Add-On Course

MUSHROOM CULTIVATION

Course code: CCBS01 Academic Year: 2023-24

Course Credits: 02 Course Duration: 1 Month (24 Hours)

Eligibility: UG level Type: Four Quadrant Approach

Department: Botany Session : I

Course Coordinator: Dr. Amanulla Khan Content Writer: Dr. Amanulla Khan

Course Objectives:

Ø Enable the students to identify edible and poisonous mushrooms

Ø Provide hands on training for the preparation of bed for mushroom cultivation and spawn production

Ø Give the students exposure to the experiences of experts and functioning mushroom farms

Ø Help the students to learn a means of self employment and income generation

Course outcome:

By successfully completing the course, students will be able to:

Ø Identify edible types of mushroom.

Ø Gain the knowledge of cultivation of different types of edible mushrooms and spawn production.

Ø Manage the diseases and pests of mushrooms.

Ø Learn a means of self-employment and income generation.

Four Quadrant (Q1-4) :

Q1: Video lecture or physical classes.

Q2: Study material that can be downloaded/printed

Q3: Self-Assessment tests through tests or quizzes and

Q4: An online discussion forum for clearing the doubts.

Scope

Mushrooms are used extensively in cooking, in many cuisines

❖ Mushrooms are a rich source of various antioxidants including Vitamin C, selenium, glutathione, and choline.

❖ It is also an excellent source of protein, fiber, and vitamin D. Thus the demand for mushroom is increasing steadily.

Opportunities

Mushroom farming is one of the most profitable agri-business that can be started with lesser investment and space.

Quadrant 1: Q1: Video lecture (Online)

E-Content

Importance & History

Importance:

Mushrooms are being used as food since time immemorial. These have been considered as the delicacy. From the nutrition point of view mushrooms are placed between meat and vegetables.
These are rich in protein, carbohydrate and vitamins. Mushrooms are low in caloric value and hence are recommended for heart and diabetic patients. They are rich in proteins as compared to cereals, fruits and vegetables. In addition to proteins (3.7 %), they also contain carbohydrate (2.4 %), fat (0.4%), minerals (0.6 %) and water (91%) on fresh weight basis. Mushrooms contain all the essential nine amino acids required for human growth. Mushrooms are excellent source of thiamine (vitamin-B1), riboflavin ( B2), niacin, pantothenic acid, biotin, folic acid, vitamin C, D, A and K which are retained even after cooking. Since mushrooms possess low caloric value, high protein, high fibre content and high K: Na ratio, they are ideally suited for diabetic and hypertension patients. They are also reported to possess anticancer activities.
India is primarily agriculture based country blessed with a varied agro-climate, abundance of agricultural waste and manpower, making it most suitable for cultivation of all types of temperate, subtropical and tropical mushrooms. It can profitably be started by landless farmers, unemployed youths and other entrepreneurs. It requires less land as compared to other agricultural crops and is basically an indoor activity. These are the ideal tools for recycling the agricultural wastes which otherwise may pose problem of disposal and atmospheric pollution.
Therefore, mushroom cultivation is not only of economic importance but also has important role to play in integrated rural development programme by increasing income and self employment opportunities for village youths, woman folk and housewives to make them financially independent.

History:

A. Button mushroom

1630: Cultivation of white button mushroom started first in France in the open on ridges made out of horse dung manure.
1707: Tournefort at Royal Academy of Science, France, mentioned about compost preparation and mushroom cultivation.
1731: French method of cultivation was introduced into England by Miller.
1779: Abercrombie described a method of composting stable horse manure in stacks.
1831: Callow grew mushroom in cropping houses warmed by fire heat and got fairly good yield (1.5 lbs/sq.ft)
1893: Costanitin pointed out that the incidence of diseases made constant changing of growing area necessary.
1902: Ferguson published details of spore germination and growing of mycelium.
1905: Duggar succeeded in making mycelium cultures from the tissue of mushroom caps.
1929: Lambert discovered that spawn could also be prepared from single spore cultures.
1937: Sinden found that about one third of monospore cultures of A.bisporus he prepared were incapable of producing fruit bodies.
1950: Sinden and Hauser introduced “Short Method ” of composting.
1973: The first strain of A.bitorquis introduced commercially by a French firm Somycel as strain No. 2017 and later by Le Lion

B. Oyster mushroom:

1917: Falck described the first successful cultivation of Pleurotus ostreatus.
1951: Lowhag was the first to grow Pleurotus on sawdust mixtures.
1962: Bano and Srivastava reported mass production on straw-based substrates and their work paved the way for large scale commercial exploitation.

