SOIL DISINFECTION WITH HOT WATER. 5 
Table I. — Soil-disinfection tests with tomato plants grown in 4-inch and 8-inch pots , 
with hot-water treatment, in February and March, 1918. 
[All the pots were filled with nematode-infested soil thoroughly mixed by sifting, soil A being without the 
addition of diseased tomato roots and soil B having such addition.] 
Size of pots, kind of soil used, and 
treatment of soil-filled pots. 
Number 
of living 
plants. 
Results observed on Mar. 7 (end of experiment). 
Nematode infestation of roots, 
Percentage, 
Plant notes. 
Height 
(inch- 
es). 
Four-inch pots, soil A : 
Immersed in boiling water- 
2§ minutes 
5 minutes . 
10 minutes . 
Check (immersed in pold water) . 
Four-inch pots, soil B: 
Immersed in boiling water — 
2?> minutes . 
5 minutes . 
10 minutes 
Eight-inch pots, soil A : 
Boiling water poured into pots 
1,000 c.c. 
2,000 c.c. 
3,000 c.c. 
Check (drenched with cold water). 
Eight-inch pots, soil B: 
Boiling v/ater poured into pots— 
1,000 c.c 
2,000 c. c. 
3,000 c. c. 
46 
J.83 
20.5 
8.8 
19.6 
16.7 
Wh 
Wh 
Wh 
Db 
(Md. 
Wh 
Wh 
Wh 
Wh 
Nad 
Nd 
Sd. 
Wh 
Wh 
Db 
Nad 
Sd. 
Wh 
5 to 6. 
5 to 7. 
..do 
.do... 
to 4. Yg. 
.do 
..do.. 
1 Abbreviations used: Db= Discolored, badly diseased; Dhg=Dark, healthy green; Hg= Healthy 
green; Md= Many discolored; Nad= Nearly all discolored; Sd= Slight discoloration; Sg= Sickly green: 
Wh= White, healthy; Yg= Yellow green. 
2 Two weeks after planting. 
