226 Report of the Botanical Department of the 



The results of these experiments, considered in connection witH 

 other experiments and observations made by the writers, indicate 

 that the average benefit from spraying potatoes in New York 

 may vary very widely in different localities and on different soils. 

 The average increase of 45 bu. per acre obtained at Riverhead is 

 probably the minimum average increase to be expected from thor- 

 ough spraying since potatoes are rarely planted on lighter, drier 

 soil than that used for the experiment at Riverhead. On the other 

 hand, the maximum average is probably over 100 bu. per acre. 

 Many thousands of acres are planted on heavy soils in low situa- 

 tions where the ravages of blight and rot are considerably greater 

 than on such land as was used for the experiment at Geneva. What 

 the mean average for the State may be cannot be stated, even ap- 

 proximately. It can only be said to be large — somewhere be- 

 tween 50 and 100 bu. per acre. 



Five to seven sprayings in the course of the season gave much 

 better results than three sprayings. Undoubtedly, the three spray- 

 ings would have made a better showing had they been applied 

 later in the season; but this was impracticable because of the 

 necessity of early spraying to control " bugs." All of our ex- 

 perience in spraying potatoes with bordeaux mixture indicates that 

 the more frequently and thoroughly the plants are sprayed the 

 better it is for them and the larger will be their yield of tubers. 



In these experiments we have been able to greatly reduce the 

 ravages of early blight, late blight, rot, tip burn and flea beetles, 

 but have not succeeded in completely controlling any of them in 

 times of severe attack. 



FARMERS' BUSIIsTESS EXPERIMENTS. 



During the season of 1911 fourteen farmers in different parts 

 of the State conducted business experiments for the Station. The 

 object of these experiments is to determine the actual profit in 

 spraying potatoes under farm conditions. The methods employed 

 were essentially the same as in previous years. An accurate rec- 

 ord was kept of all of the expense of spraying, including labor, 



