Cultivating mushrooms in a hot climate is a challenge. To overcome this issue, many different strategies can be applied. One of them is the use of a mushroom strain, which can handle the high temperature. Calocybe indica, better known as the milky mushroom, is such a mushroom.
Let’s compare this mushroom with the button mushroom and the oyster mushroom. We see that each of them prefers a different temperature range. The button mushroom 13 to 19°C, the oyster mushroom 19 to 30°C, and the milky mushroom 30 to 38°C.
While these values are the general ranges, each strain has to be tested for optimum growth. When it comes to the mycelium growth rate*, it was found that the optimum temperature is around 30°C.
Using Xylose as a carbon source and yeast extract or sodium nitrate as a nitrogen source supporting a high growth rate.
Besides these factors, the pH value influences the mycelial growth rate*. Here, a pH value of 6 shows the fastest growth.
If everything is aligned, then the highest biomass production can be found after 8 days.
The cultivation of the milky mushroom is similar to the button mushroom. Meaning a casing layer is needed to initiate the primordia formation. From start to finish, it takes around 40 days.
But first things first. It could be found that wheat straw was the best substrate for fruit body production. Other suitable substrates are paddy straw and sorghum stalks.
On the other hand, sugarcane bagasse, cotton stalks, corn cobs, groundnut hulls, or coffee waste were tested with limited success. To boost the mushroom yield, several supplements like cotton cake, soybean flour, wheat bran, and others were tested. With soybean and cottonseed cake leading to the highest mushroom yield.
How did the authors do it?
The milled straw is soaked in water for 4 to 5 hours before treating it with hot water (80°C) or steaming for 45 to 60 minutes. After the treatment, the substrate is dried until a moisture content between 60 to 70% is reached.
The substrate is then filled in bags, and layer spawning with grain spawn is applied. The incubation occurs between 25 to 30°C and 80 to 85% relative humidity for 15 to 20 days. After this period, the treated casing layer (1,5 to 2 cm thick) is applied. The bags are then transferred into the grow room, where they were maintained at 30 to 35°C and relative humidity greater than 80%. A mixture of loamy soil or garden soil with sand (1:1) with 12% calcium carbonate (pH 7) was tested successfully as a casing layer.
The first flush will typically appear within 24 to 30 days after the transfer. Over the course of 40 to 45 days, three to four flushes can be harvested.
If done correctly, you will end up with a valuable mushroom in the same category as the button mushroom and the oyster mushroom.
Subbiah KA, Balan V. A Comprehensive Review of Tropical Milky White Mushroom (Calocybe indica P&C). Mycobiology. 2015;43(3):184-194. doi:10.5941/MYCO.2015.43.3.184
Mycelium biomass instead of mycelium growth