History of Mushroom Cultivation in India

Cultivation of edible mushrooms in India is of recent origin, though methods of cultivation for some were known for many years. The important historical developments in the cultivation of edible mushrooms are as below:

1886: Some of specimens of mushrooms were grown by N.W. Newton and exhibited at the annual show of Agriculture, Horticulture Society of India.
1896-97: Dr. B.C. Roy of the Calcutta Medical College carried out chemical analysis of the local mushrooms prevalent in caves or mines.
1908: A thorough search of edible mushroom was initiated by Sir David Pain.
1921: Bose was successful in culturing two agarics on a sterilized dung medium, details of which were published in the Indian Science Congress held at Nagpur during 1926.
1939-45: Attempts on experimental cultivation of paddy straw mushroom (Volvariella) was first undertaken by the Department of Agriculture, Madras.
1941: Padwick reported successful cultivation of Agaricus bisporus from various countries but without much success in India.
1943: Thomas et al. gave the details of cultivation of paddy straw mushroom (V. diplasia) in Madras.
1947: Asthana reported better yields of paddy straw mushroom by adding red powdered dal to the beds. He suggested April-June as the most suitable period for cultivating this mushroom in central Provinces and also carried out the chemical analysis of this mushroom.
1961: A scheme entitled “Development of mushroom cultivation in Himachal Pradesh” was started at Solan by the H.P. State Govt. in collaboration with I.C.A.R. This was the first serious attempt on cultivation of Agaricus bisporus in the country.
1962: Bano et al. obtained increased yield of Pleurotus on paddy straw.
1964: Cultivation of Agaricus bisporus on experimental basis was started by CSIR and State Govt. at Srinagar in J&K.
1965: Dr. E.F.K. Mantel, F.A.O., Mushroom Expert, guided and assisted Department of Agriculture for construction of modern spawn laboratory and a fully air conditioned mushroom house. Research on evaluation of different strains and use of various agricultural wastes, organic manures and fertilizers for preparing synthetic compost were undertaken. Dr. Mantel’s consultancy concluded after a period of 7 years.
1974: Dr.W.A. Hayes, F.A.O., Mushroom Expert, guided further in improving the method of compost preparation, pasteurization and management of important parameters in the mushroom house. New compost formulations, casing materials and important parameters like nitrogen content in the compost, moisture in the casing mixture, air movements and maintenance of proper environmental factors were also standardized which raised the mushroom yields from 7 to 14 kg/m².
1977: A 1.27 crore, Mushroom Development Project was launched under U.N.D.P by the Department of Horticulture (H.P) wherein the services of Mr. James Tunney were made available. He got a bulk pasteurization chamber constructed and made available readymade compost and casing to the growers of H.P. The U.N.D.P. Project was concluded during 1982 and since then the Department of Horticulture (H.P) is running the project.
1982: The Indian Council of Agricultural Research (ICAR) sanctioned the creation of National Centre for Mushroom Research and Training (NCMRT) during VIth plan on October 23, 1982 with the objectives of conducting research on mushroom production, preservation and utilization and to impart training to scientists, teachers, extension workers and interested growers.
1983: All India Coordinated Project on Mushroom (AICRPM) was initiated during VIth Five-Year Plan on 01.04.1983 with its headquarter at National Research Centre for Mushroom Presently known as Directorate of Mushrooms.
Presently there are ten co-ordinating and one co-operating centres working under AICRPM located in 11 states. Of these,nine centres are based at State Agricultural Universities, while two at the ICAR institutes.

