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CHAPTER ONE
INTRODUCTION
1.1 Background to the study
The growth of plants depends on the availability of nutrients from the soil. Thus, it is
important that the soil should potentially provide nutrients for the growth and development of
plants. Prolonged uptake of nutrients by growing plants depletes soil of vital nutrients,
adversely affecting the growth of plants. Organic manure can be added in order to
compensate for the losses due to leaching and uptake by existing plants from the soil
(Russell, 1998).
Milicia excelsa formerly called Chlorophora excelsa belongs to the family Moraceae. The
tree is mostly found in West, Central and East Africa, extending from Guinea Bissau to
Mozambique. Milicia excelsa is a durable wood used for the purposes of exterior and interior
joinery, frames and doors, luxury cabinet works and garden furniture. Other uses include
floorings, steps and stairs, paneling and moldings, decorative veneer, plywood and the
construction of vehicle and truck bodies (Oteng-Amoako, 2006). The high demand for the
wood and its other products has resulted in over exploitation.
The species is now considered as a scarlet species; these are species that are common but
under more imminent threat. Currently it has over 200 % exploitation rate by the Forestry
Department of Ghana and requires special permit for it to be harvested (The Ghana Forest
Service, 1998). To replenish the stocking of such valuable species, its plantations were
established. Seedlings of Milicia excelsa raised for plantation purposes appear weak and
slender in form and hardly withstand the adverse conditions of the weather making it very
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difficult in raising healthy seedlings and this affects the species growth performance as well
as its survival rate in the establishment of its plantation (Irvine, 1961).
Addition of poultry manure to improve the nutrient status of the growth medium (soil) can
enhance the general growth performance of seedlings in a nursery. The introduction of
Milicia excelsa into plantations could have beneficial effects on the forest of Ghana, since it
will reduce the high dependency on the forest for Milicia excelsa species for subsistence or
commercial purposes. However, for a plantation program to yield maximum environmental
and economic benefits, healthy and good seedlings should be supplied inexpensively
(Appiah, 1998).
1.2 The Problem statement
Seedlings of Milicia excelsa raised for plantation purposes appear weak and slender in form
and hardly withstand the adverse conditions of the weather making it very difficult in raising
healthy seedlings and this affects the species growth performance as well as its survival rate
in the establishment of its plantation (Irvine, 1961). There is therefore the need to investigate
possible solutions to this problem in order to enhance the species growth performance.
1.3 Justification of the study
Manuring can help increase the nutrient status of soils depleted due to leaching and uptake by
existing plants from the soil. A lot of effort has been put into the promotion of the use of
mineral fertilizers for crop production, not much seems to have been done in the use of
organic forms of fertilization for soil fertility amelioration (MOFA, 1998).
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The use of organic manure preferably, poultry manure will help and encourage the
establishments of Milicia excelsa plantations. This will facilitate increasing supply of Milicia
excelsa timber products in the world market.
1.4 Aim and objectives
This study aims at determining the effect of organic manure on the early growth performance
and the percentage survival of Milicia excelsa seedlings.
Specific objectives
1. To determine the effect of poultry manure on the vegetative growth (stem height and
diameter) of Milicia excelsa seedlings.
2. To determine the effect of poultry manure on the percentage survival of Milicia
excelsa seedlings.
3. To determine the effect of poultry manure on the mean number of Milicia excelsa
seedling leaves over some period of time.
1.5 The research hypothesis
The research null hypothesis was that poultry manure would not provide environmental
conditions favourable for the growth and development of Milicia excelsa seedlings. However,
the alternate hypothesis for this research was that different levels of poultry manure would
provide environmental conditions favourable for the growth, development and survival of
Milicia excelsa seedlings.
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CHAPTER TWO
LITERATURE REVIEW
2.1 The Milicia Species
Milicia excelsa formerly known as Chlorophora excelsa and locally known as “Odum”
belongs to the family Moraceae. In Africa the genus Milicia, has two species, M. excelsa and
M. regia. The African species are very similar and are not distinguished in the timber trade,
but are commonly referred to as “Iroko” (Hawthorne, 1990). Milicia excelsa is currently
found in forests of Africa stretching across the West Africa sub- region from Senegal through
Cote D’ Ivoire, Ghana to Nigeria. Other places of occurrence include Angola, Mozambique
and Tanzania (Hall and Swaine, 1981). Guinko (1985) cited by Cobbinah (1992) speculated
that the presence of M. excelsa in fetish worship sites or on sites of former special cemeteries
is an indication that the species may have a wide distribution than its present range. The
Odum tree provides hard, termite-resistant, all-purpose wood which is highly
commercialized.
2.1.1 Botanical Description of Milicia excelsa
Odum is a very tall deciduous tree, which can grow to about 60 meters high and 2.5 meters in
diameter. It may have a straight cylindrical bole of about 30 meters before branching (FAO,
1986). However according to Brooks (1949), these dimension tend to be less in drier areas.
The buttress is usually short and blunt, sometimes with root spurs and large exposed reddish
brown lateral roots.
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In the young tree, the bark is smooth but later becomes rough and flaking. In the mature tree,
the rough bark has reddish-brown conspicuous lenticels and slashes very gritty with brown
spots and rapid watery latex. Venation on its lower surface looks like a sponge with
conspicuous gaps in between the veins with lateral nerves up to 12 in maximum with a simple
petiolate leaf (Hawthorne, 1990). The juvenile leaf is oblong-elliptic with serrate margin and
densely covered with hair below the leaf (FAO, 1986). It is usually light green, soft and
smooth to touch. However, as the tree grows, it puts on new leaves of different form – broad,
ovate with darker colouring and less serrated edges which are shiner (white, 1966).
