22 



SANITATION AND DISINFECTION 



As congested centers of mushroom growing develop (fig. 13) it 

 is becoming more and more apparent that cumulative losses caused 

 by fungi and insect pests can scarcely be avoided unless a carefully 

 planned program of disinfection and sanitation is made a part of 

 the routine of cultural practice. It is advisable to thoroughly dis- 

 infect the composting grounds and the mushroom house between 

 crops and to take special precautions to prevent the contamination 

 of casing soil and water. 



A few growers have concrete composting surfaces, but in most 

 cases the manure is composted on the bare ground and a sanitary 

 condition is maintained by keeping the ground free from old manure 

 and standing water between crops and by thoroughly drenching the 

 soil with a disinfectant a few weeks before assembling the manure. 

 A solution of formaldehyde made by dissolving 1 pint of fresh for- 

 malin in 15 gallons 

 of water has satis- 

 factory germicidal 

 properties for this 

 purpose and in ad- 

 dition has the advan- 

 tage of being non- 

 corrosive to metals 

 and of remaining 

 only temporarily in 

 the soil. 



It is almost a uni- 

 versal practice to 

 thoroughly disinfect 

 the inside of the 

 mushroom house a 

 few weeks before 

 filling time either 

 by burning sulphur 

 or releasing formaldehyde gas. Effective fumigation may be ob- 

 tained by either method, especially under warm, damp conditions, 

 but both sulphur fumes and formaldehyde gas are injurious to 

 growing mushrooms and special precautions are necessary when 

 fumigating a house adjacent to one in which a crop is growing. 



When sulphur is used it is usually burned at the rate of 5 pounds 

 per 1,000 cubic feet of air space. Either crude sulphur or flowers of 

 sulphur will burn readily with the aid of rag wicks soaked in kero- 

 sene. Deep containers must be used and air pockets in the sulphur 

 heap must be avoided in order to minimize the fire hazard of running 

 molten sulphur and burning sulphur spattering over the bed boards. 

 It is not advisable to burn sulphur directly on the cement floor of 

 the alley, since the heat generated may cause the cement to buckle 

 and throw out particles of burning sulphur. Some growers burn the 

 sulphur outside the house and use a forced draft to blow the fumes 

 into the house. 



Fumigation with formaldehyde is accomplished by vaporizing 

 commercial formalin — 40 per cent formaldehyde solution in water — 

 at the rate of 1 quart to 1,000 cubic feet of air space. The formalin 



Figure 13.— Mushroom houses near Toughkenamon, Pa. 



