go REPORT OF THE BOTANICAL DEPARTMENT OF THE 
other field, containing 10.5 acres, the two principal varieties were 
Rural New Yorker No. 2 and Uncle Sam. In the-larger field, a 
strip of four rows in the variety Rural New Yorker No. 2 was left 
unsprayed. This portion of the field was planted May 26. 
The sprayed rows on both sides of the unsprayed strip were 
sprayed with bordeaux mixture nine times on the following dates, 
— July 6, 18, 21, 31, August 10, 22, 29 and September 4 and 11. 
The bordeaux contained six pounds of copper sulphate to fifty 
gallons of water with lime in moderate excess of the amount re- 
quired to satisfy the litmus paper test. Water for making the 
bordeaux was obtained from the Susquehanna River at a point 
50 rods from the smaller field and 130 rods from the larger one. 
The sprayer was driven directly into the river where the water 
was about two feet deep and the tank filled by means of a cistern 
pump. Upon arrival at the potato field about one-third of the 
water was pumped from the spray tank into the lime barrel. 
To the remainder, six pounds of copper sulphate in stock solu- 
tion were added and the spray tank refilled with fime water. 
Whenever “bugs” became numerous paris green -was added to 
the bordeaux while on the unsprayed rows “bugs” were con- 
trolled by four applications of paris green in lime water. Frequent 
showers about July 20 made it difficult to manage the “ bugs.” 
On August 2 Mr. Dean notified us that blight was developing 
rapidly on the unsprayed rows. When we examined the experi- 
ment on August 9 late blight was well established on the un- 
sprayed rows and there were traces of it also on the adjacent 
sprayed rows. On August 17 Mr. Dean reported that the blight was 
then spreading very slowly and on August 30 he wrote that there 
appeared to be but little difference between the sprayed and un- 
sprayed rows. During the first ten days of September the blight 
was more active than at any other time and the contrast between 
the sprayed and unsprayed rows became pronounced. Spraying 
prolonged the life of the plants about two weeks. Late blight 
was the only important disease in this experiment and there were 
very few flea beetles. 
The items of expense for spraying 17 acres 9 times were as 
follows: 
860; iDsesceppeér, sulphate (@ Gi2¢s «ica ef ae face ogee $53.32 
Ereight; cn copper sulphate. ..is.)). p02 ils oe 1.22 
7134 Ibs, paris green -@). 26¢ to. 226.) 2. Ue ee 20.55 
Litmus paper 
TD DR itive ee ia. ae Sire 4 Os Ok Ek Oi Ae nce ot 1.25 
