शिटाके: लट्ठा या सिंथेटिक ब्लॉक

01One fungus, two production systems

Shiitake is Lentinula edodes, a wood rotting fungus. That single fact splits cultivation into two systems.

In the log system the fungus is given real hardwood. ICAR-DMR specifies broad leaved logs of 9 to 18 cm diameter from trees 15 to 20 years old, naming oak, Castanopsis, Elaeocarpus, Lithocarpus, birch and Carpinus. Sawdust spawn is driven into drilled holes and sealed.

In the synthetic block system the wood is broken down first. DMR mixes sawdust 80 kg, wheat bran 19 kg and calcium carbonate 1 kg per 100 kg, fills 1.5 to 2 kg bags and sterilises them. The fungus gets the same food in a form it can eat faster.

02Where in India each one fits

Shiitake is a cool weather crop. The DMR seasonal folder puts it in the mid hills from October to February and in the high hills from December to April, and lists it among the species for the north eastern states.

No DMR month is given for shiitake on the plains, and that absence is the answer: on the plains this crop needs a cooled room, not a season.

Logs also need something the plains rarely have: legal hardwood of the right age, shade, and water through a long wait. Blocks need an autoclave, a clean inoculation space and steady power. Pick the constraint you can actually meet.

03The numbers depend on which document you read

Shiitake is where ICAR-DMR disagrees with itself, and a grower should see it rather than be protected from it.

Yield: the shiitake folder reports 35 to 45 percent of the wet weight of the substrate. The 2011 manual, same method, reports 15 to 30 percent. That is a factor of two.

Incubation: the folder gives 60 to 80 days at 22 to 26 C; the manual's table gives 50 to 120 days at 20 to 30 C. Fruiting temperature has three published values: 12 to 25 C, 12 to 18 C and 15 to 20 C.

So publish a range, name the document, and measure your own house.

04Choosing between them

The log system is cheap in cash and expensive in time. You buy logs and spawn, then wait through a spawn run measured in seasons, with shade, watering and theft to manage. It suits hill farms with their own trees and patience.

The block system is the opposite. It needs an autoclave, heat resistant polypropylene bags, clean hands and reliable electricity, and it repays that with a defined 60 to 80 day incubation and repeated flushes on demand.

One rule holds for both. Never carry a block number into a log yard or a log number into a block room. They are different crops that happen to share a name.