Nov. 11 ,1916 Nicotine-Sulphate and Fish-Oil-Soap Sprays 
39i 
Table I .—Combined data of spraying experiments with nicotine sulphate and fish-oil 
soap in IQ14 and IQ15 at Norfolk , Va. 
Group No. 
Plot. 
(Macrosiphum) Acyrthosi - 
phum pisi (5 sprayings). 
Num¬ 
ber of 
Myzus 
persicae 
killed. 
Num¬ 
ber of 
T etra- 
nychus 
sp. 
killed. 
Wetting 
power of 
solutions. 
Nicotine 
in the 
sprays. 
Number 
alive 
before 
spraying. 
Number 
alive 
after 
spraying. 
Num¬ 
ber 
killed. 
Per ct. 
Per ct. 
Per ct. 
Per ct. 
I . 
13 
1,343 
336 
75- 0 
72.5 
79. 6 
103 
O. 0650 
I . 
9 
1,614 
308 
80. 9 
82. O 
83-3 
193 
. 0650 
4 
i, 567 
144 
90. 8 
88.9 
90. 8 
615 
.0650 
10 
1,830 
242 
86.8 
85.2 
86.9 
628 
. 0650 
11 
!> 353 
199 
85-3 
8 s -9 
86.9 
743 
.0650 
12 
i,359 
270 
80. 1 
79.8 
82.8 
75° 
. 0650 
6 
1,289 
320 
75*2 
75*i 
80. 0 
788 
. 0215 
' 7 
1,191 
355 
70. 2 
66.5 
76. 8 
754 
. 0260 
3 
1, 282 
83 
93-5 
93-8 
95- 0 
743 
.0425 
8 
1, 246 
5 1 
95*9 
95* 1 
95*o 
732 
•0575 
10 
1,830 
242 
86.8 
85.2 
86.9 
628 
. 0650 
2 . 
18 
1, 462 
934 
36. 1 
34. 9 
60, 5 
181 
• 0215 
O 
3 . 
17 
741 
51.6 
52- 1 
66. 4 
. 175 
. 0260 
3 . 
16 
1,391 
522 
62.5 
59*9 
7 1 * 4 
163 
• °3 2 5 
3 . 
15 
i>435 
445 
69. 0 
69.7 
76.9 
154 
.0425 
3 . 
14 
1,406 
404 
71*3 
7o*3 
76.9 
125 
•0575 
3 . 
13 
i,343 
336 
75* 0 
72.5 
79.6 
103 
. 0650 
4 . 
19 
i,499 
955 
36- 3 
34* 7 
60. 6 
307 
O 
4 . 
20 
1, 579 
846 
46.4 
45*3 
68.8 
363 
O 
4 . 
21 
1, 681 
891 
47.0 
44*9 
69. 0 
45° 
O 
4 . 
22 
1, 406 
600 
57*3 
55-2 
64. 4 
645 
O 
4 . 
23 
564 
575 
63. 2 
60. 1 
74- 5 
689 
O 
4-. 
24 
1,344 
497 
63. 0 
60. 3 
7i* 5 
1,067 
O 
4 .. 
25 
1,487 
39i 
73* 7 
75* 0 
78. 0 
1, 080 
O 
4. 
27 
1,334 
33i 
75* 2 
74.2 
82. 0 
1,106 
0 
4. 
27 
1, 466 
365 
75* 1 
74. 8 
82. 0 
1,112 
0 
FORMULAE TESTED 
In the preparation of contact sprays to be applied to tender plants 
the concentration of the solutions is limited between a minimum which 
is a strength sufficient to kill all the insects which it strikes and a maxi¬ 
mum which is the greatest concentration that can be applied without 
injury to the foliage. In the experiments on peas or young spinach the 
greatest concentration which could be used without injuring the plants 
was 8 pounds of soap 1 to 50 gallons of water, or a i-to-534 concentration 
of nicotine sulphate. The minimum concentration was not so sharply 
defined. 
It was the writer’s endeavor to try, so far as possible, such practical 
combinations of the two materials as were at all likely to give satisfac¬ 
tory results. In order to make the formulae more comprehensive, they 
1 A standard caustic-potash fish-oil soap was used throughout these experiments. 
