Mushroom Culture

Precautions, Characters and Storage of Spawn

PRECAUTIONS TO BE OBSERVED :

• Avoid overcooking of grains as it may lead to splitting of grains.
• Don’t dry the cooked grains on the floor. Always dry over hessian cloth spread on a raised platform or on a wire mesh tray .
• Use only recommended dose of CaCO₃ for mixing with the cooked grains. Mixing over dose reduces the fungal growth in the inoculated bags.
• Avoid further sub culturing of the second generation spawn. This leads to loss of vigour of the spawn which again leads to reduced yield. Repeated sub culturing leads to complete loss of vigour. In such cases the fungal growth may be noted in the compost beds but buttoning may be completely arrested.

CHARACTERS OF GOOD SPAWN :

• There should be proper coating of the mycelium around every grain used as substrate for spawn.
• The growth of the mycelium in the spawn bottles should not be cottony or fluffy type but it should be strandy .
• The growth of fresh spawn is more or less white. Brown coloration develops as spawn grows.
• There should not be any slimy growth in the spawn bottles which is an indication of bacterial contamination.
• There should not be any greenish or blackish spot in the spawn bottles. Such type of spots indicate that the spawn is contaminated with moulds.

Precautions during transit of spawn:

• Care must be taken during transit that spawn bottles are not exposed to bright sun light and a temperature higher than 30^oC. To avoid such risks , spawn bottles are packed in thermocol boxes containing ice cubes or should be transported during night hours when it is cool.

Storage of spawn:

• Fresh spawn should always be used for seeding and its long time storage should generally be avoided. However, the spawn can be stored at 4-6ºC for one month in case it is not used due to certain unavoidable circumstances.

Fig. 3.3 Workers busy in mixing and filling of substratum for spawn preparation



Fig. 3.4 & 3.5 Sterilized grain bags kept for incubation on shelves in an incubation room at 25 ± 1ºC after inoculation from the Master Culture bags


Fig. 3.6 A close view of PP bag containing grain substrate kept for incubation just after inoculation from Master Culture.
Fig. 3.7 A close view of the completely spread spawn bag after 20 days of incubation – ready for use.