25 
The cost of the treatment was approximately as follows: 
69 pounds copper sulphate, at 9 cents.-. $6.21 
24 hours’ labor, at 15 cents... 3. 60 
Lime and labor of preparation.50 
Total. 10.31 
from which it appears that the treatment, though made with a small hand force pump, 
and in the most thorough manner, was more than compensated for by the increased 
yield secured. 
It should be added that none of the potatoes were decayed at the time of digging, 
and that there were no indications that the blight which so injuriously affected the 
foliage of potatoes the past season on the check rows of our experimental plat, and 
throughout southern Wisconsin, was connected in any way with the potato-rot fun¬ 
gus, Phytophthora ivfestans. But whatever the affecting disease was, it is evident that 
the treatment proved a remedy for it. 
Mr. Hatch states that the Colorado potato beetle Doryphora decemlineata did not 
attack the potato plants in the treated plats, an additional point of some value in 
favor of the treatment. 
DESCRIPTION OF PLATE. 
Plate IV. 
Fig. 4. The value of mixture No. 5, as compared with that of ammoniacal copj>er 
carbonate. 
a, mixture No. 5, sprayed eight times. 
b, ammoniacal copper carbonate, sprayed eight times. 
c, check, not sprayed. 
Fig. 5. The value of ammoniacal copper carbonate as compared with Bean’s sulphur 
powder. 
a, ammoniacal copper carbonate, sprayed six times. 
b, Bean’s sulphur powder, sprayed six times. 
c, check, not sprayed. 
Fig. 6. The value of copper carbonate suspended in water as compared with that 
dissolved in ammonia. 
а, suspended copper carbonate, sprayed six times. 
б, ammoniacal copper carbonate, sprayed six times, 
c, check, not sprayed. 
Fig. 7. The effect of spraying before bloom—Fameuse. 
a, sprayed once before bloom, three times after. 
b, sprayed four times after petals had fallen. 
c, check, not sprayed. 
Fig. 8. The^effect of spraying before bloom—Canada Peach. 
a, sprayed twice before bloom, and twice after. 
b , sprayed four times after bloom. 
c, check, not sprayed. 
Fig. 9. a , eight treatments with ammoniacal copper carbonate. 
b, six treatments with ammoniacal copper carbonate. 
c, four treatments with ammoniacal copper carbonate. 
d, two treatments with ammoniacal copper carbonate. 
e, no treatment. 
