White Button Mushroom
Booklet No. 512
Mushroom Cultivation: MCS - 8
II. Preparations for Cultivation
A. Preparation of substratum
B. Facilities and equipments
C. Preparation of inoculum
III. Cultivation Practices
1. Filling the containers
3. Spawn run
5. Physical requirements
8. Care alter picking
9. Grading and packing
IV. Pests and Diseases
V. Economics of Cultivation
The white button mushroom (Agaricus bisporus) is very popular throughout the world
and is the most important mushroom of commercial significance. It can be successfully
cultivated in places where the environmental conditions are favourable. The optimum
temperature for mycelial growth is 22-25°C and that for fruit body formation 14-18°C. This
mushroom also needs a high percentage of relative humidity. The substrate tor cultivation is a
specially prepared compost. The mushroom house should have facilities for temperature control
and pasteurization. Inside the house, shelf system is usually adopted for cultivation. Buildings
are constructed of wood or hollow cement bricks or double walls.
Throughout the northern hemisphere, this species occurs wild on both sandy and rich
soils in gardens, fields and compost heaps. The first scientific experiment on the cultivation of
this species was conducted in the late 1960's. Breeding work has begun shortly afterwards and
has continued till date.
In India, the cultivation of the white button mushroom (A. bisporus) is of comparatively
recent origin. It was first introduced about two decades back in the hilly and temperate zones of
Himachal Pradesh and Jammu and Kashmir states. At-present it is being cultivated on
composts prepared using the ingredients varying from place to place.
II. Preparations for Cultivation
Any enterprise to start with, need certain preparations and mushroom cultivation is no
A. Preparation of substratum
The substratum for mushroom growing is prepared by composting of various organic
materials and cellulose materials like straw. For more details of compo sting consult booklet No.
441, Mushroom Housing and Composting. Only brief and essential description is given here.
The substratum used for the cultivation of A. bisporus must be free from contamination in order
to give regular and prolonged growth of mush- room. Dealing with organic substances,
contamination is almost inevitable. To avoid this inconvenience, the raw material of the
substratum should be selected and sterilized well so as to allow the development of the
mushroom and to prevent the growth of the competitive microflora. For hundreds of years straw
and horse manure have been used as the raw materials for substratum preparation. The natural
fermentation of horse manure produces sufficiently prolonged heat to prevent the growth of
competitive micro flora and at the same time guarantee a good growth of button mushroom.
The insufficient availability of horse manure nowadays has however caused cultivators
to use other organic material, e.g. bone and horn meal, dried cattle blood, manure of other
animals. But one should always select a substratum rich in organic substances so as to free
carbohydrates from the cellulose material like the straws of various crops.
The raw material is placed in the substratum area and prepared by a frequent turning
over to favor air circulation and to block harmful anaerobic fermentation. The following is a
popular formula for obtaining a successful substratum:
40 kg tresh chicken manure or any animal manure
600 kg straw of paddy, wheat, ragi, oats etc.
5 kg Urea
10 kg Ammonium sulphate
For more formulae consult booklet No. 441 Mushroom Housing and Composting.
The mixture is placed in heaps of 1.5 m width and 2 m height. Every third day the heap
is overturned and mixed and re-mixed to favour aerobic transformation by the contained micro-
organisms. During this phase, the temperature rises to 800 C and the mesophyllic microflora is
substituted by the thermophyllic micro organisms which remain active during the use of the
substratum. The mass should be aerated until it become homogenous, and brown in colour.
When it is squeezed, oozes a colourless liquid. It should hold about 70% of water and have a
pH of nearly eight. The material thus prepared is then pasteurized at 55-60°C for 3-6 days in
suitable pasteurization chambers. For more details on compost preparation and other related
aspects, booklet no 441 may be consulted.
Pasteurization duration depends on the maturity of the compost. It should not have any
ammonia, it should be brown to almost black in colour and should have a smooth texture. When
pressed it should not stain. The optimum humidity is from 65-72 percent. The pH should be 7-
7.2. This process reduces the number of nematodes, acarids and insects normally present in
this type of organic material and also that of the microflora, allowing the Agariculture once
inoculate a competitive growth with the other micro-organisms that colonize the substratum.
Once pasteurized, the compost must be inoculated and placed in the bags. Every
possible external contamination should be avoided when bringing the closed bags to the mush-
room bed where they are beaten on the surface, leveled and kept half-opened.
