EVALUATION OF THE AGROFORESTRY POTENTIAL OF CHRYSOPHYLLUM ALBIDUM
ABSTRACT
In the selection of trees for any agroforestry system there is the need for its evaluation, in order to get the tree species that will be suitable for a particular locality. One of such trees that can be found growing successfully in the Akuapem North District where the research was conducted is the Chrysophyllum albidum. This is one of those neglected and under- utilized wild fruit tree species of our forests. Investigations were conducted into the potentials of Chrysophyllum albidum in towns and villages such as Adawso, Asempaneye, Bewase, Kabu, Konko, Nyamebekyere, Saforo and Tinkong. Secondly, various pre- germinating treatments were applied to the seeds to establish the best treatment options. In all, there were seven treatments: T1 (seeds sown fresh), T2 ( seeds soaked in water for 8 days), T3 (seeds soaked in hot water), 100 C, T4 (seeds cracked and soaked overnight), T5 ( seeds soaked in water for 10 days), T6 (seeds soaked in water for 12 days) and T7 (seeds cracked and sown) with three replicates. A third experiment was conducted to determine the initial growth rate of the seedlings. Proximate analysis of the fruit, seeds and leaves of Chrysophyllum albidum was done to identify the nutrient status of these parts. Food product development was undertaken and sensory evaluation was carried out using questionnaires. The result obtained from the socio-economic survey revealed that in all the 8 study sites only about 49 farmers own the trees. The fruits from one tree could be sold between GH cedis 50 and 100 at the farm-gate. The results of pre-germination treatment revealed that soaking seeds in hot water at 100 0 C (T3) destroyed the embryo as none of the seeds germinated. Highest percentage germination of 87% was recorded for seeds soaked in water for 8 days (T2), followed by seeds soaked in water for 10 days (T5) and (T1 - control) with a value of 77%. The least value of 47% was recorded for seeds cracked and soaked overnight. The experiment carried out to determine the initial growth rate of the seedlings from the pre- treated seeds indicated that the height of seedlings was highest in T2 – with a mean seedling height of 33.5 cm. T6 produced the lowest mean seedling height of 27.0 cm. The result obtained from the proximate analysis of the fruit, seeds, and leaves showed that the fruit is strongly acidic with pH value being 2.9 at 22.8 degree Celsius. One gram sample each of the leaves, seeds and the fruit (fibre) analysed at the laboratory gave the following results: the leaves had 14.9% protein, 1.2% calcium, 0.5% magnesium and 0.06% phosphorus. The seeds showed a protein content of 82%, calcium 0.3%, magnesium 0.03%and phosphorus 0.03%. The fruit (fibre) had protein nil, calcium 0.6s%, magnesium 0.2% and phosphorus 0.05% The sensory evaluation test also revealed that the drink from Chrysophyllum albidum fruit had the highest overall acceptability value of 43.4 followed by Chrysophyllum albidum fruit and ginger mixed drink with a value of 41.4. The least of the overall acceptability of the drinks was recorded with the orange drink having a value of 29.1. In conclusion, Chrysophyllum albidum has great potentials in enhancing the livelihood of the people in the Akuapem North District. It can play a potential role in agroforestry systems for sustainable food production and diversification of income of the people.
