach the generative stage. This was d ue to both the lower rainfall andthe insufficient precultivation period.

With both harvests, the seed yield p er shru b w as very low, with a m aximu m of 9.6 gfor the p rovenance Benin at 7.9 MAP and 9.2 g for the p rovenan ce Burkina Faso at 25.3MAP. The provenan ce Burma showed lowest seed yields, combined w ith best vegeta-tive developm ent. The low yields at 25.3 MAP may have been du e to high p recipitation

Fig. 8. The ranking of provenances by plant height at trial locations after the first rainy season, 3.3 MAP(for provenances see Table 2).

Ranking (plant height), 3.3 MAP

Provenance

Toubacouta Samba Gueye Sao Jorge Tarrafal


29/66


in the previous rainy season, which may h ave caused strong vegetative development atthe expense of seed y ields. Yields, on a hectare basis, were very low. None of the prov-enances tested in Hellers trials reached the values reported for Thailand by Sukarin etal. (1987) and Stienswat et al. (1986).

The contents of the original seed and h arvest at Toubacouta were determ ined. Thecrude fat content is an important component of the oil yield per hectare; crude fibreand protein content are of imp ortance for eventual u se as seed cake in animal nu tri-tion, as are cru de protein an d mineral conten t (P, Ca, Mg, Na and K) for utilization asfertilizer. With all par am eters determined , analytic results showed a w ide range be-tw een the d ifferent provenan ces. Crude fat content of the original seed ranged from28.4 to 42.3%, with that of the h arvest at Toubacouta v arying between 23.2 and 38.3%(Table 5). On average, these values are in accord ance with those determ ined by Ferrao

and Ferrao (1981, 1984) and Ferrao et al. (1982) for sam ples from Cap e Verd e (Fogo an dSantiago) and Sao Tom an d Principe.

Table 5. Composition (%) of seeds (dry matter) of the original seed and one harvest

at Toubacouta of 13 provenances (Heller 1992).

Character Min. Max. Mean SE1 CV2

Original seed

Crude fat 28.4 42.3 35.6 - -Crude fibre 24.4 30.8 28.2 - -

Crude protein 13.7 22.4 19.0 - -

Ash 3.6 5.2 4.6 - -

P 0.45 0.76 0.61 - -

Ca 0.27 0.80 0.47 - -

Mg 0.36 0.46 0.42 - -

Na 0.021 0.057 0.040 - -

K 0.74 1.39 1.03 - -

Harvest at Toubacouta

Crude fat 23.2 38.3 31.9 - -

Crude fibre 25.1 35.8 31.4 - -

Crude protein 12.4 20.0 15.9 - -

Ash 4.2 5.7 4.9 - -

P 0.54 0.68 0.65 - -

Ca 0.43 0.66 0.55 - -

Mg 0.39 0.45 0.44 - -

Na 0.054 0.22 0.118 - -

K 0.70 1.22 0.97 - -

1 SE = standard error.2 CV = coefficient of variation.


30/66


The calculation of correlations of the different p aram eters for the harvest at Toubacoutashow ed significant correlations between nearly all parameters. A highly significant posi-tive relationship exists between the 1000-seed w eight, cru de fat and crud e fibre content,

wh ile the 1000-seed w eight correlates negatively with crud e fibre and ash content. Ferraoand Ferrao (1984) found highly significant correlations between seed samples from SaoTom and Principe for the 1000-seed weight and percent of crude fat content.

These provenance trials show, even in this limited survey, phenotypic variation. Theselection, however, was probably too small as provenances from the centre of originwere not well represented. In add ition, the time frame was too short for an assessmentof the yield p otential of the ph ysic nu t. The seeds u tilized in the trials could not becollected by H eller him self at the locations. Collectors w ere requested to collect from aminimu m of four healthy plants, representative of the popu lation. How ever, this could

not be verified. Accord ing to Burley and Wood (1976), samp les should be collected froma larger num ber of trees. Thus, the samp les received for the trials should not be consid -ered representative of the popu lation.

