116 Report ov rHEe BoranicaAL DEPARTMENT OF THE 
make an acre. The soil was a well drained sandy loam somewhat 
lighter than in the east field. Six applications of bordeaux 
mixture were made on the following dates: August 1, 6, 13, 28, 
September 3 and 10. The spraying was done with the same out- 
fit used in the east field and in the same manner. 
On August 31 there were traces of late blight, Phytophthora 
infestans, all along the unsprayed rows, but no material injury 
was done as yet. The sprayed rows appeared only slightly bet- 
ter than the unsprayed, being wholly free from late blight and 
somewhat darker green in color. Among the varieties Rural 
New Yorker No. 2 and Gold Coin there were a good many plants 
affected with the unknown leaf curl found in the east field; but 
the Carman No. 3 was entirely free from it. 
The test rows were dug with a potato digger on October 15, the 
yields being as follows: 
Second sprayed row on the east,?* 410 pounds of marketable 
tubers or 107 bushels 50 pounds per acre. 
Middle unsprayed row, 356 pounds of marketable tubers or 93 
bushels 38 pounds per acre. Thus the gain due to spraying was 
14 bushels 12 pounds of marketable tubers per acre. 
On the unsprayed row there were 52 pounds of culls and on 
the sprayed row 36 pounds, making a difference of 4 bushels and 
12 pounds of culls per acre in favor of the unsprayed. 
Summary.—Averaging the results in the two fields we have 
the following: 
Yield, sprayed, 136 bu. 59 lbs. of marketable tubers per acre, 
Yield, unsprayed, 115 bu. 48 lbs. of marketable tubers per acre. 
Gain, 21 bu. 11 Ibs. of marketable tubers per acre. 
There was practically no loss from rot in either field. There 
having been so little blight, the gain due to spraying was as 
large as could be expected. The only important disease in either 
field was the previously mentioned leaf curl which is only slightly 
preventable by spraying. No doubt farmers sometimes confuse 
this disease with early and late blight, but it is readily dis- 
tinguished from both these blights by the fact that it attacks only 
the margins and tips of the leaves. , 
*The yield of the second row on the west was not taken because it was 
found to be of a different variety. 
