Growing Oyster Mushroom

Dr. Ishrat Naz

Department of Plant PathologyThe University of Agriculture, Peshawar

Khyber Pakthunkhwa

Oyster Mushroom (Pleurotus ostreatus)

• Pleurotus ostreatus, the oyster mushroom, is a common edible mushroom.

• It was first cultivated in Germany as a subsistence measure during World War.

Oyster Mushroom (Pleurotus ostreatus)

• The oyster mushroom is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media. 

• Oyster mushrooms are saprophytic as they obtain there nutrients by decomposing various agricultural by-products.

Oyster Mushroom Classification

Phyllum: Basidiomycota Class: BasidiomyceteOrder: AgaricalesFamily: TricholomataceaeGenus: Pleurotus

Species of Oyster MushroomsP. ostreatusP. floridaP. pulmonariusP. columbinusP. SapidusP. populinusP. ferulaeP. fossulatusP. nebrodensisP. abieticola P. eryngiiP. albidus

P. cornucopiae P. citrinopileatus P. euosmusP. djamor P. flabellatusP. salmoneo-stramineusP. salmonicolorP. opuntiae  P. calyptratusP. cystidiosus

Natural Growth

Natural Growth

Mushrooms

• The higher, fleshy fungi bloom into a visible umbrella like fruiting body, are called mushrooms.

Edible and Non-edible mushrooms

• There are about 10,000 different species of which at least 1,290 are reported to the edible. Mushrooms are used as food as well as medicine.

Nutritional Value

• Source of protein (25-35% on dry wt., basis) • Source of vitamins-Thiamin, riboflavin, Niacin• Very low fat contents• Lowers cholesterol and triglycerol levels as well as

very low-density lipoprotein (VLDL) in blood plasma.

Medicinal value

• Anti-tumor (tumor reduction and control)

• Immune response (boost bodies ability to fight disease)

• Anti-inflammatory (relief tension due to muscle inflammation)

• Antiviral (as an immune response)

• Antibiotics (as an immune response)

• Lower cholesterol and triglycerol levels as well as very low-

density lipoprotein (VLDL) in blood plasma

Golden oyster, Pleurotus cornucopiae

P. citrinopileatus

Pink oyster, Pleurotus flabellatus

King Oyster, P. eryngii

Cultivation Technology

Substrates

• Saw Dust• Wheat straw• Rice straw• Cotton Boll • Dry Banana Leaves• Corn Cobs• Cotton Waste

Substrates

Wheat straw Shitake mushrooms on wood

Substrates

Substrates

Growing Techniques

• Soaking and fermentation of Substrates• Filling in trays or bags • Pasteurization• Spawning• Management of crop

Addition of water

• The Straw or other materials are chopped and partly shredded and then mixed with water. The optimum water content is about 70%.

Soaking and fermentation of Wheat straw

• Soaking of wheat straw• Lime 2-4% is added.• The mixture is piled up and covered with plastic sheet for 4-6

days.

Soaking in Tank

Fermentation

Containers for cultivation

• Oyster mushroom can be grown in plastic or polypropylene bags as well as in vertical or horizontal trays..

Advantages and Disadvantages

• The advantage of cultivation in trays is that the mechanization can be applied and the cultivation requires less labour.

• The advantage of cultivation in plastic bags is that the growing is used more efficiently and in small areas more substrate can be placed. The yield per unit area is higher than growing in trays.

Filling

Heat treatment (Sterilization and pasteurization)

• In order to destroy the vegetative form of competing microorganisms, the substrate is subjected to sterilization or pasteurization.

Hot water treatment

• Wheat or Rice straw can be treated with hot water (65°C ± 5°C) for 10 minutes to one hour. The excess water is drained off and discarded.

Steaming in drums

• Sterilization by steaming at 100°C in drums is more acceptable because cost is low.

• Steam the bags for 1-2 hours depending upon the substrate and volume.

Pasteurization by using steam generator

• Substrate filled bags or containers are placed in a room. Steam is introduced into the room from steam generator and the bags or containers are kept at 58-60°C for 4-6 hours.

Pasteurization by steam generator

Spawning

• Mixing of spawn into the substrate is called spawning.

Grain spawn

• After the heat treatment is completed and the substrate is cooled down to 20-25°C it can be inoculated.

• Pure culture grain spawn is commonly used. The quantity of spawn can be varied from 1-1.5% on the wet weight of the substrate.

Method of spawning

• Through spawning: Spawn is mixed through out the substrate.

• Surface spawning: Spawn is placed on top of the substrate. It is generally recommended for bag cultivation.

Spawning

Spawned bag

Through Spawning

Tying

• The mouth of the bags is tied loosely with thread or rubber bands.

• Small holes should be made in bigger plastic bags.• Plastic foil is used for covering the trays.

