20 



SPRAYING CROPS 



were first experimented with on a large scale in 

 France, and gave such satisfactory resuhs that they 

 were adopted in a practical way by many vineyardists. 

 In America they have been tised for this purpose only 

 about twenty years : yet, thanks to numerotis inves- 

 tigations and experiments, their efficiency is well 

 attested, and they are in practical use over a large 

 territory. Their principal combinations are indicated 

 below : 



Bordeaux Mixture — This ftmgicide originated in 

 France, and has become one the leading combina- 

 tions of copper salts. Since its introduction into 

 America there has been a constant tendency to dilute 

 the mixttire more and more. The restilts from the 

 diluted mixtures have been apparently as good as from 

 those of full strength, and of course the cost has been 

 proportionately lessened. The different formulas are 

 indicated below : 



Original or 22-GaUon Formula — Dissolve 6 

 potnids copper stilphate in i gallon hot water in an 

 eanhen or wooden vessel. In another vessel slake 3 

 pounds fresli lime in i gallon water. Strain the 

 latter, and add to 20 gallons water. Xow pour in the 

 dissolved copper sulphate and mix thoroughly. Keep 

 the mixture stirred while using. This strong mixture 

 is now seldom tised. 



Fifty-Gallon Formula — In 1889, while at the Ohio 

 Experiment Station. I experimented with potato blight 

 by diluting this mixtiu'e a little more than half, using 

 6 potmds copper sulphate and 4 potuids lime to 50 

 gallons water, instead of 22 gallons. This was ap- 

 plied to a number of plants besides potatoes, and 

 apparently gaA'e as good results as tuidiltited mix- 

 tures. The same formtila was also sticcessfully used 

 in 1890, and has been so generally adopted since, that 

 it is now the standard formula. 