Nevertheless, some interesting aspects were evident. By recording vegetative devel-opment, Heller (1992) discovered the existence of genotypes specifically adapted tomarginal cond itions or wh ich show strong vegetative growth du ring youth. This couldbe of importance for establishing pioneer vegetation on very marginal sites, as well asplantations to control erosion and sup ply m ulching m aterial, withou t considering seed-production aspects. The first seed yields were very low, but showed a great range. Long-

term d eterminations are necessary, however, to estimate the yield potential. Differencesin the 1000-seed weight of provenances cultivated at the same location were slight,whereas crude fat contents varied greatly. Significant positive correlations between the1000-seed weight and percentage of crude fat content indicate interesting possibilitiesfor selection, if genotypes exist where these are combined w ith high y ields. The variabil-ity of the toxic contents of the p rovenan ces was not examined in th ese trials. Recentresearch by Becker (pers. comm .) confirmed the variability in toxic contents.

Conservation of physic nut

Physic nu t is conserved in only three institutions. Three provenan ces from Costa Ricaare maintained as field collections at the CATIE, Costa Rica. The Centre National deSemences Forestires (CNSF) in Burkina Faso has 12 provenan ces from Burkina Fasoun der med ium-term storage cond itions (see Append ix I). These w ere collected mainlyfrom tw o areas in Burkina Faso. The INIDA, Cape Verde still maintains the field collec-tion established as a p roven ance trial by H eller (1991) in 1987 (Jose G. Levy 1996, pers.comm.). The existing genetic variation of physic nu t is not rep resented in the collections,as the centre of origin is represented w ith only five provenan ces from tw o countr ies.

Physic nut is conserved on -farm in the centre of origin and other regions, because itis used as a hed ge. As this cultivation system d oes not seem to change, it can be assum ed

that genetic erosion is not imp ortant at p resent. It is questionable wh ether there is anyneed to conserve more p rovenances ex situ. However, there is no survey on the extent towhich existing diversity is maintained in hedges. As the centre of origin still has to be


31/66


ascertained and th e diversity in these areas to be assessed, strategies for in situ conserva-tion cannot yet be d eveloped .

Germplasm used in afforestation programmes in different countries (India, Mali)

uses only locally available material. By doing so, good oppor tunities migh t have beenmissed for u sing material with h igher yield potential or w ith more desirable characteris-tics.

Seed storage behaviou r of Euph orbiaceae is generally orthod ox according to Ellis etal. (1985) (one exception beingHevea). Orthod ox seed storage behaviour means Maturewhole seeds not only survive considerable desiccation (to at least 5% moisture content)but their longevity in air-dry storage is increased in a predictable way by reduction inseed storage moisture content and temp erature (e.g. to those values employed in long-term seed stores) (Hong et al. 1996). Physic nut also has orthodox seeds. Two- or six-

mon th-old seeds received for the provenance trials d escribed above, were stored in un-sealed plastic bags at ambient temp eratu res (approximately 20C) for 5 mon ths and ger-minated on average by 62% (ranging from 19 to 79%) after hav ing been seeded in soil.When stored for 7 years in plastic bags (not sealed) at a temperature of approximately16oC, the seeds still show ed an average germ inating capacity of 47% (ranging from 0 to82%) wh en tested with the between p aper m ethod (Heller, pers. comm .). When theseeds w ere analyzed for their chem ical comp osition after 3 years of storage, they had amoisture conten t of 6.2% (average of all provenances).

Kobilke (1989) investigated the viability of seeds of different ages (1 to 24 months)

that w ere collected d irectly from th e sites or stored for a certain time. Seeds older th an15 mon ths show ed viabilities below 50%. One explanat ion for this rap id decrease is thatthese seeds remained at the site, having been exposed for long periods to extreme changesin levels of hu mid ity and temp erature.