Incubation

• The spawned bags are then kept preferably in a dark room until the mycelium has fully penetrated the substrate downward. It takes about 3-4 weeks.

• During spawn running stage the temperature is ranged between 25-28°C.

Incubation

Spawn running

Fructification or cropping

• Fructification or fruit-body formation is started as soon as the substrate is fully impregnated with mycelial growth.

• Ventilation, temperature and relative humidity play important role.

• By means of ventilation the temperature is decreased to desired level.

Some methods of fructification

• Remove plastic foil immediately after the completion of mycelial growth and the desired temperature of fruiting is attained.

• Wait pin heads have been formed underneath the plastic before it is removed.

Temperature

• The optimum temperature for pin-head formation and development of fruit-body of different Pleurotus species is ranged between 16-26°C.

Co2 concentration

• Although the mycelium can tolerate a high concentration of Co2.

• When the CO2 concentration is higher than 600 ppm (0.06%), the stipe (stem) elongates and the growth of the cap is prevented.

• Co2 is reduced by the introduction of fresh air into the growing room.

Elongation of stem

Light

• For the growth of mycelium, cultivation in a dark place is better than in a bright place.

• Growth of fruit bodies requires light to 50-500 lux intensity.

• A lack of light can also lead to very small pinheads and mushrooms with long stems.

Relative humidity

• Desired relative humidity during the formation of pinheads should be 90-95%.

• It should be lowered to 80-85% during the development of fruit bodies.

Further cultivation cares

• The substrate should be protected from dehydration by sprinkling water.

• Too little water dehydrates the substrate.• Too much watering encourages green mold and

rottening of mushrooms.

Production trend

• The mushroom produce in flushes.• The first flush gives higher yield.• There are total 3-5 flushes.• The interval between the flushes is 8-12 days.

Cost Effectiveness

• Avg prod of 300 bags: 20kg/week• Total prod of a cycle: 140 kg• Kohat market price: Rs. 200/kg• Price of 140 kg: Rs. 28000• Wheat straw 3 mnds: Rs. 300• Plastic bages 3kg: Rs. 300• Spawn: 20 liters: Rs. 2600• Misc. (labour etc.): Rs 6000• Total Rs. 9200• Net Profit: 28000-9200= 18800/7 weeks

Or Rs. 383 per day.

Pin head formation

Further Development

Vertical containers

Cropping

Cropping

Cropping

Cultivation on wheat straw beds

White Oyster, P. ostreatus

White Oyster, P. ostreatus

Grey tree oyster, P. ostreatus

Harvesting Stage

• Oyster mushroom should be harvested before the mushrooms show slightly curled edges.

Mature mushroom(curled edges)

• When mushroom shows curled edges, it starts to discharge spores, called sporulation stage.

• Harvesting at this stage is not recommended

Fig.1. Sciarid fly and larva. Fig.2. Phorid fly and larva.

Fig.3. Cecid fly and larvae.

SUMMARY• The paddy straw, leaves of different crops and empty corn

cobs needs chopping in to small pieces of about 3-5 cm. Threshed wheat straw, cotton waste, saw dust, cotton bolls and empty millet heads or so, may directly be used. All substrates needs soaking in water for 24 hours. After soaking, boil the same in water for about half an hour, so that substrate become moist and insect pests and other microbes present in the substrate may be killed. After this, take out the straw from water and spread on the inclined cemented floor, for cooling as well as removing of excess water from the substrate. When the temperature drops down to about normal and moisture content becomes about 80%, the spawn be mixed.

SUMMARY• The spawned substrate may be filled in polythene bags and

be placed in spawn running room under controlled temperature, humidity and light. This mushroom requires 80 to 95% humidity, 15 to 30OC temperature and white florescent light for growth and development. When pinheads (initial growth of fruiting bodies) of the mushrooms appear, open the mouth of the bags or cut at place, to facilitate the growth of fruiting bodies. Sort out the contaminated bags and destroy them away from the growing space, burning of such bags is safe for remaining crop.

HARVESTING, YIELD OF MUSHROOMS

• Most of the mushrooms are harvested through picking by hand. The harvesting of oyster mushroom could be done with the help of sharp knife or blade, at the base of the stipe. If there are many pinheads around the mushrooms, cut that mushroom very carefully, so that the near by pins do not be disturbed. Any mature mushroom (harvested or diseased), their stalks and refuse or solid portions left in the bed should be removed and destroyed, to minimize risk of diseases and pests.

The mushrooms yield the crop in cycle and subsequent flushes can be harvested till the conversion of waste in to mushroom or up to contamination or till attack of insect pests or diseases. Approximately, the mushrooms yield equal to 100% of substrate dry weight.

BE Careful…….

• The wild mushroom must not be eaten unless it is identified by experts because some mushrooms are edible while others are poisonous.