386 Report of the Mycologist of the 



No trace of late blight appeared in any part of the field. 

 There was some early blight on the unsprayed plats but not as 

 much as usual. The average observer would have said that the 

 plants on the unsprayed plats were free from disease throughout 

 the season and that it would certainly have been a wase of labor 

 to spray them. Flea-beetles and Colorado potato-beetles were 

 abundant. 



In spite of the fact that the plants appeared to be free from 

 disease of all kinds, spraying increased the yield sufficiently to 

 pay all of the expense of spraying and a fair profit besides. The 

 fact must not be overlooked that had these potatoes not been 

 sprayed, Paris green must have been applied to them with a 

 powder-gun or in some other way to keep the Colorado potato- 

 beetles in check. Practically speaking then, the expense of 

 spraying is not |4 per acre but |4 minus the expense of applying 

 Paris green alone, which, in the experiment, was $1.51. We 

 admit that $1.51 is probably high but in the absence of more 

 accurate information we are obliged to use this sum. The differ- 

 ence between $4 and $1.51 is $2.49 which is the amount of extra 

 expense per acre caused by spraying. 



By consulting the table it may be seen that spraying increased 

 the yield of merchantable tubers per acre on the four varieties as 

 follows: 



Victor Rose, 4 bushels and 47 pounds; value at 25 cents per bushel. ?1.19 

 White Elephant, 60 bushels and 34 pounds; value at 25 cents per 



bushel 15 14 



Green Mountain, 62 bushels and 5 pounds; value at 25 cents per 



bushel 15 52 



Defender, 16 bushels and 6 pounds; value at 25 cents per bushel. . . 4 02 



Comparing the values in the last column with $2.49, the ex- 

 pens* of producing them, it is seen that: 



Spraying Victor Rose resulted in a loss of $1 30 per acre. 



Spraying White Elephant resulted in a profit of 12 65 per acre. 



Spraying Green Mountain resulted in a profit of 13 03 per acre. 



Spraying Defender resulted in a profit of 1 53 per acre. 



