24 
was turning yellow and in spots becoming brown and apparently dying, while that 
of the treated portions was still fresh and green. At the last spraying (Septem¬ 
ber 2) the effect of the treatment was still more marked, the vines in the check rows 
being mostly dead or severely blighted, while very little of the blight was visible on 
the treated plats. 
During my visit to Mr. Hatch’s place in the latter part of September, the check 
rows were conspicuous by their brown and dry appearance at a distance of several 
rods from the field, while the vines in the treated areas were still for the most part 
green and growing. A frost occurred September 28, which destroyed most of the 
surviving foliage. October 9 to 15 the potatoes in the various plats were dug, as¬ 
sorted, counted, measured, aud weighed. The numerical data appear in the following 
table. The results of the treatment appear more clearly from the graphic diagram 
(Fig. 3), in which the white portion represents the yield of merchantable potatoes, 
and the diagonal lines that of the small potatoes. 
Fig. 3.— ci, after six treatments ; b, not treated. 
Plat. 
No. of 
hills. 
Merchantable 
yield. 
Total yield. 
Yields 
calculated to a uniform 
number of hills. 
No. 
Weight. 
No. 
Weight. 
Merchantable. 
Total. 
No. 
Weight. 
No. 
Weight. 
Pounds. 
Pounds. 
Pounds. 
Pounds. 
Northeast corner. 
32t 
2, 255 
835 
6, 815 
1,133 
2, 669 
988 
8,068 
1,310 
Northwest corner. 
287 
2, 530 
871 
6, 455 
1,102 
3, 350 
1,049 
8, 547 
1,459 
Southeast corner. 
340 
2, 176 
903 
7,462 
1, 320 
2, 432 
1,009 
8, 340 
1,475 
Southwest corner. 
343 
3, 075 
1,127 
6, 905 
1, 367 
3, 407 
1,249 
7, 650 
1,514 
Check. 
380 
2,125 
698 
6, 200 
1,000 
2,125 
698 
6, 200 
1,000 
The unequal number of hills in the different plats arose from two causes, viz, the 
whole area was not quite regular in outline, aud as the ground was a little sloping, 
the heavy June rains washed out some hills in places. The numbers recorded in the 
table represent the hills that matured their crop, as determined by counting before 
the potatoes were dug. 
As the check rows traversed the whole planted area in both directions, we are justi¬ 
fied in assuming that they represented an average of the whole plat so far as the con¬ 
ditions of soil and culture were concerned, and that any difference in the yield of 
these rows, and that of the average of the four treated plats, when calculated to a 
given number of hills was due to the treatment. In other words, had each of the 
four treated plats contained the same number of hills as the check rows, the aggre¬ 
gate yield from them would have been, without treatment, approximately four times 
as much as that from the check rows. Considering the yield of merchantable pota¬ 
toes, then, the four treated plats would have yielded without the treatment 4 X 698, 
or 2,792 pounds, whereas they actually yielded 4,295 pounds, or an increase, presum¬ 
ably due to the treatment, of 1,503 pounds, a fraction over 25 bushels. From the 
figures, it would appear that the applications to the southwest plat, in which the 
fungicide was used at its full strength, were most effectual, aud that for the jiotato, 
the Bordeaux mixture should not be diluted. 