B. Facilities and equipments
The main facilities in terms of space are the compost making area and the mushroom
growing room. Compost making area includes compost Ingredients storage area, mixing area,
composting area, compost sterilization area and area for storing sterilized compost. The
mushroom growing room is any room where the temperature, humidity and light can be
controlled. Usually around 24-25OC temperature and 85% humidity is maintained. Light is
controlled by closing and opening of ventilators, fixed at the bottom for incoming air and at the
top for out going air. The room is constructed using any durable material. The house should be
free from incoming rain water (leak proof) and proper drainage in case the room is washed and
The minimum required equipments for compost preparation are spades or shovels for
handling and mixing the compost mixture. For handling and mixing large quantities mechanized
help may be required. A sieve is required to sieve the compost. Other accessories may be
arranged as and when required. However, hand and feet protection and mask for those who
handle the compost is very much recommended.
The equipment for the mushroom growing room are: trays/ shelves or beds/ bags,
weighing balance, thermometer, humidity metre, buckets, baskets, scissors, knives, forceps for
picking mushroom, sprayer for spraying water, formaline, pesticides, plastic bag for storing
mushrooms, bag sealer, shelves for storing, spawns, records and accounts. Hand and feet \
protection and face masks for workers in the room are also highly recommended. There could
be several other equipments that could be added as and when required.
The first facilities required for mushroom cultivation are compost making place and
growing room. In India, for compost preparation and mushroom cultivation the marginal and
small scale mushroom farm units are using un-insulated thatched huts, mud houses and pucca
rooms. Large mushroom units are using environmentally controlled crop rooms and properly
pasteurized compost for which pasterurisation facilities are created. The containers being used
to fill the compost in Indian system of growing are trays, shelves and bags on racks. Due to
various reasons of cost, convenience, easy manage- 1ment and efficient control of pests and
diseases the third type of containers have become popular in India.
1. Trays: Usually wooden trays of 60 x 90 x 15-23 cms, accommodating 30-35 kg compost are
used in 4-5 tiers. Between top of the lower and bottom of the upper tiers 25-30 cm space is kept
for air movement. Instead of wood, trays of any other material can be used.
2. Shelves: The shelves in the form of beds of about 120 cm width and any convenient length
made up of bamboo, eucalyptus and polythene sheets in three-four tiers. These are used by
most of the marginal and small farm units in the country. The first tier is made 20-25 cms high
from floor on bamboo or eucalyptus poles. The space between two tiers is kept 55 cms. The
polythene sheet is placed over bamboo strips on the bottom of each tier. The depth of shelf is
made raising sides of polythene up to 15- 18 centimetres.
Modem mushroom farm units are using metallic shelves of 5 tiers. Each shelf act like a
bed. The poles are made up of 4 x 4 cms square galvanised iron. The width and air space
between two tiers are kept 140 cms and 56 cms respectively.
The length of the shelf bed is adjusted as per convenience. The working space between
two shelves is kept 75-90 cms. The bottom of the shelves are fabricated with 2mm iron bars on
which a polythene sheet is spread to hold the compost. Thick metallic 15-18 cms deep panels
are used on the sides.
3. Bags on racks: The polythene bags for crop growing has gained a lot of popularity amongst
the Indian mushroom growers. These are easily disposable and prevents contamination as
fresh bags are to be used only once. A polythene bag of 80x60 cms can accommodate 15-20 kg
compost up to a depth of 30-35 cms. These bags are kept in 3-4 tiers over the racks fabricated
of any conveniently available material such as bamboo/ eucalyptus or square metallic poles or
angle iron. An space of 66 cms is kept between two tiers while first tier is placed above 15-20
cms above from floor level.
C. Preparation of inoculum
The preparation of suitable inoculum is essential for the successful cultivation of
mushrooms in terms of quantity and quality. For the inoculum preparations we can use the tradi-
tional method or modern method. In the traditional method any organic substance such as
soaked rice or other cereal seeds are placed in convenient bottles and sterilised in pressure
autoclaves after water and chalk powder are added. Any available grain is selected and lime is
added at the rate of 2% per dry grain. The grain with lime is filled in bottle up to half, and water
is poured and the grain is allowed to soak for 12- 15 hours. The bottle is plugged with cotton
and auto claved at 32Ibs./ sq inch for 20 minutes. The bottle is then asceptically inoculated with
fragments of A. bisporus fruit body and incubated in dark at 24°C until the colonization of the
medium, which is completed in about three weeks time. The mushroom used for inoculation
should be well selected and should be free from pathogens and also guarantee the purity of the
variety. The pure culture prepared in this way may then be inocu- lated into the grain and lime
substratum of the bottle. Several isolations in pure culture are advised, choosing well developed
fruit bodies of different origins in order to obtain rapid growth and a vigorous strain producing
fruit bodies of good quality. In any case, this method enables an inoculation easily mixed with
the mass of the bed substratum.
