EXERCISE 54 

 MIXING SPRAY MATERIALS 



Object. To prepare Bordeaux mixture for spraying 

 apples. 



Explanation. Apple trees are sprayed to destroy fungi or 

 insects which may injure or completely destroy the crop if 

 their growth and development are not checked. In order 

 that spraying may be effective it is necessary to apply a sub- 

 stance that will destroy the fungi or insects without injury 

 to the apple tree or fruit. 



The spray material known as Bordeaux mixture has been 

 found to be effective in destroying fungi such as apple scab, 

 apple blotch, and bitter rot, usually without injury to 

 the tree or fruit. Lime sulphur, another spray material, is 

 less likely to injure some varieties of apples, but does not 

 effectively destroy the apple blotch. Where the apple blotch 

 is not present, lime sulphur may be used instead of Bordeaux 

 mixture. Lead arsenate is effective in controlling the cod- 

 ling moth, one of the insects most destructive to the apple 

 crop. A strong solution of lead arsenate will destroy the 

 cankerworm and other insects that feed upon the foliage 

 and fruit. A strong solution of lime sulphur is used to com- 

 bat the San Jose* scale. 



A common formula for making Bordeaux mixture is : 



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