104 Report oF THE BoTaANtcaAnL DEPARTMENT OF THE 
Loss from rot.—As nearly as could be estimated, the loss from 
rot was three per ct. on Series I, one per ct. on Series II and six 
per ct. on Series III. Even on the unsprayed rows the loss from 
rot was not nearly as great as in most other fields in the neigh- 
borhood. Most of the increase in yield on the sprayed rows was 
due to the prolonged growth of the plants and consequent larger 
size of the tubers. 
AS SHOWN BY CHEMICAL ANALYSIS. 
In the experiment at Geneva in 1902, fifty consecttive hills 
from a row sprayed seven times and the same number of hills 
from an adjacent unsprayed row were analyzed in order to deter- 
mine whether spraying had affected the chemical composition of 
the tubers. It was found that the sprayed potatoes contained a 
larger percentage of dry matter which consisted mostly of starch. 
(See Bulletin 221, page 254.) , : 
Similar analyses made in 1903 showed very slight difference 
between sprayed and unsprayed tubers. The percentage of dry 
matter was only .05 per ct. greater and of starch .02 per ct. 
greater in the sprayed than in the unsprayed potatoes. (See Bul- 
letin 241, page 266.) 
In 1904 analyses were again made. Fifty consecutive hills 
from a row sprayed five times (Row 5) were compared with fifty 
hills from an adjacent unspravyed row (Row 6). The chemical 
work was done by Mr. F. D. Fuller, Assistant Chemist, whose 
report is shown in the following table: 
TaBLE IX —CHARACTER AND COMPOSITION OF SPRAYED AND UNSPRAYED 
POTATOES. 
YIELD AND SIZE OF TUBERS. 


NuMBER OF TUBERS IN 50 Hits Tiers Tota] Average 
TREATMENT. =| in one, . pweight OF (weaning 
Mer- Unmer- Total hill. tubers. tubers. 
chantable.|chantable. 
| Lbs. Oz. 
Sprayed potatoes........... 223 42 | 265 5.30 104.7 6.36 
Unsprayed potatoes......... 151 70 | pak 4.42 47.8 3.42 
; 
COMPOSITION OF TUBERS. 
| AES AES IT ERIE CR SOS. Pet 
Tab Dr é | Nitrogen- 
No. TREATMENT. Water. y Ash. | Protein.| free com- | Starch. 
oO. matter. pounds. 

_———_—— | ——— | | | ss 
Per.ct. | Per ct..| Per ct. | Per ct: Per ct. Per ct. 
1735 | Sprayed potatoes...... 79.44 20.56 ie 8) 1.67 17.69 14.07 
1736 | Unsprayed potatoes.... 80 .67 19.33 2 2.06 16.05 12.61 