High levels of viability and low levels of germination shor tly after harvest ind icateinnate (=pr imary) dorm ancy. This behaviour has also been reported for otherEuphorbiaceae (Ellis et al. 1985). Kobilke (1989) also tried to break induced dorm ancy.Intervals of presoaking and drying or p artial removal of the testa p roved m ore success-ful than p resoaking alone.


32/66


8 BreedingBreeding objectives

Breeding objectives will depend on use. Oil yield w ill, in m ost cases, be the m ost impor-

tant part of physic nu t cultivation. Components that contribute to physic nu t oil yieldper hectare are: nu mber of pistillate flowers per inflorescence and subsequen t num berof capsules per shrub, number of seeds per capsule, 1000-seed weight, oil content ofseeds (%) and plants per hectare. As the maximu m nu mber of seeds per capsule islimited and the agron omic factor of plant ing density does not offer much flexibility forincreasing yields, selection shou ld focus on th e other yield comp onents.

Ferrao an d Ferrao (1984), and later H eller (1992), foun d highly significant correla-tions in different seed samples between the 1000-seed weight and percent of crude fatcontent. This might be interesting from the breeders point of view, as simp le selection

for high 1000-seed w eight could imp ly increased crud e fat contents. From this, it cannotbe conclud ed th at shru bs which p rodu ce seeds of a high 1000-seed w eight, and conse-quently a higher crude fat content, will yield more oil per h ectare. A high 1000-seedweight can also be the consequence of a low seed yield per shrub. Further research onthis is required.

Other important objectives are reduced plant height to facilitate harvesting of cap-sules and development of non toxic cultivars, where the seed cake could be used asfodder.

Breeding methodAs the p hysic nut is a cross-pollinated crop, any genetic imp rovement h as to be based onpop ulations. Mass selection would be the simp lest breeding method , wh ere sup eriorselected p lants are comp osited. Popu lations can be stepw ise improved if they remainlarge, so that ad ditive genetic variation can be used . The method of recurrent selection iswidely used in forest tree breeding. This involves concurrent cycles of selection w ith orwithou t progeny tests. There are possibilities for the breeder to modify the method . Inaddition, hybr id cultivars could be bred to use the heterosis effect. The existence of malesterile cultivars as repor ted by Foidl (pers. comm.) would facilitate crossings.

Dehgan (1984) found that em asculation was n ot necessary for hybridization in theinsect-free greenhou se. The reason for this was the absence of insect vectors and thetime lag of anth esis of staminate flowers. The standard rou tine of bagging shou ld besufficient in the field. However, to avoid self-pollination if staminate and pistillateflowers were to open simultaneously physic nut is self-compatible emasculationcould be requ ired. This can be achieved very easily as staminate and p istillate flowerslook very d istinct. Dehgan s (1984) extensive trials on intersp ecific hybridization wereaimed at investigating p hylogenetic affinities inJatropha. The find ings on the cross-ability of 20 species in th e tw o subgenera are very in teresting if such crossings w eredesired for breeding . All F

1hybrids, except J. curcas x multifida, were m ore vigorous

than the parental species. In most of the successful crossings, the physic nu t was in-volved as the maternal parent and barriers to interspecific compatibility with other

Jatropha sections are d emonstrated.


33/66


Selection based on provenance trials

The aim of a provenance trial is to estimate the d ifferences between p opu lations or envi-ronm ents relative to their produ ctivity. This is often p ursued to prod uce a base pop ula-tion for breed ing. Burley and Wood (1976) describe exact m ethod s for forest trees in theirManual on species and provenance research with particular reference to the tropics.These method s are no dou bt also app licable to shrubs such as physic nut, although thetest ph ases are shorter. Species and p rovenance trials contribute fund amental informa-tion for large-scale afforestation in th e tropics. At p resent, there is no alternative to suchtrials on rep resentative sites (Bur ley and Wood 1976). Afforestation on the basis of prov-enance trials alone can, with certain sp ecies, imp rove p roductivity by 50% (Zobel et al.

