ABSTRACT
Studies were carried out on the effects of different agro-wastes (saw dust, sugarcane baggasse and maize stalk) individually and in combination on the growth, yield, biochemical composition and polysaccharide degradating potentials of Pleurotus ostreatus and Pleurotus pulmonarius at the Department of Plant Health Management, MOUA Umudike, Abia State. The design was completely randomized design (CRD), replicated four times. Data were subjected to Analysis of Variance (ANOVA) and means separated using least LSD at 5% level of probability. Number of fruit bodies of P. ostreatus after three flushes was highest with MS substrate (72.7), followed by MS+SB substrate (70). The SD+MS substrate supported mushrooms with the best stipe length (5.4cm), followed by MS+SB (4.3cm) substrate. The MS substrate produced P. ostreatus and P. pulmonarius with the best pileus diameter and also supported the heaviest fresh fruit body weights mushroom of 57.7g and 83g at average respectively. P. pulmonarius sustained the highest number of fruit bodies with MS substrate (96.0) followed by SD+SB. The biological efficiency results indicated that the substrates were effectively utilized to varying degrees by the oyster mushrooms. For P. pulmonarius and P. ostreatus, MS+SB substrate was best utilized and recorded the highest biological efficiency. The highest nutrient value of P. ostreatus was obtained from mushrooms on SD substrate (27.17mg/100g) followed by those on SB + MS substrate (27.15mg/100g) whereas P. pulmonarius had the highest nutrient composition with SB+MS substrate (27.19mg/100g) while P. ostreatus and P. pulmonarius had the highest phytochemicals with SD substrate (1.44mg/100g) and SB substrate (1.35mg/100g) respectively. The MS substrate recorded the highest minerals (80.45mg/100g) in P. ostreatus followed by SD+MS substrate (79.99mg/100g). SD substrate was the best in enhancing the mineral content of P. pulmonarius (83.29mg/100g). The highest mean vitamin composition of P. ostreatus was in SB substrate, (3.89mg/100g) followed by SD+SB substrates (3.52mg/100g). P. pulmonarius grown with SB substrate recorded the highest vitamin content (4.08mg/100g). The result on the effect of substrates on heavy metal composition of P. pulmonarius showed no significant (p > 0.05) differences among the substrates except with SB substrate that recorded the highest Zinc content. The average heavy metal content of P. ostreatus was highest with SB substrate (0.42ppm) followed by SD and SB+MS substrates recording 0.38ppm each and the least was recorded with MS substrate (0.31ppm). Polysaccharide degrading potential of P. ostreatus was highest with SB substrate (37.86%), followed by SD+SB substrate (31.76%) and SD substrate (27.56%). The highest polysaccharide degrading potential of P. pulmonarius was recorded with SB substrate (28.29%) followed by MS substrate (20.54%). This study revealed that SD, SB, MS and their different mixtures are good substrates for the production of mushrooms. Both P. pulmonarius and P. ostreatus showed that MS+SB substrate was better utilized by the fungus. The MS, SB and SD+SB substrates could be used as potential substrates for the production of P. ostreatus and SB, SD, MS+SB and SD+SB substrates for P. pulmonarius production since they enhanced their nutrient, vitamins and mineral contents as well as bioactive compounds.
