24 



SOME FUNGOUS DISEASES OF ECONOMIC IMPORTANCE. 



Experiment No. 9. 



1,050 c. c. formalin per 1,000 cubic feet of air space. 

 Temperature before mixing reagents, 75° F. 



Thielaviopsis cultures in petri dishes. 



Checks; fungus not exposed to formaldehyde gas 



Fungus exposed 15 minutes 



Fungus exposed 30 minutes 



Fungus exposed 60 minutes 



Initial Vigorous 

 growth I growth 

 offungus. offungus. 



Hours. 



23 











190 



Hours. 



52 











286 



Experiment No. 10. 



1,100 c. c. formalin per 1,000 cubic feet of air space. 

 Temperature before mixing reagents, 66° F. 



Thielaviopsis cultures in petri dishes. 



Vigorous 

 growth 

 of fungus. 



Checks; fungus not exposed to formaldehyde gas 



Fungus exposed 15 minutes 



Fungus exposed 30 minutes 



Fungus exposed 60 minutes 



Hours. 



48 



279 











Experiment No. 11. 



1,100 c. c. formalin per 1,000 cubic feet of air space. 

 Temperature before mixing reagents, 75° F. 



Thielaviopsis cultures in petri dishes. 



Initial Vigorous 

 growth growth 

 offungus. offungus. 



Checks; fungus not exposed to formaldehyde gas 



Fungus exposed 15 minutes 



Fungus exposed 30 minutes 



Fungus exposed 60 minutes 



Hours. 



Hours. 



23 



51 



























Experiment No. 12. 



1,100 c. c. formalin per 1,000 cubic feet of air space. 

 Temperature before mixing reagents, 78° F. 



Thielaviopsis cultures in petri dishes. 



Vigorous 

 growth 

 offungus. 



Checks; fungus not exposed to formaldehyde gas 



Fungus exposed 15 minutes 



Fungus exposed 30 minutes 



Fungus exposed 60 minutes 



171 



Hours. 



50 



116 



260 