Equipments & Collection

The Equipments and Tools Required:

Ice boxes, Cutting knives, blades, rubber gloves, scissors, paper bags, polythene bags, paper napkin, old newspaper pieces, blotting paper pieces, field guide book on mushrooms, umbrella, torch, digital camera, an altimeter, a notebook and pen ,collecting baskets, loose wearing with a hat and hunter shoes.

How to Collect Wild Fungi from forests?

Different types of mushrooms appear in meadows , fields or forests just after the first showers in the rainy season The following points should be taken care while collecting wild fungi during rainy season :

The colour, shape, size and the habitat of each collection should be noted .
Attempt should be made to compare the morphological characters with the ones given in the guide book.
Do not touch the fruiting body and never try to find out its taste in a hurry.Take photographs of the mushrooms when still in the soil.
Fruit body found should first be examined carefully.
The fungi should be carefully cut or dug up with the help of a knife or hand digging tool and arranged in a single layer at the bottom of the basket.
Collected fungi should be handled as little as possible and not bruised or crushed.
Though fungi such as many polypores and hydnums do not suffer much from handling , hence these should be wrapped in paper and packed more closely.
The locality and date, also other evanescent characters, such as a distinctive smell , change of colour when gently touched or bruised and so on , should be noted .
For any unknown species, especially of the gill- fungi, a spore-print should be obtained . This is done by gently removing the stem from cap, laying the cap , gills downwards on a sheet of white paper and leaving it for some hours or overnight.
The spore- powder deposited gives the colour of the spores , which is important for identification purposes.
Since fleshy fungi can not be preserved in their natural form and colour , students should make coloured drawings that will provide permanent records.

Spawn and its Production

What is Spawn?

In dictionary term “ spawn '' actually refers to the fingerlings of fish, but here spawn means the vegetative mycelial network of a mushroom developed after the germination of one or more than one fungal spore (s) grown on a convenient medium. It comprises of the mycelial network along with a supporting medium which provides nutrition to the fungus for its growth and development.

SPAWN PRODUCTION OF MUSHROOMS

Raising or procurement of Pure culture of mushroom.

As already discussed in the earlier lesson,the pure culture of a fungus can be raised either by the spore print technique or the tissue culture technique. Once pure culture of a particular mushroom is established or procured from some reliable source, the process of production of mushroom spawn involves the following steps :

1. PREPARATION OF MASTER / STOCK CULTURE:

Preparation of master culture or mother spawn is carried out under completely sterile conditions. Pure culture raised either from tissue or spores is inoculated in a suitable substratum (wheat, sorghum or rye) which provides food to the mycelium. Ten kg. of wheat grains are boiled in 15 litres of water for 20 minutes. Water is then drained off and the grains are put over the sieve or on a wire mesh tray for 8-10 hours to dry or remove excess of water. Grains are now mixed with gypsum (calcium sulphate) and chalk powder (calcium carbonate) at the rate of 2% and 0.5%, respectively on dry weight basis. 10 Kg of dry wheat grains will require about 200g gypsum and 50g chalk powder. This will help to check the pH of the medium and also prevent sticking of grains with one another. The grains are filled into half or one litre glucose bottles or PP bags which are plugged with non- absorbent cotton and sterilized at 22 lb p.s.i pressure for 1.5-2 hours. Sterilized bottles are allowed to cool down overnight. Next day bottles are inoculated with the bits of agar medium colonized with the mycelium of pure culture. Inoculated bottles are incubated at 25± 1ºC. After 7 days of inoculation, bottles are shaken vigorously so that mycelial threads are broken and become well mixed with the grains. Two week after inoculation, the bottles are ready as stock culture for further multiplication of spawn. One bottle of stock culture or master culture or mother spawn is sufficient to multiply 30-40 grain bottles or pp bags .

2. MULTIPLICATION OF SPAWN FROM STOCK / MASTER CULTURE

Master spawn or master culture bottles / bags are further used for inoculation of large number of other grain bags / bottles prepared by the same technique and resultant is the commercial spawn. Generally few mycelial coated grains from one master culture bottle / bag will be inoculated into 30 – 40 grain bags aseptically in front of the HEPA ( High Efficiency Particulate Air ) filters of a Laminar flow and then incubated in a room at 25 ± 1 ° C for12-15 days.The commercial spawn thus prepared is used for inoculating the compost beds as seed .

