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

1

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).

2

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.

3

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.

4

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.

5

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).

6

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.

7

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.

8

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.

9

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).

10

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).

11

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

12

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).

13

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).

14

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.

15

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)

16

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.

17

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

18

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

19

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.

20

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

21

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

22

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