Melia volkensii in Kenya: current domestication and ...kimondojm.weebly.com/uploads/3/2/9/3/3293581/melia... · Melia volkensii Gürke (of the family Meliaceae) is a multipurpose

Melia volkensii in Kenya: current domestication and

improvement programme

Superior melia tree in Mutha, Kitui Photo by J.M. Kimondo

Kimondo, J.M1., Kigwa, B.K.2 and Mbuvi, M.T.E.2 November 2008

1KEFRI, Karura Forest Products Research Centre, PO Box64636 – 00620 Mobil Plaza, Nairobi

2KEFRI, Kitui Regional Research Centre, PO Box 892 – 90200 Kitui

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Melia volkensii in Kenya: current domestication and improvement programme

Introduction

Melia volkensii Gürke (of the family Meliaceae) is a multipurpose tree species endemic in the arid

and semi-arid lands (ASALs) of Eastern Africa. It is generally a fast growing tree, tolerant to dry

conditions and is compatible with most crops, though management through root and crown pruning

are recommended to minimize competition. The growth of Melia volkensii in well-managed plots in

arid and semi arid lands far exceeds those of other indigenous tree species in the same areas.

However, its wide scale planting has been constrained by lack of quality planting material. The

planting of the species has been going on for the last 20 years in small scales on the farms. This has

been mainly from collection of wildings which are then planted directly in the desired place on the

farm or in the nursery where they are managed for some time before planting out. Other planting

has been of seedlings raised in tree nursery from seeds which were generally collected from any

available tree near the nursery with little consideration of the quality of the mother tree. During the

last ten years or so, KEFRI in collaboration with two development partners, namely Japanese

International Cooperation Agency (JICA) through Intensified Social Forestry Project (ISFP) and

Belgian Technical Cooperation (BTC) through Integrated Natural Resources Management of

Ukambani (INRMU), has spearheaded the improvement programme of M. volkensii to enhance the

survival of planted trees on the farms as well as increasing the realised productivity. The programme

involved: (i) selection of phenotypically superior trees in the natural range of the species and on the

farms; (ii) testing of different vegetative propagation techniques to allow multiple replication of

identified mother trees; (iii) testing of appropriate establishment of hedgerows to allow frequent

harvesting of scions or cuttings; and (iv) establishment of clonal seed orchard. Details of each of

these steps are given below.

Species description

Melia volkensii occurs naturally in the semi arid zone of Ethiopia, Somalia, Kenya and Tanzania at

altitudes between 350 and 1700m, in areas with mean annual rainfall of 300-800mm. Though the

species can grow on most soils; sandy, clay and shall stony soils, it prefers sandy soils with good

drainage. The species is common in deciduous bushland in association with acacia-commiphora

vegetation. The tree is deciduous, shedding leaves early in the dry season with new leaves emerging

two to three weeks before the onset of rains. The shedding of leaves is actually triggered by reduced

availability of soil moisture. On cultivated lands therefore, leaves are normally shed late into the dry

season. It grows 6 to 20 metres tall with diameter of around 25 cm though bigger trees are common

in suitable environments.

The species is highly preferred for its high valued timber that is durable and termite resistant in use.

The timber is used for construction and furniture making and locally is one of the main species used

in the construction of log hive because the wood is easy to work. Besides growing fast, the species

coppices readily and is also a valued fodder (twigs, leaves and fruits) especially during the dry season

for goats, cattle and sheep.

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Selection of phenotypically superior trees

The natural stands of Melia volkensii in the wild or natural environment continue to decline

drastically because of population pressure on land for agriculture and human settlement.

Consequently genetically diverse and superior trees required to be conserved in whatever form and

propagated in large populations. In 2004, a country wide survey of Melia was carried out to identify

the location of natural stands and trees where the tree information was captured (appendix 1).

Initially 40 trees were selected in six transects as the base population for the breeding programme.

They were however re-evaluated for their form, growth vigour, apparent resistance to disease and

pest and their branching habits. During this exercise some trees were dropped while new ones were

added to the list. The guiding factor in the selection was identification of trees that could enhance

timber production. Some of the selected trees are as shown:

Table 1 Location and description of some selected plus trees of Melia volkensii

Tree No. 1

Location: Kithima Market, near Assistant chiefs office,

Kithima tree nursery on Isiolo-Meru road

Co-ordinates: 00:21:133 N; 037:33:603 E

Size: 12.0m height, 8 m clear bole, 21.5 cm DBH

Date: 5/12/2005

Class: B

Stressed: Yes, scions to be collected

Status: Secure

Tree No. 1

Tree No. 2:

