CMS COLLEGE OF SCIENCE AND COMMERCE
(An Autonomous Institution, affiliated to Bharathiar University,
Reaccredited at ‘A’ Level with CGPA 3.53/4)
SCHOOL OF BIOLOGICAL SCIENCES
MICROBIOLOGY DIVISION
SEMESTER V
EXTRA DEPARTMENTAL COURSE
“MUSHROOM CULTIVATION”
STUDY MATERIAL
1
CONTENTS
Unit: I
Page No
Mushroom Technology:
Introduction, history and scope
-
04
Edible and poisonous mushrooms
-
06
Vegetative characters
-
10
Formation and development of basidiocarp
-
12
Structure of basidiocarp - agaricus.
-
12
Importance and nutritive value of edible mushrooms
-
15
Small village unit & larger commercial unit
-
16
Principles of mushroom farm layout
-
16
Location of building plot
-
19
Design of farm, bulk chamber, composting platform
-
20
Pasteurization room & growing rooms
-
20
Principles of composting
-
24
Machinery required for compost making
-
24
Materials for compost preparation
-
25
Methods of composting- long method of composting (lmc) -
26
Short method of composting (smc)
27
Unit: II
Cultivation System & Farm design
Unit: III
Compost & Composting
-
2
Unit: IV
Spawn & Spawning
Preparation of spawn substrate
-
29
Preparation of pure culture
-
29
Media used in raising pure culture
-
30
Culture maintenance, storage of spawn
-
32
Cultivation of button mushroom (agaricus bisporus)
-
34
Oyster mushroom (pleurotus florida)
-
34
Collection of raw materials, compost & composting
-
36
Spawn and spawning
-
37
Casing and case run
-
38
Croping and crop management
-
39
Picking and packing
-
39
Unit: V
Cultivation of Button and Oyster Mushrooms
3
UNIT I
Mushroom Technology:
History and Scope:
People have been eating mushrooms for a long time. They used to go the forests and other
wild places and based on their personal knowledge of edible and poisonous mushrooms they used
to collect the edible ones. Even now some people collect wild mushrooms from the forest and eat
them. Sometimes they turn out to be poisonous and have harmful effects. In India the 'Guchhi'
mushroom was a delicacy known to the people prior to the 1950's. It came mostly from Kashmir.
Around the early 1950's the government of Himachal Pradesh appointed Shri S.S.Jain as
its first Asstt. Plant Pathologist and Mycologist for the state. He worked in the Wild Flower Hall
in Chharabra, Shimla. He was touring the interior areas of Himachal to help the apple orchardists
and the farmers control the diseases of apples, other fruits and crops like potatoes and wheat. He
noticed the poor hand to mouth condition of the poor farmers in the hilly state of HP. He wanted
to help them. While staying with some farmers in interior areas he noticed that there were rotting
twigs and branches of apple and other fruit trees and wheat straw in the barn along with cow dung
and in the environmental conditions there were a profusion of mushrooms growing in the dark
barns. This led him to think of using the waste material with the farmers for growing edible
mushrooms. He searched the literature and found that edible mushrooms were being grown in
France and Japan. He made a research proposal on growing of edible mushrooms and got the
permission for the same from the state government and obtained the mushroom spawn from Japan
and France and started a laboratory in Solan, Shimla Hills and started his research experiments on
growing edible mushrooms of Agaricus and other species, in laboratory conditions simulating
those found in Himachal Pradesh.
When he was able to grow the mushrooms successfully on substrate prepared from rotting
apple tree twigs and branches, cow dung and wheat straw etc. he published the results through the
magazine of the HP state Extension department. These results when publicized and brought to the
notice of the farmers and the poor people people in the state led to dissemination of information
and
spawn
to
them
and
mushroom
farming
4
started
in
Himachal
Pradesh.
The laboratory established by Shri S.S.Jain, the pioneer of mushroom cultivation in India later
became the only important centre for training in mushroom cultivation to farmers of Himachal
Pradesh and other states as also the mycologists and plant pathologists from all over India. Mr.
Seth and others actually worked with Shri Jain and later became important in the area of
mushrooms. Cuttack Orissa under the ICAR as a Senior Scientist Plant Pathologist and retired
from there in 1978 after having published over a hundred research papers and also having been the
Chief Editor of the International Rice journal 'Oryza'. Shri Jain had also done a monographical
study of the Stem Rot disease of rice and also discovered the bacteria Xanthomonas oryzae, which
caused the Bacterial Blight disease of rice, and Dr Devdath did his Ph.D on this bacteria and
disease. Before Shri Jain expired after prolonged coma in Apollo Hospital Delhi and a small
nursing home in Baraut, District Baghpat (Meerut), UP, he had been an award-winning President
of the Rotary Club Baraut for his excellent social service work also winning International citation
from Rotary.
5
Edible and Poisonous Mushrooms:
Although some kinds of mushrooms belong to the medicinal group, a few others belong to
the poisonous and ‘magical’ variety having mind altering and hallucinogenic properties.
Edible Mushrooms
Morel Mushroom
‘Super Food’ Morels, used in Eastern India, as a traditional medicine, considering their
therapeutic benefits hold healthy nutritive content. They help scavenge and destroy diseasecausing bacteria, preventing occurrences of serious ailments. Besides promoting immune health,
Morels are effective against cancers of the prostate and the breast. They promote metabolic
function vision health, produce energy and combat tumours.
Shiitake Mushroom
One of the most popular varieties, commonly available in supermarkets, Shiitake is a
classic vegan substitute for meat, boasting of several medicinal compounds. Abundant in Vitamin
D, these mushrooms with antiviral compounds help combat infections, keeping diseases at arm’s
length. Known in Japanese language, as the ‘Oak Fungus’ these shiitake mushrooms with loads of
lentinan are highly beneficial for preventing formation of cancerous tumors in the body.
Enoki Mushrooms
Enoki Mushrooms growing in willowy white clusters have heads resembling a cap.
Cultivated in small glass containers, these mushrooms offer health enhancing properties,
boosting immunity and providing anti cancerous benefits.
Oyster Mushroom
Oyster Mushrooms derive their name from oysters, owing to the similarity in appearance.
Potent antioxidant compounds in oyster mushrooms, have sent scientists researching their potential
benefits for treating HIV diseases. Apart from this, these mushrooms are contenders for protecting
against
cancers
and
facilitating
healthy
6
cholesterol
levels
in
the
body.
