New YorK AGRICULTURAL EXPERIMENT STATION. 113 
and of the unsprayed 184 bushels 44 pounds, making the increase 
in yield due to spraying 150 bushels per acre. There was no rot 
worth mentioning, no early blight and no flea-beetles. The gain 
was due almost entirely to the prevention of late blight. Mr. 
Dunn reports that the average yield for the whole field was 297 
bushels per acre. 
At fifty cents per bushel,2 which was the market price of 
potatoes at digging time, the 130 bushels per acre increase in 
yield was worth $65. Deducting from this $4.89, the average 
cost of spraying per acre, there remains $60.11 net profit per acre. 
Assuming that the gain due to spraying was at the same rate all 
over the field the total net profit from spraying the twelve acres 
was $721.32. Surely spraying was profitable in this case. It 
was Mr. Dunn’s first experience in spraying potatoes. 
The items of expense were as follows: 
400 ‘pounds copper sulphate at 6C......... ccc ccc ve sees $24 00 
ree OA ee rn, Co ae an Shs chs ce eee es 2 00 
BeeTIN Se Paris CLeCi ALP LOCe ys. « ofits ws ¢'ec8 #9 oo 6 etn Os ak 
reed OL D0C TAN AL LOGS fei sets ss ose snes eas 12 00 
mr eeLaOL LOt tCAM AG LOC? © 5 srs 0 + soo vin ots sages acces 12 00 
Interest and wear on sprayer............ SPE NE aaah 6 60 
Hoval cost spraying 12 acres 8 times... 7... %. as. $58 70 
The average cost of spraying. per acre was $4.89 and the cost 
per acre for each application 61 cents. 
We regard this experiment of Mr. Dunn’s as the most satis- 
factory one of the series. Although the net profit per acre, as 
given, is remarkably large, we believe it to be very nearly correct 
if we leave out of consideration the extra expense of handling 
However, this can not be done. The 
99 
22 
the increase in yield. 
*1A little less than 1,006 bushels were actually sold at this price and the 
balance stored. 
*2In these business experiments the extra expense of handling and mar- 
keting the increase has Leen left out of consideration in computing the net 
profit due to spraying. ‘This is often a considerable item as in Mr. Dunn’s 
experiment; but it seems not unfair to neglect it for the reason that in the 
expense of spraying the expense of fighting bugs is included. Strictly speak- 
ing the expense of fighting bugs should not be included in the expense of 
spraying for blight because it is something which must be done anyway. The 
extra expense of handling and marketing the increase must be estimated for 
8 
