Project proposal for mushroom farming

Introduction
Mushrooms have been valued throughout the world as both food and medicine for thousands of years.  They are a rich source of nutrition and form a major chunk of health foods. Fats occur in mushrooms in minor amounts, especially compared with protein and carbohydrates, and the fatty fraction consists predominantly of unsaturated fatty acids such as linoleic acid, they may be the perfect food for maintaining a healthy heart and cardiovascular system. Earlier Mushroom eating was restricted to specific regions and areas of the world but due to globalization, interaction between different cultures, growing consumerism has ensured the accessibility of Mushrooms in all areas. Mushrooms are increasingly gaining acceptance in different Cusines and in everday consumption. They have created a space in a common man’s kitchen. Also, current trend of consumption conveys the opportunity that lies in the area of mushroom exports.
The two most commonly grown species of mushroom in India are white Button mushroom and Oyster mushroom. Most of the production of white button mushroom in our country is seasonal. The cultivation is done using conventional methods. Usually, unpasteurized compost is used, hence yields are very low. However, in recent years, yield of mushroom has increased as a result of introduction of improved agronomic practices. Cultivation of the common white button mushroom requires technical skill. Apart from other factors, the system requires humidity, two different temperatures i.e. Temperature for spawn or vegetative growth (Spawn Run): 22-28⁰C, for reproductive Phase (fruit body formation): 15-18⁰, Humidity: 85-95% and enough ventilation during substrates that are sterilized are easily contaminated unless spawned under very aseptic conditions. Therefore steaming at 100⁰ C (pasteurization) is more acceptable.

  Pleurotus is the scientific name for Oyster mushroom. In many parts of India, it is known as Dhingri. This mushroom includes many species e.g. Pleurotus ostreatus, P. sajor-caju, P. florida, P. sapidus, P. flabellatus, P. eryngii and many other edible species. Mushroom growing is an occupation requiring perseverance, patience, intelligent observation and a skill that can be developed only through intelligent experience.

  Pleurotus mushroom requires a temperature of 20oC to 30oC, both for its vegetative growth (spawn run) and reproductive phase, i.e. for formation of fruit bodies. The suitable cultivation period at high altitude - 1100-1500 meters above mean sea level – is March to October, mid altitude - 600-1100 meters above mean sea level – is February to May & September to November and at Low altitude - Below 600 meters above mean sea level – is October to March.

 

Materials Required

1. Paddy Straw – Fresh golden yellow paddy straw free from moulds and properly stored in a dry place not exposed to rain.

2. Plastic Sheet of 400 gauge thickness – 1 sq. m. of plastic sheet is required for making one block.

3. Wooden Mould – Wooden Mould of 45X30X15 cms size each having no top or bottom but having a separate wooden cover 44X29 cms dimension.

4. Hand Chopper or Chaff cutter for cutting the straw.

5. Drum for boiling straw (minimum two).

6. Jute rope, coconut rope or plastic ropes

7. Gunny bags.

8. Spawn or mushroom culture– which can be obtained from the Office of the Assistant Pathologist, Mushroom Development Center for each block.

9. One sprayer.

10. Straw Storage Shed -10X8m size. 

Process:

Compost Preparation
 Agricultural by products like cereal straw (wheat, barley, paddy, oat and rice), maize stalks, hay, sugarcane bagasse or any other cellulose wastes can be used for compost preparation. Wheat straw should be freshly harvested, shining yellow in colour and should not have been exposed to rains. The straw should be in about 5-8cm long pieces, otherwise heap prepared by long straw would be less compact which may lead to improper fermentation. Conversely; too short straw makes heap too compact to allow enough oxygen to enter the centre of the heap and lead to anaerobic fermentation. Wheat straw or any of the above materials provide cellulose, hemicellulose and lignin, which are utilized by the mushroom mycelium as the carbon source. These materials also provide physical structure to the substrate needed to ensure proper aeration during composting for the build up of microflora, which is essential for the fermentation. Rice and barley straw are very soft, degrade very quickly during composting and also absorb more water as compared to wheat straw. While using these substrates, care should, therefore, be taken on the quantity of water to be used, schedule of turnings and adjustment to the rate and type of supplements. Since the byproducts used in composting do not have adequate nitrogen and other components required for the fermentation process, compounding mixture is supplemented with the nitrogen and carbohydrates, to start this process.

Spawning
 Spawning is mixing of spawn infor optimum and timely yields. Optimum dose for spawn ranges between 0.5 and 0.75% of fresh weight of compost. Lower rates result in slow spread of mycelium and chances for diseases and competitors may increase. Higher rates may increase cost of spawning and very high rate of spawn sometimes results in unusual heating of compost. The optimum temperature for growth of A. bisporus is 23⁰ (+) (–) 2⁰ C. Relative humidity in growing room should range from 85-90% during spawn-run.

Harvesting
Usually 3 to 4 days after opening the bags, mushroom primordia begin to form. Mature mushrooms become ready for harvesting in another 2 to 3 days. An average biological efficiency (fresh weight of mushrooms harvested divided by air-dry substrate weight x 100) can range between 80 to 150% and sometimes even more. To harvest the mushrooms, they are grasped by the stalk and gently twisted and pulled. A knife should not be used. The mushrooms remain fresh for up to 3 to 6 days in a refrigerator/cool place.

 

Mushroom house / rooms.

Cube preparing Room
 An ideal room should have an R.C.C. floor, well ventilated and dried. An R.C.C. platform of 2 cms. height should be constructed inside the room for placing the wooden frame, for making cube and another R.C.C. platform, according to necessity for draining of pasteurized bags of straw. Only those materials needed for cube making are to be kept inside the room. Care should be taken to allow inside the room, only persons preparing the cubes.

