General Tadase Biru Campus

College Of Agriculture and Natural Resource

Department Of Plant Science

Effect Of Different Sowing Depth On emergency and Growth Performance Of

Barley In Jimma Arjo Woreda In East wollegga Zone

Name ID NO
Dame Damtew RU0377/14

Practical Attachment Submitted to Department of Plant Science for the Partial

Fulfillment of the course practical attachment Plant Science (PlSC481)

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Table of Contents
1.INTRODUCTION........................................................................................................................1

1.1. Background...........................................................................................................................1

1.2. Statement of the Problem......................................................................................................3

1.3. OBJECTIVES.......................................................................................................................3

1.3.1. General Objective...........................................................................................................3

1.3.2. Specific Objectives.........................................................................................................3

2. LITERATURE REVIEW............................................................................................................4

2.1. Overview of Food Barley Production in Ethiopia................................................................4

2.2. Importance of Food Barley...................................................................................................4

2.4. Major Barley Producing areas in Ethiopia............................................................................5

2.5. Food Barley Production Constraints.....................................................................................5

2.5.1. Barley type.....................................................................................................................6

2.5.3.Barley for stock feed.......................................................................................................6

2.5.4. Life cycle........................................................................................................................6

3. BARLEY GROWTH & DEVELOPMENT................................................................................8

3.1 Germination,emergence and establishment...........................................................................8

3.1.2.Factors affecting germination, emergence and establishment.........................................8

3.1.3Effect on emergence and establishment...........................................................................9

3.2Sowing....................................................................................................................................9

. 3.3. Depth......................................................................................................................11

CHAPTER FOUR.........................................................................................................................12

4.Vegetative growth and plant development Vegetative growth..................................................12

4.1.Vegetative growth................................................................................................................12

4.2.Factors affecting vegetative growth.....................................................................................13

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 4.2.1Factors affecting plant development..............................................................................14

CHAPTER FIVE...........................................................................................................................15

5. Reproductive development........................................................................................................15

5.1 Factors affecting reproductive development........................................................................16

CHAPTER SIX..............................................................................................................................17

6. Grain development.....................................................................................................................17

6.1Factors affecting grain development.....................................................................................18

6.2 Measuring crop performance...............................................................................................19

CHAPTER SEVEN.......................................................................................................................20

7. MATERIALS AND METHODS..............................................................................................20

7.1 Description of the Study Area..............................................................................................20

7.1.2 Location, Shape and Size..............................................................................................20

7.2 Experimental Materials........................................................................................................21

7.3 Experimental procedure.......................................................................................................21

7.4 Treatments and Experimental design...................................................................................22

7.4.1 Field layout....................................................................................................................22

7.5 Data to be collected..............................................................................................................23

7.6 Preparing Work Plan............................................................................................................23

7.7, Budget by activity...............................................................................................................24

LIST OF TABLE
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Table1; preparing of work plan………………………………………..23
Table2; Budget of activity………………………………………..……24

LIST OF FIGURE
Figure 1;Location of Guder map………………………………..……21

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 1. INTRODUCTION

1.1. Background
Ethiopia is an important primary and secondary gene center for many field crop species,
including barley, that were introduced centuries ago and have since adapted and developed
wide genetic diversity. However, this broad range of genetic diversity has been eroded due to
many factors. With the objective of addressing conservation of this dwindling plant genetic
diversity in the country, the Plant Genetic Resources Centre of Ethiopia (PGRC/E), now the
Institute of Biodiversity Conservation (IBC), was established in 1976. The primary mandates
of IBC include the preservation of genetic diversity of crop plants, their wild relatives, and
native species important to Ethiopian agriculture and biodiversity. Over 65 000 accessions
from more than 120 plant species have been collected from across the country and preserved
ex situ at IBC. This germplasm collection includes a principal base collection of barley with
>15 000 accessions. The genebank serves as a reservoir of genes potentially useful for many
purposes, including resistance to diseases, pests and other environmental stresses, as well as
for traits that increase yield or food quality. Often, however, there is limited awareness of the
value and utilization of gene bank resources. In addition to genebank materials, distinct
landraces (farmer varieties) of field crops, including barley, are conserved in situ (on farm) at
12 Community Genebanks (CGBs) established over the last decade by IBC in six agro-
ecologies of the four regional States of Ethiopia. Ethiopian barley is recognized to have
typical botanical varieties with a group of inter-fertile lines distinguished by spike characters
(Zemede Asfaw, 1988). Five convarieties: deficiens, distichon, hexastichon, intermedium,
and labile have been identified from different types, of which deficiens and labile are
endemic to Ethiopia (Giessen, Hoffmann and Schottenloher, 1956). Five distichon accessions
of Ethiopian origin were repatriated from China, and are now conserved in the IBC. Other
studies noted the unique features of the cultigens of barley grown in Ethiopia (Orlov, 1929;
Ciferri, 1944; Vavilov, 1951). These and several other observations and views strengthen the
argument that barley also originated independently in Ethiopia (Endeshaw Bekele, 1983;
Mulugeta Negassa, 1985), although the site of domestication is debated (e.g. Endeshaw
Bekele, 1983; Mulugeta Negassa, 1985). Evidence from a flavonoid study raised doubt of a

