678 Commercial Mushroom Cultivation. [Oct. 



COMMERCIAL MUSHROOM 

 CULTIVATION. 



Hitherto the cultivation of mushrooms has been considered 

 highly speculative, but recent experience and the knowledge 

 gained by research now make it possible to grow fair crops with 

 a greater element of certainty. Even the most experienced 

 growers, however, are liable to failure, and the beginner should 

 not be tempted by a small initial success to embark on mushroom 

 growing on a large scale. Nevertheless, mushroom growing 

 within small limits may be made a useful adjunct to a nursery or 

 market garden, and even if failure should result, the manure used 

 may still be turned to account for other crops, so that the only 

 loss is that of the cost of labour and spawn. 



There are three stages in the life of a mushroom : (1) spores, 

 (2) mycelium or spawn, (3) mushroom. The spores may be seen 

 with the microscope on the under side of the fully developed 

 mushroom. These, when matured, fall off and are carried away 

 by the wind. Under suitable conditions the spores develop into 

 spawn in some favourable medium such as stable manure. In 

 making ordinary commercial spawn, cakes measuring 9 in. by 

 6 in. by 4 in. are pressed from a wet mixture of horse manure, 

 cow dung and loam, and in each of these cakes several small 

 pieces of virgin spawn are embedded. The cakes so prepared are 

 then stacked in a shed and covered with hot dung, producing a 

 temperature and atmosphere suitable for the growth of the 

 mycelium. When the spawn has spread through the whole of 

 the cake, the pieces are loosely stacked and dried ready for sale 

 or use. The final stage of development occurs in the bed where 

 the mycelium, having spread through the dung, forces its way 

 through the covering of soil, and forms small groups of nodules, 

 some of which develop into mushrooms. Normally the produc- 

 tion of mushrooms continues until the supply of nitrogenous 

 matter contained in the dung runs short. 



Intending growers will be well advised to buy spaw 7 n 

 ready made from a manufacturer of good repute. Spawn 

 is sold by the bushel of 16 cakes, one bushel being required 

 for every 2 J tons of dung. It should be bought dry, and a 

 cake, when broken into pieces, should show the white threads 

 of mycelium throughout the whole cake. Full instructions 

 for the preparation of manure intended for mushroom beds will 

 be found in the Ministry's Leaflet No. 276, copies of which may 



