

486 REPORT OF THE ACTING HORTICULTURIST OF THE 
seventy-two hills, or one-fourth that number, were staked off on 
each side immediately surrounding the sprayed square, thus 
obtaining the same conditions as regards the previous treatment 
of the soil. The results of this test will be found in potato 
Table No. 2. | 
It will be seen that the'sprayed portion gave a larger number 
of both merchantable and small tubers, but a larger per cent. of 
merchantable than small; also that the sprayed section had less 
than .29 of one per cent. of decayed tubers against about two per 
cent. from the unsprayed. The average weight of merchantable 
tubers from the sprayed section was 6.49 ounces as against 5.74 
ounces from the unsprayed, showing that the benefit of spraying 
lay in keeping the vines in a healthy growing ccndition until the 
tubers had obtained their normal size. While the unsprayed sec- 
tion shows a very low per cent. of decayed tubers, the probabilities 
are that had the conditions that prevailed through July, when 
the blight made its appearance continued through August and 
September, a large part of the crop would have been decayed. 
Through July the average maximum temperature was 76.5° F., 
with 3.52 inches of rainfall, conditions favorable to the blight, 
In August the average temperature was 78.5° F., with but 3.16 
inches of rain; and in September the average temperature was 
77.8° F., with but .47 inches of rainfall, creating unfavorable 
conditions for tubers to decay. While in 1890, when a large per 
cent. of the potato crop of this section décayed, the conditions 
were entirely different, the average maximum temperature for 
July being 80° F., for August 77.6° F., for September 69° F., with 
a rainfall for those months of 1.07 inches for July, 4.34 inches 
for August, and 5.81 inches for September, making 4.07 inches 
more rainfall for those three months in 1890 than this year, with 
an average lower temperature. There is, therefore, but little 
doubt that the lower temperature, combined with the excessive 
rainfall of that year, was the active agent in causing the decay 
of the potato. 
The conclusions drawn from this Eppariment seem to be that 
spraying with either Bordeaux mixture or ammoniacal solution 
should be practiced by potato growers. Even in a year of par- - 
tial exemption from blight it would pay, as Table No. 2 shows an 
increase of forty-eight bushels per acre on the sprayed section 
