122 REPORT OF THE BOTANICAL DEPARTMENT. OF THE 
sprayed rows received poison so that sprayed and unsprayed 
rows had an equal chance in this respect. When we. saw the 
experiment on July I9 the unsprayed rows were nearly dead 
with late blight while the sprayed rows on both,sides were in 
full foliage and but slightly affected. The contrast in appear- 
ance was very striking. A representative of the Station assisted 
in digging and weighing the test rows. The yields were as 
follows: 
Two sprayed rows (second and third rows on the east), 
1,636 lbs. or 236 bu. 35 Ibs. per acre. 
Middle two unsprayed rows, 1,045 lbs. or 144 bu. 44 lbs. per 
acre. 
Experiment No. 17— The high cost of spraying in this experi- 
ment was partly due to the high price paid for copper sulphate, 
viz., 12% cents per pound. The unsprayed rows were quite 
badly affected with blight and the vines died before the pota- 
toes were mature. There was but little rot. The unsprayed 
rows were kept free from “bugs” by hand picking. 
Experiment No.*18.— There was scarcely any rot even on the un- 
sprayed rows. The expense of spraying was as follows: 
Spraying materials ih. 0)... ok ode. vu nab ecko wah ties 0s etd $4.00 
46% hrs. labor @ 2o¢.. EL Reeeree ree tr Pe eN ee ee 9.30 
Totaliss Sve): (NESTA 4 aia tee ite done Gate a et eae $13.30 
Experiment No. 19.— The yields given in: Table XVI are the 
average of two tests. In each test there were three unsprayed 
rows. The yield of the middle unsprayed row was compared 
with that of the first sprayed row on one side. The yields in 
the two tests were as follows: 
First test: Sprayed row, 270 lbs. = 182 bu. 45 lbs. per acre. 
Unsprayed row, 166 lbs. = 112 bu. 21 lbs. per acre. 
Gain, 70 bu. 24 lbs. marketable tubers per acre. 
Second test: Sprayed row, 316 lbs. —213 bu. 53 lbs. per acre. 
Unsprayed row, 217 lbs. = 146 bu. 52 lbs. per acre. 
Gain, 67 bu. rt lb. marketable tubers per acre. 

Experiment No. 20.— We made an examination of this experi- 
ment on August 8 and found late blight already well started on 
the four unsprayed rows and there was also a little on the 
sprayed rows. Mr. Brown states that the unsprayed rows were 