2.1.2 Ecology of Milicia excelsa Seedlings
Milicia is a pioneer species. The seedling thus responds strongly to increase in irradiance. It
cannot survive in deep forest shade but grows rapidly in full sun. Photoblasticity in the
species accounts for its prevalence in more heavily disturbed forest, on road margins and on
farms. The seedling shows greater investments in leaves. When it happens to occur in the
under shade, it produces thin leaves with large surface area, while thick leaves are produced
in high irradiance, having lower specific area. It has high leaf turn over in all light intensities
(Swaine et al, 1997). Generally, it has high compensation and low saturation points.
The common adversary to the seedling is Phytolyma spp which cause galls to be formed on
the leaves. This disrupts the plants normal physiological processes, causing epical dieback,
growth reduction and seedling mortality. The succulent young shoots are sometimes browsed
by duikers and other animals (Irvine, 1961). The Milicia gall bug, Phytolyma spp are insects
of the order Homoptera and the family Psyllidae.
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2.2 Growth in Tropical Seedlings
A seedling is a plant in which a significant proportion of its biomass is constructed from seed
reserves, rather than from resources acquired auto-trophically (Kitajima, 1996). However, by
convention, a seedling to a forester refers to a young plant of about 2.7 m (Whitmore, 1996).
Seedlings are basically of two types, those that can do well under shade cover called shade
tolerant and those that can only survive and grow well in the presence of light, called shade
intolerant or pioneer species (Swaine et al, 1997).
The growth of a tropical tree seedling in a particular environment and their ability to adapt to
changes in that environment depend on the complex interaction of the morphological and
physiological attributes of each species. The growth and development of a seedling is in
stages. These stages are seed stage, seedling expansion stage, seedling seed- reserve stage,
seedling autonomous stage and juvenile stage (Garwood, 1996). The tropical tree species
exhibit high morphological diversity, but little is known about the functional significance of
this morphological diversity (Kitajima, 1996).
Initially the growth is primary and involves developments which terminate when direct
derivatives of apical meristems becomes mature. This growth produces roots, stem and leaves
in the seedling. Secondary growth which result from the activities of the vascular cambium,
occur in the latter stages and is responsible for the thickening of both roots and stem
(Kozlowski, 1971).
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2.2.1 Growth of Milicia seedlings
Growth can be defined as the increase in mass due to division and enlargement of cells and
may be applied to an organism as a whole or any of its parts. All living organisms begin as a
single cell, which usually divides and keeps dividing until possibly billions of cells are
formed. As the various cells mature, they usually become larger and then differentiate. Thus,
they develop different forms adapted to specific functions such as conduction, support or
secretion of special substances (Stern, 1997). According to Levetin and McMahon (1999),
apical meristems are located at the tip of all roots and stems and contribute to the increase in
length of plants. Tissues that develop from these apical meristems are part of the primary
growth of the plant and give rise to the leaves and non-woody stems and roots. Some plants
have additional meristematic tissues that contribute to increases in diameter. These are the
vascular cambium and cork cambium. Tissues developing from these are considered part of
the plant secondary growth.
2.3 Factors Affecting Seedling Growth
Seedling growth and development revolve round carbohydrate manufacture and utilization.
Factors that influence the manufacture and utilization of carbohydrates and other biosynthetic
processes, affect the growth. These factors include water, light, temperature, herbivory and
other edaphic factors (Nwoboshie, 1982).
2.3.1 Water, Light and Temperature
Of all the factors controlling seedling growth, water is the most critical. Water is the vehicle
for all physiological and biochemical processes through which life is maintained.
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In the plant, opposing effect of transpiration and water absorption controls water. Whenever
transpiration is greater than absorption, the plant becomes dehydrated. A decrease in
hydration of protoplasm of cells in the meristematic tissues usually results in cessation or
checking of cell division or cell enlargement or both. If there are no limiting growth factors,
an increase in hydration of the protoplasm of a meristem usually results in an increase in the
rate of cell division and the cell enlargement phase of tree growth. However, all phases of
tree growth are not equally affected by the attenuation in the volume of water within the
seedling (Nwoboshie, 1982).
Light is the principal limiting factor for growth in all forests (Swaine et al, 1997). Light
affects growth through its effects on photosynthesis. It affects photosynthesis in terms of its
quality or wavelength composition, intensity or irradiance and duration. Light is important for
many physiological processes such as stomatal action permeability, absorption of electrolytes
as well as athocyanin and chlorophyll synthesis (Nwoboshie, 1982). Spatial variation in light
availability leads to variation in other physical and biotic environmental factors such as
temperatures, herbivore abundance and activities of pathogenic fungi and bacteria. Thus
successful seedling establishment in the under story or light gaps hinges upon species-
specific responses to these multiple factors confounded with light environment, not merely
upon light intensity, spectral quality or sun flecks (Kitajima, 1996).
Temperature affects plant growth through its effects on biochemical processes (Fitter and
Hay, 1987). Physiological and biochemical processes in plants are catalyzed by enzymes
which are active within certain temperatures range; hence plant can only growth within these
temperatures ranges. In the tropics, this rage is between 150C and 360C.
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Within the range, the growth of some plants increases with temperature while it is opposite
for other plants (Nwoboshie, 1982).
2.3.2 Herbivory
Herbivory is the consumption of plant biomass or parts of plants by animals. The parts
usually consumed are the fruits, seeds, leaves, twigs and buds. Mammals, birds and insect
defoliators are normally responsible for this. Seedlings are more prone to herbivory and this
may cause their early death or retard the growth of seedlings, though other factors may be
favourable.