Location: Maua-Kina Road

Co-ordinates: 00:17:912 N; 038:06:022 E

Size: 8m Ht, 5.5m cler bole and 25.8cm DBH

Date: 5/12/2005

Class: C

Stressed: No, scions collected and grafted

Status: Not Secure, land sold to new owner

Tree No. 2

Tree No. 3:

Location: West of Kina in Rapsu settlement area

Co-ordinates: 00:15:719 N; 038:14:435 E

Size: 9 m Ht, 4,2 m cler bole

Date: 6/12/2005

Class: C


Status: Secured, acquired from farmer

Tree No. 3

Tree No. 4A

Location: Ishiara-Marimanti Road

Co-ordinates: 00 15 106S; 037 54 531E

Size: 21m Ht, 51cm DBH,

Date: 7/12/2005

Class: B


Status: Secured from farmer. Tree a replacement of the older nearby tree previously selected

Tree No. 4

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Table 1 (cont)

Tree No. 9

Location: Mbeere, Ishiara, nguthi sub loc.. Ishiara-Marimanti Road

Co-ordinates: 00 27 314S; 037 44 544E

Size:11.5m Ht,

Date: 8/12/2005

Class: C


Status: Secured from farmer.

Tree No. 9

Tree No.10:

Location: Embu-Ishiara Road

Co-ordinates: 00 27 586S; 037 44 739S

Size: 11m Ht.

Date: 8/12/2005

Class: A


Status: Secured from farmer.

Tree No. 10

Tree No. 11:

Location: Gatunga-Marimanti area

Co-ordinates: 00 08 609S; 038 04 048E

Size: 10m Ht

Date: 7/12/2005

Class: A


Status: Secured from farmer for 2 years

Tree No.11

Tree No. 12

Location: Next to Tharaka County Council Offices

Co-ordinates: 00 09 333S; 037 58 239E

Size: 10.5m Ht

Date: 7/12/2005

Class: C



Tree No. 12

Tree No. 1 S (Special)

Location: Mwea Riakanau , North of Riakanau Primary school

Co-ordinates:00 49 592S; 037 23 700 E

Size: 1.5 m circumference ie 47.2cm, 13mHt

Date: 8/12/2005

Class: A



Tree No 1S

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Table 1 (cont)

Tree No. 10:

Location: Mutha Inyali, Ndakani Loc.

Co-ordinates: 02 581 186N; 046 33 878E

Size: 8m Ht, 19.5cm DBH

Date: 12/12/2005

Class: A


Status: On-farm, secured from farmer for 2 years

Tree No. 10

Tree No.11:

Location: Mutha Inyali, Justus Munyalis range

Co-ordinates: 02 54 475N; 046 48 083E

Size: 8.5m Ht; 21.5cm DBH

Date: 14/12/2005

Class: B


Status: Wild, secured from farmer for 2 years

Tree No. 11

Tree No. 12

Location: Mutha Inyali, Justus Munyali range

Co-ordinates: 02 54 442 N; 046 48 089 E

Size: 11m Ht, 25.8cm DBH

Date: 14/12/2005

Class: B



Tree No. 12

Tree No. 13

Location: Mutha Inyali, Justus range

Co-ordinates: 02 54 359N, 046 47 302E

Size: 9m Ht; 20.8cm DBH

Date: 14/12/2005

Class: B



Tree No. 13

Tree No. 14

Location: Mutha Inyali, Ngaani Loc

Co-ordinates: 0253 608N; 046 44 564 E

Size: 10.5m Ht, 29cm BDH

Date: 14/12/2005

Class: B



Tree No. 14

Tree No. 15

Location: Mutha Inyali Ngaani Location

Co-ordinates: 02 53 956N; 046 44 601E

Size: 11m Ht, 18cm DBH

Date: 14/12/2005

Class: B



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From these selected trees, scions were collected and grafted on melia root stock for the

establishment of clonal seed orchard. Further, the trees had their roots exposed and severed to

encourage them to sprout and later harvesting of the same for planting. However, the sprouting of

the roots took place on the root stump away from the tree and did not develop any root hair. It was

therefore not possible to harvest these sprouts as they did not have immediate roots of their own

that they could depend on. Cuttings were also taken and trials on their rooting undertaken in Kitui

Nursery.

Vegetative propagation techniques

Several methods of mass production of melia planting material have been tested in Kitui and

Muguga. The use of tissue culture manipulation was carried out in laboratories in Muguga where

some encouraging results were realised. In Kibwezi (Fig 1a) and in Kitui (Fig 1b), grafting of scions of

melia on to root stock of melia was carried out and good results obtained. Actually, over 90 percent

success rate was realised and the main limiting factor in the use of the method is the availability of

stock.

Figure 1. Grafted Melia volkensii seedlings in (a) Kibwezi nursery (b) Tiva nursery glass house

While the above procedure meant nursing the grafts in the

nursery and then planting them in the field, it established

that the scions would be grafted directly on to established

saplings in the field and therefore allow the harvesting of

scions within a short period and also avoid the planting

process altogether (Fig 2).

