MUSHROOMS 417 



case too soon is a disadvantage. During the intervals 

 some sprinkling may be necessary to keep the beds moist. 



Moisture conditions. Proper moisture conditions at 

 all times after the beds have been started are of the 

 greatest importance. Excessive humidity in the house 

 should be avoided, but the atmosphere should be moist 

 enough to prevent rapid evaporation from the surface of 

 the beds. Molds and foreign fungi may develop if too 

 high humidity is maintained. The best mushroom houses 

 are provided with means of ventilation by which tempera- 

 tures may be regulated and the humidity of the houses 

 controlled to a great extent. 



Mushrooms require a certain amount of soil moisture, 

 just as do the higher classes of plants. There is always 

 some daily loss of moisture from the beds by evaporation, 

 and the harvesting of a successful crop also removes a 

 considerable quantity of water. Some of the old growers 

 claimed that the beds should never be watered after the 

 mushrooms began to appear, and no doubt this was often 

 responsible for light crops. Drenching and over-water- 

 ing should be carefully avoided, but there can be no 

 doubt about the value or necessity of light sprinklings 

 whenever the casing seems to indicate the need of such 

 treatment. If the casing is kept moist, but not wet, there 

 will be no danger of the compost or manure becoming 

 too dry. Contrary to the best practice in vegetable forc- 

 ing, it is desirable to water frequently but lightly, but 

 application should never be made unless there is assur- 

 ance that water is really needed. So much water should 

 never be applied that it will penetrate the casing and run 

 into the manure, for this invariably weakens the my- 

 celium, especially in the early stages of growth. No rule 

 can be given concerning the frequency of watering any 

 more than for the watering of greenhouse crops. 



Temperature. An atmospheric temperature of about 

 55 degrees is considered as ideal for the growing of mush- 