White Button Mushroom

1. WHITE BUTTON MUSHROOM ( Agaricus brunnescens Peck.)

White variety -------A. brunnescens var. albidus

Brown variety ------ A. brunnescens var. bisporus

Cream variety ------A. brunnescens var. avellaneous

This mushroom is commonly found growing in soil enriched with cow dung, horse dung or forest litters in temperate climate. A most widely cultivated mushroom in the world. The name Agaricus originated from the greek word Agaricon—with a Scythian people called Agari who were knowing the use of medicinal plants and employed a fungus called “ agaricum ”, probably a polypore in the genus Fomes . Brunnescens means brown in latin, as the colour changes to brownish after bruising . It is also called as A. bisporus because of the two spored basidium.

Description:

White button mushroom (A . brunnescens) is thick fleshed , robust with thin gills on the underside of the cap that are pinkish white in early age and darkening to chocolate brown at maturity. Cap is whitish, cream coloured or brown. Cap surface smooth to appressed and dry. The stem is short, thick adorned with a persistent membranous annulus from a well developed partial veil. Spores chocolate brown in mass, basidia bipolar ( two spored ) forming diploid spores, secondarily homothallic, clamp connection absent. Mating of compatible dikaryons typically results in development of strain which is more vigorous and high yielding. Mycelium is dingy white, moderately rhizomorphic.

White button mushroom (A. bisporus) cultivation

Nutritional Value : Button mushrooms contain 90-92 % water and only 8-9% dry matter. Also contains 3.92 % protein, 1.09 % crude fibre, 1.25 % ash, 0.19 % fat and 56 mg. niacin / 100 g weight.

Spawn production : The Master culture and spawn are produced on wheat or rye grains buffered with Calcium carbonate and Calcium sulphate.

Cultivation : Button mushrooms, including the high temperature species A. bitorquis ( 20 – 25° C ) require well decomposed manure for its cultivation which is prepared by long method or the pasteurization method of composting by mixing wheat or rye straw with supplements like chicken manure, cotton seed cake, wheat bran, urea, gypsum etc. The prepared compost is filled in polythene bags or wooden trays, spawned by through or layer spawning method and incubated in a closed room at 25 ± 1ºC and 90 % relative humidity with high concentration of carbon dioxide (5,000 to 10,000 ppm ) in the absence of light . After 10 -15 days of incubation, when mycelium of spawn completely impregnates the compost, it is covered with 1-1.5 inch layer of sterilized wet casing mixture containing FYM alone or FYM + spent compost or FYM + forest soil or soil + sand + coco coir or sand + soil + paddy ash or peat soil . The mycelium of button mushroom will not fructify unless it is covered on the surface with a layer of fine casing mixture.

Cultivation Technology of Paddy Straw Mushroom (Volvariellavolvacea, V.diplasia)

a) Nutritional value:

Paddy straw mushrooms are very tasty and good flavoured. These are known to be very nutritious having 26-30 % protein, 9-12 % fibre , 9-13 % ash , 45- 50 % carbohydrate and rich in minerals , vitamins C and B.

b) Spawn production:

Spawn is produced either in rice straw or rye , sorghum , millet or wheat grains . The mycelium in spawn bottle is fast growing, rhizomorphic to cottony, colour is typically whitish to greyish white.

c) Cultivation:

Commonly cultivated varieties of paddy straw mushroom (Volvariella) are V. volvacea ( Bull ex Fr. ) Singer, V. diplasia (Berk and Br.) Singer and V. esculenta ( Mass) Singer . This mushroom is commonly cultivated on paddy straw in the open as well as inside a mushroom house. Open cultivation method is very common among marginal and small growers.

1. Open air cultivation:

a) Preparation of beds and spawning:

In this method 100X60cm size foundation beds of 15-20 cm height are made with the help of bricks or mud under the shade, to save them from rains or direct sunlight. Paddy straw bundles of 7-8 cm diameter are made by tying them at one end. The length of these bundles is kept between 70-80 cm. These bundles are soaked in water for 16-18 hours in a water tank. For chemical sterilization of the straw, bavistin 7g and formalin 125 ml can be added in 100 litre of water. After dipping bundles in water, cover the water tank with the polythene sheet. Later ,bundles are taken out and excess water allowed to drain off on a cemented floor.

