16 
BULLETIN 837, IT. S. DEPARTMENT OF AGRICULTURE. 
pounds to 50 gallons, equivalent to 5 pounds of paste to 50 gallons, 
as a basis for comparison that year. The lj-pound rate was used 
in but two vineyards in 1916. In 1917 the 2J-pound rate was retained 
in four vineyards and the lj-pound used in seven. In 1918 compari- 
son was made between 1 pound and 1J pounds of arsenate of lead 
powder. 
Table VI.- 
-Relatlve efficiency of arsenate of lead at the rate of 1, 11, and %\ 
pounds {powder) to 50 gallons liquid, * 
Spray appli- 
cations. 
Percentage of infested grape berries. 
© 
ft 
a 
(4 
Catawba va- 
riety. 
Concord va- 
riety. 
Ives variety. 
Pounds of arsenate lead 
© 
3 
o . 
>-> 
powder to 50 gallons 
liquid 
Hi a 
F-l 
03 © 
©-W 
a 
V 
© 
03 
ft 
© 
d 
C3 
© 
© 
© 
« 

© 
"c3 
ft 
© 
© 
C 
8 
c3 
ft 
© 
>> 
© 
© 
1 
© 
a 
© 
C3 
C3 
c3 
03 
C3 
•(J 
3 
3 
g 
|M 
T3 
ft 
T3 
<o 
M 
& 
£ 
> 
02 
< 
02 
■^ 
m 
«! 
SEASON 1916. 
{I 
X 
X 
2 
3 
4 
6 
0.93 
11.90 
81. 12 
70.26 
1J 
5.56 
52.83 
2 
3 
6.42 
75.69 
5.56 
52. S3 
{I 
X 
X 
2 
3 
4 
6 
3.25 
3.34 
64.52 
43.32 
2£ 
10.41 
64.39 
2 
3 
10.41 
64.39 
3.30 
53.92 
SEASON 1917. 
f X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
1 
2 
3 
4 
5 
6 
7 
2.03 
8.86 
64.09 
78.17 
0.47 
61.61 
11 
5.84 
63.03 
.84 
.18 
2.66 
32.11 
20.60 
88.03 
0.43 
2.94 
20.14 
1.48 
42.00 
19.59 
7 
10 
4.55 
61.82 
1.04 
50.59 
1.68 
19.86 
II 
X 
X 
X 
X 
1 
2 
4 
6 
.67 
6.47 
7.72 
64.09 
79.31 
79.63 
2\ 
""".48" "36."ii" 
2.11 
39.67 
4 
5 
4.95 
74.34 
.48 
30.14 
2.11 
39.67 
SEASON 1918. 
f X 
J X 
1 x 
1 x 
X 
X 
X 
X 
1 
2 
3 
4 
0.86 
7.85 
4.78 
68.02 
0.41 
1.00 
2.54 
6.28 
4 
4 
4.78 
68.02 
.71 
4.41 
.S6 
7 85 
{I 
X 
X 
1 
1 
2 
2.08 
6.93 

7.39 
62.36 
2 
2 | 
7.39 
62.36 
2.08 
6.93 
1 All plats received Bordeaux 2-3-50 and resin soap 1 pound to 50 gallons in 1917 and 1918. Same in 1916, 
exceptlaundry soap 2pounds to 50 gallons, first application; and second application vineyards Nos. 5 and 6. 
