Casing in mushroom farming

Casing in Mushroom Farming

What is casing?

Casing means covering the compost with a thin layer of (3-5 cm thick) soil or soil- like material after the spawn running is over.

Need of Casing in mushroom farming ?

Casing soil can hold water for longer periods and so prevents drying of spawned compost. It provides conditions that stop the vegetative growth and encourage the formation of fruit bodies in mushrooms. It avoids sudden changes in temperature, (2 thereby encouraging fruiting. Casing soil also gives physical support to developing mushrooms.

Precautions while casing in mushroom farming

(i) Casing material should have all the desired qualities.
(ii) Casing material should be properly sterilized and should be made free from formaldehyde fumes before application.
iii) Casing material should be very fine and should not have big lumps.
(iv) Casing should be uniformly spread.
(v) If casing is dry, water should be sprayed with a sprayer.
(vi) Water should be sprayed over the walls and floor of the mushroom house to maintain the desired humidity.

Casing material

(i) Loam soil
(ii) Farmyard manure (well decomposed)
(iii) Clay soil
(iv) Sand
(v) Spent compost (at least 2 years old).
(vi) Formalin
(vii) Buckets
(viii) Sieve
(ix) Polythene sheet
(x) Spade
(xi) Spray pump
(xii) Maximum – minimum and dry-wet bulb thermometers.

Procedure of casing in mushroom farming

Prepare the casing material by mixing any one of the combinations given below:

  1. Clay loam soil + Farmyard Manure ( 1:1)
  2. Clay loam soil + Farmyard Manure + Sand (2:1:1)
  3. Farmyard Manure + Sand (1:1)
  4. Spent compost + Farmyard Manure + Clay loam soil (2:1:1)
  • The casing material so prepared should have qualities such as good water holding capacity, porous, absence of undecomposed material and having pH of 7-7.5
  • Check the pH of the mixture. If it is less than 7.5, add some chalk powder to raise the pH.
  • Sieve the material through a mesh to remove lumps.
  • Spread the polythene sheet over the floor and put the casing material on it.
  • Prepare Formalin solution by mixing 500 ml formaldehyde in 10 litres ( of water. This solution is sufficient for 1 cubic meter of casing material.
  • Drench the casing material with this ( solution and cover it properly with a polythene sheet in such a way that no formalin vapours could come out. Leave the casing material as such for ( 48 hours.
  • Check the moisture of casing by palm ( test before applying on the bed.
  • Remove polythene sheet and rake casing material repeatedly to remove traces of formalin. It takes about a week to make the soil free from formaldehyde fumes.
  • Check the moisture of casing soil by palm test before applying on the bed
  • Remove the newspaper sheet (in case of tray/shelves) unfold the polythene cover (in case of bags).
  • Press the compost to make a uniform surface.
  • Spread the casing material over the compost. Keep the thickness of casing material at 3-4 cm.
  • Maintain temperature at 24-26°C and relative humidity at 80-85%. It takes about 7 to 10 days for the mycelium to reach the surface of the casing layer.