5. A Report on Cultivation of Oyster Mushroom
Introduction
Oyster mushrooms are one of the most popular edible mushrooms and belong to the genus
Pleurotus and the family Pleurotaceae. Like oyster mushroom (Pleurotus ostreatus), many of
Pleurotus mushrooms are primary decomposers of hardwood trees and are found worldwide. The
type species of the genus Pleurotus (Fr.) Quel. is P. ostreatus (Jacq. et Fr.) Kummer. This
mushroom has basidia with four basidiospores and a tetrapolar mating system. Its hyphae have
clamp connections and most members of the genus, excepting a small minority, have a
monomitic hyphal system.
To date approximately 70 species of Pleurotus have been recorded and new species are
discovered more or less frequently although some of these are considered identical with
previously recognized species. Determination of a species is difficult because of the
morphological similarities and possible environmental effects. Mating compatibility studies have
demonstrated the existence of eleven discrete intersterility groups in Pleurotus to distinguish one
species from the others. Some reports indicate partial compatibility between them, implying the
possibility for the creation of another species. In context of Nepal four species of Oyster
Mushroom has been recorded;
 Pleurotus circinatus
 Pleurotus nepalensis
 Pleurotus osireatus
 Pleurotus sajor caju
MATERIALS AND METHODS
1. Selection of Substrate
Selection of substrates for Pleurotus cultivation is most important aspect. Pleurotus can
be cultivated on various substrates which are available. It can be cultivated on pure
substrate or combination of different substrates. It can be grown on
various agricultural waste materials. They grow well on a mixture of saw dust and other
combination of tropical wastes such as corn cobs and leaves, cotton waste, sugarcane
bagasse and leaves. Rice straw was used as a substrate for the cultivation of oyster which
is a common practice in Nepal.
2. Sterilization
Before sterilization rice straw is chopped to about 5 cm or smaller length. The chopped
straw is soaked in water overnight. For the best result the straw should be immersed in
boiling water drained off. If wheat straw is used, it should be softened by composting for
a week Sterilization can be done with the help of drum. There should be 4”×6” water in
the drum where three or four bricks should be kept upright position; perforated round
plate of tin should be kept on bricks. Then, the drum should be filled with moist straw. It
should be steamed for half an hour to kill all insects and wild fungus. After steam
sterilization it should be cooled either in drum itself or in big plastic bag. In context of
Sanjok Poudel, B.Sc.Ag, IAAS, Paklihawa Campus
Page 1
5. A Report on Cultivation of Oyster Mushroom
Nepal farmers are using this method for sterilization as they don’t have any other well
equipment for sterilization. So complete sterilization can not be assured by this method.
Most of farmers in our country are not taking care during sterilization. So, they have to
face contamination problem. Some farmers expose the sterilized straw in air for cooling
.Sterilized straw should not be exposed in air to avoid contamination. For Pleurotus
cultivation straw should be well sterilized.
3. Inoculation
Cultivation of Pleurotus is usually carried out in transparent polythene bags. It is not
necessary the size of plastic bag should be fixed. However experience show that small
bag is good for summer season and large size bag is good for winter season. Plastic bag
filling method is popular in Nepal. For inoculation of the spawn; it would be good to
have bag size -14” × 22” (in summer) or 16” × 26”(in winter). Spawn should be spread in
every layer of straw of 6-8 cm. height and pressed the straw slightly to make bag
compact.
Fig. Inoculation Packaging
Sanjok Poudel, B.Sc.Ag, IAAS, Paklihawa Campus
Page 2
5. A Report on Cultivation of Oyster Mushroom
Fig. Prepared Bags with Spawn & Straw.
After filling the bag with spawn and straw, mouth of the bag should be tied with thread.
Small holes should be made for aeration. Inoculation should be done with clean hand.
Ones should be careful during inoculation to minimize the possibility of contamination as
far as possible. It would be better to have a separate room for inoculation.
4. Incubation
It is the process of providing suitable environmental conditions to run mycelium well in
substratum. The packed bags or blocks are incubated in a well ventilated room where
uniform temperatur of 25ºC is maintained. Due to the lack of proper area for incubation
mushroom was incubated in cool and shady place inside the hostel. The area was all
covered with wet jute sack to provide it moist condition. Water was timely sprinkledIn
Nepal, the most dangerous problem during incubation period is Green Mould.
5. OBSERVATION:
The mushroom was then supervised thoroughly, following changes were seen,
 3rd day: no changes were seen except some dew was collected at the top of bag.
 6th day: minute threads of mycelium were spread around the spawned grain.
 10th day: white cover of fungi grows in larger area.
 15th day: a few larger areas were covered but nearly same as in 10th day.
 25th day: now the fungus covered most of the part and at that day the plastic
covered was removed and placed in another room for further cure.
6. Harvesting
During fruiting body formation ventilation should be provided so that fresh air can be
Sanjok Poudel, B.Sc.Ag, IAAS, Paklihawa Campus
Page 3
5. A Report on Cultivation of Oyster Mushroom
flow easily. Temperature and humidity should be maintained. Large size mushroom can
be produced if we cut the ball from one side. Light water spray is necessary two times per
day. When temperature is low, fruiting body matured at about 7-8 days but when
temperature is high it matured within 3-4 days. Harvesting is done when the cap has the
daimeter of 8-10 cm. picking is done by twisting gently so that it is pulled out without
leaving any stalk and also the nearby fruiting bodies are not disturbed. The base of the
stipe deep within the straw should be removed by cutting with sharpe knife.
PROBLEMS ENCOUNTER DURING WORK:

Poor quality of spawn.






Lack of sterilizing agent and properly worked isolation chamber during inoculation.
Lack of proper area for incubation.
Irregular temperature and humidity condition during the cultivation.
Problem of rodents, mites and other pest during incubation.
Growth of unwanted micro organism in growing culture.
Unavailability of good quality paddy straw.
Fig. Mushroom Ready to Mushroom
Conclusion
Mushroom cultivation is actively growing business in Nepal.Mostly four types of mushrooms are
very popular in Nepal. They are Agiricus, Pleurotus Volverella and Lentinus(Shiitake). Pluerotus
Sanjok Poudel, B.Sc.Ag, IAAS, Paklihawa Campus
Page 4
5. A Report on Cultivation of Oyster Mushroom
is most popular mushroom grown in Nepal since temperature required for mushroom is higher
than Agaricus and lower than Volvorella. Another important cause of increasing interest of
farmers to cultivate mushroom is available of raw material for all kind of mushrooms and good
environmental condition where mushroom cultivation can be done through out the year under
natural condition or on little modified environment. Although high temperature and humidity
encountered during the cultivation due to improper incubation area lead to slow mycelial growth
and yield of the mushroom. So, if propr sterilized condition along with proper atmospheric
condition can be maintained for the incubation of mushroom it can be sucssfully grown even in
lower altitude and off season condition. This can be a effective means for earning extra income
even to the resource poor farmers.
Sanjok Poudel, B.Sc.Ag, IAAS, Paklihawa Campus
Page 5