PICKERING SPRAYS. 
25 
IN VIRGINIA. 
It was considered impracticable to attempt to determine the 
weight of grapes from the different plats in Virginia. From the three 
rows sprayed with Bordeaux 26 crates of grapes were obtained, an 
average of 8§ crates per row. From the 20 rows of grapevines sprayed 
with the Pickering sprays 26 crates of salable grapes were secured, 
an average of 1.3 crates per row. No grapes were harvested from 
the unsprayed check rows. Not all of the grapes from the plats 
sprayed with Pickering spray were picked, as some of the fruit was 
small and immature. 
Adherence of Copper From Various Sprays to Leaves, 
in new jersey. 
Duplicate samples of leaves from the plats treated with the various 
sprays were gathered on June 6 (10 days after the second spraying) 
and on June 8 (12 days after the second spraying). Forty leaves 
from each set were analyzed, the results obtained on those gathered 
oh June 6 being shown in Table 8. The area of one side only of the 
leaves was considered in calculating the area figures. The outlines 
of the fresh leaves were traced on paper, and the tracings later meas- 
ured by a polar planimeter (p. 17). 
Table 8. — Adherence of copper from various sprays 
to grape 
leaves. 
Spray used. 
Copper 
sulphate 
in spray 
used. 
Copper adhering to leaves. 
Plat No. 
Parts 
per 
million 
(dry 
basis). 
Parts. 
per 
million, 
per 0.1 
per cent 
CuS0 4 
in spray. 
Mg. per 
square 
meter 
of leaf 
surface. 
Mg. per 
square 
meter 
of leaf 
surface 
per 0.1 
per cent 
CuS0 4 
in spray. 
New Jersey: 
B ....... . 
Bordeaux, 3-3-50 
Per cent. 
0.75 
.64 
.38 
.38 
.13 
.065 
.23 
.115 
.36 
1,459 
982 
750 
709 
383 
110 
110 
184 
285 
11 
1,440 
191 
18 
392 
321 
194 
153 
197 
187 
295 
170 
48 
160 
80 
64.0 
46.2 
?9.9 
27.8 
14.1 
.4 
4.2 
6.2 
10.5 
.4 
44.6 
6.9 
.7 
16.1 
8.5 
1.. . 
Pickering (A ) 
7.2 
2 
do 
7.8 
?a. 
Pickering (A) and rosin-fish-oil soap. 
Piekenng (A) 
7.3 
3... 
10.8 
4 
do 
.6 
5. . 
Pickering (C) 
1.8 
6 
7. . 
do 
do 
5.4 
3.0 
Check 
Virginia: 
A 
Bordeaux, 3-3-50 
0.75 
.64 
.38 
.38 
.13 
.23 
.36 
192 
30 
5 
103 
6.0 
1 
Pickering (A) 
1.1 
2 
do 
.2 
2b 
Pickering (A) and rosin-fish-oil soap. 
4.2 
3 
5 
Pickering (C) 
76 
89 
5.6 
12.8 
2 4 
7 
do 
3.6 
Check 
1 Trace. 
The area results show more decisively than do the weight results 
that the copper from the Pickering (A) sprays adhered to the leaves 
in proportionately greater amounts than did that from the Pickering 
