ABSTRACT
A field experiment was conducted in the Department of Forestry and Wildlife Arboretum (Lat 060 2416111N and Long 0050 37142711E) of the Faculty of Agriculture, University of Benin, Benin City. The study was designed to explore the ecology and growth response of Pentadesma butyracea to different levels of light in the understory. The experiment was a completely randomized design with four main treatments namely; dense shade, open gap, medium shade, no shade condition (control). A light meter was used to measure level of illumination in the plots. Results obtained showed that Dense Shade condition was the most suitable for the optimum growth and development of Pentadesma butyracea for all parameters measured. Plants under Dense shade had the highest measurement in germination, height, collar girth and number of leaves which was 100%, 34.52cm, 2.53cm and 6 respectively. Those in the Open gap (T1) had 50% germination, 12.58cm in height, 1.25cm in collar girth, and 3 numbers of leaves. Medium shade (T3) had 94.4% germination, 27.43cm in height, 2.32cm in collar girth, and 6 numbers of leaves while the control had 11.11% germination, 0.74cm in height, 0.11cm in collar girth and no leaves. For the purpose of domestication and ex-situ cultivation, it is recommended that P. butyracea should be grown under dense shade conditions.
CHAPTER ONE
INTRODUCTION
Distribution and Habitat
Pentadesmabutyraceais native to West Africa, from Guinea, Sierra-Leone and Cote d’Ivoire, Togo to the Democratic Republic of Congo, extending eastwards into Tanzania and Uganda, where it is cultivated.
Some of the largest occurrences are in the region of the Atakora Mountains in Togo, and in humid forestsin Cote d’Ivoire. It is abundant in wet forests. In dryer forest it is found along river banks. It occurs in specific savannah woodlands, and is a common species of dense evergreen forest. In very moist sites such as riverine and swamp forest the species develop stilt roots. In recent years, the species has been under threat in many places, mainly in forest galleries, due to its over-exploitation and unsustainable use.
Uses
It is a multipurpose species, with good quality wood which is used for construction, fences and as firewood. The wood is hard and not often attacked by insects. The young stems are used as chewing sticks and are also made into combs. The fruits are directly consumed. It is a high oil producing species; the odourless oil extracted from the seeds is used as a vegetable butter, and to make candles and soaps. The seed fat is used as an insecticide for lice. The bark is used to treat diarrhoea and dysentery. The tree is also planted for soil conservation.
Botanical Description
Pentadesmabutyraceais a semi deciduous species, partly losing its leaves during the dry season. Thetree can reach up to 35 m high and about 1.30 m in diameter. It has a straight cylindrical trunk, with horizontal and whorled branches. The bark is brownish with fissures presented in small longitudinal rectangles.
The slash yields a thick yellow juice, which dries to a reddish gum. It has pairs of ex-stipulate, simple, entire leaves, 10-22 cm long, 3.5-7 cm broad, with numerous close parallel lateral nerves. The leaves are streaked and spotted with resin glands; glandular canals on the under surface are visible by reflected light, and glandular dots are clearly visible in young and sucker leaves. Flowers of P. butyraceaare large, whitish red or greenish-white. The petals are glabrous on the inside, with 5 stamen-fascicles and divided into 5 lobes. The sepals are very unequal, up to about 5 cm long. The flowers have a fruity and heavy odour that has been described as giving off a smell similar to rancid butter, which may possibly attract bats for pollination.
Flowering and Fruiting Habit
The species has a regular annual, but discontinuous fruiting period of about nine months. Fruits, flowers and flower buttons can be found on the same individual at one time. Flowering starts in July and August and reaches its maximum in October/November. Fruiting occurs with the start of flowering and fruits mature between April and June. The species has also been described as having discontinuous and bi-annual fruiting periods in Côte-d’Ivoire; first in February-April and in July-September.
