96 Ruporr Ov tHE Boranist oF ‘titi 
“These data disclose the following facts: 
“(1) The sprayed potatoes yielded more tubers to the hill and 
of larger average size than the unsprayed. 
(2) Spraying apparently had the effect of increasing the dry 
matter of the tubers. This increase is seen to consist mostly of 
starch, the excess of dry matter in the tubers from sprayed 
potatoes being 1.4 per ct., and of starch 1.1 per ct. 
“Other things being equal, the food value of a vegetable or 
fruit is proportional to its digestible dry matter. As the increase 
from spraying is seen to be almost wholly starch, and as this 
carbohydrate is practically all digested, it is reasonable to con- 
clude that the sprayed potatoes are about 7 per ct. more valuable 
for human food than the unsprayed. 
“For the same reasons and to the same extent the sprayed 
potatoes would be worth more to manufacturers of starch.” 
THE PROFIT. 
At Gencva.— For the reasons given on page 79 no attempt was 
made to keep an account of the expense of spraying in the experi- 
ment. Nevertheless, it is worth while to consider briefly the 
probable profit. 
In central and western New York the market price of potatoes 
during October was about 50 cents per bushel. Early in Novem- 
ber the experiment potatoes were actually sold for 60 cents per 
bushel. Spraying three times increased the yield 981% bushels per 
acre. At 50 cents per bushel this increase is worth $49.25. 
Judging from previous experience, it is our opinion that spray- 
ing as thorough as in this experiment could be done on a com- 
mercial basis at an expense not greater than $2 per acre for each 
spraying, or $6 for three sprayings. This allowance is certainly 
ample. On Long Island, in 1896, the Station sprayed eight acres 
of potatoes at a total expense of 80 cents per acre for each appli- 
cation’; but, of course, the work was not done as thoroughly as 
at Geneva. Under proper management and with a supply of 
water reasonably accessible, potatoes may be sprayed at a total 
expense of $1 per acre for each application. Besides, it should 
not be forgotten that at least one, and usually two, applications 
8See Bul. No. 123 of this Station, page 241. 