Maitake Mushroom
Popularly known as "Hen of the Woods" these delectable Japanese delights comprising of
potent anticancer elements, prevent hormone- related cancers of the ovary and the breast. Maitake
mushrooms are known to treat cancer and are also used to relieve some of the side effects of
chemotherapy. Owing to the existing antiviral properties, they boost immune health, besides
lowering blood pressure and blood sugar levels.
Reishi Mushroom
Owing to the presence of gandodermic acid, an active compound, the Reishi types offer
healthy cardiac benefits. These keep the arteries from clogging, preventing sticking of blood clots
to the arterial walls. Because of this, they help maintain healthy levels of blood pressure and
cholesterol in the body.
Button Mushroom
Button Mushrooms, possessing specific kind of carbohydrates boost metabolism, thereby
keeping blood sugar levels under check. In addition to its high metabolic activity, the white button
mushrooms, loaded with selenium, help burn fat, effecting weight loss and preventing the
incidence of prostate cancer.
Poisonous Mushrooms
When foraging in the wild or after a disaster and it’s safe to go outside to look for food,
edible mushrooms can be a good source of nourishment. But there are mushrooms that are not
meant to be eaten. Be sure you know how to differentiate these from the edible ones. These are 9
common poisonous mushrooms that you might come across when looking for food.
The Death Cap and Destroying Angel mushrooms:
They contain a deadly toxin that almost always causes certain death to people who
consumed the mushrooms. Signs of poisoning become apparent 6-24 hrs after eating the poisonous
mushrooms and include: nausea, vomiting, abdominal cramps, and diarrhea. Symptoms can be
severe like violent vomiting, acute cramping, and bloody diarrhea. Uneaten specimens or at least
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good photographs of the specimens should be provided to a bona fide expert for identification in
case symptoms appear. Untreated cases cause death due to permanent debilitating liver/kidney
damage. Even survivors never fully recover from permanent organ damage.
Sulfur tuft mushrooms:
They cause mild to severe gastrointestinal irritation, generally the least troublesome form
of mushroom poisoning. Symptoms appear within an hour but can at rare times appear in 4 hours.
Symptoms may range from mild to acute: nausea, vomiting, diarrhea, and abdominal cramps.
Symptoms subside when the body gets rid of the meal but in severe cases, medical treatment and
hospitalization are needed to maintain fluids and electrolyte balance.
Fly agaric mushrooms:
They contain toxics that cause delirium, apparent innebriation, manic behavior, and a
tendency to perceive small objects as very large. Some people who ate the mushroom exhibit a
desire for intense physical activity; most experience a deep sleep, usually with visions. Nausea and
8
vomiting may also occur. Symptoms appear half an hour to two hours after ingestion and last for
up to four hours or more.
Livid Entoloma mushroom:
Poisoning is mainly gastrointestinal in nature; symptoms include: diarrhea, vomiting and
headache. Symptoms occur 30 minutes to 2 hours after consumption and last for up to 48 hours.
Acute liver toxicity and psychiatric symptoms like mood disturbance or delirium may occur.
Rarely, symptoms of depression may last for months. At least one source reports there have been
fatalities in adults and children.
Cortinar mushroom:
The Cortinar and several other mushrooms in the genus Cortinarius are poisonous and
cause acute tubulointerstitial nephritis. Some are lethal like Cortinarius rubellus and Cortinarius
orellanus. These mushrooms contain the toxin orellanine which is easy to detect because it is
fluorescent.
Deadly Fibrecap’s mushroom:
The Deadly Fibrecap’s name is no joke because it is lethally poisonous, even in small
quantities. The mushroom contains high levels of the toxin muscarine which causes: blurred vision,
increased salivation, excessive sweating, bronchial secretions, abdominal cramping, increased
gastric acid secretion, diarrhea and polyuria. If muscarine reaches the brain it can cause tremor,
convulsions and hypothermia.
Yellow staining mushroom:
Yellow staining mushroom poisoning symptoms include: are nausea, stomach cramps,
diarrhea and vomiting. The signs appear shortly after eating. The severity of symptoms varies with
the amount eaten.
Characteristic of agaricus:
Agaricus is an edible fungus and is commonly known as mushroom. In old literature it is
known by the generic name Psalliota. It is a saprophytic fungus found growing on soil humus,
decaying litter on forest floors, in the fields and lawns, wood logs and manure piles. It grows best
9
in moist and shady places and is commonly seen during rainy season. It is cosmopolitan in
distribution.
About 17 species of Agaricus have been reported from India. It is commonly known as
kukurmutta in U.P. and dhingri in Punjab. A. campestris (field mushroom), A. bisporus (A.
brunnescence; white mushroom) are common edible mushrooms. A. bisporus (cultivated
mushroom) is widely cultivated for food purposes in Solan (Himachal Pradesh). Some species of
Agaricus are poisonous (e.g., A. xanthoderma) and some species may cause gastrointestinal
disturbances in some persons (e.g., A. placomyces, A. silvaticus).
Structure of Agaricus:
It can be studied in two parts:
(a) Vegetative mycelium (living inside the soil)
(b) Fruiting body or basidiocarp (present above the soil and edible in young stage)
(a) Vegetative Structure:
Primary Mycelium:
It originates by the germination of uninucleate basidiospores carrying either ‘+’ or ‘-‘strain.
The cells are uninucleate i.e., monokaryotic. It is short lived and becomes bi-nucleate by fusing of
two compatible hyphae.
Secondary Mycelium:
It originates from primary mycelium. After fusion of the hyphae of two opposite strains,
the nucleus from one hypha migrates to the other and later gives rise to the bi-nucleate secondary
mycelium i.e., dikaryotic. It is long lived and abundant.
Tertiary Mycelium:
The secondary mycelium grows extensively under the soil and becomes organised into
special tissue to form the fruiting body or basidiocarp. The fruiting body appears like umbrella
above ground. It is made up of dikaryotic hyphae. These hyphae are called tertiary mycelium. The
mycelium is subterranean. The hyphae are septate and branched. The cells communicate with one
another by means of a central pore in the septum. It is a typical dolipore septum.
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Fairy Rings of Agaricus:
The mycelium of the Agaricus is subterranean. It has a tendency to grow in all directions
from a central point to form a large invisible circular colony. The mycelium also increases in
diameter year after year and the being at all times on the outer edge, because the central mycelium
dies away with age.
When the mycelium becomes mature at tips, sporophores are produced. These sporophores
appear in a circle (Fig. 2). These circles of mushrooms are commonly called “fairy rings”, because
of an old superstition that the mushroom growing in a ring indicates the path of dancing fairies.