TABLE OF CONTENTS
Title Page
i
Declaration
ii
Certification
iii
Dedication
iv
Acknowledgements
v
Table of Contents
vi
List of Tables
x
List of Figures
xi
List of Plates
xii
Abstract
xiii
CHAPTER 1: INTRODUCTION
1.1 Background to the Study 1
1.2 Types of
Mushroom 5
1.2.1 Edible
mushrooms 5
1.2.2 Non Edible mushrooms
6
1.3
Economic Value of Mushroom 8
1.4
Problems Associated with
Mushroom Production 8
1.4.1
Problems of commercial mushroom growers 8
1.4.2 Problems pertaining to beginners, Small and
marginal mushroom growers 10
1.5 Statement
of Problem 13
1.6 Justification of Study 13
1.7 Objectives of the Study 14
CHAPTER 2: LITERATURE REVIEW
2.1 Origin and Distribution of Mushroom 16
2.2
Mushroom Production 20
2.3 Mushroom Cultivation 23
2.3.1 Use
of Agro-wastes 23
2.3.2 Wood 27
2.4 How Mushrooms Grow in Nature 28
2.5 Oyster Mushrooms
30
2.5.1 Pleurotus ostreatus
31
2.5.2 Pleurotus
pulmonarius 35
2.6 Importance of Mushroom 37
2.6.1 Mushrooms as a source of food 37
2.6.2 Medicinal value
46
2.6.3 Economic and
industrial importance of mushroom 52
2.6.4 Agricultural importance of
mushroom 53
2.6.5 Polysaccharide
degrading potentials of mushrooms 53
2.6.6 Traditional/Cultural uses of mushrooms 55
2.7 Harvesting and Processing of Mushrooms 56
2.7.1 Harvesting 56
2.7.2 Processing 57
2.8 Pests and Diseases of Mushroom and their
Control 59
2.8.1
Diseases 60
2.8.2 Other Pests 62
CHAPTER 3: MATERIALS AND METHODS
3.1
Experimental Site 64
3. 2 Source
of Spawn Culture and
Multiplication 64
3.2.1 Spawn production/multiplication 64
3.3 Sources
of Substrates and Preparation 67
3.4 Mushroom
Cultivation 78
3.5
Treatments 78
3.6
Harvesting and Data Collection 78
3.7 Experimental Layout and Design 79
3.8 Biochemical Composition of Pleurotus ostreatus and
Pleurotus pulmonarius 81
3.8.1 Determination of moisture 81
3.8.2 Determination of crude protein 82
3.8.3 Determination of crude fibre 82
3.8.4 Determination of ash 83
3.8.5 Determination of Carbohydrate 83
3.9 Determination of Vitamin Contents of Pleurotus
ostreatus and Pleurotus
pulmoarius 84
3.9.1 Determination of riboflavin (Vit. B2)
84
3.9.2.Determination of thiamine (Vit. B1) 85
3.9.3 Determination of niacin (Vit. B3) 85
3.9.4 Determination of vitamin C (ascorbic acid) 86
3.10 Determination of Mineral Contents of Pleurotus
ostreatus and Pleurotus pulmoarius 87
3.10.1 Determination of calcium and magnesium 87
3.10.2 Sodium determination 88
3.10.3 Determination of phosphorous 88
3.10.4 Determination of iron and zinc 89
3.11 Determination of the Bioactive Components of Pleurotus ostreatus
and Pleurotus pulmonarius 90
3.11.1 Alkaloid 90
3.11.2 Flavonoid 91
3.11.3 Determination of phenols 91
3.11.4 Determination of saponins 92
3.11.5 Determination of steroid 93
3.11.6 Determination of tannins 93
3.12 Determination of Polysaccharides in the
Substrates before and after Cultivation
94
3.12.1
Hemi-cellulose 94
3.12.2
Lignin 94
3.12.3
Cellulose 95
3.13 Data Analysis 95
CHAPTER 4: RESULTS
AND DISCUSSION
4.1 Results 96
4.1.1 Effect of
agro-wastes on growth and yield of Pleurotus
ostreatus after three flushes 96
4.1.2 Effect of agro-wastes on growth and yield of Pleurotus pulmonarius after three
flushes 101
4.1.3
Effect of substrates
on stipe lenght of fruit bodies produced by Pleurotus
ostreatus after three flushes 101
4.1.4 Effect of substrates on stipe lenght of fruit bodies produced by Pleurotus pulmonarius
after three flushes 104
4.1.5 Effect of substrates on pileus diameter of fruit bodies
produced by Pleurotus ostreatus after three flushes 104
4.1.6 Effect of different substrates on pileus diameter of fruit
bodies produced by Pleurotus pulmonarius after
three flushes 107
4.1.7.