1
Barley genetic resources collection and conservation in Ethiopia Adugna Abdi

Barley research and development in Ethiopia 20 monophyletic origin of barley, arguing that
through long-term introgression, the relatively fewer wild relative genes remain swallowed
up in the gene pool of cultivated barley in Ethiopia (Åberg, 1938; Endeshaw Bekele, 1983;
Molina-Cano et al., 1987) and initial barley cultivation in Ethiopia may date to 3000 BC
(Gamst, 1969). Furthermore, very recent work considered Ethiopia an independent centre of
barley diversification and a potential domestication site (Orabi et al., 2007).

Growing barley Barley (Hordeum vulgare) is a widely grown and highly adaptable winter
cereal crop that is used mainly for stock feed and the production of malt for the brewing
industry. Barley is an annual plant that has been selected from wild grasses. It is thought to
have been an important food crop from as early as 8000 BC in the Mediterranean/ Middle
East region. Because of barley’s tolerance of salinity, by 1800 BC it had became the
dominant crop in irrigated regions of southern Mesopotamia, and it was not until the early
AD period that wheat became more widely grown

. Barley (Hordeum vulgare L.) is most important cereals in the world in terms of both
quantities produced and cultivated areas, annually, harvested area was about 140 million
tons, obtained from 50 million hectares (FAOSTAT, 2018). Ethiopia is considered as a center
of diversity for barley (Lakew et al., 1997). In the world, it ranks the fourth (wheat, maize,
and rice) most grain crops. It was categorized among the top ten crop plants in the world
(ICARDA, 2011). Similarly, barley production in the world was around 15.87 million tons
more than previous year’s projection, compared to last year production, represent an increase
of 15.87 million tons or 12.33% in barley production around the globe (USDA, 2019). Its
average yield globally, changed during the time starting from 1.39 t ha -1(in 1960) to 2.99 t
ha -1 in 2018 (USDA, 2018). European Union, Russia, Canada, USA and Argentina are the
top five barley producers globally; European Union produces the greatest quantities of barley
with an estimated production of 20.5 million tons followed by Russian federations with a
production of about 8 million tons, whereas Canada, USA and Argentina barley production
was estimated 7.3, 3.1 and 2.8 million tons, respectively (USDA, 2017).

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1.2. Statement of the Problem
To meet the demand of food for ever increasing Ethiopian population and to increase income
of farmer’s production of food barley is very important since high potential areas are
available. One of the major problems affecting food production in Africa, including Ethiopia
is rapid depletion of nutrients in smallholder farms (Achieng et al., 2010). Low availability of
nitrogen and phosphorus has been demonstrated to be a major constraint to cereal production.
As summarized by Tekalign et al., (2001) nitrogen is deficient in almost all soils and
phosphorus is deficient in about 70% of the soils in Ethiopia. This low nutrient content is due
to erosion and absence of nutrient recycling. On the contrary, most of the areas used for
production of grains, especially barley, tef, and wheat fall under the low fertility soils. Soils
in the highlands of Ethiopia usually have low levels of essential plant nutrients and organic
matter content. In Ethiopia, smallholder farmers generally apply low amounts of mineral
fertilizers to crops

1.3. OBJECTIVES

1.3.1. General Objective

To increase the production, productivity and quality of food barley through use of optimal
sowing depth in the east Wellega of Ethiopia

1.3.2. Specific Objectives

 To evaluate the effect of rates on yield and yield components of food barley varieties

 To evaluate the effect of rates on some quality parameters of food barley varieties

 To determine the optimal rate for food barley varieties under the existing input and output
price levels in the study area.