III. Cultivation Practices
Cultivation includes several aspects which are very important as the output depends on
the systematic execution of the same.
1. Filling the containers
Once the compost is sterilized and the spawns are made ready or bought from outside,
the containers are to be filled up with the compost leaving about two inches space from above.
After the containers are filled spawning is done.
Spawning is the process of mixing the spawn into the compost. The spawning is done by
manual or mechanical means at the rate of 0.5-0.75 percent by weight of compost (500-750
gms/quintal compost) filled in the tray or polythene bags. The spawning must be done as soon
as possible in the i prepared selective compost. If delayed for a few days, it is possible that
competitive fungi (weed moulds) will develop in the compost and antagonize the growth of
spawn. It is advisable to spread the spawn over the entire compost surface first, in the trays/
beds/ bags then mix it manually or mechanically. The spawned surface of the compost is
levelled and compact- ed with a ligh1 pressure. Following spawning and cleaning of the growing
room, the compost is covered with formalin/steam sterlized newspaper or polythene sheets.
3. Spawn run
Spawn-run is colonization of compost from the grain inoculum. The environmental
conditions required for a successful spawn-run are compost temperature, humidity and carbon
dioxide level. The mycelium grows best in the compost at a temperature between 24-25°C and
90-95% RH (relative humidity). The paper over the beds should be sprayed regularly with water
to prevent drying out. The floor and walls should also be kept wet with the intention to avoid the
drying out after evaporation from surface. Carbon dioxide levels up to 0.2% are beneficial and
could be achieved by recirculating air within the crop room. As soon as the mycelium begins
spreading in compost from spawn bits, the compost becomes lighter in colour and the mycelium
can be seen as thin white-threads. Seven to ten days after spawning a mushroomy smell comes
from compost and by the time it turns in a light orange-brown colour. Completion of mycelial run
in compost takes 12-14 days from spawning day. The paper or plastic sheeting should be
removed from .the beds one day before supplementing or casing. It leads the compost surface a
bit dry and promotes the mycelial growth into the casing soil.
Once spawn run in the compost in the tray is completed, the trays are to be covered with
a thin layer (2-5 cm) of soil, after removing the news papers. This is known as casing. If every
thing has gone well, then the fourteenth day after spawning will be the most suitable day to case
the beds. It helps to retain moisture and help in gaseous exchange. It also induces fruiting as
the vegetative mycelium enters into the medium which is deficient in nutrition.
Before casing the impregnated compost must be raked gently and pressed evenly, it
provides an even thickness of casing soil. The temperature of the cased beds can increase for
2-3 days after casing which must be brought down by cooling or ventilation. After casing the
temperature is to be maintained at 23-24°C for 8-10 days and relative humidity 85-90 percent.
Fresh air has to be introduced and in another 12-16 days pin heads will start to appear.
Many materials are in use for casing, but the commonly used materials are:
1. Spent compost, sand and lime (4:1:1)
2. Farm Yard manure and loam (1:1)
3. Soil and sand (1:1)
In the casing medium chalk or calcium carbonate is added to maintain the pH around
7.5. All casing materials used are to be pasteurised before use. The material with 20% moisture
are taken inside small barrels which are provided with pipes for passing steam. Pasteurisation
can also be done with chemicals like 5% formalin. More detail on casing may be obtained from
booklet no. 444.
5. Physical requirements
White button mushroom can be grown anywhere if the essential conditions are obtained
or controlled. These condiions are temperature, moisture, ventilation, CO2 concentration and
good spawn. The good spawn has already been discussed
i. Temperature, RH and CO2 concentration
After raking the mycelium in pieces grow to the surface of the casing soil then there is no
need of ventilation during these three-four days but ventilation must be started thereafter and for
good pin-heading the temperature should be lowered to 16-18°C (over 2-3 days period). It is
important to note that the air temperature in winter should not come down below 12°C. During
pin-heading the RH must be reduced to 85-90% from 90-95% along with lowering of the
The amount and temperature of the compost activity of the mycelial growth in compost
and amount of fructification affects the production of CO2 in the crop room. The CO2
concentration in the air of the cropping room should be 0.07- 0.09% v/v (700-900 ppm).