Effect of different
substrates on the fresh fruit body weight of mushrooms
produced
by Pleurotus ostreatus after three flushes 107
4.1.8 Effect of different substrates on fresh fruit body weight of
mushrooms produced by Pleurotus pulmonarius after three flushes 110
4.1.9. Effect of substrates on average yield and yield attributes of Pluerotus ostreatus and Pluerotus pulmonarius after three
flushes 110
4.1.10 Effect of different substrates on Biological
Efficiency of Pleurotus
ostreatus and Pleurotus
pulmonarius mushrooms after three flushes 113
4.1.11
Effect of substrates on average nutrient composition of Pleurotus
ostreatus and Pleurotus pulmonarius
fruit-bodies 115
4.1.12. Phytochemical composition of Pleurotus ostreatus and Pleurotus
pulmonarius mushrooms grown on different substrates
118
4.1.13 Mineral composition of Pleurotus ostreatus and Pleurotus pulmonarius
fruit-bodies produced on different substrates 120
4.1.14 Vitamin content of Pleurotus ostreatus and Pleurotus pulmonarius grown on
different
substrates 122
4.1.15 Heavy metal content of Pleurotus ostreatus and Pleurotus pulmonarius
grown
on different substrates 124
4.1.16 Effect
of Pleurotus ostreatus growth on
polysaccharide composition of
substrates after cultivation 126
4.1.17 Effect
of Pleurotus pulmonarius growth on
polysaccharide composition of
substrates after cultivation 128
4.2 Discussion 130
CHAPTER 5:
CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion 142
5.2
Recommendations 144
REFERENCES 146
APPENDICES 166
LIST OF TABLES
1: Edible mushrooms 7
2: World main producing Countries and 10 major
exporting and importing
Countries 18
3: World Production of Cultivated
Edible Mushrooms, Fresh Equivalent, from
1960–2012 22
4:
Biochemical Composition of Pleurotus Species 39
5: Comparison of minerals
concentration (mg/kg dry weight) of different
mushroom
species from different countries 44
6: Vitamin content of common edible mushrooms 45
7: Ethno-medicinal uses of
some mushrooms in Nigeria 51
8:
Diseases and pathogens noxious to Pleurotus spp. mushroom 61
9: Pests
noxious to Pleurotus species in mushroom crops 63
10: Average mean yield and morphological
characteristics of Pluerotus
ostreatus and Pluerotus
pulmonarius after three flushes 112
11: Nutrient composition of Pleurotus ostreatus and Pleurotus pulmonarius
cultivated using different substrates 117
12: Effect of substrates on phytochemical
compositions of Pleurotus
ostreatus and Pleurotus pulmonarius fruit bodies 119
13: Mineral compositions of Pleurotus ostreatus and Pleurotus
pulmonarius using different substrates
121
14:
Vitamin content of fruit bodies of Pleurotus
ostreatus and Pleurotus
pulmonarius produced on different substrate 123
15: Heavy metal content of Pleurotus ostreatus and Pleurotus pulmonarius
fruitbodies using different substrates 125
16: Polysaccharide composition of substrates before and after cultivation
of
Pleurotus ostreatus 127
17: Polysaccharide composition of substrates before and after cultivation
of Pleurotus pulmonarius 129
LIST OF FIGURES
1: Experimental layout 79
2:
Effect of different agro-wastes on production of
fruit bodies by Pleurotus
ostreatus after three flushes 97
3: Effect of
different agro-wastes on production of Pleurotus
pulmonarius
fruit bodies after three flushes 102
4: Effect of different
substrates on stipe lenght of Pleurotus
ostreatus fruit
bodies
after three flushes 103
5:
Effect of different
substrates on stipe lenght of fruit bodies produced by
Pleurotus pulmonarius
after three flushes 105
6: Effect of different substrates on pileus diameter of
fruit bodies produced by
Pleurotus ostreatus after three flushes 106
7: Effect of
different substrates on pileus diameter of fruit bodies produced by
Pleurotus pulmonarius after three flushes
108
8: Effect of different substrates on fresh fruit body weight
of mushrooms
produced by Pleurotus ostreatus after three flushes 109
9: Effect of different
substrates on fresh fruit body weight of mushrooms
produced by Pleurotus pulmonarius after three flushes 111
10: Biological Efficiency of Pleurotus ostreatus and
Pleurotus Pulmonarius
grown on
different substrates after three
flushes 114
LIST OF PLATES
1: Spawn
of Pleurotus pumonarius Specie 65
2: Spawn
of Pleurotus ostreatus Specie 66
3:
Sterilization of the Substrates 68
4: Perforated buckets containing substrates after
innoculation 69
5: Maize stalk substrate (MS) 70
6: Saw dust substrate (SD) 71
7: Sugarcane bagasse substrate
(SB) 72
8: Maize Stalk + Saw Dust
substrate (MS+SD) 73
9: Maize Stalk + Sugarcane Bagasse
substrate (MS+SB) 74
10: Saw Dust + Sugarcane Bagasse
substrate (SD+SB) 75
11: Saw Dust + Sugarcane Bagasse +
Maize Stalk substrate (SD+SB+MS) 76
12: Innoculation of the substrates 77
13: First flush of Pleurotus ostreatus with
different substrates 98
14: Second flush of Pleurotus ostreatus 99
15: Third flush of Pleurotus ostreatus 100
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND TO THE STUDY
Mushroom as the fruit of certain fungi is
analogous to apple on a tree (Davis and Aegerter, 2000) which is most often
applied to the cultivated white button mushroom (Basidiomycota, Agaricomycetes) that have a stem (stipe), a cap (pileus), and gills (lamellae) or pores on the
underside of the cap. Mushrooms as macro fungus are known to grow
on a wide variety of substrates and habitat and are large enough to be seen with the
naked eye (Chang and Miles, 1991). All mushrooms are fungi, which play
similar role as a flower or fruit
in plants that produce microscopic spores that are similar to pollen or seeds,
sometimes numbering in the trillions (Udayasimha and Vijayalakshmi, 2012). Mushrooms are important constituents of minor
forest produce, with a distinctive fruiting body which can be either epigeous
or hypogeous and large enough to be seen and picked by hand. Only fruiting body
of the mushroom can be seen whereas the rest of the mushroom remains
underground as mycelium on
decayed organic matters rich in lignin, cellulose, and other complex
carbohydrates (Ananbeh, 2003; Chang and Miles, 1992).
