Diseases of Plants 



297 



and then dissolved in 6 quarts of water. When the lime 

 is well dissolved mix the two solutions, strain, and use 

 immediately. 



Weaker solutions, such as a 2-4-50 formula, are often 

 prepared for use on 

 young plants and on 

 tender crops that are 

 injured by the stronger 

 solutions. 



Sometimes the lime 

 is of poor quality or has 

 lost its strength, or the 

 copper may be so strong 

 that it " burns " leaves 

 that it touches. The 

 solution may be tested 

 as follows : Dip a clean, 

 bright steel knife blade 

 into the prepared solu- 

 tion for 30 seconds. If 

 it is " coppery " in color 

 when removed, there is 

 not enough lime, and 

 lime water should be 

 added until the knife 

 blade does not " cop- 

 per " when tested. 



When this poison is 

 sprayed on the surface of 



C7. S. D. A. 



The proper way to carry a 



FIG. 167. 



compressed-air sprayer of the knapsack 

 leaves it kills the ger- tyP e - The strap goes over the left shoulder, 

 . and the tank is partially supported by the 



minating spores which right hand. 



