134 PLANT DISEASE 



Principal Assistant (Cryptogams), Royal Herb- 

 arium, Kew, 1899, says of Fungicides on 

 P- 32 



" From amongst the various solutions and 

 powders that have been experimented with, 

 the following have proved most effective." 



The fourth on the list is iron sulphate, and 

 on p. 37 he says 



" This preparation may be used with great 

 advantage in those cases where a disease has 

 previously existed, as it destroys existing 

 spores that may be concealed in crevices of 

 bark, brickwork, or on the ground under the 

 fruit trees. In spraying fruit trees, vines, etc., 

 the trunk and branches should be thoroughly 

 drenched, but it should be done during the 

 winter." 



In Encyclopaedia Britannica, vol. xxiv. 

 p. 240, on Fungoid Diseases on Vines, it says 



" Peronospora Viticola. This disease has 

 been successfully treated with sulphate of 



