New York AGRICULTURAL EXPERIMENT STATION. 135 
When the experiment was examined on July 20, early blight 
and flea-beetles were the leading enemies. Late blight, too, was 
becoming well established on the unsprayed rows and there were 
traces of it among the sprayed plants. The beneficial effect of 
the spraying was now just beginning to show. On crossing the 
field the unsprayed rows could be readily located by the poorer 
condition of their foliage. 
By August 1, the unsprayed rows were badly blighted and by 
August 9 they were dead except for an occasional tuft of green 
leaves at the tips of a few plants here and there. On the latter 
date the sprayed plants on both sides of the unsprayed were but 
little injured. However, they were thoroughly infested with 
late blight and it was plain that they could not long survive if 
the weather conditions should become favorable to blight. Imme- 
diately after this there came a period of wet weather and the 
sprayed plants deteriorated rapidly. The last spraying was made 
on August 17 at which time the sprayed plants were still quite 
green. 
The test rows were dug on September 8 with a potato digger. 
The yields were as follows: . 
Second sprayed row on the north, 889 Ibs. marketable tubers. 
Second sprayed row on the south, 765 Ibs. marketable tubers. 
Average of the two sprayed rows, 827 lbs. marketable tubers. 
Middle unsprayed row, 78814 lbs. marketable tubers. 
Yield per acre, spraycd, 304 bu. 36 lbs. marketable tubers. 
Yield per acre, unsprayed, 290 bu. 26 lbs. marketable tubers. 
Gain per acre, 14 bu. 10 lbs. marketable tubers. 
The yield of culls was 3114 bushels per acre for the sprayed 
and 47 bushels for the unsprayed. 
Considering the striking difference in growth the difference in 
yield between the sprayed and unsprayed rows was surprisingly 
small. We confidently expected a gain of at least 50 bushels per 
acre here and should not have been at all surprised if it had been 
as much as 75 bushels per acre. The unsprayed rows were in 
plain view from a public road and the difference was so marked 
that the experiment attracted much attention. In some cases 
farmers came several miles to see it. The sprayed rows outlived 