Mushrooms, being fungi are achlorophyllous
and hence incapable of synthesizing their own food materials. Geologically,
mushrooms existed on the earth even before man appeared on it, as evidenced
from the fossil records of the lower cretaceous period. Mushrooms offer
tremendous applications as they can be used as food and medicines besides their
key ecological roles. They represent one of the world greatest untapped
resources of nutrition and palatable food of the future. Mushrooms are
cultivated worldwide for their taste, nutritional attributes and potential
application in industries (Sunagawa and Magae, 2005; Mata et al., 2005) and they are useful for the preparation of medical
concoctions and drugs (Lim et al.,
2004). Pleurotus pulmonarius
contains appreciable levels of vitamins and phytochemicals such as
alkaloids, phenols, tannins, saponins, flavonoids and sterols which are of
great nutritional and medicinal importance (Okwulehie and Nosike, 2015a). The importance of mushrooms in
bioremediation and biodegradation has been reported by various scientists
(Adenipekun and Fasidi, 2005; Estevez et
al., 2005). Pleurotus species have been used globally for
their nutritional, medicinal and other beneficial values (Pandiarajan, et al., 2011). Mushrooms are good not only for
immune-enhancement, but also to complement western chemotherapy and radiation
therapy. People who
collect mushrooms for consumption are known as mycophagists and the act of
collecting them for such is known as mushroom hunting, or simply "mushrooming" (FAO, 2009).
Oyster mushroom (Pleurotus species) belongs to the family of
Tricholomataceae and is the second most widely cultivated mushroom worldwide
(Sánchez, 2010).
However, Obodai et al., (2003) reported that oyster mushroom is the third largest commercially
produced mushroom in the world market Pleurotus species are popular and widely cultivated throughout the world
mostly in Asia, America and Europe because of their simple, low cost production
technology and high biological efficiency (Mane et al., 2007). Moreover, the interest on oyster mushroom is increasing largely due to
its taste, nutrient, and medicinal properties (Garcha, et al., 1993). Pleurotus
species can efficiently degrade
agricultural wastes and they grow at a wide range of temperatures (Udayasimha and
Vijayalakshmi, 2012).
Species of Pleurotus (side ear) are gilled mushrooms that are
most widely cultivated and eaten. The gills produce microscopic spores that
help the fungus spread across the ground or its substrates (Miles and Chang, 2004). In comparison with other edible mushrooms, Pleurotus species need a short growth time and
their fruiting bodies are not often attacked by diseases and insect pests
(Tesfaw et al., 2015; Baysal et al., 2003) and they require carbon, nitrogen
and inorganic compounds with less nitrogen and more carbon as their
nutritional sources, suggesting that materials containing cellulose,
hemicellulose and lignin such as rice and wheat straw, cotton seed hulls,
sawdust, waste paper, leaves, and sugarcane residue can be used as mushroom
substrates (Chang and Miles, 1989).
Agro-residues
contain three major structural polymers, cellulose, hemicellulose and lignin,
which can be easily utilized or broken down by the lignocellulotic enzymes. Pleurotus species are the most efficient
lignin-degrading organisms, with the ability to produce mainly laccases (EC
1.10.3.2), lignin peroxidase (EC 1.11. 10.14) and manganese peroxidase
(EC1.11.1.13) (Adebayo et al., 2012).
