14 
The variation in regard to these was for the purpose of bringing out 
the value of early spraying, as will be shown later. 
The first spraying was made 10 days before blooming, and would have 
been applied earlier but for a delay in the arrival of some of the chemi¬ 
cals. The weather had been dry for 2 weeks and no disease was showing 
on the leaves. The next day, however, a rainy spell set in, lasting 5 
days. The second treatment was also given on a clear day and the first 
traces of black rot had been discovered the day before. There were rains 
on May 18,19, 20, and then none until June 1. The day after the fourth 
treatment there was a light rain (June 15) and this was followed by a 
drought which put an end to any infection of black rot for the season. 
In order to get a fair estimate as to the value of the various treat¬ 
ments the diseased and healthy berries on both the treated and un¬ 
treated plats were carefully counted and weighed. The weight of dis¬ 
eased fruit was estimated by counting, in several cases, the number of 
berries in a pound of sound fruit, obtaining an average number, and 
dividing the number of diseased berries by it. The results of this work 
is shown in tabular form below. 
Plat. 
Number of vines, date, 
and manner of treat¬ 
ment. 
Yield of 
sound 
fruit 
per plat. 
Average 
yield 
per vine. 
Number 
of rotten 
berries 
per plat. 
Number 
of rotten 
berries 
per vine. 
Total rot 
per plat 
in pounds 
of sound 
fruit. 
Percent¬ 
age of 
loss. 
Total 
cost of 
treat¬ 
ment 
A.... 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with Bor¬ 
deaux mixture. 
Pounds. 
260 
Pounds. 
5.20 
275 
5. 50 
1.56 
.6 
Cents. 
.54 
B.... 
8 untreated vines. 
23 
2. 87 
2,464 
308 
14 
38 
. 00 
C .... 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with ammoni- 
acal copper carbonate 
solution. 
255 
5. 10 
236 
4. 72 
1.34 
.6 
.22 
D .... 
8 untreated vines. 
20 
2.50 
2,816 
352 
16 
45 
.00 
E .... 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with Bor¬ 
deaux mixture and am- 
moniacal solution. 
255 
5. 10 
188 
3. 76 
1.06 
.4 
.40 
E .... 
8 untreated vines. 
20 
2.50 
2, 827 
353 
16 
45 
.00 
Gr . - -. 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with modified 
eau celeste. 
260 
5. 20 
68 
1.36 
.33 
. 1 
Not 
given. 
H... 
8 untreated vines. 
24 
3 
2, 466 
308 
14 
37 
.00 
I . 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with copper 
carbonate in suspen¬ 
sion . 
246 
4.92 
268 
5.36 
1.52 
.6 
. 11 
J .... 
8 untreated vines. 
18 
2. 25 
2, 998 
375 
17 
48 
. 00 
K.... 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with milk of 
lime . 
190 
3. 80 
8, 599 
172 
48. 86 
20 
.03 
Ii • • . a 
8. untreated vines . 
20 
2. 50 
2,819 
352 
16 
45 
.00 
M.... 
50 vines treated Api'il 30, 
May 15 and 30, and 
June 14, with Bordeaux 
mixture prepared in 
advance . 
230 
• 
4.60 
367 
7. 34 
2. 08 
.9 
. 54 
N ... 
8 untreated vines . 
22 
2. 75 
2,126 
266 
12 
35 
. 00 
O .. 
50 vines treated April 30, 
May 15 and 30, and 
June 14, with Bordeaux 
mixture, one-half 
strength prepared in 
advance . 
180 
3. 60 
8, 730 
174.60 
49. 60 
21.50 
.27 
1 J .... 
8 untreated vines . 
17 
2.12 
2, 372 
284 
13 
43 
,00 
