SOIL DISINFECTION WITH HOT WATER. 



Table I. — Soil-didnfvction tests with tomato plants grown in 4-inch and 8-inch pots , 

 ivith hot-water treatment, in February and March, 191S. 



(All the pots were filled with nematode-infeslod soil thoroiichly mixed liy siftint;, soil A being without the 

 addition of diseased lomalo roots and soil B having such addiliou.] 



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 



P5 



.2 o 



a I 



2 '3 



f^2 



Plant notes. 



Hcighl 

 (inch- 

 es). 



Col- 



Four-inch pots, soil A : 



Immersed in boiling water — 



2J minutes 



10 minutes . 



Check (immersed in cold water). 



Four-inch pots, soil B: ■ 



Immersed in boiling water — 



2J minutes 



5 minutes . 



Eight-inch pots, soil A : 



Boiling water poured into pots — 



1,000 CO 



3,000 c.c. 



Check (drenched with cold water)... 



Eight-inch pots, soil B: 



Boiling water jjoured into pots — 



1,000 c.c 



2,000 c.c 



3,000c.c 



1« 



1» 



il 



^20. 5 



° 1 



16.7 



Wh 



Wh 



Wh 

 Db 



fMd. 



JWh 



Wh 



Wh 



Wh 



Nad 



Db 



Nad 



Sd. 



Wh 



5 to 6. 



5 to 7. 



..do.. 



5 to 6, 



5 to 7. 



.do.. 



k to 5. 



..do.. 



4 to 5. 



.do. 



Hg. 

 Hg. 



Hg. 



Sg. 



Hg. 

 Hg. 

 Hg. 



3 to 4. 1 Yg. 

 Dhg. 



Dhg. 



Sg. 



Yg. 



Dhg. 



Dhg. 



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 xjlanting. 