The fairy rings are generally composed of dark green and light green bands of grass. The
outer ring of probably luxuriant growth of grass (dark green band) is due to the fact that actively
growing edge of mycelia attacks protons and other organic substances of soil liberating ammonia
in excess. This is converted into nitrate by nitrifying bacteria which is subsequently absorbed by
the grass leading to stimulated growth.
Development of the Basidiocarp or Sporophore:
The development of the basidiocarp takes place from the subterranean mycelial strand
known as rhizomorph. After absorbing sufficient food material mycelium produces fruiting bodies,
which are very small in size and remain underground.
11
These tiny, pin head structures come above the soil under favourable conditions (i.e., after
rain or when enough moisture is present in the soil). These are the primodia of basidiocarp. These
primordia enlarge into round or ovoid structures and represent the ‘button stage’ of the basidiocarp.
A longitudinal section of button stage shows that it can be differentiated into a bulbous basal
portion representing the stalk region and an upper, hemispherical part which at maturity forms the
cap or pileus region. A ring like cavity (gill chamber) develops at the junction of stalk and pileus
region. At this stage the basidiocarp is not fully open but the young pileus is connected with stalk
by a membrane known as partial or inner veil or velum. Due to rapid absorption of water and food
material, the stalk further elongates. The button projects above the soil and elongates considerably.
The growth is very slow at the lower portion of the button while it is very rapid at the upper portion.
As a result of such growth the button develops into umbrella like cup. Velum gets broken
due to enlargement of the cap and elongation of the stalk. It exposes the hymenium or the gills.
Atkins (1906) described the development of basidiocarp as hemiangiocarpic i.e., the hymenium is
at first enclosed but becomes exposed at maturity. Simultaneously, the development also takes
place in the gill region. The tissue of the upper region of the gill chamber differentiates into slow
and fast growing alternate bands called primordiutn of gills. Gills or lamellae are of three types
i.e., long gills, half length gills, quarter length gills.
Structure and Anatomy of Basidiocarp:
The mature fruiting body can be differentiated into three parts i.e., stipe, pileus and annulus
1. Stipe:
It is the basal part of the basidiocarp. In this region the hyphae run longitudinally parallel
to each other. A transverse section of stipe shows that it is made up of two kinds of tissue, i.e., (a)
Compactly arranged hypahe in the peripheral region known as cortex, (b) loosely arranged hyphae
(with inter spaces), in the central region known as medulla.
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2. Pileus:
The stipe at its top supports a broad umbrella shaped cap called pileus. The mature pileus
is 5 to 12.5 cm in diameter. From the underside of the pileus hang approximately 300 to 600 strips
or plates of tissues known as gills or lamellae. The gills are white or pinkish in young condition
and turns brown or purplish black at maturity.
A transverse section of the gill (T. S. of gill):
1. Trama:
It is the middle part of the gill. This region is made up of loosely arranged interwoven mass
of plectenchymatous tissue of long, slender hyphae. These hyphae run, more or less,
longitudinally.
2. Sub-Hymenium or Hypothecium:
The hyphae of the trama region curve outwards towards each surface of the gill. They end
in small diametric cells forming a compact layer known as sub-hymenium.
3. Hymenium or Thecium:
It is the outermost layer and lies on the surface of sub-hymenium covering both sides of
the gill. Some branches emerge out almost at right angle to the sub-hymenium and develop a
palisade like layer consisting of basidia (fertile) and the paraphyses (sterile) Some of the sterile
cells become enlarged and project beyond the basidial layer. They are called as cystidia.
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Development of Basidium:
The basidia are spore producing bodies. The young basidia arise from the terminal, binucleate cells of the sub-hymenium layer (Fig. 7 B 1). As the basidium grows, the two nuclei of
the dikaryon fuse to form the synkaryon (karyogamy, Fig. 7 B 2). The diploid nucleus soon
undergoes meiosis to form four haploid nuclei (Fig. 7 B 3). Simultaneously, four narrow tube-like
structures develop at the top of the basidium. These are called sterigmata (sing, sterigma). The
sterigmata swell at their tips and each forms a small, single basidiospore by budding.
A large vacuole develops in the basdium due to which the cytoplasm and nucleus (one in
each) migrate into the budding basidiospore (Fig. 7 B 4-5). Thus, four haploid basidiospores are
formed in a basidium. Out of the four basidiospores, two are of ‘+’ strain and two are of ‘-‘ strain.
The young basidiospore is un-pigmented but it develops brown or black pigments at maturity. In
A. bisporus two basidiospores are produced. The mature basidiospore is attached obliquely at the
top of the sterigmata. It has minute projection at one side of its attachment called hilum or hilar
appendix (Fig. 7B 6).
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Nutritional Value of Mushrooms: Nutrient Roll Call
Why edible mushrooms are considered a healthy food? In terms of nutrition they contain:
Protein - Most mushrooms have a high protein content, usually around 20-30% by dry weight.
This can be useful for vegetarians or anyone looking to increase the protein content in their diet.
Fiber - Helps lower cholesterol and is important for the digestive system.
Niacin and other important B vitamins - As certain B vitamins are found in animal tissue but
not plants, this can be another good supplement for vegetarians.
Vitamin D - Essential for the absorption of calcium.
Copper - Aids in helping the body absorb oxygen and create red blood cells.
Selenium - An antioxidant that helps neutralize free radicals, thus preventing cell damage and
reducing the risk of cancer and other diseases. Mushrooms contain more selenium than any other
form of produce.
Potassium - An extremely important mineral that regulates blood pressure and keeps cells
functioning properly. A large portobello mushroom is said to have more potassium than a banana.
Other important minerals - Such as phosphorous, zinc, and magnesium.
Low levels of fat, calories, and sodium
No cholesterol
Yet the nutritional value of mushrooms can be measured in more ways than just strictly dietary.
Further health benefits are gained from:
Polysaccharides - Complex carbohydrates that stimulate the immune system.
Enzyme inhibiting activity - Mushrooms can inhibit the production of certain enzymes such as
aromatase, which the body uses to make estrogen. This could reduce the risk of breast cancer.
15
UNIT II
Cultivation System & Farm design:
Fundamentals of cultivation system- small village unit:
White button mushroom is a temperate mushroom requiring cooler climate for its growth.
It is an indoor crop and is an ideal tool in converting agricultural wastes in to proteinaceous food.