The success of these activities can only be achieved when

the cuttings obtained from the grafted trees can be rooted

en-mass and distributed to potential tree growers.

Currently this is one step that has only achieved marginal

success. While some cuttings have actually rooted (Fig 3a,

b, c), their production in large numbers has remained a

challenge. It is apparent that the rooting success depends

Figure 2. Grafted sapling in Tiva, Kitui on a number of factors that need to be in specific quantum.

Research continues in this area and more need to be done.

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Figure 3. Vigorously growing rooted cuttings at Tiva, Kitui (a) potted seedlings (b) exposed roots (c) two

rooted seedlings at different stages of development

Establishment of melia hedgerows

Hedgerows are normally established to ensure the parent material is kept at the juvenile stage

where irrigation and fertilization can be carried out to ensure vigorous growth. As a result, the hedge

can be harvested more frequently therefore allowing the access of adequate planting material.

Experience so far in the country has revealed

that Eucalyptus grandis should be

established at a spacing of 0.4m by 0.8 m

and between every two rows, a 1 metre

space is left to facilitate harvesting of scions

(Fig 4). There exists no experience in as far as

Melia volkensii is concerned. With due

regard to the broad branching habit of Melia

volkensii, other wider spacing were put in

the trial in November 2006 short rain season.

The other set up was 1m by 1m by 1m and

1m by 1m with a 2m space between every

two rows of seedlings.

Figure 4. Hedge row established at 0.4m by 0.8m and 1m

between pairs of rows of Melia volkensii seedlings

With a wider spacing, the crowding of

branches of neighbouring trees is

reduced as compared to the closely

spaced ones above (Fig 5). However, the

canopy of trees is also intertwined at the

age of two years.

Figure 5. Hedgerows established at 1m by

1m and 1m between rows of Melia volkensii,

at Tiva

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Where an even wider space is

allowed between pairs of seedlings,

the canopies are barely touching at

two years (Fig 6). This implies that

this could be at least the minimum

arrangement to facilitate the growth

of the trees to a reasonable diameter

that could support a large number of

sprouts and at the same time allow

access during harvesting. If larger

diameters of stumps are necessary it

may require that a wider spacing

between pairs of hedgerows are

utilised with the cutting of the trees

Figure 6. Hedgerows established at 1m by 1m and 2m between carried out at later age (Fig 7).

pairs of rows of Melia volkensii at Tiva

During the cutting of the tree to initiate the

sprouting process, cutting must be carried out

above the grafting point (see arrow in the

inset of Fig 7) so that the sprout realised are

those that originated from the scion part and

not the root stock. Actually all sprouts from

the root stock should be removed

immediately they start developing.

Figure 7. Grafted seedlings established at Tiva in

2005 at a spacing of 2m by 4m at age 3.5 years.

Way forward

The current research efforts are geared towards domestication of melia for timber production. As

the species has different uses, it is possible to carry out an improvement programme for other

purposes. The controlling factor in most situations remains the selection of the appropriate mother

trees to provide germplasm that meets the desired product. For instance, selection for drought

resistance requires identification of mother trees in extremely dry environments for collection of

scions. This assumes that there is no dilution effect due to the stock utilised.

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Appendix 1: Tree data collection sheet 1. District……………………………………………………………. 2. Division…………………………………………………………… 3. Location…………………………………………………………… 4. Sub location……………………………………………………….. 5. Transect name…………………………………………………………… 6. Ecological zone…………………………………………………… 7. Altitude…………………………………………………………….. 8. Latitude…………………………………………………………….. 9. Longitude…………………………………………………………… 10. Location of tree (a) on farm ((b) In the wild (c) Others

(specify) 11. Tree No. …………………………………………………………….. 12. Dbh…………………………………………………………………. 13. Height……………………………………………………………….. 14. Clear bole height……………………………………………………. 15. No. of branches …………………………………………………….. 16. Size of branches………………………………………………………. 17. Tree health (1) Die back (2) Diseased (3) Pest 18. Deforms/Defects score………………………………………………….

(1) Excellent (None) (2) Moderate (3) Few (4) Many (5) Extreme

19. Canopy condition:………………………………………… (1) Green with full canopy (2) Fruiting with full canopy (3) moderate canopy

4) Shedding leaves (5) No leaves

20. Bole quality……………………………………………………………………….

1) Spiral grains on bark (2) less spiral (3) No spiral bark (4) Normal plain

bark

22. Benchmark of selected tree: 1) Type ……………………………… 2).Distance……………………………….3). Direction…………………………….

23. If on-farm… Yes/No Name of the farmer…………………….

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