1988). Systematic provenance trials at different locations have not yet been carried ou twith the physic nut to the necessary extent, and material from th e centre of origin has notbeen sufficiently screened. The genetic background of the physic nu t grown in Africaand Asia is un clear. It is not know n from w hich genetic basis it derives or how wide thegenetic basis of p lants is in those areas.

Provenance trials are usua lly carried ou t at several sites. Certain proven ances mayd iffer relatively from others if cu ltivated at d ifferent sites, wh ich is d ue to GxE interac-tion. Ranking of families, provenan ces or species can chan ge completely, or a chan ge ofproductivity without inversion of ranking can take place with a change in location

(Namkoong et al. 1988; Zobel et al. 1988). Zobel et al. (1988) described many examp les oftrop ical forest trees, with interaction being significant in som e cases. A GxE interactionalso occurred in trials with physic nu t (Heller 1992). Additional well-planned prov-enance trials wou ld make it possible to select provenances better adapted to local condi-tions.


34/66


9 Production areasThe cultivation of physic nut was of economic importance in Cape Verde. Silveira (1934) esti-mated that 8000 ha w ere planted with physic nut, which represented 12% of the islands total

surface or 16% of their cultivated area. The whole seed production was exported to Lisbon foroil extraction and soap production. Maximum exports from Cape Verde were 5622t in 1910and 4457t in 1955. Exports of seed contributed in certain years for up to 60% of the totalmonetary value of the islands agricultural exports (Fig. 9). Seeds have not been exported since1970, in spite of the fact that old plantations still exist and there has been a new reforestationeffort with physic nut. Apart from Cape Verde, physic nut was cultivated only in some coun-tries of West Africa and Madagascar for seed exports to Marseille. Plantations establishedrecently in d ifferent countries had varying objectives:

q reforestation for erosion control in Cape Verde

q erosion control with h edges and combined oil prod uction (diesel fuel) in Maliq oil prod uction on 10000ha in marginal areas of Ind ia (Patil and Singh 1991).q establishm ent of 1200 ha of physic nu t energy p lantation for prod uction of me-

thyl esters in N icaragu a (Foidl, pers. comm.).

Fig. 9. Export of physic nut seeds from Cape Verde during the period 1900-1970 (Silveira 1934; Grillo 1951).

Exports (t)Mon. value of totalagric. exports (%)

------- Exports (t)

- - - Monetary value (%)

Year


35/66


10 EcologyLike many other Jatropha species, physic nut is a succulent that sheds its leaves duringthe d ry season. It is, therefore, best adapted to arid and semi-arid conditions. Most

Jatropha spp . occur in the following seasonally dry areas: grassland -savanna (cerrad o),thorn forest scrub and caatingas vegetation, but are completely lacking from the moistAmazon region (Dehgan and Schu tzman 1994). The current d istribution of ph ysic nu tshows that introduction has been most su ccessful in dr ier regions of the tropics w ith anaverage annu al rainfall of between 300 and 1000mm. Good examples are Cape Verdeand Mali. Mnch (1986) repor ts that ph ysic nu t even withstood years withou t rainfall inCape Verde. However, it also grows successfully with higher p recipitations.

As physic nut occurs mainly at lower altitudes (0-500 m), it can be concluded th at itis adapted to higher temp eratu res. The areas where it has been collected in the centre of

origin and from wh ere the material was taken for provenance trials show average an-nu al temperatures well above 20C and u p to 28C. Physic nu t withstood slight frost inthe Ch das Caldeiras, Fogo (app roximately 1700m altitude) (Kiefer 1986). It is notsensitive to d aylength.

It grows on well-drained soils with good aeration and is well adap ted to m arginalsoils with low nu trient conten t. On Cap e Verde, the physic nu t is foun d especially in thestony ribeiras i.e. dry stream courses (Fig. 10a), and on rocky slopes w here it is spreadby seeds. In heavy soils, root formation is reduced. Physic nu t is a highly adaptablespecies, but its strength as a crop comes from its ability to grow on p oor, dry sites.

