The Dandelion in Colorado 
15 
METHODS USED AND RESULTS OBTAINED IN 1915 
1 
Plat No. 
Treatment 
of Plat 
Dates 
Plants 
Number of 
Percentage 
of Plants 
Killed 
Cost of 
Treatment 
Material 
Used 
Labor, 
Minutes 
Before 
After 
1 
Check 
plat, un¬ 
treated 
— 
659 ! — 
! 
—- 
— 
^ I _ 
i 
0 
Sprayed 
once with 
solution 
July 6 
859 
696 
19 
$.04 
1 
1 gal. 1 4 
1 
3 
Sprayed 
twice with 
solution 
July 6 1 630 
and 21 | 
349 
45 
.08 
2 gals. 
8 
4 
Sprayed | July 6 
3 times | and 21 
with solu- ! Aug-. 5 
tion 1 
913 
10 
98.9 
.12 1 3 gals. 
1 
1 
1 
12 
1 Check 1 1 
r> j plat, un- 1 — 1 1031 
1 treated I I 
— 
— 
_ ! _ 1 _ 
! i 
6 
Gasoline 1 
put on 1 July 3 
each 1 and 10 
plant 1 
634 
32 
95 
.25 
0.33 gals. 
55 
7 
Two appli- 1 
cations of 1 .Tuly 13 
dry iron | and 28 
sulphate 1 
649 
80 
Esti¬ 
mated 
.15 
4.75 lbs. 
15 
1 Check 
S 1 plat, un- 
1 treated 
■—- 
520 
1 
1 
1 1 
~ 1 1 
9 
All plants 
dug out 
June 30 
665 
235 1 64.7 
1 
"0 1 - 
120 
10 
One late 
spraying 
with iron 
sulphate 
solution 
Sept. 21 
650 
233 
64 
.04 
1 gal. 
4 
The solution of iron sulphate used was made by dissolving 
D4 pounds of the dry granular salt in each gallon of water, thus 
making approximately a 15-percent solution. The pump used was 
an ordinary bucket spray pump with an extra length of hose at¬ 
tached and with a three-foot stick wired to one side near the nozzle 
to serve as a handle in directing the spray (Fig. 12). In most cases 
two men worked together, one to operate the pump while the other 
held the nozzle. 
The costs were determined upon an estimate of 20 cents per 
hour for labor and 2 cents per pound for granular iron sulphate, 
delivered in 100-pound bags. These figures, while true at the time 
of starting the experiments, are possibly somewhat low at the 
present time. The lawn was well sodded and was well cared for 
during the experiment. It was not allowed to suffer by drought 
and was clipped about once a week during the season of active 
growth. The low results following the first spraying of Plats II, 