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2. LITERATURE REVIEW

2.1. Overview of Food Barley Production in Ethiopia

In Ethiopia, barley (Hordeum vulgare L.) is one of the first domesticated cereals, most staple
and subsistence crop cultivated in about 811,782.08ha with a total annual production of 1.77
million tons (CSA, 2019). Ethiopia is considered as a center of diversity for barley, it can be
cultivated at altitudes between 1500 and 3500m, but the most suitable areas for the plant are
those with altitudes ranging from 2200 to 3000 m.asl (Lakew et al., 1996). According to
Kaso and Guben (2015), barley is a staple food crop for many Ethiopians, especially for
highlanders and it is also able to grow at all elevations, and cultivated by small holders in
every region of Ethiopia. However, it performs best at the higher elevations in the northern
and central regions of the country. Ethiopia is ranked twenty-first in the world in barley
production with a share of 1.2 percent of the world’s total production (USAD, 2014).
According to same author, barley cultivation is widely distributed across the country on over
one million hectares of land and by more than four million small holder farmers. Barley is a
high-opportunity crop, with great room for profitable expansion, particularly when connected
with the country’s commercial brewing and value added industries. Since the major barley
producing areas of the country are mainly located in the highlands (Grandson and
Macpherson, 2005). Ethiopia is the second largest barley producer in Africa and accounts
nearly 25% of the total production in Africa (FAO, 2014). According to Kemelew and
Alemayehu (2011), among the major cereals, barley ranks fifth in area, productivity and total
production in Ethiopia. In Ethiopia in 2018/19 the national area coverage, production and
productivity of barley were estimated to be 811,782.08 ha, 17,675,184.47qt and 2.17 tons/ha,
respectively (CSA, 2019).

2.2. Importance of Food Barley

In Ethiopia, barley has an immense cultural and nutritional position; it can be used for both
food and malt in Ethiopia. Ethiopia produces mostly food barley, with its share estimated to
be 90%, while that of malt barley having a share of 10% (Alemu et al., 2015). According to
Abraha et al., (2013) barley is used for making local recipes, bread, porridge, soup, and
roasted grain and for preparing alcoholic and non-alcoholic beverages in 20 different ways.

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Its straw is a good source of animal feed. It is also used for thatching of roofs and bedding
(Bekele et al., 2005).

2.5.2. Barley for other human foods.

The trade for barley products (such as flour, flakes or grits), other than malt, for human
consumption is small. For these products grain quality standards are not quite as tight as for
malting. Most of the barley used for food is milled and processed, so it should be of a similar
standard to wheato-row barley are used in the domestic malting industry.

2.5.3.Barley for stock feed

Barley is used as stock feed, especially in the intensive pig, poultry, dairy and beef
industries. This demand is met by varieties specifically grown as highyielding feed types
(e.g. Tilga) as well as grain that does not meet the quality requirements for malting or human
food.

2.4. Major Barley Producing areas in Ethiopia

Barley produced in all regions of Ethiopia, but the major producers are Shewa, Gojam, Arsi,
Gonder, Wollo and Bale, from where more than 85% of the total production comes (Adugna
A, 2008). In some parts of Ethiopia, barley is produced twice annually (bimodal rainfall), i.e.
during the main rainy season, Meher (from June to September), and the short rainy season,
Belg (from February to April). Belg barley is important in Wollo, Bale and Shewa. Barley
has a number of attributes that makes it desirable among farming communities in the country
because it is a source of food and suitable for the Belg season; it performs well in marginal
areas; provides an earlier harvest than some other cereals; and requires low investment .

2.5. Food Barley Production Constraints

Despite its great significance in the farming system of the country, barley production is
constrained by many confounding factors. The major production limiting concerns are poor
soil fertility, frost, water logging, and insect pests like aphids and barely fly, leaf diseases
like: scald, blotch, smuts, and leaf rust, moisture stress, low-yielding varieties, and
inadequate agronomic practices (Bekele et al., 2005). As a result, assuming the genetic

5
potential of the crop, the national average (2.17t ha1) is relatively lower than the world
average (2.99t ha-1) (USDA, 2018).

Biotic stresses like disease, insect pests, and weed infestations contribute to lower rates of
yields in Ethiopia. Diseases (such as scald, net blotch, spot blotch, and rusts) and insect pests
(such as aphids and barley shoot fly) reportedly can cause yield losses of up to 67 and 79
percent, respectively (Sinebo and Yirga, 2002). Yield gains from weed control, on the other
hand, ranges from 14-60 percent depending on the location and type of weed (Negewo et al.,
2011). Similarly, abiotic or non-biological stresses like poor distribution of rainfalls in
lowland areas and low soil fertility due to soil erosion and poor soil drainage are named as
causes of significant yield losses in food barley production (Abera et al., 2011).

2.5.1. Barley type

There are two forms of barley, determined by the number of rows of grain along the head.
Two-row barley types have only one fertile spikelet per side of the head. In sixrow barley, all
three spikelets per side of the head are fertile. Two-row types are the most commonly grown.
The two-row barleys can be used for malting, human food or stock food, with the quality
required and the price varying for each end-use. The only current use of the grain of six-row
barley is for stock feed. It is generally sown for grazing only.