In early days its cultivation was mainly confined to the hills. In the eighties growers realized the
potential of this crop and started its cultivation in the northern plains in the winter when the climate
was suitable for its growth.
Seasonal cultivators of this mushroom are using traditional methods of its cultivation and
are mainly cultivating this mushroom in the thatched structures employing long method of
composting. They usually take single crop in the entire season and are harvesting 12-15 kg
mushrooms/ 100 kg compost. Environment controlled units are cultivating this mushroom round
the year by having suitable infrastructure at their disposal which includes a modern composting
yard having bulk pasteurization facilities. Of late few of them have shifted to indoor composting
while new upcoming units have chosen to produce their compost entirely by indoor method.
Besides these facilities they are having insulated cropping rooms and other ancillary structures
required for mushroom cultivation. Few of the bigger units are having their own spawn lab and
processing unit as well. An entrepreneur can start mushroom cultivation modestly using seasonal
growing houses and after gaining sufficient experience can shift to round the year cultivation
employing suitable climate control facilities. Suitable infrastructure including different
machineries are required at the farm to carry out different operations to govern the whole process
of cultivation in such a fashion so that one gets optimum returns from his farm in this competitive
environment.
A. Selection of Site and Pre-Requisites
Before selection of site, the following points have to be taken into consideration for greater
operational efficiency and cost effective production of mushrooms at the farm:
16
1. Chosen site should preferably be away from the municipal limits and entrepreneur should
purchase sufficient land in one go looking to the future expansion.
2. The site should be serviced by a motorable road, or nearer to a road head to reduce costs on
transportation of raw materials to the farm/finished product to the market.
3. Plentiful availability of water at the site either through a perennial source or should have
sufficient underground water.
4. Easy availability of raw materials especially straw and poultry manure around the chosen site at
cheaper rates in the area.
5. Availability of cheap labour in abundance.
6. Uninterrupted proper power supply at the chosen site.
7. Nearness to the market for the proper disposal of the produce.
B. Components of a Mushroom Farm
For round the year cultivation of this mushroom employing environment-controlled conditions a
medium size plant would require under mentioned components.
1. Spawn unit
For producing in-house spawn for self requirement and for sale to other units. This will have under
mentioned major components.
a Cooking/autoclaving room: For boiling the grains and sterilization of the bottles/pp bags.
b Inoculation room: For inoculation of the sterilized bottles/ pp bags
c Incubation room: For incubating the inoculated bottles. Insulated and provided with AC.
d Cold Store: For storage of prepared spawn for its further disposal
17
Besides above some ancillary structures like office, small lab space, delivery area, etc. may also
be required. Machineries required: Air conditioners, Laminar flow system, Autoclaves, BOD
incubators, Boiler, Boling cattles, Refrigerators, racks, pH meter, gas stoves, etc.
2. Composting unit
This will have under mentioned main components for production of compost
a. Pre wetting area: For dumping of raw materials and their pre wetting (uncovered).
b. Composting yard: For making piles out of the wetted materials (covered)
c. Phase-I bunker: For phase -I composting (incase indoor composting is employed).
d. Phase -II tunnels: For performing pasteurization and conditioning of the compost.
e. Casing soil chambers: For pasteurization of the casing soil.
f. Spawning area: For spawning of the prepared compost
Besides above certain ancillary rooms like boiler room, underground service room, store
room, workers room, etc. would also be required Machineries viz., boiler, blowers, air handling
units, gratings, digital thermometers, compost retaining boards, ventilation system for phase -I
bunkers would be required by a medium size farm (up to 200 TPA). Large farm besides above
may require a front end loader (Bobcat) and other compost handling equipments including turner,
filling line, etc.
3. Cropping unit
A cropping unit will have series of insulted rooms of designated size depending upon the
production targets. Besides rooms there will be AC/ compressor room, packing room, central
corridor housing air handling units and pipelines.
Machineries required: Insulted doors, central chilling station (ammonia or freon based), air
handling units, computer based controllers (optional), racks, and trolleys, harvesting trays, etc.
18
would also be required. For continuous electric supply to phase-I, phase- II tunnels and cropping
rooms, generators of desired capacity would also be needed.
4. Post harvest handling unit
It will have under mentioned components:
a Pre-cooling chamber (cold room): For storing the mushrooms before canning
b Canning hall: For housing the canning line for processing
c Laboratory: For quality control of processing
d Store: For housing the processed can
General Layout/Location of Various Units
The layout is so planned that all the infrastructures required to be built are accommodated
in least possible land without over looking mushroom cultivation requirements. The general layout
of a mushroom farm has to be carefully planned after selection of the site, keeping in view the
several factors including accessibility of road to the composting yard as raw materials are to be
dumped here for their processing to the compost. Wind direction is also kept in mind for choosing
the location of the composting facilities. During most of the time of the year wind should flow
from cropping area to the compost yard and not vice versa. Phase-I bunkers are constructed in line
nearer to the phase -II tunnels for their operational convenience and also to avoid heat losses.
The bulk chambers are built nearer to the Phase-I bunkers. Both these structures are preferably
built away form the road at the distant end of the yard so that the distant end of the phase -II tunnels
opens nearer to cropping rooms and away from composting yard The foundation of the buildings
is dug on the firm ground. The underground water pipes, electrical cables and sewers are laid well
before the actual construction starts. The entire site area should preferably be fenced or brick
walled for security reasons. In areas where land is scarce, double story cropping houses can be
built to economize on space. The cropping rooms are generally built in double rows with a
path/gully in between for various operations and services.
19
a. Composting platform
The components of composting unit will depend upon the method of compost production
chosen. If one is going for indoor compost production, in such a case requirement of composting
yard will be greatly reduced and it will be 1/3 of the normal yard required when one has chosen
SMC. Now a days trend is for indoor compost production due to environment legislation. In such
a case a small pre wetting area, and small covered composting yard would be required with
minimum of two-phase-I bunkers and one phase-II tunnel. Size of all these structures would
depend upon the production targets of the unit and size and numbers of the tunnels.
b. Bulk Chamber:
This area is constructed nearer to the road. It is a simple cemented structure having a saucer
like depression in the center so that it looks like a lagoon and water remain collected during the
prewetting of the compost ingredients. Center of the lagoon should be around 1 ft deep. Excess
water of the lagoon is collected in a goody pit built specially for the purpose at a convenient place
around PWA for its reuse
Pasteurization room:
A modern farm employing either indoor method or SMC essentially requires this facility.
