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Diseases of Economic Plants 



ing at 80° C. gave best results in killing both the fungi and 

 the weed seeds. When one section of the bed is treated, the 

 pan is lifted and carried to another portion, and the operation 

 repeated until the entire bed is steamed. 



Fig. 236. — Disinfecting with steam by the inverted-pan method. 

 After Johnson. 



The inverted-pan method is particularly applicable in 

 disinfecting greenhouse benches or flats. Streaming steam 

 from the heating system passed into the pan for one and one- 

 half hours suffices. A steam hose connecting the pan with a 

 traction engine makes a serviceable out-of-door outfit. 



The Sargent method. — Disinfection by a system of 

 steam pipes arranged in the form of a harrow, with hollow, 