The herbivores often prefer the young and fleshy leaves that may be rich in nutrients such as
nitrogen, phosphorus and potassium. According to Hall and Swaine (1986) plants have
defensive mechanisms to prevent being preyed upon. These mechanisms include hairs,
phytotoxins and thorns, shedding of damaged leaves and high leaf turn over in short-lived
leaves. Shade-tolerant seedlings appear to show greater defense and storage allocation than
the pioneer or shade intolerant seedlings (Kitajima, 1996).
2.3.3 Edaphic Factors
Although soil may vary considerably in structure and in physical, chemical and biotic
properties, the rate of growth of a seedling is influenced by those properties of the soil. From
the soil, the plant derives its nutrients and it is a storehouse for water and oxygen, all of
which are necessary for the physiological processes associated with growth.
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Hence the relative abundance of these factors in a particular soil, determine the rate at which
the seedling will grow on the soil (Brady, 1990).
2.4 Plant Fertilization
Fertilizer is any substance which is incorporated into the soil to increase crop growth and
yield by providing one or more of the elements essential for plant growth. Fertilizers are
applied to promote healthy growth, assist plants to overcome adverse effects of diseases or
insects or to correct mineral deficiencies, increase growth rate and maintain satisfactory vigor
(Evans, 1992).
Fertilizer can be applied anytime during the growing season if a seedling’s leaves turn
yellowish, experience extreme slow growth or some other signs. If fertilizers are to be applied
under hot, dry conditions, it is important to water the seedlings soon after the fertilizer
application so that the salt from the fertilizer does not damage the seedling root system
(Swanson, 2000). Plants need a number of essential elements to enable them to grow and
reproduce. These elemental nutrients may be classified as micronutrients and macronutrients.
The macronutrients (primary nutrients) include Nitrogen (N), Phosphorus (P) and Potassium
(K). Plants need these elements in relatively large quantities for their metabolism processes.
The most important of the macronutrients is Nitrogen (N) which is the most limiting nutrient
in the soil. It is generally known that nitrogen determines the yield of most crops more than
any other nutrient element provided there is adequate rainfall or water supply (Halley, 1982).
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The micronutrients Copper (Cu), Zinc (Zn), Manganese (Mn), Boron (B), Molybdenum
(Mo), Iron (Fe), Chlorine (Cl), Calcium (Ca), Magnesium (Mg) and Sulphur (S) are needed in
relatively small amounts and are generally found in sufficient quantities in normal pH
balanced soils. However, a deficiency in any of these nutrients can affect the health of
seedlings. The macronutrients have a role in building the structure of plants, whereas
micronutrients are important in enzyme systems and contribute to the plants function rather
than its structure (Halley, 1982; Brian and West, 1996).
2.5 Organic Fertilizer
Organic fertilizers are obtained from living sources, an example is manure. The most
noteworthy advantage of organic fertilizers is the fact that they are mostly insoluble and
therefore are slower to release nutrients to plants. This reduces the leaching effect that results
from most chemical fertilizers that causes so many problems (Zublena, 1996). Organic
fertilizers also help to improve soil quality. The consistent use of chemical fertilizers creates
plant life dependent upon synthetic fertilization as these fertilizers only work at the plant
level.
Through the introduction of organic matter and resulting improvement of the soil and
stimulation of the soil microbial activity, an environment can be created to support plant life
and provide a slow and consistent flow of nutrients to the plants. Organic fertilization is one
of the options for creating a long lasting and healthy plant-soil environment that is
ecologically responsible and economically viable for long term run (Hileman, 1972).
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2.5.1 Poultry Manure
Poultry manure is described as dropping from birds, which are kept domestically, especially
chickens. Chicken manure is the richest animal manure in terms of N, P and K (Russell,
1998). According to Hileman (1972), poultry manure is an excellent source of nutrients that
can be used in most fertilizer programs. The growth of the poultry industry in Ghana and the
corresponding increase in quantity and availability of poultry manure as well as its associated
environmental hazards has made it prudent to put poultry manure into an efficient use such as
raising seedlings in the nursery. Poultry manure has been found to be environmentally safe
source of fertilizer than inorganic fertilizer. Studies carried out to investigate the residual
effects of inorganic fertilizer on soil, destroyed soil organic and increased pests and disease
activities. The management of poultry manure can be a valuable source of nutrients for plants
and still ensure the safety of the environment (Brady, 1984).
2.5.2 Nutrient Value of Poultry Manure
Poultry manure is the most valuable of all manures produced by livestock. It has been used as
a source of plant nutrients and as a soil amendment. The type and amount of nutrients in
poultry manure and the nutrients’ eventual availability to plants may vary considerably
(Halley, 1982). Some factors affecting nutrient value of applied poultry manure include: type
of ration fed, method of collection and storage, amount of feed, bedding and/or water added,
time and method of application, soil characteristics, the crop to which manure is applied and
climate (Halley, 1982; Zublena et al., 1993). Hileman (1972) described poultry manure as
organic manure with high fertilizer value which is successfully used on wide variety of crops
as a valuable source of plant food. Increasing levels of various harmful elements (copper and
arsenic) and inorganic salts (sodium, calcium, potassium and magnesium) in feed will
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increase their concentrations in manure. There is concern about the potential toxic effects to
plants of high concentration of heavy metals and salts in soil, as a result of high application
rates of manure to the land. Generally, as the percent moisture of animal waste material
decreases, the percent nutrient content increases (Gale, 1997).
Table 2.1 the Percentage Composition of Poultry Manure
Manure Organic matter Ash N P2O5 K2O
Fresh manure 80 20 6.0 4.0 2.0Dry matter)
Old manure 65 35 3.5 6.0 2.8(Dry matter)
Source: Smith (1962).