The bulk pasteurization chamber is principally used for phase-II of composting for pasteurization
and conditioning of the compost.
In Bulk pasteurization chamber compost is handled in bulk inside the tunnel or chamber
and hence the name bulk chamber. The compost after phase-I is filled into specially built chamber,
which is properly insulated and provided with steam connection and air blowing system for recirculation. The compost is filled in the chamber on top of its grated floor built over the plenum.
The plenum has an air circulation duct used during pasteurization/conditioning.
Floor should be properly insulated with thermocol/glass-wool 5 cm thick (15 kg/m2
density). The insulation is covered with isolating membrane of PVC sheeting followed by 5 cm
cement floor and finally the finish. Such floor is constructed for both cropping room and the
20
chamber. The steam line is also connected at the entry point of the blower. The walls and ceiling
can be damp proofed by coating bituminous paint on inside over the cemented surface, which will
also serve as an effective vapour barrier. The grated floor inside and the work floor outside should
be of the same height for operational convenience especially when tunnel has to be filled
mechanically.
Spawn unit
The layout plan of a spawn laboratory is given. A total built in area of 60 x 30 x 12 should
be good enough to house the entire spawn unit. This area will be divided into different work areas
like boiling/autoclaving room, inoculation room, incubation room (insulated and with AC), cold
room (heavily insulated with chilling facilities), store, office and delivery area.
Growing rooms:
Since mushrooms are grown indoors under simulated environment specially created for
mushroom growth, the cropping rooms are required to be built specially for the purpose Two types
of cropping rooms are built suiting to particular requirement - those required for seasonal growing
and those for environment controlled growing round the year.
Structural details special to cropping rooms
i. Floor
The floor must be well laid out and should be strong enough to take the heavy load of metal
racks to be kept inside for growing mushrooms. The floor should be insulated with insulating
material 5 cm thick (sheets of thermocol or glass wool or polyurethane). The insulation should be
protected by a PVC sheeting, below and above, against moisture
ii. Walls
The walls are made of brick 22.5 cm thick, which are given a smooth finish with cemented
plaster. The insulation sheets are fixed on the walls (5 cm thick thermocol, glass
wool/polyurethane), with the use of hot coal tar. Holes are drilled on four corners of the
21
sheet/inside the cement wall for expansion fasteners which are fixed by screwing in the nail with
4"-5" long steel wire tied on its head.
iii. Roofs
The roof is made of RCC (1 : 2 : 4) 12-15 cm thick. The inside is given a cement plaster
finish for application of insulation (as explained for the wall). The roof on the outside is protected
by tarring it on top, followed by 10 cm thick loose soil, 5 cm thick mud capping and finally the
tiles.
iv. Doors/vents
The doors of the bulk chamber and the cropping room are made of wood or angle iron
frame covered on inside and outside with aluminum sheets/GI sheets with insulation of 5-7 cm in
the middle. The doors will have a rubber gasket lined on inner periphery so that the door becomes
air tight when closed.
v. Lighting arrangement
There should be a provision for tube lights and a mobile strong light for inspection in each
cropping room. The tube lights should be protected with water proof housing. The tube lights
should be fitted on all the walls vertically at various heights to facilitate lighting of all beds.
vi. Water connection and sewers
One clean water pipe line (1" or 1.25") with tullu pump installed to it for delivering clean
water for spraying should be provided in each room. Underground drainage line for carrying the
washings from the room and wash basin discharge should be laid before construction of the
building. This waste water line should be connected to the common sewer
vii. Gallery
The gallery between the rows of cropping rooms should be wide, (12-15 ft) to allow
efficient performance of various operations. The height of the gallery should be same as for the
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growing rooms alternatively it may be about 8' with a false ceiling, leaving another 5 ft above for
pipeline and space for AHUs.
viii. Racks
Racks are made up of the angle iron for horizontal and vertical support with iron mesh
strips used for the shelves for housing compost. Length (vertical axis) of the racks is generally
made up of 5 cm thick angle while horizontal support is made up of 3.5-4 cm thick. Width of the
each shelf on the racks should not be more than 135 cm in any case as width more than that creates
hindrance in performing various operations during cropping and most important of that is
harvesting. Cultivation can be done in bags or in shelved beds.
ix. Air Handling Unit
This unit is employed for creating proper weather inside the growing room specific to white
button mushroom. Air handling unit is generally installed in each room at the top of the door,
which is made up of aluminium or G.I. Sheets. In certain cases it can also be placed on the top of
the floor of the growing room or in the corridor. Indirect cooling of air through chilled water (560C) is generally employed in mushroom cultivation. Mushroom generally require 225 m3 of air
per hour per ton of compost from the boiler to generate required humidity in combination with air
pressure or can employ fine jets, which produce fine mist of water in the humidifier section of the
AHU. PVC eliminators, eliminate the free water going inside the growing room. Booster fan in
combination with supply air fan supplies fresh air inside the AHU through fresh air dampers.
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UNIT III
Compost & Composting:
Principles of composting:
Composting biologically speeds up the decomposition of organic wastes into a soil-like
material. Heat and carbon dioxide are also produced in the process. Composting can take place
under either aerobic (with air) or anaerobic (without air) conditions. Aerobic composting is faster
and is the subject of this brochure. Making your aerobic compost pile work properly requires that
you take a little care to control three things:
a) The mix of materials put into the composter,
b) aeration, and
c) moisture.
Materials
For best results, the micro-organisms breaking down the organic materials in your compost
pile require a mix of materials containing carbon and materials containing nitrogen. An ideal mix
is 25 to 30 times more carbon than nitrogen. A mixture of materials with higher carbon content
takes longer to break down and a mixture with higher nitrogen content generates odours. It’s
important to mix different materials to achieve a proper balance of carbon and nitrogen in a
composter. Some materials that can be mixed are shown in the Table on the back of this pamphlet.
Aeration
A compost pile must be aerated to provide oxygen that the micro-organisms need to survive
and avoid the generation of odours. This can be achieved by mixing in coarse materials like leaves
or green twigs to create air voids and periodically turning the pile with a pitchfork or shovel. As a
general rule, turning the pile once a week should be sufficient. More frequent turning could result
in the pile becoming too cool for the micro-organisms to work.
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Moisture
Moisture is also required by the micro-organisms in a compost pile. Too dry a mixture of
materials will inhibit their activity. Excessive moisture will also hinder aeration. As a general rule,
the material should be as wet as a squeezed out sponge.