2.5.4. Life cycle

The growth and development of the barley plant is a complex process. During the life cycle
of the plant, many of the growth stages overlap, and while one part of the plant is
commencing development, another part may be towards the end of development and
changing little, at a minimum rate The barley grain The barley grain is the reproductive unit
of the barley plant as well as the end-use product (Figure v). A barley grain can be broadly
divided into three components (Figure vi): • husk • endosperm • embryo (the young plant,
including the coleoptile, three or four embryonic leaves, and the rootlets). In most varieties,
the proportion of each component of the grain is 7% to 13% husk, 70% to 80% endosperm
and 2% to 5% embryo. Once filled, the barley grain is 70% carbohydrate, and 97% of this is
starch (Figure vi). The protein content is between 8% and 15%, depending on the final grain

6
weight; this equates to 4 to 10 mg. The type and content of protein and of other constituents
such as cell walls can significantly affect the brewing process and final beer quality.
Therefore, only specific varieties are suitable for malting. Husk The outer protective covering
of the seed. Lemma and palea generally adhere to the endosperm. Aleurone A layer of
protein surrounding the endosperm that secretes enzymes to break down starch reserves in
the endosperm during germination.

Embryo Contains the main plant structures, so it holds all the elements of the growing plant.
It is made up of the scutellum, plumule (shoot) and radicle (primary root). It is found at the
point where the grain is attached to the spikelet. Scutellum A shield-shaped structure that
absorbs the soluble sugars from the breakdown of starch in the endosperm.Endosperm Tissue
that surrounds the embryo and provides energy for germination. The germinating seed relies
on these reserves until it has developed a root system and sufficient leaf area for
photosynthesis. The endosperm makes up the bulk of the grain and stores carbohydrate in the
form of starch from which the fermentable sugars are formed during malting.

7
CHAPTER THREE

3. BARLEY GROWTH & DEVELOPMENT

These features can be used to help identify grass species. Leaves are produced in a set order,
on alternate sides of the stem. A leaf is counted as emerged when the ligule is fully visible.
The final leaf to grow before head emergence is the flag leaf. Tillers Tillers are lateral
branches or shoots that arise from buds in the axil of the leaves at the base of the main stem.
Primary tillers are produced from the leaves of the main stem and can form their own,
secondary tillers. Stem The stem is made up of nodes and internodes. Nodes are where
structures such as leaves, roots, tillers and spikelets join the stem. The internode is the tissue
between adjacent nodes that elongates as the stem grows. The stem is wrapped in the sheaths
of the surrounding leaves. This structure of stem and leaves gives strength to the shoot,
helping to keep the plant upright.

3.1 Germination,emergence and establishment

Introduction Under the right conditions, a viable barley seed germinates. This chapter covers
germination, emergence and establishment of the barley plant life cycle Germination is
slowed when the soil oxygen concentration is below 20%. During germination, water softens
the seed coat to make it permeable to oxygen, so dry seeds absorb almost no oxygen.
ermination has three phases: • water absorption (imbibition) • activation • visible
germination.

Germination begins when the seed absorbs water and ends with the appearance of the radicle.

3.1.1. Establishment

The plant is established once it has roots and a shoot. It no longer relies on reserves in the
seed once it produces its own energy from photosynthesis.

8
3.1.2. Factors affecting germination, emergence and establishment
 Oxygen is essential to the germination process. Seeds absorb oxygen rapidly
during germination and will die without sufficient oxygen.
 Dormancy In a barley seed, germination begins after a very short period of
dormancy. Some level of seed dormancy
 Moisture Soil moisture influences the rate of germination. Germination is rapid if
the soil is moist. When the soil dries to near the wilting point, the speed of
germination slows. When the soil reaches the permanent wilting point,
germination will take 10 days at 7°C instead of taking 5 days at 7°C when there is
adequate moisture.ancy is necessary to help prevent ripe grain from germinating
in the head before harvest.
 Temperature Effect on germination Germination rate depends on temperature.
The ideal temperature for barley germination is between 12°C and 25°C, but
germination will occur between 4°C and 37°C.

3.1.3Effect on emergence and establishment

High temperatures during establishment cause seedling mortality, reducing the number of
plants that establish. In hot environments, the maximum temperature in the surface soil can
be 10°C to 15°C higher than the maximum air temperature, especially with a dry, bare soil
surface and high radiation intensity.. Brief exposure to extreme soil temperatures can also
restrict root growth and tiller initiation.

Seed storage A seed is a living organism that releases moisture as it respires. The aim of seed
storage is to preserve the viability of the seed for future sowingNutrition Adequate nutrition is
essential for good plant growth and development, yield and grain quality. Nutritional requirements
vary depending on potential yield and soil fertility status. Soil tests or nutrient budgeting are a useful
way of measuring soil fertility and calculating fertiliser requirements before sowing. Historically,
rates of fertiliser

 Seed treatment Seed treatments are applied to control diseases such as smuts,
bunts and foliar diseases and to control insect.

