26 



DISEASES OF ECONOMIC PLANTS 



This strong solution is particularly for grapes, potatoes, 

 and tomatoes; crops which possess good resistance to the 

 copper of the mixture, and upon which a strong solution 

 is desired. 



Copper sulphate 



Lime 



Water 



Weak Solutions 

 2 — 2 — 50 



2 pounds 



2 pounds 



50 gallons 



50 



Copper sulphate 



Lime 



Water 



2i pounds 



6 pounds 



50 gallons 



Plants with sensitive foliage, such as the stone fruits, 

 peach, plum, cherry, and apricot, are injured by the stronger 

 solutions, and very weak solutions must be used upon them. 



There is no certainty as to what strength of mixture ie best. 

 To most crops no damage can come from the use of as 

 strong a solution as the 6-4-50, yet it is possible that all 

 of the benefit can be derived from a 4-4-50 mixture. If 

 so, there is loss of material through use of the stronger 

 solution. This matter is still open to experimentation. 



In the preparation of the Bordeaux mixture it is well 

 to have on hand stock solutions of copper sulphate and of 

 lime. The stock solution of copper sulphate is made by 

 dissolving a certain number of pounds of copper sulphate 

 in one half the nimiber of gallons of water. For example : 

 80 pounds of copper sulphate in 40 gallons of water. Every 