TABLE OF CONTENTS
DECLARATION … … … … … … … i
DEDICATION … … … … … … …… … ii
ABSTRACT… … … … … … …… … iii
ACKNOWLEDGEMENT
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TABLE OF CONTENTS… … … … … … …… v
LIST OF TABLES… … … … … … …… … x
LIST OF FIGURES… … … … … … …… xi
LIST OF PLATES … … … … … … …… … xii
Chapter One … … … … … … …… … 1
1.1 Background of the Study … …
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1
1.2 The Problem Statement … … … … … … 5
1.3 Justification of the Study … … … … … … 7
1.4 Aim and Objectives … … … … … … 8
1.6 Research Questions … … … … … … 8
1.5 Organization of the Study … … … … … 9
Chapter Two … … … … … … …… … 10
Literature Review … … … … … … … … 10
2.1 Chrysophyllum albidum in Agroforestry … … … … 10
2.2 Meaning of Agroforestry … … … … … … 11
2.2.1 Need for Agroforestry … … … … … 12
2.2.2 Characteristics of Agroforestry … … … … 12
2.3 Agroforestry Potentials of Tree and Shrub Species … … 13
2.3.1 Nitrogen Fixation …
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2.3.2 Soil Improvement … … … … … … 15
2.3.3 Soil Conservation … … … … … … 16
2.3.4 Windbreaks and Shelterbelts
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17
2.3.5 Supply of Fuelwood, Timber, Food and other Products … 18
2.2.6 Potential Negative Effects of Trees on Soils … … 20
Chrysophyllum albidum………………21
Taxonomy of Chrysophyllum albidum G. Don ……21
The Tree of Chrysophyllum albidum ………23
Nutritive Value of Chrysophyllum albidum Fruit … …25
Ecology and Distribution of Chrysophyllum albidum …26
2.4.5 Relationship with Environment … … … … 27
2.4.6 Chrysophyllum albidum Cultivation … … … 29
2.4.7 Dormancy of Seeds … … … … … … 30
2.4.7.1 Types of Seed Dormancy … … … … … 31
2.4.7.2 Causes and Methods of Breaking of Dormancy …
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2.4.8 Pests and Diseases of Chrysophyllum albidum … … 34
2.4.9 Post–Harvest Pests and Diseases of Chrysophyllum … 35
2.4.10 Post-Harvest Handling and Treatment … … 36
2.4.11 Uses of Chrysophyllum albidum … … … … 38
Chapter Three …
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3.1 Selection Of Study Area …
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40
Description Of The Study Area ……………40
Relief and Drainage … ……………42
Vegetation42
Soils and Climate ………………44
Population, Ethnicity and Economic Activities ……44
Study Methodology And Data Collection …………46
Socio-Economic Survey ……………46
Experiments To Determine Germination Percentages …48
Initial Growth Rate Experiments (Growth Parameters) …49
Proximate Analysis of Fruit, Leaves and Seeds ……50
Food Product Development …………50
Data Analysis and Analytical Tools ……………51
Limitations of the Study ………………52
Chapter Four… … … … … … …… … 54
Results… … … … … … … … … 54
Characteristics of Respondents ……………54
4.1.1 Age Distribution of Respondents … … … … 55
4.1.2 Educational Level of Respondents … … … … 56
4.1.3 Ethnicity … … … … … … …… 56
Land Ownership and Size of Farm Holdings ……57
Number of C. albidum trees owned by Respondents …58
Marketing Strategies of Fruits …………58
Cumulative Mean Daily Germination ……………60
4.3. Initial Growth Rates of C. albidum Seedlings … … … 61
4.4 Proximate Analysis of fruit, leaves and seeds … … … 65
4.4.1 Nutritive value of various parts of Chrysophyllum albidum …65
4.5 Food Product Development … … … … … …… 65
4.5.1 Drinks…… … … … …… … … 66
4.5.2 Pastries … … … … … … …… 72
Chapter Five … … … … … …… … … 78
Discussion … … … … … … … … … 78
Chrysophyllum albidum as a Source of Livelihood for the People …78
Germination of Chrysophyllum albidum Seeds ………80
Initial Growth Rate of Chrysophyllum albidum Seedlings ……82
Proximate Analysis of Chrysophyllum albidum Fruit,
Leaves, and Seeds 83
Food Product Development ………………84
Agroforestry Potential of C. albidum… …………85
Nitrogen Inputs and Soil Improvement ………85
Chapter Six …… … … … …… … … … 88
Conclusion And Recommendations … … … … … 88
6.1 Conclusions … … … … … … …… … 88
6.1.1 The implication of the results … … … … 89
6.2 Recommendations
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References …… … … … … … … … 93
Appendices … … … … … … … …… 102
Appendix 1: Questionnaire For Socio-Economic Survey …… … 102 Appendix 2: Tables … … … … … … … 116 Appendix 3: … … … … … … …… … 120
LIST OF TABLES
Table 3.1: Treatments for the germination test experiment… … … 49
Table 3.2: Hedonic Scale of Sensory Evaluation… …
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Table 4.1: Level of education of tree owners interviewed… …
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Table 4.2: Number of C. albidum trees owned by respondents… … … 58