Materials for Compost Preparation:
By preparing compost, you are creating an ideal medium for mycelial growth. Basic
mushroom compost is made up of wheat straw, horse manure and gypsum (calcium sulfate). There
are a variety of optional ingredients that may be added. A brief outline of some materials used in
making composts follows:
Straw:
Serves as a carbon source (carbohydrate) source wheat — considered the best — contains
xylan oat, barley - break down more rapidly than wheat rye — breaks down slower than wheat
also corn cobs, oak and beech leaves, etc.
Other Carbohydrate Sources:
Rice straw, molasses, brewer's grains, cottonseed meal (provides the fatty acid — linoleic
acid — which is reported to stimulate yields.
Manures:
Nitrogen source, provides organisms essential to composting horse — most commonly
used, fresher the better poultry — higher in nitrogen and phosphorous than horse, not so rich in
potash (provided in wheat straw), faster and hotter than horse, use dry pig and sheep — must be
used before they become sticky - used partly dry
Other Nitrogen Sources:
Blood meal (dried blood), bone meal urea, ammonium sulfate ((NH4)2SO4) Gypsum:
calcium sulfate (CaSO4) — essential to mushroom compost preparation — prevents the compost
from becoming too "greasy" — by forming an equilibrium matrix with the water, also helps the
colloids to flocculate producing a compost with a more granular structure with increased water
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holding capacity: provides Ca++ ions; a mineral essential to mushroom growth: helps to prevent
the loss of nitrogen (from the breakdown of proteins during the act of composting) by chelating
the ammonia
Compost Preparation
The substrate for cultivation is specially prepared compost. The mushroom houses should
have the facilities for temperature control and pasteurization. Buildings are constructed of wood
or hollow cement bricks or double walls. The shed is partitioned into small compartments and
provided with trays. Environmental conditions like temperature, relative humidity and ventilation
are controlled inside the shed by installing suitable equipment.
Long Method
The composting is done on a cement floor. It can be done in the open or under a roof, but
sides are to keep open.
a) Natural compost:
This compost is traditionally prepared by using horse manure and the barn waste consisting
of straw bedding of wheat of barley. These are taken in the proportion of 4:3 and to this mixture,
generally 100 kg of chicken manure and 5 kg of urea are added per tonne of substrate. The manure
is kept as heap of about one metre height and is regularly examined and turns down repeatedly
when it emits ammonia smell. This is o be done for every three – four days. Finally every tone 25kg of gypsum is added.
b) Artificial Compost:
Many formulae are available and ingredients to be used vary according to the locality and
availability of materials. A widely used formula in india is is given below:
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Formula
Quantity
Wheat straw (chopped to 8-2- cm)
250 g
Wheat bran
25 kg
Ammonium sulphate of Calcium ammonium 4 kg
nitrate
Urea
3 kg
Gypsum
20 kg
Chopped wheat straw is spread over the floor and water is sprinkled thoroughly to wet the
straw. Mix all the ingredients except gypsum. Finally the mixture stacked to a height of one metre
and compacted using wooden boards. This mixture is turned periodically on 5th, 10th, 14th, 18th,
22nd and 26th day. The gypsum is added in two equal splits on the 14th day and 18th day.
Short method
The short-term compost involves two phases of operation, outdoors composting and steam
pasteurization. The commonly used formula is give below:
Formula
Quantity
Chopped Wheat Straw
100 g
Chicken manure
400 kg
Barley
72 kg
Urea
14.5 kg
Gypsum
30 kg
Compost Production by Short Method
Phase: I Outdoor Composting:
Barley and chicken manure are added to wheat straw and stacked after adding sufficient
water to completely wet the same. The stack can be 3.3 X 2.5 X 1 m size. Turnings are given on
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the 2,4,6 and 8th days. The pH to be adjusted to 8.5 and the compost filled into trays for
pasteurization.
Phase: II Stream Pasteurization
Stream or dry heat is introduced to establish an aerobic fermentation and the temperature
maintained between 52 -60° C inside the compost. Usually it is done in a room well insulated
where the trays are properly kept and after this all ventilators are closed and steam is introduced
to raise the temperature to 52-54° C for four hr and afterwards fresh air is introduced and steam
supply cut off.
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UNIT IV
Spawn and Spawning
Mushroom spawn is the mushroom mycelium growing on a given substrate. It serves as
the seed or planting material in mushroom cultivation. Spawning is the inoculation of the culture
into the substrate or compost, it is the actual planting of spawn and requires much care depending
on the species of mushroom and the technology being followed. Generally the following steps are
suggested.
Facilities required for spawn preparation:
While exact area of the spawn laboratory would depend on several factors, an area
90x30x13’ can easily house a moderate spawn unit. The lab is divided into different work-areas
like cooking/autoclaving room, inoculation room, incubation room insulated with air-conditioning,
washing area, store office and one cold room heavily insulated for storage of spawn.
Equipment of spawn laboratory
1. Two steam autoclaves (30” dia, 40” h) electrically or steam operated.
2. One boiling vessel,
3. Laminar flow
4. One refrigerator
5. One BOD incubator
6. One pH meter
7. Glassware
8. Chemicals
Preparation of pure culture:
Tissue culture:
Mushrooms used in tissue culture should be atleast 24 to 48 hours old. Any part of the
mushroom may be used, although the cap especially the lower portion where the gill plate joins
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the stem is considered the best tissue for excision. Whenever possible, the mushroom should be at
the button stage of development. The mushroom is cut lengthwise from cap downwards. With a
flamed needle, a small piece of the internal tissue of the broken mushroom is cut and inserted into
agar bottle. The inoculated bottles are incubated at 25+1oC preferably in darkness for about 10-15
days.
Spore culture:
Collect aseptically large sized healthy mushroom with membrane (veil) still intact, surface
sterilize the mushroom, mount on a wire stand over a Petridish under glass beaker already sterilized
in an oven at 160 o C for about 2 h and cooled. The spores get deposited as spore print. The spores
are stored under sterile condition in a refrigerator for future use. These spores can be used for direct
inoculation of wheat extract agar medium or Lambert's agar medium.