About 30 percent of the total nitrogen in fresh manure is in the form of undigested food
residues; the remaining 70 percent is urinary nitrogen consisting of nearly 10 percent as
ammonium compounds and 60 percent as uric acid (Table 2.1). The faecal nitrogen is
relatively stable, but uric acid is a very high unstable compound in moist conditions and will
change into urea and ammonium salts even at fairly low temperatures. The loss of nitrogen is
only about 10 percent if fresh manure is dried quickly at a high temperature. It is best
therefore to spread manure directly on the field in wet weather; the rain facilitates the
incorporation of ammonia and soluble nitrogen compounds into the soil, where they are
absorbed and speedily converted into nitrates (Smith, 1962).
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2.5.3 Positive Effects of Poultry Manure
The effect of farmyard manure on humus is evident in the tropics. Agboola et al. (1975)
reported that a moderate application of manure on crop soils in the rainforest zone was
sufficient to slow down humus decomposition, which progress only half as fast as with
mineral fertilizers. The sorption power; that is the soil’s capacity to store and release
nutrients is also improved by manure application. Significant results have been obtained
when manure was applied to wetland rice (Müller-Sämann and Kotschi, 1994). Manure also
aids in reducing the incidence of some plant diseases. Mathur and Sinha (1966) studied the
influence of manuring on seedling-rot, root-rot and wilt of guar and found that the incidence
in all the cases was considerably reduced in manured soil. The reduction in disease incidence
was attributed to the increased plant vigour resulting from the high nutritive status of the
manured soil.
2.5.4 Potential Harmful Effects of Poultry Manure
In areas of intense poultry production, over fertilization of land with poultry manure occurs.
The result is suspected groundwater and surface water problems as excess nutrients run-off
the land or leach into groundwater supplies. Fresh stable manure is prone to form organic
acids. These are rapidly processed by soil organisms, which can lead to an overload of
oxygen and nitrogen in freshly manured soils (Gale, 1997). The C/N ratio of fresh manure is
often too high. This can result in a temporary N block such that hardly any nitrogen from
manure will be available in the following period. Manures are also costly per unit of plant
food (Halley, 1982; Müller-Sämann and Kotschi, 1994).
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CHAPTER THREE
RESEARCH METHODOLOGY
3.1 Study Area
The experiment was conducted at the Faculty of Renewable Natural Resources
Demonstration Farm (KNUST-Kumasi). This area falls within Moist Semi-deciduous
Vegetation Zone of West Africa. The area is characterized by a bimodal rainfall pattern with
the major wet season between May and July. This area experiences a short dry season in
August and a long one between December and March. The annual rainfall of the area ranges
between 1250 mm -1500 mm. The soil in the study site belongs to the family Ferric Acrisols
in the soil taxonomy. Ferric Acrisols are loamy sand, well drained but strongly acidic (Adu
and Asiamah, 1992).
3.2 Research Design
The experimental design used in this field experiment was a Randomized Complete Block
Design. The randomized complete block design is one of the most widely used experimental
designs in natural resources research. Blocking is done to reduce experimental error by
eliminating the contribution of known sources of variation among experimental units (Nkyi,
2009). Two-month old Milicia excelsa seedlings were obtained from the Forestry Research
Institute of Ghana (FORIG), Kumasi-Ghana. The poultry manure was obtained from the
Animal Science Department of the Faculty of Agriculture (KNUST-Ayeduase). Other tools
and equipment used included cutlass, rake, watering can, tape measure, hand fork and hoe for
the preparation of the planting bed.
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The plant parameters measured were the height (cm), stem diameter (mm) and the number of
leaves. According to Mohr and Schopfer (1995), height and stem diameter are some of the
frequently used methods of measuring the growth of multi-cellular living systems and often
advantageous to use several characteristics for the same system.
Leaves are also an important part of plants; they help in the process of photosynthesis. Leaves
have their own definite shape and arrangement according to requirements of the plant. Leaves
trap energy from sunlight and convert it into pure compounds. Leaves were counted visually.
An electronic caliper was used in measuring the stem diameter while the height was
measured with a meter rule. Data on the height, stem diameter and number of leaves were
collected two days after transplanting and then fortnightly over the twelve weeks of the
research. The experiment was conducted from 23rd November, 2010 to 19th February, 2011.
3.2.1 Experimental Design and Layout
The experimental design used was a Randomized Complete Block Design. The study was
carried out in three blocks, each block consisting of five plots (Figure 3.1). The poultry
manure was applied at the rate of 17,500 kg/ha as recommended by Zublena et al., (1993).
Five levels of the poultry manure were used for the experiment. T1 (0.0 Kg), T2 (0.90 Kg),
T3 (1.80 Kg), T4 (2.70 Kg) and T5 (3.60 Kg)
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BLOCK 1 BLOCK 2 BLOCK 3
Plot 1=T2 Plot 1=T2 Plot 1=T3
Plot 2=T4 Plot 2=T5 Plot 2=T2
Plot 3=T1 Plot 3=T4 Plot 3=T5
Plot 4=T5 Plot 4=T1 Plot 4=T4
Plot 5=T3 Plot 5=T3 Plot 5=T1
1.0 m 0.5 m 1.0 m 0.5 m 1.0 m
Figure 3.1 RCBD Experimental layouts with the allocated treatment.
3.2.2 Experimental Procedures
Three beds representing the blocks of size 1.0 m × 5.0 m (5.0 m2) each and plots with
dimensions of 1.0 m × 1.0 m (1.0 m2) were constructed with spacing of 50 cm between the
blocks and plots making the total plot length of 7.0 m with an area of 7.0 m2. The various
treatments were randomly allocated to the plots (Fig 3.1) with eight seedlings per plot.
