148 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
The two-acre field——The potatoes in this field were of the variety 
Sulphic Beauty and planted May 15. They were sprayed seven 
times — July 3, 8, 22, August 1, 17, 28 and September 2. The 
total quantity of bordeaux used was 650 gallons. Paris green was 
used with the bordeaux twice; viz., on July 8 (two pounds per 
acre) and July 22 (one pound per acre). Three rows 323 feet long 
were left unsprayed. Paris green in water was applied to these 
rows twice (July 7 and 20) by means of a knapsack sprayer. The 
chief enemy was late blight which caused the death of the un- 
sprayed rows about September 1 while the sprayed rows were still 
quite green on September 13 when they were killed by frost. No 
damage was done by bugs. The test rows were dug by hand Sep- 
tember 22 with the following results: 
Second sprayed row on the east, 382 lbs. marketable tubers. 
Second sprayed row on the west, 357 lbs. marketable tubers. 
Average of two sprayed rows, 369% Ibs. marketable tubers. 
Middle unsprayed row, 282 lbs. marketable tubers. 
Yield, sprayed, 276 bu. 49 lbs. marketable tubers per acre. 
Yield, unsprayed, 211 bu. 16 lbs. marketable tubers per acre. 
Gain, 65 bu. 33 Ibs. marketable tubers per acre. 
It was plain that spraying had checked the rot. There was 
practically no rot on either sprayed row while on the unsprayed 
row rotten tubers were frequent. The yield of small and rotten 
tubers was 24 bu. 32 lbs. per acre for the sprayed and 69 bu. 28 
Ibs. per acre for the unsprayed. 
The nine-acre field—The variety in this field was Enormous No. 
9, planted May 18. They were given five sprayings, the total 
quantity of bordeaux used being 1,755 gallons. The dates of spray- 
ing were — July 10, 26, August 14-17, 28 and September 2. Paris 
green was used in the first two sprayings — seven pounds on July 
to and fifteen pounds on July 26. The three unsprayed rows, 1,419 
feet long, were treated with paris green in water on the same dates. 
Toward the close of the season the unsprayed rows were plainly 
inferior to the adjacent sprayed rows. They died about two weeks 
earlier. In fact, the sprayed rows were still partly green when frost 
came. The test rows were dug by hand September 23 and the fol- 
lowing yields obtained: 
Second sprayed row on the east, 1,382 Ibs. marketable tubers. 
Second sprayed row on the west, 1,540%4 lbs. marketable tubers, 