Multispore culture:
For raising culture, spore suspension is prepared in sterilized distilled water. One ml of
spore suspension containing more than hundred spores is mixed in each test tube containing about
5-7 ml of sterilized wheat extract agar or Lambert's agar liquid medium (45 o C) and slant are
prepared. The slants are incubated at 28 o C for spore germination for about 2 weeks. The mycelial
threads become visible on slant surface. Then the single spore cultures are raised
Culture media preparation:
The pure culture of cultivated mushroom can be raised on the following media:
1. Wheat extract agar medium: Boil 32-g wheat grains with one litre of distilled water for
about 2 hours and filter after 24 h. Add 20g agar to a litre of filtrate and boil. pH of the
medium is maintained at 6.5. Fill about 5ml of medium in each test tube. Autoclave test
tubes at 15 lb. psi for 20 to 30 minutes.
2. Lambert's agar medium: Add 10 g glucose, 0.5 g magnesium sulphate, 1.9 g potassium
dihydrogen phosphate and 20 g agar to one litre of distilled water. The remaining process
is the same as for wheat extract agar medium.
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3. Malt extract agar medium: Add 20 g malt extract and 20 g agar to one litre of distilled
water and boil for 5 minutes. The remaining process is the same as for wheat extract agar
medium.
4. Compost extract agar medium: Boil 200 g ready synthetic compost with 2 litres of
distilled water for about 2 h and filter after 24 h. Add 35 g agar to 2 litres of filtrate. Adjust
pH of medium at 6.5-7.0. Fill about 5 ml medium in each test tube and sterilize at 20 lb.
psi for 1 h.
5. Potato dextrose agar medium: Boil 250 g peeled potatoes in one litre of distilled water
till these become soft and filter. Add 20 g dextrose and 20 g agar to the filtrate and raise
volume of water to one litre. The remaining process is the same as for wheat extract agar
medium
Culture maintenance:
The spawn should be fast growing in the compost, early cropping after casing, high yielding and
should produce better quality of mushroom. In order to maintain the quality, the spawn grower
should take care of the following:
1. Select high yielding, early producing and better sporophore quality strain for preparation
of spawn.
2. Select unbroken and good quality grain for spawn production.
3. Boiling of grains should be done according to the suggested procedure to maintain about
48-50 per cent moisture in the grains.
4. The pH of boiled grains should be adjusted to pH 6.5-7.5 by mixing appropriate quantity
of calcium carbonate and gypsum.
5. Prepare spawn from mother culture only. Do not multiply from spawn to spawn.
6. The inoculation should be done in a double chambered closed air-tight inoculation room
or under laminar flow.
7. Shake the inoculated bottles throughly and incubate at 24 -26 oC for the growth of
mycelium.
8. Sort out and remove the contaminated bottles from spawn room regularly.
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It is a general experience that spawn prepared on jowar (Sorghum bicolor) or wheat grains
gives higher yield over the spawn prepared on bajra, barley, or kodo grains. Both spawn producer
and buyer should ensure the following.
1. There should be proper coating of mycelium around grain used as a substrate for spawn
production. No loose grains should be seen in the bottle or bags. The grains left over
without mycelial coating invite contamination in the compost during spawn-running.
2. The growth of mycelium in the spawn should be silky or strandy type. It should not be
cottony because it may lead to stroma formation in casting layer, which interferes with air
exchange and absorption of water the casing resulting in lower yields.
3. The growth of spawn should be white. Brown colouration develops as spawn grows. Fresh
spawn gives higher yield than the old one.
4. There should be no greenish or blackish spot in the spawn. Such spots indicated
ontamination.
5. There should be no slimy liquid in the spawn which indicates bacterial contamination.
Preservation and storage of culture
Proper maintenance of pure cultures of cultivated mushroom is necessary to maintain
vigour and productivity. There is no satisfactory way to check and evaluate the qualities of spawn
by any rapid on the spot examination. The strains of cultivated mushroom must be suitably
preserved and carefully tested from time to time for vigour and productivity.
Conventional methods of culture preservation
Periodic transfer: Stock cultures are maintained by periodic transfer on a suitable solid substrate
or natural/semi -synthetic agar media.
Isolation: Pure cultures are raised by using single or mass basidiospore isolation or tissue culture
technique from freshly harvested fruit bodies
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Freezing methods of culture preservation
The most effective methods are freeze-drying (Lyophilization), and freezing and storing in liquid
nitrogen.
1. Freeze-drying and freezing: It is most economical and effective method of long-term
preservation of sporulating fungi. For freeze drying, strains are grown on plates containing
suitable agar medium. Three plugs of the advancing edge of the culture are removed with
the help of a 5 mm sterile cork borer and transferred in heavy-walled borosillicate glass
ampules for freeze-drying and storing in liquid nitrogen.
2. Cryogenic freezing Freeze: drying and freezing methods of preservation cause freezing
injury to biological systems. There are compounds that protect living cells and organisms
against damage due to freezing and thawing.
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UNIT V
Cultivation of Button and Oyster Mushrooms:
Growing Oyster Mushrooms
A mushroom farming business can be mean big profits in just a few weeks. Plus, starting
your own business growing oyster mushrooms for profit is fairly easy. In fact, here’s how to get
started in just six easy steps.
1. Get your spawn and substrate
You’ll need a spawn to start the culture. You can produce your own spawn using a sterile
culture, or you can buy ready-to-inoculate spawn, which are carried by suppliers. Producing your
own can be cheaper in the long run, but the start-up costs can be high, so chances are buying the
ready-to-inoculate spawn is the way to go for you.
You’ll also need to buy the substrate. Many growers use straw or wood chips. Straw is
generally the preferred method. You want straw that can be chopped up into little pieces.
2. Prepare the substrate
First, chop the straw into short pieces. Next, wet the straw. Now it’s time to heat the straw
in boiling water. Continue boiling for half an hour and then remove the straw and drain it. Next,
spread out the straw on a clean surface and let it cool down.
3. Pack the plastic bags
Now it’s time to pack plastic bags with the straw and spawn. Pack two or three inches of
straw into the plastic bag and then lightly sprinkle the spawn on top. Repeat this until you’ve
almost filled the bag, close the top and poke holes in the bag.
4. Incubation
Now it’s time for incubation. Keep the growing area at around 78 degrees F. Places the
bags on a shelving unit. Remember to stop any threats of natural light getting into the room. Cover
windows and cracks. Use a red “darkroom” light when you need to check on your bags. When you
start to notice tiny pinhead mushrooms near the air holes in your bag, then you’re ready to move
on to the next step.
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5. Fruiting
For your fruiting room, you need a high level of humidity. The temperature will need to be
65 to 70 degrees F. Unlike the incubation room, you’ll actually need a lot of natural light—at least
12 hours a day. To shock your mycelium, which will force it into fruiting, move the bags to a cool
place for a day, such as a basement or other cool place, and then move them back to the fruiting
room. Next, cut away the bag, which allows mushroom growth to take place.
