Oyster Mushroom

INTRODUCTION  

Oyster mushroom (Pleurotus sp.) belonging to Class Basidiomycetes and Family Agaricaceae is popularly known as ‘dhingri’ in India and grows naturally in the temperate and tropical forests on dead and decaying wooden logs or sometimes on dying trunks of deciduous or coniferous woods. It may also grow on decaying organic matter. The fruit bodies of this mushroom are distinctly shell or spatula shaped with different shades of white, cream, grey, yellow, pink or light brown depending upon the species. It is one of the most suitable fungal organisms for producing protein rich food from various agro-wastes or forest wastes without composting.    

                                           Oyster Mushroom

Origin

Cultivation of a sp. of oyster mushroom (Pleurotus ostreatus) was initiated on experimental basis in Germany by Flack during the year 1917 on tree stumps and wood logs.  Growing technology was perfected in USA by Block, Tsao and Hau. 

Cultivation of different varieties of oyster mushroom was initiated in Bangladesh, India in the early sixties.  Commercial cultivation began in mid-seventies.

Botanical Description

The oyster mushrooms have three distinct parts- a fleshy shell or spatula shaped cap (pileus) , a short or long lateral or central stalk called stipe and long ridges and furrows underneath the pileus called gills or lamellae. The gills stretch from the edge of the cap down to the stalk and bear the spores. The spores are smooth, cylindrical and germinate very easily on any kind of mycological media within 48-96 hrs. The mycelium of Pleurotus is pure white in colour.

  

Production

Oyster mushrooms are the third largest cultivated mushroom. China, the world leader in Oyster production, contributes nearly 85% of the total world production of about a million tonnes. The other countries producing oyster mushrooms include Korea, Japan, Italy, Taiwan, Thailand and Phillipines. The present production of this crop in India is only around 1500 tonnes due to low domestic demand. Another inhibiting factor is that export demand orders are large and can be met only if a linkage is developed between producer, cooperatives and exporters.

       

Economic Importance

The economic importance of the mushroom lies primarily in its use as food for human consumption.  It is rich in Vitamin C and B complex and the protein content varies between 1.6 to 2.5 percent. It has most of the mineral salts required by the human body.  The niacin content is about ten times higher than any other vegetables. 

The folic acid present in oyster mushrooms helps to cure anemia. It is suitable for people with hyper-tension, obesity and diabetes due to its low sodium : potassium ratio, starch, fat and calorific value. Alkaline ash and high fibre content makes them suitable for consumption for those having hyperacidity and constipation. A polycyclic aromatic compound pleurotin has been isolated from P. griseus which possess antibiotic properties.

The spent straw can be re-cycled for growing oyster mushroom after supplementing with wheat or rice bran @ 10-15 % and also for preparing compost of white button mushroom after suitable supplementation with nitrogen rich horse or chicken manure (sun-dried before use). The spent straw can be used as cattle feed and also for bio-gas production, The slurry can be used as manure.

              

 MARKET ANALYSIS AND STRATEGY

  Demand and Supply Patterns

This mushroom is not as popular as white button mushroom in the domestic market. A few units are cultivating it commercially for export market. Cultivation of this mushroom on commercial basis would be more profitable as compared to white button mushroom as capital costs are low.

The cultivation of this variety of mushroom is very simple and economical in rural areas where raw materials and facilities required are easily available.

Marketing of fresh oyster mushroom does not pose any problem at present due to very low production. However, as production increases linkage of producers with domestic markets and export oriented processing units will need to be developed to ensure remunerative prices to the producers.

Generally, export orders are too big to be met by a single grower and as such co-operatives have to be encouraged to pool their produce for trading the crop in a dried powder form in international markets.

   Import / Export Trends

About 11,797 tonnes of fresh mushrooms and 4,099 tonnes of preserved mushrooms were exported to foreign countries viz. U.S.A., France, Ireland, U.A.E., Russia etc. during the period 2001-2002. The quantity of oyster mushroom exported is much lower than that of button mushrooms which constitute the major share of exports.