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3.2Sowing

 Seedbed Barley seed needs good soil contact for germination. This was
traditionally achieved by producing a fine seedbed by multiple cultivations.
Good seed–soil contact can now be achieved by the use of press wheels or
rollers. Soil type and soil moisture influence the choice of covering device.
Between 70% and 90% of seeds sown produce a plant. Inappropriate sowing
depth, disease, crusting, moisture deficiency and other stresses all reduce the
numbers of plants that become established. Field establishment rates can be
60% or lower if seedbed conditions are unfavourable. Seedbed preparation is
also important to emergence. A cloddy seed bed can reduce emergence rates,
as the clods reduce seed–soil contact, stop some seedlings reaching the
surface, and allow light to penetrate below the soil surface. The coleoptile
senses the light and stops growing, and a leaf is produced while still below the
surface. Cloddy soils also dry out more Sowing Seedbed Barley seed needs
good soil contact for germination. This was traditionally achieved by
producing a fine seedbed by multiple cultivations. Good seed–soil contact can
now be achieved by the use of press wheels or rollers. Soil type and soil
moisture influence the choice of covering device. Between 70% and 90% of
seeds sown produce a plant. Inappropriate sowing depth, disease, crusting,
moisture deficiency and other stresses all reduce the numbers of plants that
become established. Field establishment rates can be 60% or lower if seedbed
conditions are unfavourable. Seedbed preparation is also important to
emergence. A cloddy seed bed can reduce emergence rates, as the clods
reduce seed–soil contact, stop some seedlings reaching the surface, and allow
light to penetrate below the soil surface. The coleoptile senses the light and
stops growing, and a leaf is produced while still below the surface. Cloddy
soils also dry out more quickly. Depth Sowing depth is the key management
factor for uniform rapid emergence and establishment. The ideal depth to sow
barley is generally 20 to 30 mm, depending on the availability of moisture and
the variety. Depth is particularly important in varieties with short coleoptiles.
Sowing depth influences the rate of emergence and the percentage of

10
 seedlings that emerge (see Figure 1–6). Deeper seed placement slows
emergence; this is equivalent to sowing later. Seedlings emerging from greater
depth are also weaker and tiller poorly. Crop emergence is reduced with
deeper sowing. The coleoptile may stop growing before it reaches the soil
surface, and the first leaf then emerges from the coleoptile while it is still
below the soil surface. As the leaf is not adapted to pushing through soil, it
usually buckles and crumples, failing to emerge and eventually dying. Plant
population Plant population is influenced by seeding rate, row spacing and
emergence percentage. Emergence percentage is calculated as the number of
seedlings quickly.

. 3.3. Depth
 Sowing depth is the key management factor for uniform rapid emergence and
establishment. The ideal depth to sow barley is generally 20 to 30 mm,
depending on the availability of moisture and the variety. Depth is particularly
important in varieties with short coleoptiles. Sowing depth influences the rate
of emergence and the percentage of seedlings that emerge (see Figure 1–6).
Deeper seed placement slows emergence; this is equivalent to sowing later.
Seedlings emerging from greater depth are also weaker and tiller poorly. Crop
emergence is reduced with deeper sowing. The coleoptile may stop growing
before it reaches the soil surface, and the first leaf then emerges from the
coleoptile while it is still below the soil surface. As the leaf is not adapted to
pushing through soil, it usually buckles and crumples, failing to emerge and
eventually dying.

3.4. Barley population

 Is influenced by seeding rate, row spacing and emergence percentage.

Emergence percentage is calculated as the number of seedlings.

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CHAPTER FOUR

4.Vegetative growth and plant development Vegetative growth

Introduction Once the barley plant is established, it begins vegetative growth. Its root
system continues to develop, leaves are initiated and tillering begins. Chapter 2 explains
vegetative growth and the factors that affect the growth and development of the plant .

4.1.Vegetative growth
During the vegetative growth phase the roots, leaves and tillers develop and the plant begins
storing nutrients for the rest of the growth cycle. This is a period of high nutrient uptake, and
its progression is influenced by moisture and temperature levels.

Growth is the increase in the size and number of leaves and stems that produces a
quantitative change in biomass. It is time based and is facilitated by photosynthesis, so it is
directly related to water use and light interception

Development is the process of the plant moving from one growth stage to another. The rate
and timing of plant development are determined by variety, photoperiod and temperature.

Root growth The function of the root system is to absorb nutrients and water for plant
growth. Healthy roots, unrestricted by soil constraints or disease, are essential to maximise
yield. Roots also synthesise growth regulators or plant hormones. Barley has a fibrous root
system consisting of two parts, the primary and secondary roots (Figure 2–1). These have
different functions and stages of development.

