34 
BULLETIN 1451, U. S. DEPARTMENT OF AGRICULTURE 
Table 11. — Summary of treatments of individual, marked barberry bushes with 
furfural 
Date of 
treat- 
ment 
Date of 
final 
observa- 
tion 
Quantity 
of chemi- 
cal per 
bash 
Method of 
application 
Bushes cut off or 
left standing 
I Location of area 
Bushes 
treated 
Bushes 
killed 
Per- 
centage 
killed 
July 15 
Aug. 15 
Oct. 17 
July 15 
Aug. 15 
Oct. 17 
July 15 
Aug. 15 
Oct. 17 
July 15 
Aug. 15 
Oct. 17 
July 15 
Aug. 15 
Oct. 17 
July 15 
Aug. 15 
Oct. 17 
Total . 
1925 
May 22 
...do 
...do 
...do 
—do 
...do 
...do i 
...do 
—do 
—do 
...do 
--do 
—do 
...do 
—do 
—do 
...do 
—do 
Pints 
Drench. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
do.. 
Cut off... 
do.... 
do.... 
Standing. 
do 
do- 
Cut off 
do.... 
do.... 
Standing. 
do.... 
do.... 
Cut off... 
do— 
do.... 
Standing. 
do./.. 
do.... 
. Gurnee, 111. 
do 
do 
do-.-t— 
J do 
do 
do 
.1 do 
. ; do 
do 
. do 
do 
. do 
do 
. do 
. do. 
.1 do 
. do 
80 
80 
100 
60 
80 
80 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
S4 
93 
It is probable that an application of -2 quarts per bush would be 
a safe application to recommend for general use, although more trials 
should be made before any general recommendation is made. 
Furfural is only very slightly soluble in water, and it is probable 
that the failure of 1 pint per bush to produce death in every case is 
due, to the poor distribution of the chemical in the soil. In all the 
experiments large quantities of dilute solutions have been more 
effective than small quantities of concentrated chemicals. If furfural 
could be diluted with some cheap liquid, thus increasing its volume 
without a corresponding increase in cost, it might be a very satis- 
factory herbicide, even at its present cost. 
PETROLEUM GAS OIL 
Petroleum gas oil is a distillation product of petroleum and is used 
in the manufacture of gas. It is a light oil with a kerosenelike odor, 
but is considerably heavier than kerosene. It was quoted at 7 cents 
a gallon; delivery charges would have to be added, however, thus 
considerably increasing the cost in the field. 
No greenhouse tests were made with this material. The results of 
the field tests are shown in Table 12. 
Table 12 shows that out of 153 bushes treated only 4 lived, and 3 
of these were treated by applying the oil in a circle around the crown 
rather than as a drench directly around the base of the stalks of the 
plants. As none of the chemicals studied produced satisfactory re- 
sults when applied in a circle around the bush, these two treatments 
need not be considered. It then appears that but 1 bush out of 113 
survived, or that over 99 per cent were killed. This places petroleum 
gas oil among the very best chemicals studied, from the standpoint 
of effectiveness. It also ranks high from the standpoint of cost, but 
when availability is considered, this reduces its ranking. However, 
in a few localities it is readily available and should be given con- 
sideration. 
