Low cost technology for growing mushrooms

Thangjam Subhalakshmi *

State Level Krishi Mela, 2014 at Iboyama Sumang Lila Shanglen, Imphal in January 2014 :: Pix - Ashok Ningthoujam

People have harvested mushrooms from the wild for thousands of years for food and medicines. Of the estimated 1.5 million species of fungi, about 10,000 produce the fruiting bodies we call mushrooms. The Chinese first cultivated shiitake (Lentinula edodes) mushrooms around 1100 AD, with domestication efforts beginning centuries earlier.

Agaricus is the leading mushroom crop worldwide and accounted for 99% of the 1997 United States’ mushroom production. Oyster mushrooms (Pleurotus spp.) were more recently domesticated, and now rank second in world production. Shiitake mushrooms, which are very popular in Asian cultures, rank third. Most growers operate small farms and focus on local markets.

Mushrooms lend themselves to many different growing systems from simple and inexpensive to highly sophisticated and expensive. This article will provide information on how to raise mushrooms with minimal expenditure. It is an easy production technique which the small marginal farmers can easily adopt.

MATERIAL REQUIREMENT

Substrate

A large number of agriculture, forest and agro-industrial byproducts are useful for growing oyster mushroom. Substrates should be fresh, dry and free from mould infestation.

Oyster mushroom can utilize a large number of agro-wastes including straw of wheat, paddy and ragi, stalks and leaves of maize, jowar, bajra, and cotton, sugarcane bagasse, jute and cotton waste, peanut shells, dried grasses, sunflower stalks, used tea leaf and discarded waste paper.

It can also be cultivated using industrial wastes like paper mill sludge, coffee byproducts, tobacco waste etc. About 1.5 – 2.0 kg of good substrate will be required per bag of 80 cm x 40 cm size.

MUSHROOM SPAWN

Three to four-week old non-contaminated spawn @ 10% of dry weight of the substrate is required for the purpose. Spawn of good quality should be collected from a reliable source. Further, the species/variety should be chosen based on the temperature and relative humidity of the cropping season of the locality. Just prior to use the 200 gm Spawn is extracted from the bottle with hooked iron rod and divided into four parts.

POLYTHENE BAG

Transparent polythene tube of 125-150 gauge with a dimension of 80 cm x 40 cm is suitable for oyster cultivation. Bags of 60 cm x 40 cm may also be used for the purpose. The bags can be reused for the second crop after proper cleaning.

SUBSTRATE PREPARATION

o Chopped the straw to 4-5 cm size by chaff cutter
o Soaking of straw in chalk powder, mixed water 6-8 l @ 1kg 100 water for pasteurization.
o Soaking in hot water at 65 C-70 C or you can boil the substrate for 30 minutes. This pasteurization method will either kill or suppress the growth of competitor moulds for 25-40 days after spawning.
o Drain excess water and maintain moisture content of 60 C
o Dry the substrate by spreading it in a clean polythene by leaving it overnight. The floor where you dry the substrate should be sterilized first.

RAISING OF BAG

One end of polythene is tied with rubber band and 1 part of substrate is put to a height of 15cm. Substrate is then gently pressed and one part each of spawn (50g) spread at the periphery close to polythene. Likewise, four such layers are made and the bag is closed at the upper end after pressing the substrate.

For a bag out of 2 kg of dry straw, 200g each spawn and supplement will be used. 15-20 small holes (0.5 cm diameter) should be made on all sides to facilitate gas exchange. Instead of layer spawning, mixed spawning may also be followed where the required quantity of spawn is mixed with the prepared substrate (soaked straw) and incorporated into the bag.

The bags are then incubated in a well ventilated room at 25C. During the mycelial growth bags should not be opened.

AFTER CARING

Once the mycelium has fully colonized the substrate forming a thick mycelial mat, it is ready for fruiting. Contaminated bags with mould may be discarded while bags with patchy mycelia growth may be left for a few more days for completion of the mycelia growth. These bags are opened after 15-16 days.

The bundles after opening are arranged on shelves at a distance of 20 cm between each bag in the tier or hanged with plastic rope. Appropriate temperature (20-30C), humidity (70-80%) and light (200 lux) with good ventilation should be maintained in the cropping room. Bags are watered twice daily depending upon the weather condition.

HARVESTING

Primordia (small eggs) appears within 4-5 days of opening the bag that came to the harvestable stage 3-4 days later. The mushrooms should be harvested when the cap begins to fold inwards. Picking is done by twisting the mushroom gently without disturbing the surrounding fruit bodies. Crop should not be watered before harvesting.

The second crop appears after 7-10 days. Hence, within a 45 days crop period, 3-4 crops are expected. With exception, under suitable growing conditions, a biological efficiency of 100% is achieved in commercial farms. Yield Per Bag : 1.5 -2.0 kg

OYSTER MUSHROOM

Commercial mushroom production requires high levels of management input and skill. A common mistake new growers make is to believe that growing mushrooms is easy. Each species requires specialized treatment to produce consistent yields of high-quality, marketable mushrooms. Another common mistake is to start too large and diversify too soon.

Trying to learn a single crop is difficult enough, and mastering several different mushroom crops at once may be impossible. Some spawn suppliers offer starter kits and instructions. Using small starter kits will allow you to gain some experience with different mushroom crops with minimum investments in time and money.

For further details contact:-

Public Relation & Media ,
Management Cell,
CAU, Imphal