Mushroom

1. PREPARATION OF CASING MIXTURE, ITS
TYPES AND METHODS
INTRODUCTION:
Casing is the layer of peat moss or other substrate that covers
compost colonized with fungal mycelium that acts to trigger the fructification process
and as a water reservoir for the developing mushrooms. Peat casing has been shown
to be superior to other types of casing materials. Typical casing for the North American
market is sphagnum peat moss mixed with some type of buffering limestone. Harte
Peat (HP) is deep dug, mature black peat imported from Ireland. The deep dug,
mature black peat of that area is a common casing material used in the UK, and has
limited exposure in North and Latin America.
It has been reported that the milled black peats produced a cleaner
mushroom, unless the pinning occurred too deep in the casing layer. However, no
information was reported on other fresh quality characteristics and yield results varied
between experiments. Furthermore, the use of commercially prepared casing
inoculums (CI) is a common practice on farms in North America, and it has been
observed by the author at some farms, to result in faster mycelia colonization of the
casing. The objective of this research is to determine how different amounts of black
peat (HP) mixed with North American sphagnum influence mushroom yield, size and
fresh quality. It is also to determine to how a reduced CI rate with deep dug peat will
influence crop timing.
Why Casing is required ? :- Casing is helped to convert vegetative growth into
mushroom. If casing is not done then there is no formation of mushroom. If there is
some growth of mushroom then it is very less. Casing also helped to maintain proper
moisture condition in the compost.
TYPES:
Casing is a 3-4 cm thick layer of soil applied on top of spawn run compost and is a pre-requisite
for fructification in mushroom beds & is generally practiced in milky
mushroom species (Calocybe indica).
Casing materials:
Earlier sub-soil material or organic matter rich soils were used as casing in button
mushroom cultivation. Presently peat is the most desirable casing material used
worldwide with excellent mushroom yields and superior fruit body quality. However,
pest is not available in India. The other alternative recommended materials are,
● Well decomposed Farm Yard Manure (FYM) preferably two years old

2. ● Well decomposed Spent Mushroom Compost (SMC) (two years old anaerobically
decomposed)
● Composted coir pith (coir industry waste) (well decomposed & water leached)
● 1:1, 2:1 and 1:2, v/v of well decomposed FYM and SMC
● 1:1, v/v of decomposed FYM or SMC with composted coir pith
● Decomposed powdered bark of some forest trees
● Paper industry waste
● Burnt rice husk is also in use along with decomposed FYM (2:1, v/v) in seasonal
cultivation of button mushroom in Haryana and Punjab with reasonable success
COUNTRY TYPE OF CASING USED
Denmark Peat/ chalk
France Local sub-soil mixture
Holland Black peat/moss peat/moss/sand
India Farmyard manure + loam soil/CaC03;
Farmyard manure +
3 years old spent compost/CaC03
Poland Peat/Chalk
Korea Clay loam sub soil /hydrated lime
Russia Peat/chalk
Taiwan Clay loam sub soil /chalk
U.K. Moss peat/chalk
U.S.A. Local sub soil, peat/chalk
Quality of casing materials: Good casing materials should have,
● Soft texture
● Light weight
● High water holding capacity
● High porosity
● Deficient in available form of C and N
● Neutral pH (7.0 – 7.5)
● Low conductivity (400-600 μ moh)

3. METHODS OF PREPARATION
Casing treatment
Casing material should be treated properly before its application on the spawn run
compost and the steps involved are:
● A heap of casing material is made
● It is wet up to 50-60% water holding capacity
● trays are filled and shifted to pasteurization chamber
● Steam pasteurization at 60-65°C for 6-8 hours
● Auto-Cooling
Alternatively,
● a heap of casing material is made on a cemented platform
● it is wet up to 50-60% water holding capacity
● the wet casing is drenched with formalin @ 1 litre/m3 (40% formaldehyde) by
mixing with shovel
● it is covered with polythene sheet and the outer periphery is sealed thereafter by
pouring sand/soil on outside margin
● the material is kept for 24-48 hours in sun for fumigation effect
● then the cover is removed after 48 hrs and the material is exposed to open air and
sunlight by spreading over with clean tools and permitting the formalin fumes to
escape in to air for 2-3 days before it is used as casing (formalin treatment effect
decreases at low temperature due to inadequate fumigation).
METHOD:
The selected basic material for preparation of casing soil such as Farm yard manure
was obtained from Agro-farm, B.H.U. and other casing materials, coir pith, saw dust,
vermi-compost and sand were obtained from commercial outlet Varanasi. Six casing
mixture formulations and used as casing for investigations.
i.Coconut Coir pith +FYM+ Saw dust (1:1:1).
ii. Vermi compost + Saw dust +FYM+ Sand (1:1:1)
iii. Coconut Coir pith +FYM(1:1)
iv. Coconut Coir pith +Vermi compost + FYM + Saw Dust + Sand (1:1:1:1:1)

