26 BULLETIN 169, U. S. DEPARTMENT OF AGRICULTURE. 
Table VI. — Injury to pines and weeds by miscellaneous disinfectants — Continued, 
Disinfectant. 
Days from 
treatment 
to- 
Injury to pines. 
Plat. 
Substance 
used. 
Per square 
foot. 
Sow- 
ing. 
Weed 
exami- 
nation. 
Weeds present in 
plats. 
Ounces. 
Solu- 
tion. 
P. divaricata: x 
Series 519 (6 
None 
Pints. 
M o 1 1 u g o very 
abundant, f ol - 
lowed by grass, 
Amaranth us. 
Portulaca, and 
Euphorbia in the 
order named. 
checks). 
F 
Ammonia 2 
Mercuric chlo- 
rid. 
(....do 
•(Sodium chlo- 
[ rid. 
Lime-sulphur 
do 
Ferrous sul- 
phate. 
Cupric sul- 
phate. 
Hydrochlori c 
acid. 
Nitric acid 
(....do 
\Sulphuric acid 
do 
do 
do 
Heat, 80° C. or 
greater for 
not less than 
10 minutes. 
do 
0.5 
.063 
.063 
.188 
.313 
.75 
.5 
.281 
.562 
1.125 
.188 
.125 
.25 
.25 
.375 
( 4 ) 
( 5 ) 
2 
2 
} 2 
2 
2 
2 
3 
3 
3 
1 
1 
2 
3 
3 
34 





34 

34 
34 

34 
34 
34 
Few 
Few 
66 
32 
32 
32 
32 
32 
66 
32 
66 
j- 32 
66 
66 
66 
32 
32 
Record lost 
( 3 ) 
All seed killed 
Three-fourths o f 
the seed killed 
by unknown 
factor. 
Germination good. 
Record lost 
Moderate to heavy: 
Very heavy 
Record lost 
Very slight 
Record lost 
do 
do 
None 
U 
V 
None. 
Do. 
R 
s 
L 
Records lost. 
None. 
Nearly as many as 
in checks. 
Do. 
Grass, very few 
plants at edge of 
plat. 
Do. 
Do. 
K 
P 
M 

C 
D 
A 
H 
Grass and Mollugo, 
each 7 or 8 plants; 
Amaranthus, 1. 
Grass, 3 plants. 
Grass, 7 or 8 plants. 
Grass, 7 or 8 plants; 
Portulaca, 1 or 2. 
G 
do 
1 Watered 0.3 inch, twice daily. 
2 Plats covered tightly for 3 days after treatment to prevent too early evaporation. 
3 Nearly all seed killed; heavy injury to those which germinated. 
4 Upper 2\ inches of soil heated. 
6 Upper 6 inches of soil heated. 
DISCUSSION OF MISCELLANEOUS DISINFECTANTS. 
HYDROCHLORIC AND NITRIC ACIDS. 
Hydrochloric and nitric acids were used in series 501, plats C and 
J; 512, plats A, C, D, F, G, and K; 514, plats F and G; 516, plats 
A and C; 518, plats F and P; and 519, plats M, O, and P (Table VI). 
Injury by them seems to take place in just the same way as that 
caused by sulphuric acid, and the injured seedlings presented the 
same appearance as those injured by sulphuric acid. (See PI. I, 
figs. 2 and 3.) Pine seeds were not killed by the amounts used at 
sowing, but the apices of the radicles in some plats were killed by 
the acid residue in the surface soil after germination began. Injury 
may be prevented, as with sulphuric acid, by waterings sufficiently 
frequent to prevent the concentration of the acid in the surface soil. 
« 