Reference points of 1cm above the soil surface of the seedlings were marked with non-
poisonous indelible ink to provide consistency at the point of the height and diameter
measurement. The total number of experimental plots was fifteen. The poultry manure was
applied at the rate of 17,500 Kg/ha as recommended by Zublena et al., (1993). Rates of
poultry manure application were therefore applied based on the following calculation;
10000 m2 (1 hectare) = 17500 Kg.
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7.0
m
1.0 m2 (plot size) =
1. 0 m2 X17500 Kg10000 m2
= 1.75 Kg/plot ≈ 1.80 kg/plot (average application).
The recommended rate per plot was halved, doubled and multiplied by one-half to achieve
the various treatment levels. Five levels of the poultry manure were used for the experiment.
T1 (0.0 Kg, control), T2 (0.90 Kg, halved), T3 (1.80 Kg, recommended rate per plot), T4
(2.70 Kg, multiplied by one-half) and T5 (3.60 Kg, doubled). The poultry manure was
applied to the soil two weeks before transplanting the seedlings to the experimental plots to
allow the ammonia to be nitrified so that it will not burn the young plants as recommended by
Smith (1962).
3.3 Cultural Practices on the Experimental Plots
Seedlings were transplanted from the poly bags when they were two months old. The
transplanting exercise was undertaken late in the afternoon after the bed had been watered
thoroughly. According to Hilary (2009), the best time of day to plant is in the late afternoon
when the sun is not so hot.
By taking advantage of this time of day, the new plants are able to acclimatize overnight.
Strong sun and wind have a potentially adverse effect on new transplants and unless watered
carefully, and in some cases sheltered from the wind and sun, they can severely wilt. This
places the plants under stress at the very beginning of their growing cycle. This is not a good
idea because sometimes they never bounce back and do not thrive as well as they could
have. Watering of the transplanted seedlings was done immediately after transplanting and
twice daily and evenly with each plot receiving about the same volume of water. Plots were
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not watered after heavy rains due to high incidence of fungal infestation when the plant
roots are overwatered (Swanson, 2000).
Weeds that appeared on the beds were controlled by hand-picking to prevent competition for
water, nutrients, space and light. Weeds that appeared between the beds were hoed to
eliminate any type of competition. According to Townsend and Sinden (1999), weeds host
pests and diseases that can spread to cultivated crops. Weeds also impose costs on producers
in two ways; through reductions in the quality and quantity of yields, and increases in input
requirements for weed control. This cost may have economic consequences for the wider
community if a large number of farmers are affected, leading to variations in supplies and
prices of commodities.
3.4. Data collection
An indelible ink was used to mark each seedling 1cm above the soil, where the diameter and
height readings were taken so that irregularity of the soil around the seedlings would not
affect the recording. Initial measurements of both the heights and the diameters were taken
two days and two weeks after transplanting and application of the treatments respectively.
Subsequent readings were taken every two weeks for a period of three months within which
seven readings were recorded.
3.5 Data Processing and Analysis
All data collected were subjected to a one-way Analysis of Variance (ANOVA). Microsoft
excel was used to compute the increment of the various plant parameters measured. Least
Significant Difference (LSD) was used to separate treatment means that differed
significantly. Any treatment mean with a difference more than the calculated Least
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Significant Difference was interpreted as significant and ascribed ** and those without any
significant difference were ascribed ns.
This was done for all the plant growth parameters measured with the exception of the
survival percentage. Coefficient of Variation was used to ascertain the acceptance of the
experiment as recommended by Nkyi (2009) that the Coefficient of Variation should not be
greater than 20 percent, otherwise the number of blocks should be increased or the
experiment rejected.
The Chi-Square (X2) method with the formula: X2 =∑ {
(Observed value-Expected value )2
Expected value}
was used to determine the significance of the poultry manure on the seedling percentage of
survival at a significant level of 5%. A Chi- Square value higher than the calculated value
renders the effect insignificant and vice versa. The results are represented using appropriate
graphs and tables.
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CHAPTER FOUR
RESULTS
4.1 Height measurements of Milicia excelsa seedlings
Almost all the treatments T1 (0.0 Kg) T2 (0.90 Kg), T3 (1.80 Kg), T4 (2.70 Kg) and T5
(3.60 Kg) showed increment in height throughout the experimental period. However,
Treatment (T1) and Treatment T5 showed a decrease in height in the eighth week with
Treatment T1 recording the minimum increment in height and Treatment T4, the highest
increment in height, (Fig.4.1). The experiment showed that, from the 2nd to the 6th week
there were low increments in height for all the treatments. Treatment T1 and Treatment T5
had the same increment within the first four weeks. However Treatment T1 had a decrease in
height between the 6th and 8th week. From the 10th to the 12th weeks, Treatment T4
recorded the highest mean height increment (Fig 4.1).
The Analysis of Variance (ANOVA) carried out indicated that the treatments were
significantly different at 5% level of significant on mean height increment of the seedlings
(F0.05, 4, 8= 8.40 ≥ F0=3.84). Least Significant Difference (LSD) analysis revealed that, there
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were significant differences between T1 (0kg) and each of T2 , T3, T4 and T5 but no
significant difference among T2 and T3, T5 as well as between T3 and (T4 and T5). It was
observed that there is a drastic decrease in the height increment between week 6 and week 8
The initial mean height increment for all the treatment levels recorded after fertilization were;
T1= 9.17 cm, T2= 9.88 cm, T3= 10.13 cm T4= 9.70 cm, T5= 10.00 cm as against 19.25 cm,
23.72 cm, 25.19 cm, 30.28 cm and 24.00 cm for treatments T1, T2, T3, T4, and T5,
respectively as the values recorded at the time the experiment was terminated on 19th
February, 2011.
