94 REPoRT OF THE BOTANIST OF THE 
to give the rows an equal chance in every respect except in the 
matter of spraying, but, somehow, error crept in. This is an 
Ulustration of the inaccuracies which may occur even in the most 
carefully planned and carefully managed field experiments. 
Yields by series.—The yield by series is shown in the following 
table: : 
TABLE IV. YireLtp By SERIES AT RIVERHEAD. 




{ 



Series. Rows. DATES OF SPRAYING. baci 
| | Bu. Ibs. 
Tov} 2,5; 8: and-11: 7--May-26, Jane 20-and July 22. 22 5.-— aoa 295 20 




| 
—— __ 

II....| 1,4, 7 and 10..| May 26, June 3, 20, 30, July 11, 23 and Aug. 5.) 315 35 


TH; -c:8, 6,9 and 12.2)-Not-eprayedseican, avert 267 40 


Increase in yield due to spraying three times, 27% bushels 
per acre. 
Increase ir yield due to spraying seven times, 45 bushels per 
acre. 
Loss from rot.—At Riverhead there was no loss from rot, not 
even on the unsprayed rows. 
AS SHOWN BY CHEMICAL ANALYSIS. 
With the potato the question of quality is less important than 
with many other vegetables and fruit. For the most part, 
potatoes are potatoes so far as their food value and cooking qual- 
ities are concerned, although it is true that some varieties are 
recognized as being preferable to others in these respects; also, 
tubers grown in certain localities where the soil is supposed to 
be especially suited to the potato command a somewhat higher 
price. For a given variety buyers usually have a uniform price, 
except for lots in which the tubers are scabby or much out of the 
ordinary size. In short, sprayed potatoes sell for the same price 
as unsprayed ones, because consumers recognize no difference 
between them. 
As for the effect of spraying on the quality of the tubers, it 
appears to be simply a question of maturity. When a potato 
plant dies prematurely from blight its tubers must of necessity be 
