New York Agricultural Experiment Station. 245 



doing a very poor job with the spray outfit; and, worse yet, the 

 majority, probably, are not spraying at all. 



In the ten-year experiment on the Station grounds at Geneva 

 five to seven very thorough sprayings increased the yield at the 

 rate of 97 . 5 bushels per acre on the average. In the series of farmers' 

 business experiments conducted during the last nine years of the 

 same period the average increase in yield due to spraying was only 

 36.1 bushels per acre.* It appears that the better results obtained 

 in the Station experiment were due, chiefly, to the thoroughness of 

 the spraying. If so, it behooves farmers to spray more thoroughly. 

 However, some hold that such spraying as was done in the Station 

 experiments would not have increased the yield so much in farmers' 

 fields. We think there may be some truth in this. Undoubtedly, 

 the largest returns from spraying are to be obtained in fields in which 

 the cultural conditions are favorable to large yields. 



By means of the experiments reported in the present bulletin it 

 was sought to obtain information on some of the points above men- 

 tioned. An attempt was made to find out what thorough spraying 

 will accomplish in farmers' fields. To be more explicit, the objects 

 of the experiments were three: 



(1) To determine how much the yield in farmers' fields may be 

 increased by very thorough spraying; 



(2) To determine how efficient are the spraying methods now 

 employed by farmers; 



(3) To furnish object lessons for farmers in their own fields. 



THE EXPERIMENTS. 



Rush was selected as the location of the experiments chiefly for 

 two reasons: (1) Because potatoes are grown extensively there; and 

 (2) because we were able to secure there a suitable man to do the 

 spraying, viz., Mr. H. F. Keyes, a student in the New York State 

 College of Agriculture, who performed the work during his summer 

 vacation. In June, Mr. Keyes visited potato-growers in the vicinity 

 and secured permission to spray a portion of one row (290.4 feet 

 long) in each of 66 fields. After the potatoes came up a careful 

 selection of rows was made and the portion to be sprayed marked 

 at both ends by means of stakes driven in the ground. In the 

 selection of these rows care was taken to avoid dead-furrows, back- 



* Bulletin No. 349 of this Station. 