Fruit and Seed Description
The fruits are reddish-green, broadly ellipsoid and pointed, up to 11 cm broad and 15 cm long berries containing yellow flesh with several seeds embedded in it. An adult tree can produce up to 500 fruits. An individual fruit weighs an average of 0.60 kg, of which approximately 0.12 kg is seed.
There are 3 to 10 seeds embedded in the yellowish fruit pulp. The seeds are large with flattened sides and dark red embryos from which the oil is extracted. The average thousand seed weight is 30 kg. The average oil content of the entire seed/nut is 36.0 %. The seeds are naturally dispersed by elephants.
Processing and Handling
The seeds rapidly germinate within the fruit; therefore fruit removal before sowing is not required.
Storage and Viability
Seeds are recalcitrant. Fresh seeds that are conserved in moist jute bags maintain 100% viability after 1 month. However, when using polyethylene bags, only 15% germinate. Drying does not improve germination; dried seeds stored for two months in ambient conditions germinated to 14% within three months.
Sowing and germination
Fresh seeds germinate well under shade at ambient conditions. Germination starts after about 15 days and reaches 98% after two months of sowing. Germinated seeds grow into normal seedlings in nurseries, reaching 10-28 cm high after 4 monthsPentadesmabutyraceasabine belongs to the familyGuttiferae. It common names are African butter tree, tallow tree, Kanya and Krinda or tama.(Malinke cote d’ivoire).
In some parts of Benin,the tree is known as” Aborpor,”but this name is applied to several hard wooded trees used for making frames(Aborpor”) for weaving cloth, the timber used for this purpose, must be hard and must not pick up.(Kennedy,1936).
Pentadesmabutyraceaoccurs naturally from Guinea Bissau to Cameroun and Western most DR Congo. It is a multi-purpose tree that provides non-timber forest products (NTFPS).
Pentadesma comprises about 5species, all in tropical Africa. Although all pentadesma species yield edible fat, there is only information on the use of Pentadesmabutyracea.
Growth and Development
Tree first flowers when about 8m tall. Flowering occurs during a large part of the year but mainly during the main rainy season. In Gabon trees flowers from March to September. The flowers produce large amounts of nectars which is eaten by monkeys; they are probably important pollinators.
In Gabon fruits are produced mainly from October to December and in Benin from March to June. They are eaten by elephants and monkeys which dispersethe seeds.(Abbiw,D.1990.,Hawthorne,W.D. and Parren,M.P.E.2000).
Ecology
Pentadesmabutryracea occurs in tropical rainforest on moist or swampy ground, mostly river banks. It does not occur where mean annual rainfall is less than 1000mm. It prefers deep soils. In Ghana it is strongly associated with leached soils. In Benin it occurs naturally in riparian forest.(A.K.Natta,Sinadouwiron,T.A.,Sinsin,B.and van der Maesen,L.J.G 2003).Spatial distribution and ecological factors determining the occurrence of pentadesmabutyraceasabine(clusiacea) in Benin.
Statement of problem
Due to the importance and uses of Pentadesmabutyracea in recent years, the species has been under threat in many places,mainly in forest galleries due to its over exploitation and unsustainable use. pentadesmabutyracea is a shade loving plant and thrives optimally,it’s natural regeneration have been found to be associated with parent trees.
Justification of the study
In Nigeria, there appears to be an increase rate of depletion of Pentadesmabutyracea, particularlyduring timber exploitation and increasing deforestation.However,not much work has been done to conserve this resilent climax species, particularly in the area of domestication.
The incorporation ofPentadesmabutyraceaand other NTFPs into agroforestry practices will no doubt improve rural livelihood by providing employment and increasing income of the local poor in local communities and areas.
Objectives of the study
- To investigate the germination rate of pentadesmabutyracea seeds under different light regimes
- To determine the effect of canopy gap on the germination of pentadesmabutyracea seeds
- To study the morphological features of pentadesmabutyracea during seedling stage