"Siemens" have introduced a CO2 measuring instrument with a range of between 0.0 -CO2 v/v
ii. Watering of the beds
The beds are sprayed at the rate of 1 litre/meter square (with water containing 2%
formalin just after casing. One day later they are sprayed at the same rate with water containing
I 2% malathian/nuvan. The cased beds should be kept moist applying water spray once or twice
in seasonal growing and an alternate day under controlled conditions. The quantity of !water
depends upon the temperature and state of ventilation.
It is advisable to finish watering 15-24 hours before picking, this ensure the quality of
mushrooms and preventions from bacterial blotch.
Pin head start appearing in the trays in 12-15 days after casing and the cropping
continues for another two or three i months. Regular periodical watering is the most important
item of work during this period and watering is to be done carefully by gentle spraying.
The right stage of picking is when the mushroom cap is firmly attached and still closed.
As soon as the grills could be seen, the mushrooms are graded as 'B' or medium and in next
advancing stage as 'C' or coarse. Usually the buttons are collected every alternate days, when
they are about 2-5 cm in diameter. They are harvested by gently twisting with least disturbance
to casing soil. Harvested mushrooms are gently cleaned and packed in thin polythene bags for
The yield is highly variable and depend on the quality of the compost as on the proper
crop management. In the west, where technology is highly advanced, average yields of 20kg/
m2 are usual. However, in India, and the other developing countries, where primitive technology
involving the long method of composting without pasteurization is employed, the yields vary
from 6-8 kg/m2.
8. Care after picking
After picking all the beds should be examined for dead mushrooms, leftover of stalks
and detached pin heads and buttons. They must be taken out from the bed very carefully and
disposed off. The period between two flushes is called intermediate break or intermediate flush.
The mushroom comes out during intermediate break may not be as good as in flushes. The
spraying of water should be done after filling the holes by preserved casing soil. The
temperature should be kept within the range (1.6-1. 7DC) in case of controlled conditions. The
spraying of fungicides or insecticides may be done during the intermediate flushes. One should
be very careful about the doses and necessity of the chemicals.
9. Grading and packing
Mushrooms are very delicate and start perishing soon alter picking. They have to be
handled with care: (i) their brushing during harvesting period should be avoided, (ii) they should
be gently placed in the collecting baskets and not heaped to avoid injury due to mutual
pressure; (iii) it is advisable to water the beds after picking and not before to avoid soil sticking
to the caps.
Bulk of the sale in India, especially in metropolitan towns like Delhi, is of the tresh
mushrooms. Only a traction of the Indian produce is canned. For sale as tresh mushrooms, they
are generally graded according to the accepted international standards. They are as follows:
Mushrooms with membrane closed only just forming, stem length not exceeding 2 cm
and cap measuring 3-6 cm across.
Mushrooms with membrane well developed or just opening with cap retaining a
pronounced cup shape, stem length not exceeding 2.5-3.0 centimetres.
Mushrooms which have advanced beyond the cup stage, the cap forming a letter 'T' with
the stalk, cap diameter 5-7 cm and stem length not exceeding 2.5 -3.0 cm. These mush- rooms
are also called 'flats'.
Mushrooms are highly perishable and therefore they have to be processed for
preserving to prolong their shelf-life. The mushrooms are preserved by various method like
drying, freezing, dry freezing and canning etc. which are described in detail in booklet no. 450
entitled, Mushrooms; Post harvest technology.
IV. Pest & Diseases
A number of pests and diseases occur during mushroom growing. The major ones are
briefly described here.
Many insect pests attack the button mushrooms. Small larvae of flies, mites, nematodes,
springtails etc. damage the fruit bodies. Some of these Including the nematodes, affect the
spawn also. Absolute cleanliness is to be maintained in mushroom houses, to prevent insect
Small dark flies with slender bodies can be seen in large numbers. The larvae of these
flies which are about 6-7 mm long cause severe damage since they tunnel into the mushrooms.
The phonils also cause damage similar to spring tails, tiny organisms with stout antennae, crawl
about in mushroom beds, feed on the mycelium and stalk of buttons. Besides these insects, a
number of mites also damage the mushrooms.
Nematodes are a chronic problem in mushroom cultivation. They feed on the
mushrooms turning them brown, watery and stunted.
Control measures include proper preparation of compost, complete sanitation in the
mushroom house and periodical and judicious use of insecticides. Lindane dust at the rate of 80
giquintal to be added at the time of compost preparation, usually during the 7th turn.