Week 2 Week 4 Week 6 Week8 Week 10 Week 120
1
2
3
4
5
6
7
8
9
T1
T2
T3
T4
T5
Weeks after transplanting
Hei
ght
incr
emen
t (c
m)
Fig 4.1 Mean Height increments of Milicia excelsa seedlings.
4.2 Diameter measurements of Milicia excelsa seedlings
Diameter increments were observed for all the treatments throughout the experiment period,
(Fig 4.2). For the first six weeks after the application of the treatments, the increments were
high for all treatments except treatment T5 which had a low increment of 8.69 cm. The
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increments for all the treatments decreased from the 8 th to the 10th week. There were steady
increments for treatments T1, T3 and T4 between week 10 and week 12 while treatments T2
and T5 were not significantly different. Treatment T4 had the highest mean increment
followed by T3 and T2 with treatment T1 recording the least mean diameter increment.
The results of the Analysis of Variance (ANOVA) showed that, all the treatments had no
significant effect on the diameter increments of the seedlings at a significant level of 5%
(F0.05,4,8 = 3.74 ≤ F0 = 3.84). Least Significant Difference (LSD) showed that, there were
significant differences between T1 (0.0 Kg) and T4 (2.70 Kg), and treatments T4 and T5 (3.6
Kg) but no significant difference among T1 and each of T2 (0.9 Kg), T3 (1.80 Kg), and T5.
Again, there were no significant difference among T2, T3 and T4.
Week 2 Week 4 Week 6 Week8 Week 10 Week 120
0.2
0.4
0.6
0.8
1
1.2
T1
T2
T3
T4
T5
Weeks after transplanting
Dia
met
er in
crem
ent
(mm
)
Fig.4.2 Mean diameter increments of Milicia excelsa seedlings.
4.3 Mean Number of Leaves of Milicia excelsa seedlings
23
All the treatments showed increment in mean number of leaves throughout the experimental
period. However, Treatment T1 (0.0 Kg) showed the lowest increment and Treatment T4
recorded the highest increment, (Fig.4.3). The experiment showed that, from the 2nd to the
6th week low increments were recorded for all the treatments, (Fig 4.3). Between the 6th and
10th week, there were steady increments of the mean number of leaves for Treatments T2
(0.9 Kg), T3 (1.80 Kg), T4 (2.70 Kg and T5 (3.60 Kg) while Treatment T1 still remained
almost the same as the first six weeks.
From the 10th to the 12th week, the mean number of leaves remained the same for all the
treatments except treatment T4. Analysis of Variance (ANOVA) at 5% significance level
showed that poultry manure had a significant effect on mean number of leaves (F0.05, 4, 8=
48.81 ≥ F0=3.84). Least Significant Difference (LSD) showed that, there were significant
differences between almost all the treatment means but no significant difference among T1
and each of T2, and T3 as well as between treatment T3 and treatment T4. The mean number
of leaves at the end of the study period were T1=7.67, T2=7.67, T3=10.00, T4=19.67 and
T5=14.0
24
Week 2 Week 4 Week 6 Week 8 Week 10 Week 120
2
4
6
8
10
12
14
16
18
T1
T2
T3
T4
T5
Weeks After Transplanting
Mea
n N
um
ber
of
Lea
ves
Fig.4.3 Mean Number of Leaves of Milicia excelsa seedlings.
4.4 Percentage Survival of Milicia excelsa seedlings
Three months after transplanting, the percentage survival of the Milicia excelsa seedlings
ranged from 87.50% to 100% (Fig4.4). There were significant differences in the rate of
survival between the various treatments with a survival expectancy of 60% (x²=30.74 >
23.70, p=0.05). All the treatments recorded no mortality during the first six weeks after
transplanting. However, treatment T1 recorded three plants mortality representing 12.50
percentage of mortality in the eighth week. All other treatments recorded mortality as low as
zero percent. The total mortality over the entire study occurred in the first eight weeks. There
was no mortality after 8 weeks of the experimental period and all the treatments (T2, T3, T4,
and T5) except treatment T1 had the same percentage survival of 100 percent throughout the
study period.
25
T1 T2 T3 T4 T580
85
90
95
100
105
Treatments
Per
cen
tage
Su
rviv
al
Fig.4.4 Percentage survival of Milicia excelsa seedlings
CHAPTER FIVE
DISCUSSION
5.1 Height increments of Milicia excelsa seedlings
All the treatments increased in height throughout the study period, Fig 4.1. Analysis of
Variance (ANOVA) tested at 5% significance level showed a significant effect of poultry
manure on the mean height increments. However, the degree of increment varied among the
26
treatments. There was low height increments recorded for all the treatments between the 2nd
and 6th weeks and even a decrease in seedling height increment for the 8 th week. This might
be due to the fact that the poultry manure applied had not yet fully decomposed to reach the
roots of the seedlings for it to be absorbed. Therefore the little fertility in the soil was then
used by the seedlings. The significant increase in the height of the Milicia excelsa seedlings
might be due to the nutrient contribution from decomposing poultry manure. The effect of T4
(2.7 Kg of manure) was greater than that of T1 (0 Kg of manure). This revealed a sharper
growth with increasing rate of manure application. This confirms the assertion by Duryea and
Brow (1984) that seedlings grown at fairly higher fertilization levels produced higher growth
rates.
From the 8th to the 10th week, there were steady and sharp increases in heights for T1, T4 and
T5; however, T2 and T3 almost had a constant stem increment. Smith, (1962) reported that
poultry manure may be of little immediate value in correcting nutrient deficiencies since it
takes time for it to decompose and release nutrients to plants roots. The role played by the
three primary nutrients (N P K) is vital in the process of plant development.
