Utility of grafting in tree domestication with reference to Allanblackia parviflora A. Chev. D. 1\. Ofori ct a!.,

UTILITY OF GRAFTING IN TREE DOMESTICATION PROGRAMME WITHSPECIAL REFERENCE TOALLANJJLAC/(fA PARV/FLORA A. CIIEV.

D. A. Ofori1*; T. Peprah1; S. lIenneh2; J. B. Yon Berg3; Z. Tchoundjeu4;R. Jamnadass 5 and A. J. Simons 5

I Forestry Research Institute of Ghana, Council for Scientific and Industrial Research. P. 0. Box 63,

KNUST, Kumasi, Ghana, Tel. +2335160123, Fax +2335160121, Email: dofori@csir-forigorggh2Nove Development Ghana, P. 0. Box CT 1112, Accra, Ghana.

31nternational Tree Seed Centre, Plot 24 Kentinkrono/Nsenie, P. 0. Box 63, KNUST, Kumasi

~World Agroforestry Centre (ICRAF), Yaounde, Cameroon5 World Agroforestry Centre (ICRAF), United Nations Avenue, Gigiri, P. 0. Box 30677-00100,

Nairobi, Kenya

ABSTRACT

Agricultural biodiversity and provision ol alternate livelihoods for farmers have become critical issuesjor sustainable management of biological resources as well as poverty reduction in rural areas. This isbeing done through cultivation of a wide range offood crops, vegetables, Fuits and medicinal plants.One of such Fuit trees being encouraged in agroforestry systems is Allanblackia spp., hence the need forsustainable supply of improved early Fuiting planting stock. Grajiing was adopted for production ofearly Fuiting high yielding planting stock to satisfY farmers needs. Two methods o.l grafting tried wereside veneer grajiing and cleji grafting The mean grafiing success for side veneer grajiing (50.21%) wassignificantly lower than that of cleji grajiing (79.8%). Clonal differences in grafiing success were quitesubstantialrangingFom 70 to 87.5%for cleji grajiing and 42.8 to 57.8%for side veneer gr{1fting Graftsflowered within 12 months afier grajiing even though the flowers could not develop into Fuits. Thissuggests that grafiing could be a tool for mass propagation of desirable genotypes ofA. parviflora withreduced gestation period.

Keywords: Fruit tree, agroforestry, domestication, vegetative propagation, clone

INTRODUCTION

Biodiversity plays a central role in household food

security and income generation and hence has a

positive impact on human livelihoods (poverty

alleviation, nutrition, health, employment, andenvironmental rehabilitation). However, much of

the world's biodiversity especially in the tropics is

being irreversibly lost through extinction caused

by the destruction of natural habitats (Wilson,

1988). In Ghana for instance, deforestation hasclaimed an enormous toll on the environment,

Ghana Journal of Forestry, Vol. 23 & 24, 2008

economic deterioration and human welfare. For

various reasons such as logging and clearing for

cash crop cultivation, the rainforest in Ghana hasdwindled from 8.2 million ha to 1.62 million ha

over the past 100 years with a deforestation rate of

0.77 to 1.4% per annum. Currently only aboul20% of the original forest remains (MES, 2002),

with these forest fragments mostly surrounded by

subsistence and commercial agricultural lands,most of which are devoid of trees. These warranl

an integrated approach for balancing conservation

needs with livelihoods and development priorities.

4

Utility of grafting in tree domestication with reference to Allanblackia parvitlora A. Chev. D. A. Orori et aI.,

There is therefore, the need to diversify farmer'slivelihood options through the development ofsustainable poverty reduction and forestmanagement strategies.