12
Primary root system The primary (seminal or seedling) roots are the first to appear after
germination. Between five and seven roots grow and branch as they extend deep into the soil.
These roots form the deepest root system and, given adequate moisture and soil structure,
they can grow to about 2 m in depth. However, under most NSW conditions they rarely
exceed 1.5 m, and they can extract soil moisture to this depth.

Secondary root system The secondary (adventitious) root system develops from the crown
of the plant and is closely linked to tiller development. Dry conditions at tillering can inhibit
secondary root development, causing the plant to rely solely on primary roots to produce
some grain. The nodal roots grow horizontally for a while, before growing downwards and
branching; this means that the layers of soil close to the surface are dominated by nodal
roots.

Root volume The barley plant’s fibrous root system develops horizontally and vertically,
producing five to 10 times more surface area than plants with tap root systems.

Rate and depth of rooting In central NSW, the average rate of root growth (after crop
establishment) has been measured at about 1 cm/day, resulting in a final depth of 4.4 cm
from a late-May sowing. At the two-leaf stage the primary roots have a maximum depth of
7.8 cm

Leaf growth Following plant emergence, the shoot apex continues producing leaves until it
undergoes a change to the reproductive phase, when the head is formed.

Tiller growth (Z23–Z29) The barley plant produces additional shoots called tillers, which
develop from buds at the base of the stem. Some of these will produce a head (ear). There is
a characteristic sequence of production and arrangement of tillers in barley.

4.2.Factors affecting vegetative growth

Prior to establishment, plant growth is fuelled by reserves stored in the endosperm of the
grain. Once the first two leaves have unfolded, growth relies on energy produced by the plant
through photosynthesis.

 Photosynthesis and respiration

13
 Photosynthesis equation 6CO2 + 6H2O light C6H12O6 + 6O2 carbon dioxide + water

carbohydrate + o2

Respiration equation C6H12O6 + 6O2 6CO2 + 6H2O + energy carbohydrate + oxygen carbon dioxide +
wate + energy

 Transpiration
 Leaf area
 Moisture
 Nutration

4.2.1Factors affecting plant development

The major factors affecting the length of each growth stage are vernalisation, photoperiod,
thermal time and variety characteristics. The significance of these factors depends on
whether the barley is a spring or winter type. Leaf and tiller appearance, senescence (the
aging and drying of leaves and nonproductive tillers) and plant height are components of the
canopy structure that are determined by variety and sowing date.

 Vernalisation
 Basic vegetative period
 Photoperiod
 Thermal time is a calculation of accumulated temperature.
 Sowing time The interaction of variety characteristics and environmental
conditions determines the phasic development of a crop and, in particular, its
flowering time. Recommended sowing times are determined by assessing the
flowering times of varieties in different environments at a range of sowing
times. The maturity times of varieties available in NSW vary greatly.

14
CHAPTER FIVE
5. Reproductive development
Introduction The reproductive phase of the barley plant continues the process of
determining final yield. Vegetative growth prepares the plant to form the developing head
and yield components. Management and environmental conditions during vegetative growth,
and environmental stresses during the reproductive phase, determine the maximum yield that
can be set by the plant within its genetic potential. Knowledge of the stages of reproductive
development helps farmers manage the plant during this phase to minimise the effects of
various stresses and maximise yield.

Reproductive development The reproductive phase begins when the shoot stops forming
leaves and begins forming a head; this process is known as floral initiation. Within the head
are the developing floral structures. This is a complex phase with a number of developments
happening at the same time. (See Introduction which shows the development stages of the
barley plant, including the overlap in reproductive development.

Floral initiation The first sign of floral initiation is the formation of double ridges on the
mounds on either side of the apical dome.

Double-ridge stage In the vegetative stage, the shoot apex consists of a series of single
ridges that produce leaves. When the apex begins to elongate or extend, the ridges form too
quickly to grow into leaves, so the cells reorganise to produce the head instead.

Triple-mound stage At the triple-mound stage each double ridge differentiates further into
three distinct bumps or mounds. Awn primordium stage At this stage the head is 4 mm long

15
and the plant has between 7 and 12 leaves. The meristematic dome (at the tip of the head) has
ceased dividing. The head has its full complement of spikelets, and the initiation of all the
structures within the median spikelet is complete

Stem elongation Stem elongation begins at the end of the awn primordium stage. It is the
result of elongation of the internodes.

