New YorK AGRICULTURAL EXPERIMENT STATION. 99 
ever, the actual difference in growth must have been consider- 
ably greater than this since the unsprayed plants could have 
made but little growth for two weeks before they were all pro- 
nounced dead. 
All through September the contrast in appearance between the 
Sprayed and unsprayed rows was very striking, being greatest 
about September 16 when a photograph of the field was taken. 
(See Plate II **.) Since the experiment field was located beside 
a much traveled highway leading into Geneva, many farmers 
passing the field in going to and from the city watched the prog- 
ress of the experiment with much interest. Several said that 
they could not have believed that spraying could make such a 
difference had they not seen it. But great as was the difference in 
growth, the difference in yield was even more remarkable. 
At Riverhead.—As previously stated, bugs were kept under 
control on all the plats and so had nothing to do with the differ- 
ences in the appearance of the foliage. Flea-beetles, on the con- 
trary, were a very important factor. They were quite plentiful 
the last of May and about July 17 they again appeared in such 
numbers that the unsprayed rows were soon severely injured. 
On July 21, there was a strong contrast in appearance between 
sprayed and unsprayed rows and by August 9 the unsprayed 
rows (Series III) were practically ruined. Even the rows of 
Series I (at that time sprayed twice) were severely injured, but 
on Series II (already sprayed three times) the damage was slight. 
(See Plate V.) 
This was one of the most severe attacks of flea-beetles the 
writers have ever seen. % 
Late blight, Phytophthora infestans, first appeared on the 
unsprayed rows August 10 and quickly killed the remnants of 
foliage left by the flea-beetles. Early blight, too, caused slight 
injury on the unsprayed rows. But the increase in vield on the 
sprayed rows in this experiment is chiefly due to the fact that 
the bordeaux gave partial protection against the ravages of flea- 
beetles. 
As nearly as could be determined, the dates marking the death 
of the plants onthe different series are as follows: Series I, 
August 27; Series II, September 1; and Series III, August 14. 
“Much difficulty has been experienced in getting photographs to show 
properly the contrast in appearance between blighted and unblighted rows 
of potatoes in our spraying experiments. In Plates II, III and XV this 
difficulty has been partially overcome by sifting air-slaked lime over the 
dare ground on the unsprayed rows. 