Table 4.3: Marketing strategies of fruits by tree owners… … … … 60
Table 4.4 Mean Percentage Germination of C. albidum Seeds … … … 61
Table 4.5: Effects of pre-germination treatments of seeds on
the initial growth rate of C. albidum seedlings … … … 61
Table 4.6: ANOVA of Height of Seedlings … … … … … 62
Table 4.7: ANOVA of Breadth of Leaves … … … … … … 63
Table4.8: ANOVA of Length of Leaves … … … … … … 63
Table 4.9: ANOVA of Number of Leaves …… … … … … 64
Table 4.10: Nutritive value of various parts of Chrysophyllum albidum … … 65 Table 2: No. of Seeds germinating on a particular day after sowing
C. albidum seeds … … … … … … …… … 116
Table 3: Anova Of Height Of Seedlings … … … … … … 117
Table 4: Anova Of Diameter Of Leaves … … … … … … 117
Table 5: Anova Of Length Of Leaves … … … … … … 118
Table 6: Anova Of Number Of Leaves … … … … …… … 118
Table 7: ANOVA of Number of Root Hairs … … … … … 119
LIST OF FIGURES
Figure 3.1: A Map showing the study area … … … … … 31
Figure 4.1: Towns surveyed and the number of tree owners interviewed … … 54
Figure 4.2: Age distribution of tree owners …
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Figure 4.3: Appearance/colour of products (Drinks) … … … … 67
Figure 4.4: Aroma of Products (Drinks) … … … … … … 68
Figure 4.5: Texture of products (Drinks) … … … … … … 68
Figure 4.6: Mouth feel of products (Drinks) … … … … … 69
Figure 4.7: Sweetness of products (Drinks) … … … … … 70
Figure 4.8: Aftertaste of products (Drinks) … … … … … 71
Figure 4.9: Overall acceptability of products (Drinks) …
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Figure 4.10: Appearance of products (Food) … … … … … 72
Figure 4.11: Aroma of products (Food) … … … … … … 73
Figure 4.12: Texture of products (Food) … … … … … … 74
Figure 4.13: Mouth feel of products (Food) … … … … … 74
Figure 4.14: Sweetness of products (Food) … … … … … 75
Figure 4.15: Aftertaste of products (Food) … … … … … 76
Figure 4.16: Overall acceptability of products (Food) … … … … 77
LIST OF PLATES
Plate 4.1: Some of the pastries prepared with C. albidum fruits … … … 66 Plate 1: The seeds of C. albidum 120
Plate 2: The fruits of C. albidum 120
Plate 3: Seedlings of C. albidum during the pre-germination
treatment experiment 121
Plate 4: A typical C. albidum tree 121
CHAPTER ONE INTRODUCTION
Background of the Study
Ghana is an agricultural country. About 60% of the population are engaged in agriculture (Tweneboah, 2000). Agriculture serves as a source of employment, food, income, foreign exchange and raw materials for most of the nation’s industries; among other benefits. Notwithstanding, the manner in which the farming systems are carried out in the country has had some detrimental effects on the land, specifically on the soil. This has therefore led to poor soil fertility and a reduction in crop yields. The desire of farmers to increase production or output and incomes has led to the indiscriminate use of agro-chemicals like fertilizers, and pesticides. These rather tend to worsen the situation. The use of these chemicals can cause health hazard to lives and also our environment (Tweneboah, 2000).
Before the introduction of modern agriculture (where agro-chemicals, improved planting materials and mechanization are used), farmers in Ghana were practising the traditional system known as the shifting cultivation. Shifting cultivation is a rotational system in which after a period of cropping, soil fertility is restored by a fallow of natural vegetation (forest or savannah). It is fully sustainable with adequate lengths of fallow and under low population densities, but these circumstances are rarely found today (Young, 1997). Rising human population is a threat to the continued use of traditional shifting cultivation practices. These are gradually failing to meet the people’s food and energy needs. Efforts to increase agricultural production to overcome food shortages have brought about
environmental degradation: deforestation, soil erosion and soil fertility losses (Oppong, 2002). Furthermore, rising populations mean the situation would worsen unless measures are taken to improve the use of available land. Farmers must be able to produce food, fodder, fuel wood and building materials on the farm without opening new land for cultivation (Agbleze et al., 2002). Approximately 112,000 hectares of tree cover are lost every year through improper farming practices and over exploitation of wood resources (Agbleze et al., 2002). As a result, there is the need for a sustainable land-use system.