A bamboo frame exactly of the size of the bed on foundation is kept on the floor. Now place four bundles of paddy straw (water soaked) side by side over bamboo frame, keeping tied end in one direction. Place another set of four bundles over it but this time tied end in opposite direction. In this way 8 bundles make the first layer of bundles. Scatter the grain spawn about 8-12cm from the edges of the layer bundles. Spread the spawn along with powdered arhar pulse or gram flour. Wheat bran or rice bran can also be added. Place the second row of the bundles and spawn on it as described earlier. Likewise third and fourth layer of bundles are also placed and spawned. Finally, the square shaped bed is covered with a transparent polythene sheet and bed temperature of 32 ± 1 ° C is maintained . Within 7-8 days mushroom mycelium permeates the straw completely and at this stage the plastic cover is removed. If the surface of the bed appears to be dry, spray water with the help of water sprayer at least once in a day.

b) Fruiting and harvesting:

Mushroom fruiting occurs nearly 18-20 days after spawning at favourable moisture and temperature conditions .Fruiting continues for another 10-12 days. In paddy straw alone , yield of 12-14 kg /100 kg of wet substrate can be obtained.
Harvesting of mushroom is done when volva just breaks and mushroom exposes from inside. In any case mushroom should be harvested before it opens. Paddy straw mushrooms are very delicate in nature and can be stored under refrigerated condition for 2-3 days only. Drying of mushroom can be done under shade or in sunlight.

Composting

Composting: Compost can be prepared by two methods :

Long method of composting
Short or pasteurization method of composting

1. Long Method of Composting:

A) Formula developed by Mushroom Research Laboratory, Solan

Wheat straw ----------- 1,000 Kg or

Paddy straw ----------- 1,250 Kg

CAN ------------- 30 Kg

Super phosphate ------- 25 Kg

Urea -------- 12 Kg

Muriate of Potash ---- - 10 Kg

Wheat bran ---------- 100 Kg

Molasses ------------ 16.6 litres

Gypsum ------------- 100 Kg

Folidol dust ------------ 750 g

B) Formula developed by IIHR, Bangalore

Paddy straw ---------- 150 Kg

Maize stalks ---------- 150 Kg

Ammonium sulphate ---- 9Kg

Super phosphate ------- 9 Kg

Urea --------- 4 Kg

Rice bran ------------- 50 Kg

Cotton seed meal ------ 15 Kg

Gypsum ---------------- 12 Kg

Calcium carbonate ----- 10 Kg

Long method of composting was first advocated in India by Mantel et al. (1972). To begin with the composting process, clean the composting yard thoroughly and wash it with 2% formalin solution. Wheat straw or any other base material to be used is spread in a thin layer of 8-10 inches thickness over the floor of composting yard. Sprinkle water over the straw with a hose pipe and wetting of straw is done repeatedly at least 2-3 times a day for 2 days with the help of forks. Before mixing with the wet wheat straw, the ingredients like urea, CAN, super phosphate,wheat bran etc. (except insecticides and gypsum) are thoroughly mixed , wetted with water and then covered with damp gunny bags 14-16 hours before use.

Preparation :

Day 0: On this day fertilizer mixtures are spread evenly on the pre- wetted straw. This mixture is made into a stack with the help of wooden boards or pile formers . Dimensions of pile should be 5x5x adjustable length. Height and width of the pile should not be more than this otherwise pile may become too hot due to high temperature and the anaerobic conditions may prevail in the centre which may not yield good quality compost.
Day 1-5: Start monitoring the temperature of the heap. Temperature should start rising after 24-48 hours of stacking and reach 65-70°C in central core. If the moisture of the mixture is less, than water can be sprayed. Watering should be stopped as soon as leaching starts from the bottom of pile. If water starts leaching in large quantity then it should be collected in a guddy pit and put on the top of the pile.

