ERADICATING THE COMMON BAEBEEKY 
35 
Table 12. — Summary of treatments of individual, marked barberry bushes ivith 
petroleum gas oil 
Date of treat- 
ment 
j Quan- 
Date of final SXj ? Method of ap- 
observation j ™f™£ plication 
bush 
1 
Bushes 
cut off or Location of 
left stand- area 
ing 
Bushes 
treated 
Bushes 
killed 
Per- 
centage 
killed 
Apr. 28,1922 
Do 
Oct. 8, 1921 
Do 
Oct 31,1921 
July 10,1922 
Do 
Oct. 16.1922 
\Gallons 
July 3, 1923 1. In circle of 1- 
foot radius. 
do 1 1.0 do 
June 29,1923| 1.0 Drench 
do. J .5 do 
July 3,1923; 1.4 do _. 
do _ 1.0 do 
do ; 1.0 do 
do 1.0 do 
Standing. Gurnee, 111.. 
Cutoff— J do 
Standing.' BlackEarth, 
1 Wis. 
Cutoff... do 
Standing.! Gurnee, 111.. 
...do ■ do 
Cutoff...' do - 
Standing.! do 
20 
20 
10 
20 
36 
20 
20 
7 
18 
19 
10 
20 
36 
20 
19 
7 
90 
95 
100 
100 
100 
100 
95 
100 
Total..! .!. 
153 
149 
97 
1 1 : 
1 
GASOLINE 
Gasoline tried on potted barberries killed the plants in two weeks 
when 21 cubic centimeters was applied to the surface of the soil. The 
action was slow, but death finally resulted. Twenty-one cubic centi- 
meters applied to an 8-inch pot is the equivalent of about 0.5 gallon 
in the field. At about 11 cents a gallon the price was very satis- 
factory, and it was thought worth while to make further tests. The 
results of field tests, given in Table 13, justify this decision. 
Table 13. 
-Summary of treatments of individual, marked barberry bushes with 
gasoline 
Quantity 
! Bushes 
Per- 
Date of 
Date of final 
of chem- 
Method of ! cut off 
Location of 
Bushes 
Bushes 
treatment 
observation 
ical per 
application i or left 
area 
treated 
killed 
killed 
bush 
j standing 
Gallons 
| 
May 5,1923 
July 15,1924 
0.5 
Drench. _. Cutoff 
Gurnee, 111... 
10 
8 
80 
July 3. 1923 
July 14,1924 
.5 i...do ...do 
do. 
7 
7 
100 
Aug. 10,1923 
do. 
.5 ...do ...do. 
do.. 
10 
3 
30 
Sept. 10. 1923 
do. 
.5 
...do L.-do 
do-. 
5 
5 
100 
May 5. 1923 
July 15,1924 
.5 
...do Standing.. 
do. 
8 
8 
100 
July 3, 1923 
July 14,1924 
.5 
...do L.-do 
do.. 
7 
4 
57 
Aug. 10. 1923 
do._ 
.5 
...do L..do 
do 
10 
10 
100 
Sept. 10, 1923 
do.. 
.5 
...do L.-do 
do 
5 
5 
100 
Oct. 16,1922 
July 3, 1923 
1.0 
...do. J Cutoff 
do._ 
20 
20 
100 
May 5, 1923 
July 15,1924 
1.0 
...do. L_-do 
do-. 
10 
10 
100 
Aug. 10, 1923 
July 14,1924 
1.0 
...do ...do 
do. 
10 
10 
100 
Sept. 10, 1923 
do.- 
1.0 
— do. ...do 
do. 
5 
5 
100 
Oct. 16,1922 
July 3, 1923 
1.0 
...do. ' Standing.. 
do.. 
20 
20 
100 
May 5,1923 
July 15,1924 
1.0 
...do ...do. 
do. 
10 
10 
100 
July 3. 1923 
July 14,1924 
1.0 
...do !...do. 
do- 
10 
7 
70 
Aug. 10. 1923 
do. 
1.0 L.-do !...do 
do 
10 
■ 10 
100 
Sept. 10, 1923 
d'o.. 
1.0 i— do. ...do 
1 
do._ 
5 
5 
100 
Total. . 
162 
147 
91 
i ! 
In the study of other chemicals it had been determined that an 
application was most effective in killing a barberry bush when ap- 
plied as a drench to the ground among and around the bases of all 
shoots of the plant. This method was, therefore, followed with 
gasoline. The unknown point was the quantity necessary to kill a 
bush of given size and whether this w T ould be equally effective at 
