498 Report of the Mycologist of the 



brown, brittle, circular spots on the leaves. These spots usually 

 have their origin in flea-beetle injuries. The disease works slow- 

 ly. It never rots the tubers. The cause of the disease is a para- 

 sitic fungus, Macros porium t^olam. 



In 1895 there was considerable loss from late blight in the 

 eastern part of Long Island, but very little in the western part. 

 The early blight did considerable damage in all parts of the 

 island. 



It is impossible to estimate, even approximately, the amount 

 of damnge done nniinal'.y by these two blights, but the results 

 of the spraying experiment reported in a subsequent portion of 

 this Keport go to show that the damage is considerable. 1 am 

 confident that it is much greater than farmers generally realize. 



Spraying Potatoes. 



The object of spraying is to prevent the two diseases, early 

 blight and late blight; and it has been proven by numerous 

 experiments that spraying will prevent both of these diseases. 

 Moreover, it has been shown that the yield can be increased 

 I'liough to ]>ay considerably more than the expense of spray- 

 ing. It has been so thoroughly tested by experiment and in prac- 

 tice that we are warranted in making the statement that spray- 

 ing should be made one of the regular operations in potato cul- 

 ture as much as the application of fertilizer or the cultivation. 

 The question awaiting an answer is not, " Will it pay to spray? " 

 but rather, " What is the most economical method of spraying? "* 



In order that farmers might see what can be accomplished by 

 spraying potatoes on Long Island, the following experiment was 

 made. It was also desired to compare five applications with 

 three. 



The experiment was made at Floral Park, N. Y., on a field of 

 potatoes belonging to Mr. F. P. Baylis. Mr. Baylis kindly gave 

 me permission to use four and one-half acres of the field for a 

 spraying ex])eriment. The experimental plot had been planted 

 to potatoes for four consecutive seasons, during which time it 

 had been fertiliiied practically alike all over. It was divided into 