If necessary the trays are to be sprayed with malathion (50% EC in 10 litres of water)
two days after spawning and two days before casing.
Mushrooms are subjected to many fungi, bacterial and viral diseases. Unless precaution
is taken these diseases may cause severe damage to the crop. Some of the common diseases
are the following.
i. Soft mildew or cobweb
It is caused by the fungus Dactylium dendroides, resulting in fluffy, white cobweb like
growth in the casing soil. The colour later on changes to pink with age. The relative humidity in
the mushroom house has to be regulated. Affected area has to be treated with Dithane Z- 78
ii. Brown plaster mould (Papulospora byssina)
A common disease on trays, as a white cloudy growth, later the colour changes to
brown. The fungus spreads fast and causes heavy reduction in yield. Proper preparation of
compost will reduce chances of infection.
Other diseases include, white plaster mould! (Scopulariopsis fumicola), olive green
mould (Chaetomium olivaecarum), green mould (Trichoderma viride), truffle dis- ease
(Pseudobalsamina microspora), bubble disease (Mycogone perniclosa), etc. Weed mushrooms
like Coprinus lagopus and C. conatus are also common contaminants.
Bacterial disease caused by Pseudomonas tabaci is also common. It causes brown,
sunken blotches on the pileus. They arise as small spots which are yellowish dark brown in
colour and later they coalesce to form big blotches. Usually the disease spreads through
contaminated casing soil.
Few viral diseases also are known to affect mushrooms. However, none of them are
reported from India. There are reports from other countries and are known by various common
names like Brown disease, dieback, watery stripe, xanthomonas disease etc. in accordance
with the symptoms observed. If the mushrooms house is dry, the affected mushrooms are
shriveled, leathery and become brown in colour.
Under high humid conditions the stripe becomes watery and, grey. More than six
different viruses are known to affect the mushrooms. Following measures are suggested.
1. Heat. the growing room along with trays and compost at 70°C for 12 hours after the harvest
of the crop.
2. Treat the trays and other equipment with 4% sodium pentachloro-phenate 0.5-1.0% solution.
3. Disinfect mushroom house properly with 4% formaldehyde solution.
For more details on problems in mushroom cultivation booklet no. 453 may be consulted.
VI. Economics of Cultivation
Mushroom farming on the cottage scale is economically sound and even quick
remunerative. The average yield is approximately 40% of the quintal dry straw. It is possible to
take two crops during the winter months. The cost of production per kilogram of mushroom work
out to be Rs.. 15-16, variable according to local price fluctuations The whole sale price of
mushrooms during year 1995-96 at Delhi was about Rs. 26/kg. That leaves a handsome profit
of Rs. 10-11 per kg mushroom. With experience, a grower can always hope to increase this
yield of mushroom.
A. Recurring Cost
(For two crops in the area of 200 sq. ft. shed, values arbitrary)
1. Straw 15 q. @ Rs. 100/q. Rs. 1500.00
2. Wheat bran 120 kg @Rs. 3/kg Rs. 360.00
3. Fertilizers (Urea -18 kg, CAN -20 kg) Rs. 154.00
4. Gypsum 100 kg @ Rs. 0.50/kg Rs. 50.00
5. Chemicals & pesticides Rs. 75.00
6. Spawn 50 bottles @ Rs. 10/bottle Rs. 500.00
7. Labour cost Rs. 1000 p.m. for 5 months Rs. 5000.00
8. Miscellaneous Rs. 800.00
Total Approx. Cost Rs. 8,439.00
B. Non-Recurring Expenditure
1. Cost of construction of mud houseof area
of 200 sq. ft. and shelves @ Rs. 20/ sq. ft. Rs. 4000.00
2. Cost of equipment Rs.prayer, implements etc.) 1000.00
Total Rs. 5000.00
C. Depreciation and interest
@ 25% of Rs. 50000.00Rs. 1250.00
D. Expected yield 600 kg (from 2 crops)
Estimated turnover from 600 kg @ Rs. 26/kg Rs. 15,600.00
Expenditure (Rs. 8450 + 1250) Rs. 9700.00
Profit Rs. 5,900.00
Cost of producing 1 kg mushroom is
I approximately Rs. 15-16
Net profit per kg mushroom is approximately Rs. 10-11
Approximate cost analysis of mushroom cultivation at small, medium and large scale has
also been done in book number 456 entitled "Mushrooms: Marketing and Economics". It may
give additional help for economic analysis of mushroom project.