172 Report oF THE BoTANICAL DEPARTMENT OF THE 
distinctly that the difference between sprayed and unsprayed rows 
was just one bushel on two rows 34 rods long which is at the rate 
of 1124 bushels per acre. Excessively wet weather is largely re- 
sponsible for the small yields. 
Experiment No. 32.—One row near the center of the field was 
left unsprayed. The gain due to spraying amounted to one bushel 
per hundred hills or 54 bu. 27 lbs. per acre. The total yield on 
6% acres was 1,500 bushels which is at the rate of 230 bu. 46 lbs. 
per acre. 
Experiment No. 33—The bordeaux was applied five times at the 
rate of 60 gallons per acre. The expense of spraying includes only 
labor and chemicals. No allowance is made for wear of sprayer. 
Experiment No. 34.—Unsprayed rows were left in each of three 
varieties. On the variety Carman the gain due to spraying was 
63 bushels per acre; on Mammoth Whiton, 34% bushels; and on 
Rural New Yorker No. 2, 681% bushels, making an average gain 
of 55% bushels per acre. 
Experiment No. 35.—The percentage of rot was very much less- 
ened by spraying. 
Experiment No. 36.—One half acre was sprayed four times, % 
acre twice, one acre once and ¥% acre left unsprayed. The half 
acre sprayed four times yielded 143 bu. 23 Ibs. or at the rate of 
286 bu. 46 lbs. per acre; while the unsprayed half acre yielded 
only 72 bu. 36 lbs. or at the rate of 145 bu. 12 lbs. per acre. On 
the unsprayed half-acre the loss from rot was heavy; on the sprayed 
half-acre much less. 
Experiment No. 37.—The loss from rot was at the rate of one 
bushel per acre on the sprayed rows and 29 bushels per acre on the 
unsprayed ones. 
Experiment No. 38.—There was apparently but little blight, yet 
there was some rot both on sprayed and unsprayed rows. 
Experiment No. 39.—The sprayed rows outlived the unsprayed 
ones about 12 days. On sprayed rows the loss from rot was about 
Ir bu. per acre and on the unsprayed ones 22 bu. per acre. 
Experiment No. 40.—In this experiment the enormous gain was 
mostly due to the prevention of rot. About three-fourths of the 
unsprayed potatoes rotted while there was only a little rot among 
the sprayed ones. 