Fig. 10. (a) Physic nut in ribeira, Fogo, CapeVerde; (b) germination; (c) rooting pattern of plants

originating from direct seeding (left), transplantingof precultivated seedlings (top right) and directplanted cuttings (bottom right), approximately 2years old.

a

c

b


36/66


11 AgronomyGrowth and development

With good moistu re conditions, germination needs 10 days (Fig. 10b). The seed shell splits,

the rad icula emerges and four little peripheral roots are formed . Soon after the d evelop-ment of the first leaves, the cotyledons wither up an d fall off. Further growth is sympo-dial. With seeding in the mon th of May, a stem length of 1m w as reached in Thailand after5months of growth (Sukarin et al. 1987). A terminal flower was formed . The authorsobserved two flowering peaks, one in November and the other in May. In permanentlyhumid equatorial regions, flowering occurs th roughou t the year. Fruit developm ent needs90days from flowering un til seeds mature. Further developm ent corresponds to rainyseasons: vegetative growth d uring the rainy season and little increment du ring the dryseason. Old p lants can reach a height of up to 5m. With good rainfall conditions, nu rsery

plants bear fruit after the first rainy season, with d irectly seeded p lants bearing for the firsttime after the second rainy season. With vegetative prop agation, the first seed yield ishigher.

Table 6. Seed yield of the physic nut (per shrub and hectare).

Age Yield

Reference Location (years) Shrub (g) Hectare (kg)

Avila (1949) Cape Verde ? 700-900 n.d.1

Bhag Mal (pers. comm.) India 3 n.d. 1733

Foidl (pers. comm.) Nicaragua ? n.d. 5000

Henning (pers. comm)2 Mali ? n.d. 2640

Ishii and Takeuchi (1987) Thailand ? n.d. 2146

Larochas (1948) Mali ? n.d. 8000

Martin and Mayeux (1984) Madagascar ? 3000-3500 n.d.

Matsuno et al. (1985) Paraguay 3 n.d. 100







Naigeon (1987) Cape Verde ? n.d. 1750

Silveira (1934) Cape Verde ? n.d. 200-800

Stienswat et al. (1986) Thailand 1 318 794

Sukarin et al. (1987) Thailand 1 63.8 n.d.

Zan (1985) Burkina Faso diff. 955 n.d.

1 n.d. = not determined.2 Survey on hedges: 0.8kg seeds per m hedge. Hectare yield assumes a distance of 3m between thehedges.


37/66


Reports in the literature on p hysic nut yields are contrad ictor. Table 6 lists the seedyields per shrub and hectare in d ifferent countries. In most cases, information on the ageand propagation method of the plants, variation between years are missing. At least 2-3t

of seeds/ ha can be achieved in semi-arid areas. The fruit is harvested by hand and fruithu lls and seeds are separated manually. The best pickers in Nicaragua harvest up to 30kgof fruits hou r, which wou ld m ean approximately 18 kg of seeds.

Freitas (1906) repor ted tw o harvest times, correspond ing to the flowering times. Ob-servations of other authors showed that the m ain harvest occurs several month s afterthe end of the rainy season, since flowering is connected to vegetative developm ent. Thephysic nut can reach an age of abou t 50years (Larochas 1948; Taked a 1982).

Propagation methods

Avila (1949) and Freitas (1906) have described several trad itional prop agation m ethod son Cape Verde: d irect seeding, precultivation of seedlings, transplanting of spon taneou swild p lants and d irect planting of cuttings. All possibilities for crop establishment arelisted below (Mnch 1986; Kobilke 1989).