The significant increase in the height of the seedlings might be due to the nutrient
contribution from decomposing poultry manure.
The application of 2.7 Kg of manure T4, performed better than when 0.9 Kg of manure T2
was applied. The performance of T4 (2.7 Kg of manure) could be attributed to the increased
supply of nitrogen (N). This might have increased the meristematic and development
activities through the differentiation of tissues and have therefore increased growth with
respect to the height of the seedlings. This result confirms the findings of Mohan and Sharma
27
(1992) who worked on the effect of nitrogen and sulphur on the growth and yield of mustard
seedlings.
Hileman (1972) described poultry manure as organic manure with high fertilizer value which
is successfully used on a variety of crops. Zublena et al. (1993) also noted that the organic
matter in soil improves moisture and nutrient retention. These properties of high fertilizer
value, improvement in moisture and nutrient retention helped in increasing the rate of growth
and subsequently produced viable and healthy seedlings that can withstand adverse weather
conditions. Therefore the presence of these nutrients in sufficient amounts resulted in
vigorous growth of the seedlings. From the 10th to 14th week, the mean height increments
continued to increase for all the treatments except for T1. Organic fertilizers are one of the
options for creating a long lasting and healthy plant-soil environment that is ecologically
responsible and economically viable for long term supply of nutrients for plant growth and
development (Gale, 1997).
The research alternate hypothesis for this research that different levels of poultry manure
would provide environmental conditions favourable for the growth, development Milicia
excelsa seedlings is therefore accepted and the null hypothesis rejected.
5.2 Diameter increments of Milicia excelsa seedlings
All the treatments (T1, T2, T3, T4 and T5) had no increasing effect on the seedling stem
diameter throughout the study period according to the Analysis of Variance (ANOVA) tested
at 5% significance level of the Milicia excelsa seedlings. Also, the degree of increment varied
among the treatments with T1 being the least and T4 as the highest. Low increments in
28
diameter were recorded for all the treatments between the 2nd and 6th week. This might be due
to the fact that the poultry manure applied was being used for apical meristematic growth.
Initially the growth is primary and involves developments which terminate when direct
derivatives of apical meristems becomes mature. This growth produces roots, stem and leaves
in the seedling. Secondary growth which result from the activities of the vascular cambium,
occur in the latter stages and is responsible for the thickening of both roots and stem diameter
(Kozlowski, 1971).
5.3 Mean Number of Leaves of Milicia excelsa seedlings
All the treatments showed increment in mean number of leaves throughout the experiment
period. However, Treatment one T1 showed the minimum increment and Treatment T4
recorded the highest increment, (Fig.4.3). Analysis of Variance (ANOVA) at 5% significance
level showed a significant effect of poultry manure on the mean number of leaves.
This significant increment might be due to the availability of nutrients for plant growth
especially in the leaf tissues. This confirms the assertion by Kozlowski (1971) that the initial
growth of seedlings is primary and involves developments which terminate when direct
derivatives of apical meristems becomes mature.
This growth produces roots, stem and leaves in the seedling. Secondary growth which result
from the activities of the vascular cambium, occur in the latter stages and is responsible for
the thickening of both roots and stem diameter. The alternate hypothesis for this research that
different levels of poultry manure would provide environmental conditions favourable for the
29
growth, development Milicia excelsa seedlings is again accepted and the null hypothesis
rejected.
5.4 Percentage Survival of Milicia excelsa seedlings.
Three months after transplanting, the percentage survival of the Milicia excelsa seedlings
ranged from 87.5 to 100 percent (Fig4.4). According to a Chi-Square (x2) test carried out it
revealed that, there was a significant effect of the poultry manure applied to the seedlings
with a survival expectancy of 60 percent at significant level of 5%. All the treatments (T1,
T2, T3, T4 and T5) recorded no mortality during the first six weeks after transplanting.
However, three mortalities of plants were recorded during the first 8 weeks representing
about 12.50% of mortality in the eighth week for treatment T1.
All other treatments recorded mortality of 0%. The total mortality over the entire study
occurred in the first eight (8) weeks with only one plant dead. This might be due to low
supply of water to the seedling growth and development during the dry season of the
research. Nwoboshie, (1982) reported that of all the factors controlling seedling growth,
water is the most critical. Water is the vehicle for all physiological and biochemical process
through which life is maintained. Whenever transpiration is greater than absorption, the plant
becomes dehydrated. A decrease in hydration of protoplasm of cells in the meristematic
tissues usually results in cessation or checking of cell division or cell enlargement or both. No
mortality was encountered after the first 8 weeks throughout the three months of the study
period.
30
The percentage of the seedling survival may be as a result of the improved level of the soil
nutrient for the plant growth, development and survival. The alternate hypothesis for this
research that different levels of poultry manure would provide environmental conditions
favourable for the growth, development and survival Milicia excelsa seedlings is accepted
and the null hypothesis rejected.
CHAPTER SIX
CONCLUSIONS AND RECOMMENDATIONS
6.1 Conclusions
6.1.1 Effect of poultry manure on vegetative growth of Milicia excelsa
seedlings
31
The study indicates that poultry manure is a valuable fertilizer because application of the
poultry manure resulted in a significant effect on the mean stem height of Milicia excelsa
seedlings. However, there was no significant effect on the species diameter.
6.1.2 Effect of poultry manure on the percentage survival of Milicia excelsa
seedlings
Again the poultry manure had a significant effect on the percentage survival of the Milicia
excelsa seedlings. An application rate of 27000 Kg/ha was capable of enhancing the survival
of the Milicia excelsa seedlings by 87.50 percent over the control.
