The document provides details on the cultivation process of white button mushrooms (Agaricus bisporus), including composting, spawning, casing, climate requirements, and harvesting. It describes the long and short methods of composting, which involve mixing straw with fertilizers like chicken manure and monitoring temperature during decomposition. After composting is complete, spawning introduces mushroom mycelium, followed by casing with a moist soil mixture to initiate fruiting. Proper temperature, humidity, and ventilation must be maintained throughout cultivation for optimal mushroom growth.

1. CULTIVATION OF WHITE BUTTON MUSHROOM (Agaricus bisporus)
The three main operations in the button mushroom growing are i) Composting
ii) Spawning and iii) Casing. Each operation is important for getting a good yield but composting
may be termed as heart of the process and is therefore the most important.
Composting
Compost formulation
Compost prepared from wheat straw and other fertilizers is termed as synthetic compost.
The main aim of computing the formulations is to achieve a balance between carbon and
nitrogen compounds. The initial nitrogen content of the compost pile should be 1.5 – 1.75% at
stacking gives best results. Nitrogen levels below or above these levels are attacked by different
moulds which ultimately reduce the yield. At stacking, C: N ratio is adjusted to 25-30:1 which
comes down to 16:1 after composting is over. The formula in use by SKUAST-Jammu is:
Wheat straw = 500kg
Chicken manure = 200 kg
Oil cake = 25 kg
Rice/Wheat bran = 50 kg
Gypsum = 50 Kg
Urea = 4 kg
Composting Process
Long method: The compost should be prepared on clean concrete floor in the composting yard.
The composting yard should be covered by rain shelter to protect the compost pile from rain.
To begin the composting process, the composting yard should be cleaned thoroughly with water
and washed with 2% formalin solution. Wheat straw or any other base material to be used is
spread on the floor up to the height of 9-12 inch and the straw is wet thoroughly by spraying
water and turning the straw with the help of iron forks. Proper wetting requires about 4-5 times
water of the weight of the wheat straw. Once the straw is wet, it is kept as such for 24 hours. All
the fertilizers including chicken manure, wheat bran, oil cake are mixed together and water is

2. sprinkled over them so that they become moist. The mixture is then covered with gunny bag.
This process of wetting of wheat straw and fertilizer is referred as day (-1).
Day 0: On this day, the fertilizer mixture is spread on the wet wheat straw and mixed
thoroughly with the help of iron forks and made into a stake (pile) of 1 m. x 1 m. :
height x breadth and of any length.
Day 1-5: Temperature of the pile should be regularly monitored. Temperature should start
rising after 24-48 h of stacking and should reach 65-700C in the central core.
Water is sprayed if moisture is less. Watering should be stopped as soon as
leaching starts from the bottom of the pile.
Day- 6: First turning should be given to the stack. The aim of turning is that every portion
of the pile gets equal aeration and water for proper decomposition of the base
material; otherwise it may lead to non selective compost.
Day –10 In second turning stack is broken open and remade as indicated above. Water may
be sprayed if required.
Day- 13 In third turning, gypsum is added and restacked.
Day –16 Fourth turning and restack as above
Day –19 Fifth turning and restack as above
Day –22 Sixth turning and restack
Day –25 Seventh turning and restack
Day –28: Filling day – The pile is broken open and checked for the smell of ammonia. If
there is no ammonia smell, the compost is spawned after cooling to ambient and
filled in polybags. If ammonia smell persists, one more turning is given after 3
days. The moisture content of the compost should be around 60-65%. Spawning
should be done @ 0.5–0.75 % on weight of finished compost basis.
Short method of Composting: Short Method of Composting is accomplished in two phases
viz. Outdoor composting and Indoor composting.

3. Phase-I: Outdoor composting
Like long method of composting, this phase starts with the wetting of raw materials. After
thorough wetting, a stack is made out of such materials to encourage aerobic fermentation. After
two days the stack is broken, water is added to the dry portion and another similar stack is made.
O-day:
On this day, stack is broken, full quantity of urea is added and a high aerobic stack is made.
The size of the stack should be kept up to 5 feet height x 5 feet width. The length of pile depends
on the quantity of substrate. Turning can be done manually by fork or by mechanical turners
specially designed for the purpose.
Day-2: First turning
Day-4: Second turning
Day-6: Third turning and required quantity of gypsum is added
Day-8: The compost is filled in the peak heating rooms or bulk chambers
Phase-II: Indoor composting
After phase-I, compost is loosely filled manually or by filling machine in the tunnel up to
the height of 6-7 feet. Immediately after filling, all the doors are closed and the blower fan is
switched on to bring down the compost temperature uniformly to 450C. The difference in
compost temperature and air temperature should not be more than 30C. When the compost
temperature reaches 450C, fresh air is stopped and the compost temperature starts rising by self
generation of heat. Temperature needed for pasteurization of compost (570C) may reach in 10-12
hours. Compost is kept at this temperature for 6-8 hours for effective pasteurization and during this
period it requires some air for that 10% dampers are opened. Blowers should be kept on during the
entire period of phase-II. When pasteurization is completed, the compost is ready for conditioning.
To achieve this, compost temperature is maintained at 45-500C by slight introduction of fresh air.
Supply of steam at this stage is stopped and is required only when the temperature in the tunnel
goes below 450C. The conditioning will last for 3-5 days or till ammonia go below 10 ppm. After
conditioning, compost is cooled down to 23-250C by introduction of more fresh air. The entire
process of phase-II is generally accomplished in 7-8 days.