Generative propagation (seeds) Vegetative propagation (cuttings)

q Direct seed ingq Transplanting of precult. plants

* seed bed (bare roots)* container

Factors influencing crop establishment of plants propagated by different methodsare:

Generative propagation (seeds)

q direct seeding seeding dep th, date and quality of the seedq transplanting type an d length of precultivation, planting d ate

Vegetative propagation (cuttings)

q direct p lanting character of cuttings (length, d iameter, age), cu tting time,storage, fungicide treatment, planting time and dep th

q transplanting as with d irect planting of cuttings and precultivation of seeds.

Not all factors are of equal importance. Successfu l precultivation is characterized byhigh germination rates of seeds, high sprou ting rates of cuttings and survival. Basingthe p ropagation m ethod on rainfall cond itions p lays a decisive role in th e survival andproperties of the p lant in the field.

Comparative research on the influence of different propagation m ethods on su rvivaland vegetative developm ent was condu cted by Kobilke (1989) in Cape Verde and by Heller(1992) in Senegal in nearly identical trials. The following methods were tested: direct

q Direct plan tingq Transplanting of precultivated plants

* seed bed (bare roots)* container


38/66


and vegetative development was condu cted by Kobilke (1989) in Cape Verde and by Heller(1992) in Senegal in nearly identical trials. The following methods were tested: d irectseeding; transplanting of bare root plants (precultivated in seed bed or in the wild); trans-

planting of plants with root ball (precultivated in polyethylene bags); transplanting ofprecultivated cuttings and direct p lanting of cuttings.

The survival rate at Sao Jorge, Cape Verde, was significantly h igher than th at obtainedusing correspond ing method s in Senegal. The ranking of various treatments with respectto survival rate did not change for the different locations. Both vegetative cultivation meth-ods and method s of generative precultivation w ere more successful than d irect seeding(Fig. 11). Since interaction w as not significant, the different environm ents had no sp ecificinfluence on the plants p ropagated by d ifferent methods.

Differences in seed yields between different propagation methods could not be de-

termined in th is trial because the observation period w as too short. How ever, in anotherexperiment designed by Heller (1992) in Senegal in 1987, to compare direct seeding,transplan ting of seedlings and d irect planting of cut tings of different d iameters, differ-ences in seed yields w ere detected. The first seed yield of cuttings of >30mm d iameterwas significantly h igher than that of precultivated p lants (Fig. 12). No significant d iffer-ences were found between precultivated p lants and the other two treatments or amongthe cutting treatments. In the second harvest no significant d ifferences could be deter-mined.

In another series of trials, Kobilke (1989) and H eller (1992) investigated the influence

of planting time, cutting length, storage and fungicide application on th e surv ival anddry matter accumu lation of cuttings p lanted d irectly. Thitithanavanich (1985) investi-

Fig. 11. Comparison of survival

rates (%) of plants propagated bydifferent methods at Samba Gueyeand Sao Jorge, 1988 (Kobilke 1989;Heller 1992). Cultivation method

Survival rate (%)


39/66


gated the root formation of physic nut cuttings of different diameters (1, 2 and 3 cm) andlengths (15 and 30 cm) in the nursery bed. Thicker cuttings formed m ore roots than thethinner ones. Cuttings of 30-cm length developed m ore roots and their survival rate was

higher than cuttings of 15-cm length . Narin-Sombunsan an d Stiensw at (1983) show edthat treating cutt ings with IBA (ind ole-butyric acid) horm one d id not p romote root for-mation. The rooting of stem cuttings is influenced m ore by rooting media; good aerationand drainage proved profitable. Accord ing to Hartm ann an d Kester (1983), the follow-ing two factors are generally responsible for sprou ting: the age of the p lant from wh ichcuttings are taken an d the position of the cutting within the plant.

Factors responsible for the su rvival of d irect seeding (seeding time, seeding d epth )were stud ied by Heller (1992). Based on year ly averages, the low survival rates ford irect seeding (19.8%) are striking, whereas the same provenance seeded in polyethyl-

ene bags for provenance trials show ed a germ ination of 68%. The survival rate dependednot only on so

Promoting the Conservation and Use of Under Utilized and Neglected Crops. 01 - Physic Nut

Documents