These enzymes are non-specific biocatalyst mechanism which have been used for
bioremediation process due to their ability to degrade, heterocyclic, reactive
and polymeric dyes (Baldrian and Snajdr, 2006; Forgacs et al., 2004). White-rot basidiomycetes are among the most potent
organisms capable of biodegrading and detoxify a wide range of wastes and
pollutants. These fungi selectively attack lignin and related compounds by
producing one or more of phenol-targeting redox enzymes, namely the peroxidases
and laccases/phenol-oxidases (Ntougias et
al., 2012). Mushrooms therefore have the ability to secrete high levels of
lignin-degrading enzymes and novel enzyme variants, with desirable properties
for biotechnological applications (Adebayo et
al., 2012). Therefore, the huge amounts of lignocel-lulosic biomass can be
potentially bioconverted into different high value raw materials and products
such as bio-ethanol, enriched animal feed, cheap energy sources for microbial
cultivation (mushrooms included) and enzyme production, biodegradation and
bioremediation of toxic organic compounds (Anwar et al., 2014; Asgher et al.,
2013; Irshad et al., 2013; Ntougias et al., 2012). The nature and nutrient
constituent of the mushroom substrate also have an effect on the mycelium
growth, mushroom quality and crop yield (Kües and Liu, 2000).
There are both
edible and non-edible mushrooms. The edible
mushrooms are rich sources of
carbohydrates, proteins, vitamins, and minerals (Ananbeh, 2003).
Several species of oyster mushrooms are very important as food and in
the field of medicine. Pleurotus species are rich in protein, minerals
(P, Ca, Fe, K, and Na) and vitamins (thiamine, riboflavin, folic acid, and
niacin) (Szabová et al., 2013). Apart from food value, their medicinal value for diabetics and cancer
has been emphasized (Sivrikaya et al., 2002). Numerous mushroom species contain a wide range of metabolites as
antitumour, antigenotoxic, antioxidant, antihypertensive,
antiplatelet-aggregating, antihyperglycaemic, antimicrobial, and antiviral
activities (Chang, 2007). Mushrooms have
been found effective against cancer, cholesterol reduction, stress, insomnia,
asthma, allergies and diabetes. Due to high amount of proteins, they can be
used to bridge the protein malnutrition gap. Mushrooms as functional foods are
used as nutrient supplements to enhance immunity in the form of tablets. Due to
low starch content and low cholesterol, they suit diabetic and heart patients.
One third of the iron in the mushrooms is in available form. Their
polysaccharide content is used as anticancer drug. Even, they have been used to
combat HIV effectively (Nanba, 1993; King, 1993). Biologically active compounds
from the mushrooms possess antifungal, antibacterial, antioxidant and antiviral
properties, and have been used as insecticides and nematicides. Mushrooms have
been universally recognized now as food with high demand and are grown on
commercial scale in many parts of the world including Nigeria. The increased demand
for mushrooms could be contingent upon the phenomenal rise in the unit costs of
the conventional sources of animal proteins such as beef, pork, chicken and
fish (Aletor, 1995: Okwulehie and Odunze, 2004). The cultivation of mushrooms
is environmentally friendly. The problem of air pollution may be avoided by
using mushrooms to bioprocess the lignocellulosic waste materials,
which may later be used as highly proteinaceous feed for livestock (Belewu,
2003). Fruiting may also be
stimulated by mechanical injury and chemical treatments (Hibbett et al., 1994). There are also various
additives that are known to stimulate fruiting, example rice bran, cassava peels etc. (Fasidi and Kadiri, 1993).
In addition, lipids such as crude and refined vegetable oils, as well as fish
oil may also be used to stimulate fruiting (Martin and Patel, 1991). The fact
that mushrooms can be cultivated on
materials that would
otherwise be considered as waste makes it a valuable venture in self-sustaining
and empowerment of communities in future.
Mushrooms can
not only convert lignocellulosic waste materials into human food, but also can
produce notable nutriceutical products, which have many health benefits. They
provide people with an additional vegetable of high quality, and enrich the
diet with high quality proteins, minerals and vitamins which can be of direct
benefit to the human health and fitness. Edible mushrooms are highly nutritious
and can be compared with eggs, milk and meat. The extractable bio-active
compounds from medicinal mushrooms would enhance human immune systems and
improve their quality of life. The content of essential amino acids in mushroom
is high and close to the need of the human body. Mushroom is also easily
digestible and it has no cholesterol content (Oei, 2003).
1.2 TYPES OF MUSHROOM
There are
edible, non -edible and medicinal mushrooms (Sieger, 1998). A number of species of mushrooms are poisonous; although some resemble certain edible
species, consuming them could be fatal and deadly (Sieger,
1998) whereas several others can cause severe and unpleasant symptoms (Hawley, 2010).