Day 6: First turning: On this day first turning is given to the stack. The aim of turning is that every portion of the pile gets equal aeration and water for proper decomposition of the base material. The correct method of turning is as follows :
Remove about 1 feet compost from top and side of pile, shake thoroughly so that excess of ammonia is released and it is exposed to the air properly, and keep this portion on one side. Now remove the central and bottom portion of the pile, shake these with the forks and keep them separately. Now the new pile is made with the help of boards keeping the central portion at the bottom. Top and sides portion should be placed at the centre while bottom part comes on the top and sides. During pile formation watering is done ,if required.
Day- 10: 2nd turning. Break open the stack, remove it as indicated above, water may be added if required and restack it .
Day-13: 3rd turning: Restack and add required quantity of gypsum
Day-16: 4th turning
Day-19:5th turning
Day-22:6th turning
Day-25:7th turning : add required quantity of Folidol dust
Day 28: Filling day.Break open the pile and check for the smell of ammonia , if it still persists, give an additional turning after 3 days. This way compost is prepared by long method in 28-30 days.

2. Short or Pasteurization Method of Composting :

Formula given by Mushroom Research Laboratory , Solan

Wheat straw ( chopped ) ------ 1000 Kg

Chicken manure ------------ 400 Kg

Brewer’s grain or wheat bran -- 72 Kg

Urea --------------- 14.5 Kg

Gypsum --------------- 30 Kg.

This is done in two phases. Phase- I is done in the composting yard while phase II, inside a closed chamber called pasteurization chamber or tunnel (bulk chamber) with the help of aerated steam for pasteurization and conditioning of compost.
Phase I: Phase - I involves pre-wetting of straw and mixing of ingredients in the straw as in long method. But in this case turning is given after every 48 hours (2nd day). During third turning or on 6th day total amount of gypsum is added in the compost. After 4th turning on 8th day, the compost is filled in pasteurization tunnel on 10th day.

Phase –I of composting ------ first turning after mixing urea and pile being formed with the help of a Pile Former (1) third turning being given by breaking the heap and adding water (2), picture of a front loader tractor (3) and compost turning machine (4) for mechanical composting

Phase II: (Pasteurization )

After filling partially decomposed compost in pasteurization chamber or tunnel, a temperature of 48-50 ° C is maintained for next 2-3 days by circulating the inside air. Then with the introduction of steam, temperature of the tunnel is raised to 58-60ºC for 6 hours.
Fresh air is then allowed to enter the room so as to bring down the temperature to 50-52°C which is maintained for 3-4 days for conditioning. When ammonia smell gets eliminated, then fresh air is introduced in the tunnel to cool down the temperature of the compost to 25-28°C. By pasteurization method, compost is prepared within 18-20 days.

Diseases and mould problems in mushroom cultivation and their management

A. FUNGAL COMPETITORS OR INDICATOR MOULDS OR WEED FUNGI:

While some fungi, bacteria and viruses directly attack mushroom fruit bodies causing pathogenic diseases, a large number of harmful fungi are encountered in compost and casing which may not be directly pathogenic , but may cause harm to the crop during spawn run and cropping stages. These are known as Competitor moulds as they compete for food with mushroom mycelium or " Indicator moulds " as presence of each mould indicates some deficiency or fault in compost or casing and also called as " Weed fungi " because of their undesirable occurrence.

The following are some of the established vectors of contamination :

Air
The mycelium or spawn
The substrate or the compost
Casing materials
Growers or workers hands
Equipments, containers and tools
Water
Insects and animals.

(1) Conidiophores and conidia of Aspergillus sp

(2) Torula sp

(3) that occurs frequently in mushroom compost

1) GREENMOULD:

It is the most common mould and found in beds of every type of mushroom cultivated. Mainly three types of fungi Trichoderma , Penicillium and Aspergillus have been found to be associated.

Symptomatology:

Green patches appear in compost , spawn , on casing surface and also sometime on the mushroom surface, engulfing the fruit bodies with its white and greenish mycelium causing Trichoderma blotch disease.. The pathogenic species of Trichoderma like Trichoderma harzianum, infect the fruit body, otherwise green moulds try to spread rapidly and cover entire compost structure depending upon the quality of compost and environmental conditions .The appearance of green mould indicates poor quality compost, unhygienic cropping conditions and low compost pH .