5.1 Factors affecting reproductive development

 Moisture stress
 Moisture stress before anthesis
 Moisture stress at anthesis
 Temperature
 Heat stress
 Cold and freezing
 Flowering time
 Nutrition and Nitrogen

16
CHAPTER SIX
6. Grain development
Is the period from fertilisation of the ovum to physiological maturity and is the final stage in
the life cycle of the barley plant. Carbohydrates and protein are deposited in the grain as it
grows and ripens. Final grain yield is determined during this phase and is influenced not only
by current conditions and management decisions, but by events that have preceded it. Grain
quality is greatly affected by the conditions during grain development. In barley, grain
quality is of particular importance, as malt barley is an important end-use product. Chapter 4
explains how the grain develops and reaches physiological maturity, and gives details of the
environmental conditions that influence its progression. In many cases these processes are
similar to those observed in wheat.

Grain development is the period from fertilisation to physiological maturity when fertilised
florets fill and ripen to form grain. Growth of the barley grain after fertilisation can be
divided into two main stages: cell division and grain-filling.

Cell division commences at fertilisation and continues for approximately 14 to 30 days,

depending on the genotype, environmental conditions, and position within the head. Given
that final grain weight (an important yield and quality parameter) is closely related to
endosperm cell number, any factor that influences cell division is of great importance.
During cell division the endosperm volume increases rapidly. This increase is mainly a
function of increasing cell number, rather than increased individual cell size.

Grain-filling starts about 5 to 10 days after flowering and continues until the grain is ripe.
Grain filling uses assimilates (amino acids and sugars), i.e. the products of photosynthesis.
Starch is synthesised in the grain from these sugars while proteins are produced using amino
acids.

Sources of carbohydrate There are two principal sources of carbohydrate during grain-filling.
Under favourable conditions, the main source is current photosynthesis from green leaves,

17
supplemented by photosynthesis by other plant structures, namely the stem, glumes and
awns.

The other source is carbohydrate reserves that are stored, mainly in the stem, but also in the
leaves, from photosynthesis before grain-filling. These reserves are stored in the form of
water-soluble carbohydrates, particularly fructans.

Sources of protein Most of the nitrogen that is converted into protein is taken up before
flowering, stored in the leaves and remobilised during grain fill. Nitrogen is an important
component of chlorophyll and the enzymes involved in photosynthesis. As the plant
develops, nitrogen is remobilised from older leaves (which then stop photosynthesising and
senesce) and moved to younger growth, and eventually to the grain after flowering. The plant
can take up nitrogen after flowering, provided that the root system is healthy and the soil is
moist. Whereas nitrogen applied early in the season will increase biomass and grain yield
potential (provided that there is enough water), late application tends to mainly increase grain
protein concentration.

Physiological maturity Finally, the vascular system supplying the grain with water and
nutrients is blocked and the grain stops growing and turns brown. This is physiological
maturity. The mature barley grain comprises mainly starch (75% to 85%), protein (about 9%
to 12%) and water (about 8% to 12%).

6.1Factors affecting grain development

grain-filling occurs as temperatures increase. The temperature increase is usually
compounded by decreasing soil moisture levels. These environmental conditions affect the
rate and duration of grain fill, influencing grain size and protein content and quality.

Moisture Adequate soil moisture is essential during grain-filling for transpiration and
photosynthesis. Crops with high levels of pre-flowering biomass use a lot of soil moisture
and are at increased risk of running out of water during grain fill. Moisture stress reduces the
photosynthetic capacity of the crop by causing the premature death of leaves, thus reducing
the length of the period in which carbohydrate can be transferred to the grain. The rate of
starch synthesis in the grain also falls during moisture stress.

Pre-harvest sprouting Along with many other commercial crop species, barley has lost much
of its dormancy as it has become domesticated. Malting barleys, in particular, have very little
dormancy. This makes them susceptible to germinating before harvest. This process is known
as pre-harvest sprouting. Pre-harvest sprouting reduces seed viability and lowers grain
quality.

Temperature Grain development is very sensitive to temperature, which affects: • grain

weight • the source of carbohydrate • the quality of the protein.

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Nitrogen is an essential component of protein, and its availability during grainfilling is
important in dete.

Disease may reduce both the canopy size and the duration of green leaf. The crop then
depends more on stored reserves to complete grain fill. Generally this leads to lower yields
through reduced grain weight. remaining final yield and quality

Grazing The impact of grazing on yield is highly variable and depends on many factors,
including the growth stage, the timing of stock removal, the duration of grazing, and seasonal
conditions.

6.2 Measuring crop performance

Yield There are two main components of yield: • number of grains per unit area • average
grain weight. Grain number is set at about flowering time, with average grain weight being
set afterwards. Recent improvements in barley yield have come about as a result of increases
in grain number rather than increased average grain weight. Given the importance of grain
number to yield it is important to prevent unnecessary stress on the crop prior to flowering.
The importance of grain number to yield also means that an approximation of yield can be
made during the grain filling period (See In the paddock: estimating yield).

