SPOT DISEASE OF THE VIOLET. 



INTRODUCTION. 



The subject of this paper is one of the most widespread and destruc- 

 tive maladies known to attack the violet. The disease has been dis- 

 cussed in the florists' journals under a variety of names, such as leaf 

 spot, leaf rust, leaf blight, smallpox, etc. More commonly, however, 

 the trouble is known as the " violet disease," growers not generally 

 recognizing the fact that there is more than one malad}^ attacking the 

 violet. The disease occurs throughout this countr}' wherever the violet 

 is grown, and is probably of American origin. The cultivation of the 

 violet has been abandoned in many sections of the country on account 

 of its ravages, while in others it has become necessary to adopt new 

 methods of handling the plants during the growing season. 



Five or six years ago, for example, 50,000 to 75,000 square feet of 

 glass in the vicinity of Alexandria, Va., were devoted to the cultiva- 

 tion of this crop, but on account of the disease the industry has been 

 practically abandoned. A large grower near Boston, Mass., was 

 forced, a few years ago, to abandon growing stock plants at his place 

 on account of this trouble. He had to have them grown for him dur- 

 ing the summer, at considerable expense, in localities that were free 

 or comparatively free from the disease. After transferring these 

 plants to his place in the fall and setting them in the houses he expe- 

 rienced little or no difficulty in keeping them healthy during the 

 remainder of the season. Many other instances of the destructive 

 nature of this disease could be cited. 



The large amount of florists' litcn-ature relating to this subject when 

 collected and condensed was found by the writer to contain only a con- 

 fused mass of contradictory opinions regarding both the cause and 

 treatment of the disease. This is not strange to one familiar with the 

 violet. All growers know the violet to be variable, seldom if ever 

 behaving any two seasons alike. Practical growers recognize the fact 

 that methods of handling the plants followed with little disease and 

 good results during one season may, though rigidly adhered to, result 

 in disease and failure the next. It is also a well-known fact that gi'ow- 



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