70 ReEporRT OF THE BOTANICAL DEPARTMENT OF THE 
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 7% per ct.; 
on sprayed rows only an occasional tuber. 
TABLE I].—YIELD BY SERIES AT RIVERHEAD IN 1902, 






Series. Rows. Dates of spraying. Yield per acre. 
Bu. lbs. 
I Kee eye ae ere ileL INCL ae eeowe May 26, June 20 and July 12.....: ..) 295 20 
RAMs Sere a A Aw veand 1 Ole May 26, June 3, 20, 30, July 11, 23 
andAug, Stay tigate Onin eee 312 oo 
[Wh es See eee SO OkanGal 2 seer by Notispravyed ih. 7th tthe ee eee 267 40 

Gain due to spraying three times, 2724 bu. per acre. 
Gaim 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. 
Tas_e III.—YieLp sy SERIES AT GENEVA IN 1903. 


CESS IED IED = = EAE DR, | 
Series. Rows. Dates of spraying. Yield per acre. 
: Bu. lbs. 
1B ye Meese, ea 1, 456,510 and'13 2a) julyi f4,-238and Awe O6rea eee 262 — 
See oleae | 2,5, 8,11 and 14..| July 7; 2) Aug®7, Zand Septs3.”. .) 292 10 
ND ee at wR SOs Latand 157." Not sprayed. 1a ee ee ee 174 20 




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. 
