74 Diseases of Greenhouse Crops 



Relation of Temperature and Humidity in 

 THE Greenhouse 



The investigations of Blake show (Table 12) that 

 the humidity decreases in direct proportion to an 

 increase in temperature. The opposite occurs when 

 the temperature is lowered. 



Table 12 

 Humidity as Affected by Temperature 



Date, 

 1914 



Outdoor- 

 Weather 

 Conditions 



Time 



of 

 Day 



Ventila- 

 tion 



Heat 



Temper- 

 lUture in 

 Housd 



Humidity 



Feb. II 



Fair 



11:00 A.M. 



Yes 



On 



70 



72 



Feb. II 



Fair 



10:30 A.M. 



Yes 



OS 



64 



90 



Feb. 12 



Fair 



1 :30 P.M. 



None 



On 



62 



72 



Feb. 12 



Fair 



4:00 P.M. 



None 



On 



64 



70 



Feb. 13 





11:30 A.M. 



None 



OfiE 



68 



80 



Feb. 13 





3:30 P.M. 



None 



On 



65 



75 



Feb. 14 



Fair 



2:1s P.M. 



None 



OflE 



71 



82 



Feb. 14 



Fair 



5:00 P.M. 



None 



On 



61 



69 



Feb. 16 



Fair 



2:00 P.M. 



Yes 



OflE 



65 



95 



Feb. 16 



Fair 



5:00 P.M. 



None 



On 



63 



79 



Feb. 17 





8:00 A.M. 



None 



On 



60 



89 



Feb. 17 





1:00 P.M. 



Yes 



OflE 



67 



95 



Feb. 18 



Snow and rain .... 



8:00 A.M. 



None 



OfiE 



67 



90 



Feb. 18 



Snow and rain. . . . 



3:45 P.M. 



None 



OflE 



64 



86 



Feb. 20 



Fair 



11:00 A.M. 



Yes 



OfiE 



67 



90 



Feb. 20 



Fair 



4:30 P.M. 



None 



On 



64 



85 



Feb. 21 



Fair 



8:00 A.M. 



None 



On 



71 



65 



Feb. 21 



Fair 



1:00 P.M. 



Yes 



OfE 



72 



! 78 