  Incubation Room

 A room for spawn running.
This room can be either an R.C.C. building or an Assam type room (i.e., any separate room in the house) and should be installed with shelves made of clean whole bamboo in three tiers for keeping the block. The first tier should be 100cms above the ground and the other tiers should be at least 60cms apart.

 

Cropping Room
 An ideal house/room would be an R.C.C. building installed with proper insulation and provisions for heating and cooling the rooms. However, an indigenous low cost house has been recommended using locally available materials like bamboo, thatch and mud plaster. Walls of split bamboo plastered evenly with a mixture of mud and cow dung may be made.

 In order to provide a crude insulation system, a second wall is made all around the house keeping about 15cms space between the first wall and the second. Mud plastering should be done on the outside of the outside wall. The air space in between the two walls will act as an insulator, since air is a bad conductor of heat. An even better insulation could be provided if the space between the walls is filled with well dried thatch. The floor of the house should preferably be of cement but where it is not possible, a well-beaten and plastered mud floor will suffice. However, more care will have to be taken in case of a mud floor. The roof should be made of thick thatch layers or preferably asbestos sheets. A false ceiling is essential to avoid contamination of unwanted materials from the thatch roof. Besides the front door, ventilators should also be provided from both the upper and lower sides of the front and the rear side of the room for proper exchange of air inside the room. The house/room should be installed /framed with horizontal and vertical bamboo poles required for hanging the block after the incubation period. The vertical poles can also be arranged in a 3 (three)-tier system as the incubation shelves. Poles should be preferably 60cms away from the walls and in between each row of three tiers, a minimum space of 1m should be maintained. A cropping room of 3.0 X 2.5 X 2.0 m will accommodate about 35 to 40 cubes.

 

Method
 Chop the straw either manually or mechanically into bits of 3-5cms in length and pack in gunny bags. Boil water in a drum. When the water start boiling, place the gunny bag along with the straw in the boiling water and boil as such for 15 to 20 minutes. Then remove the gunny bag from the drum and leave as such for 8 to 10 hrs. to drain the excess waters and also allow the straw to cool. Care should be taken that the bag is not open till the time of block making, as this will contaminate the boiled straw. The desirable moisture content of the straw can be tested by squeezing the straw in between the palms, and see that droplets of water do not trickle out from the straw.
Another method of pasteurization of the straw is by steaming. This method requires little modification of the drum. (Punch a small hole in the lid of the drum, and while boiling the straw, seal the surrounding of the lid with a rubber tube). The chopped straw should be previously wetted and excess water drained off. Place a few stones in the drum and pour water only at the level of the stones. Boiled the wetted straw by keeping it in a bamboo basket and place the basket over the stones inside the drum. Close the lid of the drum and seal the rim of the lid by means of a rubber tube. The steam generated from the boiled water will pass through the straw and pasteurize it. After boiling, transfer the straw into a previously sterilized gunny bag and leave it as such for 8-10 hrs. for cooling.
Take a wooden frame and place on a smooth floor. Place jute ropes, two vertically and one horizontally. Line the frame with a plastic sheet, previously sterilized by dipping in boiled water.

 

-     Fill approximately 5cms of boiled straw and compress it with the help of a wooden lid and sprinkle spawn over the whole surface.

-     After the first layer of spawning, put another 5cms of straw and again sprinkle spawn over the surface, compress it as in the first layer. In this way, continue to sprinkle spawn over the layer of straw for 4 to 6 layers till the straw is in level with the top of the frame. Only (1) one packet of spawn should be used for one cube or block.

-     The plastic sheet is now folded over the top of the frame and tied down with help of jute ropes previously placed below the plastic.

-     After tying, the frame can be removed and what is left behind is a rectangular block of straw.

-     Punch holes (2mm diameter) on all sides of the block for aeration.

-     Place the block in an incubation room, side by side in shelves in single layer only taking care that they are not place directly on the floor or on the top of each other as this will generate excess heat.

-     The temperature of the block should be maintained at 25⁰ C. This can be noted by inserting a thermometer into the holes of the block. If the temperature rises above 25⁰  C, it is advisable to aerate the room, and if the temperature falls, the room should be slowly heated up.

-     It takes 12 to15 days for the spawn to spread throughout the straw and when the entire block has been completely white, it is a sign that spawn running is over.

-     After spawn running, remove the ropes as well as the plastic sheet from the block. Tie the block vertically with coconut rope and hang it in a cropping room. From this stage onwards, the relative humidity of the room should not be less than 85%. This can be maintained by periodically spraying water on the walls and floor of the room. If it is a cemented floor, it is advisable to pour water on the floor so that water always remains on the floor. If the block shows signs of drying light, spraying can be done with the help of sprayer.

-     Within a week to 10 days, tiny pinheads will be seen on the surface of the block and these will grow into full-size mushrooms within a day or two.

-     When fruits bodies start forming, the requirement of air is increased. Therefore, once fruit bodies start forming, it is essential that there is an exchange of fresh air every 6 to 12 hrs, by opening the ventilator provided at the front and backside of the room.

-    The fruits bodies (mushrooms) are ready for picking just when the periphery of the caps starts turning upward. This will be evident as small crinkles appear on the side of the piles (cap). To harvest the mushrooms, take hold of the stripe (stalk) at the base with thumb and forefinger and with a gentle anti-clockwise twist, detach the mushroom from the straw without disturbing the straw or any small mushroom growing alongside. Do not use knife or scissors for harvesting. The block will again come to fruiting after about a week.

  Yield
Mushrooms appear in flushes. About 2 to 3 flushes may be harvested from a single cube. The yield of the first flush is more and then gradually decreases, giving a total yield of 1.5 kg to 2 kg of fresh mushroom from one cube. Then the cube is disc