246 REPORT OF THE DEPARTMENT OF BOTANY OF THE 
Gain due to spraying three times, 98% bu. per acre. 
Gain due to spraying seven times, 123% bu. per acre. 
The unsprayed rows died two weeks earlier than the sprayed 
rows, owing chiefly to a severe attack of late blight. They were 
also somewhat injured by flea beetles, but there was no early blight. 
On unsprayed rows the loss from rot was 714 per ct.; on sprayed. 
rows only an occasional tuber. 
Taste I].— YieLp By SERIES AT RIVERHEAD IN 1902. 


SERIES. Rows. Dates of spraying. Yield per acre. 
Bu. lbs. 
ie te ata 2,0, and Li...) May 26, Jane 20-and July i2e.-ee. See 295 20 
ID grees 1 4,7 and 10...| May 26, June 3, 20, 30, July 11, 23 and Aug. 5.| 312 35 
VeWas 3,6; GF and*l2 52% INotspraveduade aes ok he ee eee eee 267 40 


Gain due to spraying three times, 2724 bu. per acre. 
Gain due to spraying seven times, 45 bu. per acre. 
In this experiment there were only traces of early blight and no 
late blight. The larger yield on sprayed rows was due to partial 
protection against flea beetles which were rather plentiful at times. 
There was no rot. 
RESULTS IN 1903. 
TaAsLe IJI— Yietp spy SERIES AT GENEVA IN 1903. 



SERIES. Rows. Dates of spraying. Yield per acre. 
Bu. Ibs. 
hora 147 LOand Loe iil oranda duets) lOmin 262 — 
A Lest siseeys 2,5,8, lland14.| July 7, 21, August 7, 21 and September 3....| 292 10 
THEE 370, 9,42 and J5.|Notispraveds tt «taut scot ece eee ee ee 174 20 

RL ES ey | 
Gain due to spraying three times, 88 bu. per acre. 
Gain due to spraying five times. 118 bu. per acre. 
Three sprayings prolonged the life of the plants 11 days; five 
sprayings 18 days. There was no early blight and the injury from 
flea beetles was only slight. Late blight was again the chief enemy. 
The loss from rot was even less than in 1902. 