6. Harvest
Just before your mushroom caps are fully uncurled, that’s when it’s time to harvest. To do
so, twist the stem off as near to the growing block as you are able to. You’ve now harvested your
mushrooms.
Growing Button Mushrooms
Mushrooms, is an important table delicacy, contains proteins, vitamins and minerals, is low in
calories (less than35 calories per 150 gm), salt, fat and has no sugars, starch and cholesterol. There
are over 2000 species of edible mushrooms. In India we have about 50 species which can be
consumed safely.
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White Button Mushroom
This mushroom is commonly known as Temperate mushroom, European mushroom or simply the
Button mushroom.
These essentially include two species”
1. Agaricus bisparus - needs temperature range 14-25˚C.
2. A.bittorquis – needs temperature range 19-30˚C
A.bittorquis which is cultivated widely requires temperature of 23-25˚C for spawn run and 1418˚C for fructification and cropping. This range of temperature is available under natural
conditions in Uttarakhand State and adjoining plains from October to February. The cropping
period can be extended up to March end, provided the weather does not warm up.
The cultivation procedure for both A.bisparus and A.bittorquis is almost the same, expecting the
temperature range requirements.
Step for Mushroom Cultivation
1. Compost preparation
2. Spawning or seeding
3. Casing
4. Cropping and crop management
Compost Preparation
Spread the wheat straw on the floor (preferably a container) and wet it thoroughly with clean water
until the moisture content is 70-75 %. The whet straw is the kept as such for 48 hours. Spread the
wheat bran (choker) separately and mix the fertilizers (CAN, urea, superphosphate and Murate of
Potash) and moisten it with water. This mixture is made into a heap and covered with polythene
sheet for 48 hours. This mixture is then broadcasted on the wet wheat straw and mixed using a
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pitchfork. The loss of nutrients due to leaching must be avoided and the run off water, if any should
be mixed back with the straw. Next a stack (Pile) of 5x5x5 feet is prepared using 3 wooden boards.
This compost will weigh about 570-580 kg at 67-70 % moisture content and is sufficient to lay
about 12 sq meter of bed area. Beds are prepared using 50 kg of this compost per sq meter tray
box container. 22-24 trays of size 100x50x20 cubic cm size can be laid.
A good quality compost should possess the following characteristics:
1. It should be dark brown.
2. It should not emit any ammonical smell
3. The compost straw should have amorphous texture
4. The pH value should be between 7.0-8.0
5. It should have adequate moisture (67-70%)
Span and Spawning:
Spawning means implanting the mushroom spawn or seed in the compost. Spawning means
implanting the mushroom spawn or seed in the compost. There are 2 types of spawns i.e. the grain
and the manure spawn. The grain spawn is better. Spawn should be used at the rate of 5g per kg
of the compost. One sq meter of compost will require 250 g of spawn. The spawn should be used
as early as possible after procuring it. It should be kept in a cool place (20˚C). To prepare for
spawning, first dismantle the compost pile and allow it to attain room temperature. Test it for
correct pH (7-8) and moisture (67-70%) and id need be adjust these within the prescribed limits.
Three types of containers can be used for filling the compost as under:
Wooden crates emptied out from fruits and vegetables, fabricated to make 7” deep boxes
Polythene bags of 18” width or Shelf system arranged in the shape of racks.
The wooden racks should be washed with water and disinfected with 4% formaldehyde solution.
The containers are filled the compost and spawned.
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The spawn is taken out of the bottle and then implanted in the compost as under:
1. Single layered
2. Two layerers
3. Mixing
In the single layered method the compost is filled into the crates up to 6” depth and the spawn is
spread at the top surface and slightly pressed into the compost. For the two layered method, the
containers are filled up to 3” depth and spawned with 1/3 of the required quantity of spawn. Then
more compost is added to bring it to the level of 6” depth and the remaining 2/3 rd quantity of
spawn is evenly distributed on the surface and slightly pressed in. In the mixing method, the spawn
is mixed in the compost and this is then filled into the containers.
All the three methods are unique – In the single layered spawning gives better results for early
sowing of the crop – The two layered spawning is suitable for late sowing – mixing method is
preferred for cultivation in polyethylene bags.
The trays/bags/shelves are filled with the compost, spawned and are then moderately pressed to
make a smooth surface. The spawned surface is then covered wit newspaper sheets. These are then
kept in the growing rooms and sprayed with water regularly to keep the sheets moist.
Casing and case run:
The practice of covering uniformly the spawned impregnated compost surface with a suitable soil
mixture is called casing.
It should have neither big lumps nor should it be very fine powder.
It should possess good water holding capacity.
It should be porous enough to allow free flow of gaseous exchange.
It should not be infected by pests or pathogens.
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Its pH value should be 7-8.5.
Material for Casing Soil & Disinfections
1. Farm yard manure (1 year old)
2. Garden soil (4:1)
3. Spent Compost (2 years old)
It should be disinfected either by steam or chemicals. Chemicals used are 4% solution of
formaldehyde and 20g Furadan per 100 kg of casing soil. 2 quintals of the casing soil is sufficient
for 10 sq meters of bed area. The treated soil is covered with polyethylene sheet for at least 10
hours. It then opened and turned again and again to free it from fumes of formaldehyde. It can be
used immediately or can be stored for recasing the beds during cropping.
Procedure for Casing
The trays/beds show initiation of spawns run after 2-3 days of spawning. It takes about 2 weeks
for the trays to show 80-100% coverage with white mycelial growth. At this stage the newspaper
sheets are removed and spawn run surface of compost is covered with 1-1 ½” thick uniform layer
of soil casing. One sq meter bed area requires about 20 kg casing soil. The trays are then sprayed
with water once/twice a day to keep the casing layer adequately moist.
Picking and packing:
After about 10 days of casing small pinheads start appearing, scattered on the surface of the casing.
The increase in size and become small buttons in the next 4-5 days. In another 3-5 days they are
ready to be harvested. In brief it takes about 30-35 days to harvest after the spawning. The button
mushrooms are the picked by gentle twisting of the buttons and cutting the stalk at the bottom with
a sharp knife. It is important to note that while picking mushrooms from the tray beds small pits
are formed in the casing layer. These pits should be filled with fresh casing soil. You will be able
to get more mushrooms by doing this. The next watering should be carried out after every
harvesting. On an average the crop can be harvested for 50-60 days.
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