4. v. Vermi compost +FYM(1:1)
vi. Coconut Coir pith + Vermi compost + Sand (1:1:1).
First coir pith was soaked in water for 24 hours before mixing.
Initially individual casing materials , FYM, Sawdust, coconut coir pith, sand and vermi
compost were sterilized in a horizontal autoclave at a temperature of 100ºC for 20
minutes. Sterilized casing materials were taken out to cool down at normal room
temperature by spreading on well cleaned cemented floor. After that all the casing
materials are mixed by the required proportions.
CASING APPLICATION:
 the fully spawn run bag is unfolded and the top surface is made even by gentle
pressing with hands
 Before casing the newspaper sheet or polythene sheet is removed in general
the thickness of casing 1-1.5”.
 Casing should be done after sowing of 15-20 days when the mushroom
mycelium is spread completely.
 Light spray of water on spawn run compost
 Application of 4-5 cm thick layer of casing uniformly using iron rings of 4 cm
height or wooden blocks
 Water spray in installments immediately after casing application.
PRECAUTIONS:
● Casing material should not be sieved but used as such with clumps, which permits
more air spaces in casing
● Top casing surface should have small mounts and valleys
● Care should be taken to prevent re-infection of the casing materials
● Store casing material in a sterilized /clean room before use in polythene bags or
synthetic cloth bags
● Apply water to casing in a few installments so that water does not run into spawn
run compost.
PREVENTION OF CONTAMINATION OF GREEN MOULD TO THE CASING MIXTURE:
 Green mould easily contaminates to the growing chamber.
 The following control measures can be undertaken:
 HEAT METHOD:-
I. Frame a spoon & heat it.
II. Quickly open the chamber and scoop out with the spoon and again close the
chamber lid.
III. Re-heat the spoon and repeat the process.

5.  CHEMICAL METHOD:-
Mix one part of peroxide + 20 parts of water
 Sterilisation of casing material at 79°F should be done to avoid future
contaminations.
YIELD COMPARISON OF DIFFERENT FLUSHES:
It is evident that the highest yield of flush obtained from the
casing mixture of CCP+VC + FYM + SD + sand (i.e. 1199.99 g) followed by CCP + FYM+
SD,VC+ FYM,VC+ SD +FYM+ Sand and CCP+ VC + Sand (i.e. 1033.67 g, 886.00 g, 883.00
g and 833.00 g) respectively. The casing mixture CCP + VC + FYM + SD + Sand and CCP +
FYM showed the significant difference. Casing mixture CCP + VC + FYM + SD + Sand
showed the highest yield whereas CCP + FYM (i.e. 753 g) showed lowest yield in the
harvesting of second flush. The result indicated that the significant difference between
the casing VC + FYM and CCP+VC + FYM + SD + Sand and CCP+FYM+ SD,CCP+VC+ Sand.
{ FYM } { Coconut coir pith } { Vermi compost }
{ Spent mushroom Manure } { Saw dust } ( Sand }
{ Paper Industry wastes }
[ MATERIALS USED FOR PREPARATION OF CASING MIXTURE ]

6. [ CASING MIXTURE ]
[ LAYERING OF CASING MIXTURE ] [ FUNGAL GROWTH ON CASING ]
[PRESERVATION OF CASING MATERIAL] [GREEN MOULD GROWTH ON CASING]
[ PRE-TREATMENT OF FORMALIN ] [ HEALTHY MUSHROOM GROWTH ]