In order to stabilize tTagile small-holder farmingsystems, incorporation of biodiversity andenvironmental conservation practices should beconsidered within/around the remnant forest

tTagments. Incorporation of agroforestry treeproducts (AFTPs) in farming systems as analternative livelihood as well as contributing tolandscape connectivity and environmentalconservation is becoming a hot issue of late. Formaximum benefit of increased tree diversity onfarm lands for sustained productivity, there is aneed to update the list of priority species anddevelop methods for propagation of desirablegenotypes as well as methods for their integrationinto farming systems (Atangana et al., 2006,Tchoundjeu et al., 2006). In doing so attentionshould be paid to high valued AFTPs (wild fruittrees, medicinal plants etc) that provide benefits tosmall holder farmers (Simons and Leakey, 2004,Tchoundjeu et al., 2006). This is in accordancewith the participatory domestication of high­valued tTuit trees, nuts and medicinal plantsadopted by World Agroforestry Centre (ICRAF)that has been on-going in West and Central Africasince 1998 (Tchoundjeu et al., 1998,2006)

Allanblackia parviflora, an indigenous fruit treespecies is being accepted by fanners for use inagroforestry systems with both environmental andeconomic benefits. It is a medium sized tree

reaching about 40 m high with narrow crownthereby casting minimum shade on the companioncrops. It has other uses such as timber andmedicinal purposes (Ofori et al. 2006; Abbiw,1990). Several wildlife species such as Brush­tailed porcupine, Squirrel and Giant rat alsodepend on it for their survival (Siaw et al., 2003).The seed oil is of prime importance as a foreignexchange earner and is being developed as a rural

Ghana Journal of Forestry, Vol. 23 & 24, 2008

based enterprise in many African countriesnotably Ghana, Nigeria, Cameroon and Tanzania(Shrestha and Akangaamkum, 2008). CurrentlyUnilever requires 2000 tons of Allanblackia seedsfrom Ghana but only ]00 tons (only 5%) aresupplied annually on average (Oppong, 2008).Up-scaling of the supply of Allanblackia seedsmight result in the species becoming another'Golden tree' for AtTica in the near future.

The Need for Grafting AI/anb/ackia in theDomestication Process

Extensive research studies have been conducted

by the Forestry Research Institute of Ghana incollaboration with the World Agroforestry Centreon methods of domestication as well as provisionof improved genotypes for multiplication (Ofori etal. 2008a). This was achieved through collectionof AI/ab/ackia parviflora fruits throughout thedistribution zone in Ghana. The tTuits and seedswere characterized and 58 trees were selected on

the basis of high yielding (Peprah et al., 2008) andwere therefore recommended for mass

propagation. Workshops on domestication ofAllanblackia have been organized by WorldAgroforestry Centre (WAC) (W AC, 2006),Forestry Research Institute of Ghana (FORIG) andWAC (Ofori et al., 2008b) and NovelDevelopment Nigeria (Ofori, 2008). Some of themost critical questions emerging on domesticationof Allanblackia are:

• How can Allanblackia be propagated?• How do farmers obtain improved

planting stocks?• How long does Allanblackia take to

flower and fruit?

Four-year old seedlings being monitored atFORIG have not shown any signs of floweringand it is anticipated that seedling-grownAllanblackia may not flower until ]0 years.Secondly, the species is dioecious and seedlings

43

Utility of grafting in tree domestication with reference to Allanblackia parviflora A. Chev. D. A. Ofori et aI.,

will grow to be either male or female. In order toavoid these problems, vegetative propagation hasbeen adopted to mass produce the desiredgenotypes (right proportion of elite females andmales) as well as capturing quicker genetic gains.Grafting was adopted since most agricultural fruitsgrafted have been found to flower earlier thanseedlings. The question raised with this approachwas whether the phenomenon of maintenance ofontogenetic age (maintenance of the reproductivematurity) will occur in scions of Allanblackia aftergrafting and if yes, to what extent will graftingreduce the gestation period?

MA TERIALS AND METHODS

Scions were collected from the branches of 15

mature trees (fruit bearing trees located at Afosu,Kwame Nkrumah University of science andTechnology - Kumasi and New Edubiase) andthen grafted onto one to two years old seedlings ofA. parviflora in a greenhouse at FORIG, Kumasi,Ghana. Grafting methods used were cleft graftingand side veneer grafting. For each tree 60 graftswere made; 30 grafts each for side veneer graftingand cleft grafting methods. The scions wereenclosed in clear polythene bags for the first weekafter grafting to prevent them from excessive lossof water. The grafts were inspected weekly andfinal assessment was made at week four at which

time grafts were clearly labeled as successful orunsuccessful. The grafting success (Gs) wasexpressed in percentages as Gs = [(n/y) 100],where n is the number of successful grafts and y isthe number of grafts made. The data wereana lysed to find the differences between the twografting methods using T-test with each clone asone experimental unit.

