TEMPERATURE, MOISTURE, LIGHT 



directly killed by the temperature of a warm 

 day, but rather is it due to the great stimulus 

 given to the growth of other organisms at 

 the higher temperature. These other or- 

 ganisms may be insects, fungi, and bacteria, 

 and many of these either crowd out, or 

 directly attack the mushroom mycelium or 

 the young pin heads. The high tempera- 

 ture, therefore, operates by making some 

 other condition of the environment injuri- 

 ous. Indeed, if other organisms could be 

 largely eliminated from the mushroom bed, 

 we might find that mushroom production 

 were possible at a considerably higher tem- 

 perature. 



At any rate, by experiments with pure 

 cultures, it has been shown that mushroom 

 mycelium is not directly injured at from 70° 

 to 85° F. Pure cultures of Agaricus cam- 

 pestris grow well up to 85° F. so long as 

 sufficient moisture is present. This is posi- 

 tive proof that the conditions for growth in 

 pure cultures are different from what they 

 are in the mushroom bed, and this difference 



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