Number of heads is the first yield component and is set by tiller number/m2. Tiller number
depends on initial plant population, the variety, and the environmental conditions
(particularly nutrition). In most barley crops, the plant produces more tillers than will survive
to produce heads. Stress and competition for nutrients cause tiller death.

Weight per grain The weight per grain is commonly expressed as 1000-grain weight. Factors
that affect the 1000-grain weight include: • variety • nitrogen • plant density • post-flowering
environmental conditions • grain position within the head • root and foliar diseases.

Yield compensation A barley crop responds to improving or deteriorating conditions

throughout the season. The ability to compensate means a crop can produce yield even when
one or more of the yield components is affected by environmental conditions. However,
maximum yield is more likely when yield components are balanced.

Grain quality is as important in barley as it is in wheat. Barley grain is used mainly for
brewing and stockfeed. In contrast to the stockfeed market, there are much more stringent
quality criteria that must be met to achieve malt quality barley.
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Harvest index The harvest index is a measure of the proportion of above-ground biomass that
is grain. Newer, higher yielding varieties have increased harvest index rather than plant
biomass.

Water use efficiency is a measure of how efficiently crops have used available moisture. It is
defined as grain yield divided by the water available to the crop. (See In the Paddock:
Calculating water use efficiency.)

7. MATERIALS AND METHODS

7.1 Description of the Study Area

The study will be conducted at Jimma Arjo which is located in Oromia Regional State East
Wellega Zone. It bounded by Chaliya Woreda in West, 12km from Ambo town in the west,
MidakegnWoreda in North, and TikurInchinitWoreda in South. This town has latitude and
longitude 89667(8’58 N) and 377667 (37’46 E) respectively, with an elevation of 1800 meter
above sea level. This town is highly exposed to informal settlement which harshly endangers
the growth of town. Beside other critical reason is that there is no former research has done
on informal settlement in this town. The final reason is to inform the government the fact
informal settlement is badly affecting the society .

7.2 Experimental Materials

From different barley varieties, variety will be used as a planting material to implement this
research experiment. Further experimental materials includes spade, peg, measuring tape,
rope record book pen Materials were used as a planting materials.

7.3 Experimental procedure

The experimental site will be selected and all unwanted materials such as stones, straw weed,
plant remains and other substance were removed. Land preparation will be carried out at the
beginning of rain using labor. After the preparation of the area, the plots were leveled

20
manually. Planting will be done a week later after preparing the experimental area and

planting of a seed per hole at 10 cm will be done. Beside to this, all other agronomic
practices such as weeding, cultivation and fertilization were done uniformly for each plot as
per recommendation at the appropriate time.

7.4 Treatments and Experimental design

The experiment will be consists of three sowing depth spacing (1cm,4.4cm,7.8cm,)laid out in
randomized complete block design (RCBD) with three treatments and three replications.
Three levels of sowing depth spacing (16cm, Spacing between plots and between blocks
were 0.5m and 1m respectively. Treatments were assigned randomly to each plot .Each plot

treatment will be 4m length. To eliminate the border effect two outer most rows (one from
each side) were considered as the border rows.

7.4.1 Field layout

The experiment comprised of three treatments were laid out as;

Rep1 Rep2 Rep3

1m T2
T1 T3

0.5m 4m
T3 T1 T2

T2
T3
T1

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 4.88m

T1=1m

T2=4.4cm

T3=7.8cm Figure 2Experimental field layout

7.5 Data to be collected

Data were collected from different growth parameter of barley such as: Days to 50%
emergency: - number of days from date of sowing to the date when 50% of the plants was
recorded.

 Plant height (cm):- it will be measured by using a ruler starting from soil surface to
the top by taking five randomly selected representative samples plants from the
middle two rows of middle plants and the mean was recorded.
 Number of leave (counting):- number of leaf per plant will be counted from each plot
of five samples.

 Length of leave (cm): it will be measured from the end of the sheath to the tip
of the leaves from the sample plants.

7.6 Preparing Work Plan

No Activities Time /seasons

October November
1 Land clearing 

2 Ploughting 

3 Planting 
4 Watering 
5 Weeding
6 Growth data
collection

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 7 Yield data
collection

Table 1Preparing Work Plan

7.7, Budget by activity

No. Imputes/materials/ Unit Quantity Price/unit(ETB) Total price

1 Daily labor No 5 120 600

2 Seed Kg 1 100 100
3 Chemical/fungicides Liter -- -- --

5 Meter length 3 50 -
6 Rope meter 70 -- --
7 Shovel No 1 -- --
8 Fork No 3 -- --
9 Digging hoe No 5 120 600
10 Photo copy No 25 3 75
Total 85 389 1421 birr

Table 2Budget by activity

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