1.2.1 Edible mushrooms
Edible
mushrooms are widely used as human food (Chang, 1999a). Many of them
grow in the forests and farmlands and they include; Pleurotus species, Termitomycetes,
Volvoriella species and Agaricus species (Table 1). There are at least 12,000 species of fungi
that can be considered as mushrooms with at least 2,000 species showing various
degrees of edibility (Chang, 1999b). Many edible mushrooms have long been used
for medicinal purposes.
1.2.2 Non
Edible mushrooms
A number of species of mushrooms are poisonous. Even though some resemble certain edible
species, consuming them could be fatal (Sieger, 1998)
due to their secondary
metabolites that can be
toxic and mind-altering. Although there are only a small number of deadly species, several others can cause particularly
severe and unpleasant symptoms (Hawley, 2010). Examples
include; Amanita virosa, Amanita pantherina, Inocybe
patouillardii, Cortinarius speciosissimus, Cortinarius
orellanus, Gyromitra esculenta, Psilocybe spp.,
Paneolus spp., Gymnopilus spp., Conocybe spp., Amanita
muscaria, Amanita pantherin, Lycoperdon
spp., Amanita phalloides,(Philips, 1994; Miles and Chang,
1997). Many non edible species have also gained important medicinal usage,
examples include; Auricularia auricular,
Trametes (Coriolus) versicolor, Flammulina velutipes, Ganoderma lucidum,
Grifola frondosa, Hericium erinaceous, Lentinus edodes, Schizophyllum commune,
Tremella fuciformis and Poria cocos (Philips, 1994; Miles and Chang, 1997).
Table
1: Edible mushrooms
Scientific names Common names
|
Boletus edulis
|
Cep
|
|
Cantharellus cibarius
|
Chanterelle
|
|
Coprinus comatus
|
Shaggy inkcap
|
|
Cratarellus cornuopiodes
|
Horn of Plenty
|
|
Hydnum respondum
|
Hedgehog fungus
|
|
Laetiporus sulphurous
|
Chicken of the Woods
|
|
Lepiota procera
|
Parasol mushroom
|
|
Lepiota saeva
|
Field blewit
|
|
Marasimus oreandes
|
Fairy Ring Champignon
|
|
Morchella esculenta
|
Morel
|
|
Sparassis crispa
|
Cauliflower fungus
|
|
Tuber aestivum
|
Truffle
|
Sources; Philips, (1994);
Miles and Chang, (1997)
1.3 ECONOMIC
VALUE OF MUSHROOMS
Not many
people are aware of the economic value of mushrooms. Mushroom is a saprophytic
organism and hence it utilizes organic and agricultural waste. This reduces the
burden of farmers to dispose his farm wastes. Additional income is obtained
through quality mushrooms production by utilizing these residues. Mushroom
cultivation both seasonal and commercial gives handsome income to the growers.
The employment generation through cultivation and associated allied activities
is so immense. The value addition to mushrooms in terms of quality products is
another economic avenue. The positive use of spent mushroom substrate viz.,
biofuel, biogas production, manures, potting medium, etc also generates
additional revenue to the farmer (Rosmiza,
et al 2016).
1.4 PROBLEMS
ASSOCIATED WITH MUSHROOM PRODUCTION
1.4.1 Problems of commercial mushroom growers
The problems of large scale mushroom production are different from the small,
marginal and seasonal growers/farmers. The major problems of large scale
mushroom growers are;
i) Lack of good quality spawn
The yield of mushroom to a great extent
depends upon quality of spawn. Good quality spawn should be free from diseases
with high yield potential. The non- availability of quality spawn is a common
problem of commercial production of mushroom due to change of source of spawn
every year in the search of quality spawn. Generally, the private spawn
producers are not well equipped with the knowledge and facility for mushroom
breeding and cannot claim development of new high yielding strains. In fact,
the spawn producers procure the mother culture of mushroom from Government
organization or prepare the culture by selecting a healthy mushroom and using
it for making commercial spawn of mushroom with their own brand name (Suharban et al., 1991).
ii)
Uncontrolled price structure of mushroom
Price fluctuation is a major problem in
mushroom production. When there is a glut in the market, the price of mushroom
falls but as the demand increases or shortage of mushrooms in the market, the
prices rise. Thus there is always an uncertainty in market price of mushroom
which reduces the amount of net profit and discourages the mushroom growers.