90

80Vl

70Vl

<I) 60u u=sVl 5001)

c;E40

ro•... 300';f!.

20

100 -

I

Cleft Side

Method of grafting

Figure 1: Effect of different grafting methods on grafting success of A llanblackia parviflora

Ghana Journal of Forestry, Vol. 23 & 24, 2008 44

Utility of grafting in tree domestication with reference to Allanblackia parviflora A. ehev. D. A. Ofori et aI.,

RESULTS AND DISCUSSION

There was a significant difference (P = 0.00) inthe success rate of the two grafting methods. Thegrafting success obtained for the cleft grafting washigher than that of side veneer grafting (Figure 1).Clonal differences in grafting success were quitesubstantial. Grafting success for cleft graftingranged from 70 to 87.5% (Figure 2) while that ofside veneer grafting ranged from 42.8 to 57.8%(Figure 3). The cleft grafting method was thenused for mass propagation of the 58 recommendedplus trees at two Rurai Resource Centres. At 12months after grafting, five grafts from threedifferent clones started flowering at the RuralResource Centre at Apeasuman (Plate 1). Theflowers aborted after 3 weeks. The abortion of the

flowers was not surprising since the plants weretoo small to support the development of fruits.This phenomenon has also been observed in 2­year old grafts of Allanblackia floribunda inCameroon (Asaah et al., 2008).

Even though none of the flowers developed intofruits, the observation was very exciting since itwas an indication of maintenance of reproductivematurity in the scions collected from reproductivematured trees. Farmers should therefore expectthat planting A. parviflora grafts could drasticallyreduce the gestation period. Even though graftingis labour intensive compared to cuttings, graftingsuccess has generally been higher than cuttings(Ofori et al., 200Sc, Atangana et al., 2006). Thiscoupled with the probable reduction of thegestation period gives grafting a great potential inthe domestication process of indigenous fruittrees. Planting grafts in mother blocks as sourcesof genetic materials for multiplication could alsobe advantageous in the elimination of frequenttrips to the forest for collection of materials forpropagation. This is because grafting maintainsontogenetic age thereby reducing the gestationperiod and hence less cost of operation.

Plate 1: Allanblackia parviflora grafts that flowered one year after grafting

Ghana Journal of Forestry, Vol. 23 & 24, 2008 45

Utility of grafting in tree domestication with reference to Allanblackia parvillora A. ehev. D. A. Ofori et al..