In recent years agroforestry has been proposed as an alternative to unsustainable farming systems. A sustainable land-use system is that which meets the needs for production of present land users, while conserving for future generations the basic resources on which production depends (Young, 1997). Agroforestry is an approach to sustainable land use that does not require huge investment (Agbleze et al., 2002). “Agroforestry is a collective name for land-use systems in which woody perennials (trees, shrubs) are grown in association with herbaceous plants (crops, pastures) or livestock, in a spatial arrangement, a rotation or both; there are usually both ecological and economic interactions between the trees and other components of the system” (Lundgren, 1982). For the purposes of this study one of the early definitions is relevant, this is stated as “Agroforestry is a sustainable land-use and management system that increases total production, combines agricultural crops, tree crops and forest plants and/or animals simultaneously or sequentially, and applies management practices compatible with the cultural patterns of the local population” (Bene et al., 1977).
Underlining all aspects of the role of agroforestry in maintenance of soil fertility is the fundamental proposition that trees improve soils. The following facts provide enough evidence that trees apart from the direct products obtained from them improve soils.
The soil that develops under natural forest and woodland is fertile (Rhoades, 1997; Young, 1989a). It is well structured, has a good water-holding capacity and has a store of nutrients in the organic matter. Farmers know they will get a good crop by planting on cleared natural forest.
The cycles of carbon and nutrients under natural forest ecosystems are relatively closed, with much recycling and low inputs and outputs.
The practice of shifting cultivation demonstrated the power of trees to restore fertility lost during cropping.
Experience of reclamation forestry has demonstrated the power of trees to build up fertility on degraded soil; (Young, 1997).
Most indigenous tree species are being under-utilized in agroforestry as there is over- emphasis on the use of exotic species just because there were thought to be easier to manage than indigenous species and their products more saleable (Wood and Burley,1991). However, indigenous species, including Chrysophyllum albidum, are well adapted to the environment where they are found to grow. Once farmers know and use them, farmers can easily adopt them into their agroforestry systems. Some of these indigenous species being fruit trees can play major roles in both socio-economic and environmental development in Ghana.
The major socio-economic benefits of using fruit trees as components of agroforestry systems can be summarized as: production of various products and by-products, regular contribution to the cash economy of the farmer, possibility of staggered production of minor foodstuffs during lean periods of staple food availability, generation of employment potential for the farmer, risk minimization and economic complimentarity in the sharing of scarce resources of production (Nair, 1985).
The environmental merits of fruit trees in agroforestry systems also stem from their micro-site enrichment and macro-site amelioration capabilities. There are strong indications of better organic matter relations (and all consequential benefits) and improved nutrient cycling (and therefore a better nutrient economy) in the soil-plant system of fruit tree- based agroforestry practices. Moreover, appropriate planting and management schedules can be devised for using fruit trees for soil conservation and as windbreaks and shelterbelts (Nair, 1985).
Chrysophyllum albidum (White Star Apple) is an indigenous fruit tree species growing successfully in the Eastern Region, especially, Akuapem North District, parts of the Brong-Ahafo and the Central Regions of Ghana. This tree is a cash crop and can be compared favourably with cocoa. Yet, it has received very little research attention, neither is it grown on a large scale by farmers. It is mostly found in backyard farms with other agricultural crops.
The Problem Statement
In many countries, agroforestry is often considered a branch of forestry or environmental conservation. This has grave consequences when it comes to the allocation of resources to departments or divisions of already marginalized institutions. Tree tenure is also another constraint. Some countries have laws that make all trees, including planted ones government property (Beniest, 2001). Such laws effectively undermine attempts to persuade farmers to plant trees. Another impediment to the progress of agroforestry is the difficulty inherent in technology transfer. The unavailability of experienced agroforestry extension officers and the poor infrastructure in countries where agroforestry is acutely needed are a few examples that can be cited. Even though having trees or leaving trees on the farmlands is age-old practice to the farmers, farmers are not familiar with tree planting and management. They are also not willing to take risks considering the relatively long-term character of agroforestry interventions. Besides, there are many down- to- earth management constraints to be overcome before agroforestry systems can be implemented.