This problem gets aggravated during peak production months, because there is no
minimum support price from the Government even in states with good number of
mushroom farmers (Paul et al., 2001).
iii) Lack of pre-cooling and storage facility
for fresh mushroom
This is a severe problem being experienced by
large mushroom growers. During the peak production period, growers are unable
to dispose of their fresh mushroom on the same day and they are forced to keep
it for the next day. In such a situation, the quality of fresh mushrooms
deteriorates and it also loses weight as it is a highly perisable commodity
which can only be stored for about 12 hours at room temperature and 2-3 days at
50C. In order to combat this problem, mushroom growers require a
common facility of cold room where they can store their produce for 2 to 3 days
and also a pre-cooling unit for keeping the quality of mushroom (Paul, et al., 2001).
iv) High
transportation charges
Although, agro and animal wastes may be
available and plenty in a particular area and their availability may not be
evenly distributed, and because of different climate and topography of land,
different kinds of crops are raised in different parts of the country. For
instance, wheat and paddy straw may be
easily available at cheaper rates in the northern region of a
country while the same is a scarce
commodity in the southern region and
since mushroom cultivation is based on agro-waste, the raw materials required
for its cultivation are usually transported from the northern region to the
southern region (Nigeria) in huge
quantity and mushroom growers have to pay high transportation charges resulting
in avoidable increase in cost of production and reduction in net profit (Singh,
et al., 2004).
v) Commercial rate of electricity tariff
Both small and
big mushroom growers pay electricity charges at commercial rate, although
mushroom farming is an agricultural activity. This has led to high cost of
production due to increase in tariff and recurring expenditure on mushroom
farming (Suharban et al., 1991).
vi) Lack of marketing facilities
When
large quantities of mushrooms are harvested per day at large mushroom
farms, then marketing becomes a major problem. Mushroom growers cannot dispose
of large quantity of mushroom more than the daily demand in the local market
and in nearby cities. In such a situation, he has to dispose of the remaining
quantity of mushroom either at a distress-price or he has to transport it to
different places where demand of mushroom is high. But the problem is
delivering the fresh mushroom from the producing area to the consumer beyond a
distance, since mushroom is a perishable vegetable and can’t be stored at room
temperature for more than 12 hours. It is only possible when it is transported
in refrigerated vans which is currently not available. As a result the
mushrooms deteriorate in quality and quantity and the grower is made to incur
heavy losses (Singh, et al., 2004;
Suharban et al., 1991).
1.4.2 Problems
pertaining to beginners, Small and marginal mushroom growers.
Problems of small and marginal mushroom growers are much different from those
of large scale mushroom growers. The small and marginal mushroom growers are
generally seasonal growers, taking only 1 to 2 crops of mushroom in a year
under natural conditions. Hence the nature of problems of these growers are
different than the large mushroom growers. The major problems pertaining to
small and marginal mushroom growers and farmers who want to start mushroom
farming at a moderate scale are as follows:
i) Lack of
availability of quality spawn and compost
Mushroom
cultivation is a complex process which demands technical expertise especially
for spawn and compost production which are costly. The small and marginal
farmers are generally uneducated and economically poor. The production of spawn
and compost is a difficult technical job for them which also require heavy
investments. They can only raise a mushroom crop by procuring the requisite
inputs – spawn and compost from various other sources (Suharban, et al., 1991).
Spawn is not easily available and it is being produced by very few Government
departments and private producers. Thus, spawn is usually procured by mushroom
growers with great difficulties (Suharban, et
al., 1991). Similarly, the seasonal mushroom growers and newly trained
farmers try to avoid the complex process of compost preparation due to fear of
failure and lack of finance. As an alternative to this they generally procure
ready-made compost, but areas to get ready made compost is a major problem.
Thus the non-availability of requisite inputs – spawn and compost is an
impediment in fast spread of mushroom cultivation (Paul et al., 2001).
ii) Complex
process of obtaining loan/finance
Mushroom cultivation demands heavy investment
in the initial stages. The small and marginal seasonal mushroom growers who
want to expand their temporary mushroom farms and those farmers who want to
start afresh are usually unable to invest the required amount of money from
their own pocket. Therefore, they approach the financial institutions to obtain
loan for this purpose. But the formalities of these financial organisations are
so complex that the seasonal mushroom growers and farmers cannot get the
finance easily. This is a practical problem facing small, marginal and seasonal
mushroom growers and farmers (Paul et al.,
2001; Suharban et al., 1991).
iii) Lack of
low cost mushroom farm design
A scientifically designed mushroom farm needs
heavy investment and hence is out of reach of small and marginal mushroom
growers/farmers. Therefore, there should be a low cost mushroom farm design
available, based on locally available material and as per local climatic
conditions. The seasonal mushroom growers in some areas are growing mushroom in
thatched mud houses, in which maintaining the required temperature and humidity
for mushroom cultivation is very difficult. These kinds of structures need
refinement by scientific community to ensure availability of an appropriate low
cost farm design (Suharban et al.,
1991).