6.1.3 Effect of poultry manure on the mean number of leaves of Milicia
excelsa seedlings
Poultry manure also had a significant effect on the mean number of leaves and can therefore
be applied to Milicia excelsa seedlings for raising healthy and good seedlings in the nursery
as well as for its plantation establishment.
In general, the introduction of Milicia excelsa into plantations by enhancing its early growth
performance could have beneficial effects on the forest of Ghana, since it will reduce the high
dependency on the forest for Milicia excelsa species for subsistence or commercial purposes.
6.2 Recommendations
Since the poultry manure significantly increased the growth of the Milicia excelsa seedlings,
their application should be encouraged for the production of strong and healthy seedlings for
32
plantation purposes with a recommended rate of 27,000Kg/ha. This will serve as a substitute
for inorganic fertilizers thereby reducing cost of inputs for the farmer.
It may be worthwhile considering the application of poultry manure in the early stages of
seedling nursing so as to reduce plant shock during transplanting. Further research should be
carried on the seedlings for a long period of time of about thirteen to fifteen months, so as to
ascertain the findings obtained from this research work.
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APPENDICES
APPENDIX 1 Analysis of Variance (ANOVA) for Poultry Manure on the Mean Stem Height of Milicia excelsa seedlings
Sources of Variation Sum of squares Degree of Freedom Mean sum of squares F0 F-critical
Treatment 216.78 4 54.20 8.40** 3.84
Blocks 53.80 2 26.90 4.17ns 4.46
Residual 51.61 8 6.45
Total 322.19 14
**Significant at α = 5% ns Not significant at α = 5% C.V = 10.00%
37
APPENDIX 2 Least Significant Difference (LSD) for Mean Stem Height at 5% Significance level
Least Significant Difference Treatment Means Differences in Treatment Mean
4.790 y₁=19.25 y₁ - y₂=19.25-24.05= 4.80*
y₂=24.05 y₁ - y₃=19.25-27.53= 8.28*
y₃=27.53 y₁ - y₄=19.25-30.70= 11.45*
y₄=30.70 y₁ - y₅=19.45-25.45= 6.20*
y₅=25.45 y₂ - y₃=24.05-27.53=3.48ns
y₂ - y₄=24.05-30.70= 6.65*
y₂ - y₅=24.05-25.45= 1.40ns
y₃ - y₄=27.53-30.70= 3.17ns
y₃ - y₅=27.53-25.45= 2.08ns
y₄ - y₅=30.70-25.45= 5.25*
* = Significant at 5% Significance level. y₁=T1, y₂=T2, y₃=T3, y₄=T4, y₅=T5
ns= Not significant at 5% Significance level.
APPENDIX 3 Analysis of Variance (ANOVA) for Poultry Manure on the Mean Number of Leaves of Milicia excelsa Seedlings.
Sources of Variation Sum of squares Degree of Freedom Mean sum of squares F0 F- critical
Treatment 312.4 4 78.10 48.81 * 3.84
Blocks 1.20 2 0.60 0.38ns 4.46
Residual 12.80 8 1.60
Total 326.40 14
**Significant at α = 1% ns Not significant at α = 5% C.V = 10.68%
38
APPENDIX 4 Least Significant Difference (LSD) for Mean Number of Leaves at 5% Significance level
Least Significant Difference Treatment Means Differences in Treatment Mean
2.390 y₁=7.67 y₁ - y₂=7.67-7.67=0.00ns
y₂=7.67 y₁ - y₃=7.67-10.00= 2.33ns
y₃=10.00 y₁ - y₄=7.67-19.67= 12.00*
y₄=19.67 y₁ - y₅=7.76-14.00= 6.33*
y₅=14.00 y₂ - y₃= 7.67-10.00= 2.33ns
y₂ - y₄=7.67-19.67= 12.00*
y₂ - y₅=7.67-14.00=6.33*
y₃ - y₄=10.00-19.67= 9.67*
y₃ - y₅=10.00-14.00= 4.00*
y₄ - y₅=19.67-14.00= 5.67*
* = Significant at 5% Significance level. y₁=T1, y₂=T2, y₃=T3, y₄=T4, y₅=T5
ns= not significant at 5% Significance level.
APPENDIX 5 Analysis of Variance (ANOVA) for Poultry Manure on the Mean Stem Diameter of Milicia excelsa Seedlings
Source of Variation Sum of Squares Degrees of Freedom Mean Sum of Squares F0 F- critical
Treatment 2.66 4 0.665 3.74ns 3.84
Blocks 4.21 2 2.107 11.84** 4.46
Residual 1.42 8 0.178
Total 8.30 14
**Significant at α = 1% ns Not significant at α = 5% C.V = 10.58%
39
APPENDIX 6 Least Significant Difference (LSD) for Mean Stem Diameter at 5% Significance level
Least Significant Difference Treatment Means Differences in Treatment Mean
0.796 y₁=3.66 y₁ - y₂=3.66-4.05= 0.39ns
y₂=4.05 y₁ - y₃=3.66-4.14= 0.48ns
y₃=4.14 y₁ - y₄=3.66-4.68= 1.02*
y₄=4.68 y₁ - y₅=3.66-3.46= 0.20ns
y₅=3.46 y₂ - y₃=4.04-4.14= 0.09ns
y₂ - y₄=4.04-4.68=0.63ns
y₂ - y₅=4.04-3.46=0.59ns
y₃ - y₄=4.14-4.68= 0.54ns
y₃ - y₅=4.14-3.46=0.68ns
y₄ - y₅=4.68-3.46=1.22*
* = Significant at 5% Significance level. y₁=T1, y₂=T2, y₃=T3, y₄=T4, y₅=T5
ns = not significant at 5% Significance level.
40
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