00o~<n

\000r--

~~~ <...;>-<...;>~~ 0000 00<n ~~00

r.., r--r--00-

r--r--r--100.00

90.00Ul

80.00Ul

(l) 70.00u U::l 60.00UlbJ)

50.00c;£; 40.00ro •.....tJ 30.00

";:{(

20.000

10.000.00

Clones

Figure 2: Clonal differences in grafting succes of Allanblackia parviflora usingcleft grafting method

oo70.00

60.00Ul

Ul 50.00(l) uu::l 40.00Ul

bJ)C¢:30.00

ro•.....tJ 20.00

";:{(

0 10.00

0.00

---- ~- 'm _- -"I

--r--

\0

'r)

Clones

Figure 3: Clonal differences in grafting succes of Allanblackia parviflora usingside veneer grafting method

Ghana Journal of Forestry, Vol. 23"& 24, 2008 46

Utility of grafting in tree domestication with reference to Allanblackia parviflora A. Chev. D. A. Ofori et aL

ACKNOWLEDGEMENT

We are grateful to the farmers who own the treesfrom which scions were collected. We are also

grateful to Mr. Francis Owusu Nuamah whoundertook the grafting operation and Dr. IanDawson for his useful comments to improve thismanuscript.

REFERENCES

Abbiw, D. (1990) Useful Plants of Ghana; WestAfrican uses of wild and cultivated plants, TheRoyal Botanic Gardens, Kew, 6-231.

Atangana, A. R., Tchoundjeu, Z., Asaah, E. K.,Simons, A. J. and Khasa, D. P. (2006) Domesti­cation of Allanblackiafloribunda: Amenability tovegetative propagation. Forest Ecology andmanagement, 237: 246-251.

Asaah, E., Tchoundjeu, Z. and Alain, T. (2008)Allanblackia propagules growth & developmentupdates in Cameroon. Allanblackia meeting,Forestry Research Institute of Ghana, Kumasi,Ghana, 11th - 13thNovember2008.

Ministry of Environment and Science (2002)National Biodiversity Strategy for Ghana,Ministry of Environment and Science, Pp 55.

Ofori, D. A. (2008) Report on training workshop-on propagation of Allanblckia species ForestryResearch Institute of Nigeria, Benin City, Nigeria,9-12 July 2008.

Ofori, D. A., Peprah, T., Addo-Danso, S. andCobbinah, J. R. (2008a) Management of Geneticresources of Allanblackia parviflora in Ghana.Annual report 2007, Pp. 9

Ofori, D. A., Peprah, T., lIenneh, S. andBosompem, S. A. (2008b) AllanblckiaDomestication Project; Report on training

Ghana Journal of Forestry, Vol. 23 & 24, 2008

workshop on vegetative propagation ofAllanblckia parviflora, CSIR-Forestry ResearchInstitute of Ghana, Kumasi 25th to 29th February,2008.

Ofori, D. A., Peprah, T., Vonberg, J. andHenneh, S. (2008c) Status of domestication ofAllanblackia parviflora in Ghana, Allanblackiameeting, Forestry Research Institute of Ghana,Kmnasi, I I-13 November 2008.

Ofori, D. A., Peprah, T., Siaw, D. andCobbinah, J. R. (2006) Domestication ofAllanblackia in Ghana. In: Muasya, S.; Rutatina,F.; Munjuga, M. and Simons, A. J. Status andProspects for Allanblackia Domestication inTanzania. CD-ROM Compilation, ICRAF,Nairobi, Kenya, ISBN 92 9059 196 X;

Oppong, K. (2008) Allanblackia seed oil supplychain management in Ghana. Allanblackiastakeholders' workshop, Sanaa Lodge, CapeCoast, 30th July 2008.

Peprah, T., Ofori, D. A., Siaw, D. E. K. A.,Addo Danso, S. D., Cobbinah, J. R.,Tchoundjeu, Z., Jamnadass, R. and Simons, A.J. (in review) Reproductive biology andcharacterization of A Ilanblackia parviflora A.Chev. In Ghana. Genetic Resources and CropEvolution

Siaw, D. E. K. A., Cobbinah, J. R., Kankam, B.0., Derl<yi, S. A., Oduro, K. A., Agyili, J. andPeprah, T. (2003) Allanblackia floribunda, finalreport submitted to Unilever Ghana Limited byForestry Research Institute of Ghana, Pp 69.

Shrestha R. B. and Akangaamlmm, A. D.(2008) Novella partnership, a partnership forpoverty reduction through sustainable enterprisedevelopment based on Allanblackia, SNV Ghana,Pp 20.

47

Utility of grafting in tree domestication with reference to Allanblackia parviflora A. Chev. D. A. Ofori et aI.,

Simons, A. J. and Leakey, R. R. B. (2004)Treedomestication in tropical; agroforestry.Agroforestry Systems 61: 167-181.

Tchoundjeu, Z., Asaah, E. K., Anegbeh, P.,Degrande, A., Mbile, P., Facheux, c., Tsobeng,A., Atangana, A. R., Ngo-Mpeck, M. L. andSimons, A. J. (2006) Putting participatorydomestication into practice in West and CentralAfrica, Forests, Trees and Livelihoods 16:53-69.

Tchoundjeu, Z., Duguma, B., Fondoun, J. M.and Kengue, 1.. (1998) Strategy for thedomestication of indigenous fruit trees of Westand Central Africa: case for frvingia gabonensis inSouthern Cameroon. Cameroon Journal of

Biology and Biochemical Sciences 4:21-28.

Ghana Journal of Forestry, Vol. 23 & 24, 2008

WAC (2006) SIlT training workshop onAllanblackia domestication, Compilation ofWorkshop proceedings and related documents,World Agroforestry Centre, Nairobi, Kenya, 2327October 2006.

Wilson, E. O. (1988) The current state ofbiological diversity. In: Biodiversity (Eds. Wilson,E. O. and Peter, F. M.), National Academy Press,Washington, D. C. 3-18.

48