iv) Lack of
training facilities
Training is an essential component for
successful adoption of the technology of mushroom
farming in which many States are lacking. Few
Agricultural Universities are providing only preliminary guidance on mushroom
farming to limited number of farmers. Hence this is a major problem which
discourages the farmers to take up the cultivation of this non-traditional crop
(Paul et al., 2001).
v) Inadequate
testing and diagnostic facilities
Besides technical expertise, mushroom
cultivation also demands hygienic conditions in its surroundings. To maintain
hygienic conditions in the village situation by local farmers is very difficult
and thus chances of occurrence of insect pests and diseases are much more which
sometimes damage mushroom crop to a great extent. The extent of losses can be
reduced if the causes of loss is diagnosed on time and remedial measures taken
urgently. However, there are very few research organizations where quality
parameter testing and pest and diseases diagnostic facilities are existing.
These facilities are inadequate or are entirely lacking (Suharban et al., 1991).
1.5 STATEMENT OF PROBLEM
Disposal of agricultural
wastes has been a source of primary concern in
today’s world since they are rich in nutrients and their disposal without
pre-treatment can cause leaching in the field, and environmental pollution and
hazards. Agricultural wastes are rich in various types of nutrients and their
disposal is difficult to manage. Due to excess nutrients which are wasted and which could be made
beneficial to man in different ways by turning them into edible products or
into commercial ventures like biogas. This study was therefore aimed at using some of the
available agricultural wastes in the production of some edible mushrooms to
enhance human health and reduce environmental pollution.
1.6 JUSTIFICATION OF STUDY
Large volumes of unused lignocellulosic by-products are available in
Nigeria. These by-products are usually left to rot in the field or are disposed
through burning (Tesfaw et al., 2015). Using locally available lignocellulosic substrates to cultivate
oyster mushroom is one solution to transform these inedible wastes into
accepted edible biomass of high market and nutrient values (Tesfaw et al., 2015). To overcome the problem of environment
pollution, mushroom cultivation using these agricultural wastes is an
eco-friendly method to reduce the level of nutrients in the wastes to
acceptable range to be used as manure. Also, defined combination of these
agricultural wastes in mushroom production gives high yield of mushroom in a
cost effective manner. Hence, mushroom production could lead to high demand of
agricultural wastes, thereby constituting a waste management method (Nicolcioiu
et al., 2016).
Agricultural
waste provides the opportunity for cost effective mushroom farming. Even after
being used for mushroom cultivation, it can be used later as manure in the
field since the nutrient contents are now at acceptable range for crop
production. Cultivation of mushroom on these residual wastes is one of the most
eco-friendly practices to fight environmental pollution caused by
them. Various researches are in progress to exploit the potential of
agricultural wastes either by using them in combination or by giving them pretreatment. Therefore the cultivation of
mushroom serves as an efficient and economically viable means for the
conversion of lignocellulose waste materials to high quality protein food. This
is expected to open up new job
opportunities especially in rural areas (Hussain, 2001).
Mushrooms are eaten as meat substitutes and
flavouring. In general, edible mushrooms are low in fat and calories, rich in
vitamin B and C, contain more protein than any other food of plant origin and
are also a good source of mineral nutrients (Bahl, 1998). Currently, high
biofuel prices have caused an increase in food prices and food scarcity in many
countries (World Bank, 2004). To alleviate hunger and malnutrition in a world
of rising food prices, cultivation of mushrooms is a very reliable and
profitable option.
1.7 OBJECTIVES
OF THE STUDY
The broad objective of the study was to evaluate the effects of different
substrates (Agro-wastes) on the growth, yield, biochemical composition and polysaccharide degradation potentials of Oyster mushrooms (Pleurotus ostreatus and
Pleurotus pulmonarius)
Specific objectives of the study:
1. To determine the effect of various substrates/agrowastes [saw dust
(SD), maize stalk (MS), Sugar cane bagasse (SB) and their combinations] on the
growth and yeild of Pleurotus ostreatus and Pleurotus pulmonarius.
2. To evaluate the effects of the agro-wastes on the biochemical compositions and nutritional values of Pleurotus ostreatus and Pleurotus pulmonarius.
3. To evaluate the bioactive compounds of the substrates before use and
after harvest of the mushrooms
to assess the polysaccharide degrading potentials of Pleurotus ostreatus
and Pleurotus
pulmonarius.
4. To determine the best substrates for effective and efficient production of Oyster
mushrooms to increase substrate options in mushrooms cultivation.
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