4. Attributes of good compost:
1. It should be dark brown in colour with inoffensive sweet smell.
2. It should not be greasy or sticky.
3. It should be free from smell of ammonia.
4. Moisture in the ready compost should not be more than 65-70%.
5. There should not be any visible growth of undesirable fungi except fire fangs.
6. It should be free from insects and nematodes.
Spawning:
Spawning means broadcasting spawn in compost. This provides points for further growth
of mushroom mycelium in compost.
Methods of Spawning:
a) Surface spawning: Spawning is done by broadcasting on to surface of compost after
lifting 1–1½ inch top compost. After broadcasting of spawn, the lifted compost is put
back and pressed to make uniform top surface.
b) Layer spawning: Spawning is done in two to three layers after leaving uniform gap
between the layers.
c) Thorough Spawning: Here the grain spawn is mixed thoroughly with the compost.
After spawning, the bags/ trays are kept in a spawn running room for complete spawn run
which takes about 15-20 days for completion.
Casing: After the completion of spawn run, casing is applied on the spawn run bags. Casing
means covering the spawn run compost with a suitable material. For conversion of vegetative
phase in to reproductive phase, casing is needed in case of button mushrooms. The thickness of
casing layer should be 1-1.5 inches.
Properties of good casing soil:
1. It should have very high water holding capacity
2. It should be sufficiently porous
3. The pH should be between 7.0 - 7.5
4. It should be free from pest & diseases
5. It should be nutritionally deficient and fairly of open texture and should not pan even
on application of water.

5. Sterilization: Casing soil must be sterilized. This can be done by chemical means with
formaldehyde if steam sterilization facility is not available. For ½ cubic meter of casing soil,
spray 1½ liters of formalin (40%) in two buckets of water. It should be treated 10-15 days
before use. The treated soil should be covered with tarpaulin or polythene sheet completely for
48 hours so that disinfection is effective.
Casing formulation: A casing mixture of 2 year old FYM, garden soil and sand in the ratio of
4:2:1 is an ideal casing mixture.
Climate requirement:
Air temperature: Air temperature has to be regulated at each stage. During the period of spawn
run, the air temperature of 23+ 20C should be maintained in the spawn running room, during fruit
body initiation after casing it should be around 15-180C and during cropping it should be
maintained at 14+ 20C.
Humidity: Mushrooms require high relative humidity for their development. Relative humidity
around 90% should be maintained during the entire period of crop. For increasing humidity in
the room, wet gunny bags can be hung from the windows, which should be regularly watered.
Ventilation: Very little ventilation is required during spawn run. Ventilation should be increased
after casing, otherwise pinheads may not form. During cropping ventilation should further be
increased. About 2-4 air exchanges per hour are sufficient.
Watering:
During spawn run: If the spawning is done in polythene bags, no watering is required till spawn
run is complete.
After casing: Watering should be done only to keep the casing layer moist. While watering,
water should never percolate down to compost and the water should not be directly sprayed on
pinheads.
During cropping: No watering should be done directly on pinheads, once they start developing,
as they are extremely delicate. When these grow to the size of a pea, regular watering is
necessary to keep the surface moist. Several watering are preferable to one heavy application.
Watering should be done immediately after picking.
Harvesting: The mushrooms should be harvested by gently holding the mushroom fruit bodies
between the thumb and fingers, twisting slightly and pulling out the fruit bodies, so that the
broken pieces are not left out in the trays / bags and moreover surrounding fruit bodies are not

6. disturbed. For the same reason, harvesting by cutting is not recommended as cut portion develop
bacterial rot, which may spread to the healthy mushroom. After harvesting, the lower portion of
the stalk with adhering debris etc. should be cut with the help of clean knife/ blade
Packing: Owing to comparatively high cost of mushroom and low shelf life, consumers prefer to
buy in small lots. Generally 200g packs are preferred. Best containers for packing of mushrooms
are poly bags of about 100 gauge thickness having 2-3 perforation to facilitate air exchanges.