84 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
somewhat inferior to the sprayed, but the contrast was not 
marked. On the sprayed portion of the field the vines completely 
covered the ground making a very fine showing. 
During September the late blight made considerable progress 
on the check rows and the lower yield of these rows is chiefly 
due to its ravages. 
The items of expense for spraying 22 acres of potatoes six 
times were as follows: 
850..lbs. copper sulphate @ 63462: 3.,0) its...) oc eye tioned $57.37 
12)sacks slime. @): 456.394.2803) SPE a ig 5.40 
4. sacks: lime. @. 30¢ §09), . an okie Da eth ha ee «er 1.20 
eo bs. arsenic) @). B46) 0 abe s 0h Gopi cetae us alae s Eat eee ceo 
7or lbs! sal''soda "@2 AE sas Ie shes Paso Behe | Mabie amie en e013 
6 days’ work for two men and two teams @ $8..............:... 48.00 
Wear On ‘sprayer '\. ps1 6. See cub cade d Kp oie iuace ne Wipe Ue ee 10.00 
Total no (oo Naik tee Da a RE cate hay cee a oe $124.80 
Thus the total expense of spraying was $5.67 per acre or 
94 cents per acre for each application. 
The test rows were dug October 5 with a potato digger. The 
rows were 1,237 feet long, but owing to lack of time the test 
was confined to 700 feet at the east end. Had the entire length 
of the rows been included the difference in favor of the sprayed 
rows would probably have been less because of less damage from 
blight toward the west end. Although’ the rows were supposed 
to be thirty-three inches apart measurement showed them to be 
only 2.7 feet. Accordingly, the latter figures have been used 
in computing the yields, which were as follows: | 
Second sprayed row on the north, 916 lbs. marketable tubers. 
Second sprayed row on the south, 935 lbs. marketable tubers. 
Average of two sprayed rows, 925% lbs. marketable tubers. 
Average of two unsprayed rows, 717 lbs. marketable tubers. 
Yield, sprayed, 355 bu. 24 lbs. marketable tubers per acre. 
Yield, unsprayed, 275 bu. 20 lbs. marketable tubers per acre. 
Gain. 80 bu. 4 lbs. marketable tubers per acre. 
There was no loss from rot. The yield of culls was at the rate 
of ten bushels per acre for the sprayed rows and 11 bu. 8 lbs. 
for the unsprayed rows 
At 35 cents per bushel, the market price of potatoes in Silver 
Springs on October 5, 80 bu. 4 lbs. of potatoes would be worth 
$28.02. Subtracting $5.67, the expense of spraying, there remains 
a net profit of $22.35 per acre. 