The raising, establishing, protecting and managing of trees require skills and sustained efforts new to many farmers. Water availability for nurseries, protection of young plants against domestic animals, extra time needed to manage more than one component, minimizing negative interactions between trees and crops, all these factors are likely to require additional resources, both labour and capital, which may be beyond
the means of poor farmers. Credit and aid schemes have to be provided to ensure the possibility of wide participation in the establishment phase of agroforestry systems and
technologies (Beniest, 2001). In addition to the above problems, many indigenous species have potentials to be used as agroforestry species, however, they have not been explored enough to promote them in agroforestry.
In many tropical countries, an important point of discussion is whether multipurpose tree species used in agroforestry should be indigenous or exotic. The most important factor in all cases is to make the best choice for the farmer and for the site. In modern farming, there may have been an over-emphasis on exotic tree species for agroforestry mainly because they were thought to be easier to manage than indigenous species and their products more saleable (Wood and Burley, 1991). This has, however, not always been true since there are situations where farmers have been unable to manage the exotic tree species.
Traditionally, there are many important lesser-known indigenous tree species that are neither planted nor adequately explored to discover their potentials to be included in agroforestry systems, but that, nevertheless, provide farmers with valuable products and services. One of such species is Chrysophyllum albidum (White Star Apple). However, the genetic base of many of these species is being reduced as a result of deforestation and there is also a lack of information on their ethno-botanical and socio-economic potentials. This study therefore seeks to identify and evaluate potentials of Chrysophyllum albidum as potential agroforestry tree and the gains from its tree products in the Akuapem North District.
Justification of the Study
The resource potentials of indigenous trees can be tapped through the process of domestication. Researchers have to identify these trees with the help of farmers, who know, appreciate and depend on these species for a number of tree products, before embarking on domestication (Leakey, 1994). Before proper domestication can occur, in agroforestry systems, there is the need for the tree species identified to be evaluated so as to discover their potentials in any specific locality. This should include, indigenous multipurpose species that are common locally, as well as those that are less well known or that have specialized uses. Many of these species can be identified during diagnosis and design exercises, ethno-botanical surveys or specialized marketing studies. Although the fact that local farmers currently utilize a particular species does not necessarily imply that it will be suitable for a specific agroforestry technology, such information at least suggests that the species should be examined since it is known to survive and to be acceptable under local conditions (Wood and Burley, 1991). This study shall indicate how Chrysophllum albidum can be integrated in the farming system to achieve an optimal benefit for the farmer. Farmers would also benefit from the scientific procedures and treatments given to the seeds to enhance their germination. These treatments and procedures would afford farmers in the study area an opportunity to increase the number of seedlings available to them for planting and hence increase the number of trees of Chrysophyllum albidum they own. The management practices of seedlings that would be recommended in this study would be modern scientific agronomic practices that farmers can adopt for fast propagation and growth of the plant.
The detailed botanical description of the plant given in this study would help agronomists and other scientists to identify the plant growing elsewhere with ease. The medicinal properties of the plant provided in this study can be explored for herbal medicine which has currently been introduced into the study of medicine at the Kwame Nkrumah University of Science and Technology. The findings of this study will increase the scientific knowledge in the field, the appropriate method for breaking the seed dormancy to enhance germination as well as the development of food products using C. albidum.
Aims and Objectives
The general aim of the research was to carry out an evaluation of Chrysophyllum albidum (White Star Apple) and its domestication in the development of agroforestry in the Akuapem North District. The objectives were
1. To investigate and evaluate Chrysophyllum albidum as a source of livelihood for the people in the Akuapem North District.
2. To investigate and recommend the appropriate pre-treatment for germinating the seeds.
3. To analyze the nutritive value of the fruits, leaves and seeds; and investigate the uses of Chrysophyllum albidum.
Research Questions
The objectives of the study were used to formulate research questions as a guide. The research questions formulated were:
1. What contributions do Chrysophyllum albidum tree make towards the livelihood of the people in the Akuapem North District?
2. How can the seeds of Chrysophyllum albidum be treated to enhance their germination?
3. What are the nutritive values of Chrysophyllum albidum and other uses of its fruits?
Organization of the Study
This study is divided into six chapters. Chapter one is an introduction of the study. Chapter two is a review of relevant literature on Chrysophyllum albidum, the role and characteristics of trees used in agroforestry. Chapter three describes the study area, the research methodology, which includes the experiments conducted, sources of data and a description of the data analysis. The results of the study are presented in chapter four. Chapter five is a discussion of the results and its implications. Chapter six provides a summary of the study, the conclusions and recommendations.
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