REMEDIAL MEASURES. 
73 
Table XXVII. — Effect of poison spray against the grape root-worm as shown by occur- 
rence of larvie at roots of vines in sprayed and uns prayed plats in I)ai idson < ineyard 
in 1907, 1908, and 1909, at North East '. Pa. 
DIGGINGS MADE IN SUMMER OF 1907. 
Number of larva?. 
Date of examination. 
Number 
of vines. 
Variety and age of 
vines. 
u„. 
sprayed 
plat. 
Sprayed 
plat. 
September 5, 1907 
1 
Young Concord. . . 
Old Concord 
92 
G 
Do 
1 
91 
H 
1 
Do 
1 
Young Niagara 
0 
DIGGINGS MADE IN SUMMER OF 1908. 
August 26, 1908 
August 25, 1908 
Do 
Young Concord. . 
Old Concord 
Young Niagara... 
214 
40 
86 
4 
58 
5 
DIGGINGS MADE IN SUMMER OF 1909. 
September 8-9, 1909 ... 
September 10-15, 1909 . 
September 11-15, 1909. 
Young Concord. . . 
Old Concord 
Young Niagara.... 
39 
0 
13 
0 
17 
0 
Table XXVIII. — Davidson vineyard. Effect of spray applications on the crop yield 
for the seasons 1908 and 1909 at North East, Pa. 
FOR SEASON OF 1908. 
Year. 
Variety and age of 
vines. 
Treatment. 
Plat 
Plat 
yield. 
/alue per Value per SmSt 
basket. acre. 
1908 
1908 
1908 
1908 
1908 
Young Concord Sprayed '. 
.do Unsprayed.. 
Acre. 
Old Concord. 
do 
Young Niagara . 
Sprayed. 
Unsprayed... 
Sprayed. 
.do Unsprayed. 
Lb.baskets 
101.8 
81.8 
502.0 
455.0 
231. 4 
150.4 
Cents. 
13 
13 
13 
13 
9 
9 
$26.26 
21.06 
80. 97 
78.91 
62. 37 
40. 50 
FOR SEASON OF 1909. 
1909 
1909 
1909 
1909 
1909 
1909 
Young Concord 
do 
Old Concord... 
do 
Young Niagara 
do 
Sprayed... 
Unsprayed 
Sprayed... 
Unsprayed 
Sprayed... 
Unsprayed 
1 
I 
435.8 
11 
$95. 70 
$47. 9*1 
i 
217.0 
11 
47. 74 
■ 
1.039.0 
11 
152. 35 
39. 70 
3 
836. 0 
11 
112. 65 
| 
158.2 
28 
132. 72 
61.32 
J 
85.0 
28 
71.40 
The effect of the spray on egg deposition was obtained by stripping 
all of the loose bark from 25 consecutive vines in the sprayed portion 
and also in the check rows, making an actual count of the number of 
egg clusters deposited on an equal number of consecutive vines in the 
sprayed and unsprayed plats. This has proved to be one of the best 
w T ays to determine the immediate direct effect of spray applications. 
These examinations were made at a time, determined by careful 
