212 AGRICULTURAL EXPERIMENT STATION. [Jan. 



shall, without injuring the plant, kill or at least prevent the 

 germination of fungus spores which may alight upon it, and 

 which would, under natural conditions, germinate there and 

 infect the plant. Many such preparations have been pro- 

 posed and tested, a few with encouraging results. While 

 this whole subject is but little developed as yet, two formulae 

 may be given which promise to be quite generally useful : — 



Copper Mixture of Gironde or Bordeaux Mixture. 



A. Dissolve six pounds sulphate of copper (blue stone) in 

 sixteen gallons water. 



B. Slake four pounds quicklime with six gallons water. 



C. AVhen cool, mix ^-1 and B, stirring thoroughly. 



Blue Water or Eau Celeste. 

 Dissolve one pound sulphate of copper in four gallons warm 

 water ; when cool, add one pint commercial ammonia and eighteen 

 gallons water. 



The latter of these may be applied by means of any 

 apparatus which thoroughly distributes it ; but the former 

 requires the use of a spraying pump, with a special agitating 

 nozzle to keep it evenly and thoroughly mixed, since the 

 lime is simply held in suspension, without being dissolved. 



It seems hardly necessary to point out that a vigorously 

 healthy plant will be far less subject to the attacks of fungi, 

 and will suffer far less from such attacks, than a poorly 

 nourished one. Both theory and experience point to this 

 obvious conclusion. 



After a plant is too far gone to be saved, measures should 

 be taken to prevent the infection of neighboring plants, still 

 intact, and of plants of the same kind, in the following 

 season. With the latter object in view, one should destroy 

 the affected parts, and especially any dead or fallen parts or 

 refuse, which may harbor the spores of the fungus during 

 the winter. In dealing with fungi which produce resting 

 spores, these precautions should be taken with especial 

 thoroughness. The destruction of infectious material should 

 be as complete as burning can make it, for nothing less than 

 this will assure the death of all the spores contained in it. 

 In dealing with any fungous disease, one of the secrets of 

 success may be summed up in the word, thoroughness. 