Causal organism:

The most common species of Trichoderma appearing in mushroom beds are Trichoderma viride , T. koningi , T. harzianum . T. hamatum and several species of Aspergillus and Penicillium. Rifai in 1969 revised and has proposed nine different species of Trichoderma .Trichoderma viride is the most commonly occurring weed mould whereas ,T. koningi and T. harzianum have been reported to be competitors as well as pathogenic to button mushroom producing blotch symptoms on fruit bodies.

Epidemiology:

The fungus mainly enters spawn laboratory or the cropping room through air, dust particles, contaminated overall or hands, infected spawn, contaminated equipments and machinery; vectors like mites , mushroom flies etc. The compost quality mainly determines the establishment and growth of this mould. Poor quality compost prepared under unhygienic conditions, high moisture conten , use of straw having short texture for composting, highly pressed compost heap during composting, low pH of compost, high humidity etc; are the predisposing factors for the growth and development of the fungus.

Control methods or management:

There should be complete hygiene inside and around the mushroom farm, compost ingredients should never come in contact with the soil particles; proper turnings, conditioning and pasteurization of compost is a must, use of foot dips at the doors of cropping rooms, lesser use of formalin sprays, proper cleaning of equipments and tools, use of clean and washed clothes, early removal of infected bags etc; are some of the recommended methods of control.Spray of some fungicides like 0.1 % carbendazim, thiabendazole ,mancozeb ( 0.2 % ) etc. on cropping beds have been found effective in controlling the mould.

2) OLIVE GREEN MOULD:

During spawn run stage, small military green coloured cockle burrs appear sometimes in the compost which is easily recognizable and that affect the yield . The occurrence of these moulds were first reported in India by Gupta et al ,1975 and Thapa et al, 1979.

Symptoms:

The initial signs of fungus consists of appearance of greyish - white aerial mycelial growth in the compost just after spawning confused with the growth of mushroom mycelium . These mycelial structures later on give rise to small, round , military green or grey green cockle burr ( 1 / 16 inch diameter ) structure in the compost strictly adhering to the straw.

Causal Organism:

Mainly two fungi Chaetomium olivaceum and C. globosum have been observed occurring in mushroom beds.

Epidemiology:

The spores of Chaetomium are already present in the compost or they may come through air and casing materials . It has been found that during compost pasteurization process , mainly at peak heat or kill stage ( 59-60 º c ) , it should never be processed in the absence of fresh air or Oxygen . Absence of aeration during peak heat or kill may lead to compost damage which favours the appearance and development of these fungi.

Control Methods:

In case of pasteurization process , the peak heat or kill should be done at 58 – 59 ºC for 3-4 hours in the presence of fresh air or aerated steam . Carbendazim ( 0,05 % ) and Dithane Z-78 (.2 % ) have been found to be effective in controlling the mould only in case of minor damage of the compost.

3) BROWN PLASTER MOULD:

The mould appears as white mycelial growth on the surface of compost during spawn run stage and also on the casing surface slowly changing colour from white to light brown to cinnamon brown and finally changed to rusty in appearance.

Causal Organism:

Papulospora byssina is the fungus responsible for causing brown plaster mould . The mycelium is initially white which later turns brownish , septate , producing clusters of brown coloured , spherical bulbils.

Epidemiology:

The fungus mainly enters through air, spent compost, casing material or the containers as well as the workers’ hands. But a wet, soggy and improperly pasteurized , bad quality compost favours its rapid growth . It commonly occurs on compost prepared by long method of composting .A greasy and wet compost is vulnerable to infection.

Control methods:

Good hygiene and preparation of good quality compost removes the chances of its appearance and further development . Addition of good quality gypsum is recommended and proper turning of compost with attentive pasteurization procedures help in preventing this mould. Sometimes spray of some fungicides like carbendazim , TPM , TBZ ( 0.05 % ) and Dithane Z-78 or Dithane M-45 ( .025 % ) have been recommended for its control .