10 



BULLETIlSr 818^ U. S. DEPARTMENT OF AGRICULTURE. 



Photographs were taken to illustrate the more important results 

 secured. 



Table III. — Soil-disinfection tests with tomato plants grown in 4-inch pots, with hot 

 water treatment, in May and June, 1918. 



[Two kinds of soil w'ere used: Soil A was nematode and fungus infested; B was uninoculated fresh green- 

 house soil.J 







Num- 



Results observed on June 12 (end of experiment). 























ber of 









Rhizoc- 













plants. 



Nematode infestation 



tonia in- 



Notes on disease, size, and vi 



gor of 













of roots. 



fection of 





plants. 





Kind of soil and 















roots. 









treatment of 























soil-filled pots. 

















«4-l 



















cq 













u 















d 



03 



a 



1-5 



> 



3 



2 



3 



1 







With 

 stem 

 galls. 



Damped- 



Height 

 (inches). 



Vigor.i 





^ 



o 



O 



m 



'^ 



s 



H 



Ph 



^ 



(i 









Soil^: 













j 

















Immersed in 































boiling 































water— 

































( 1 



40 



41 































None 



None.... 



4to5|... 



1 



2J minutes 



\ 2 



8V 



37 































...do 



...do 



...do 



Ihv. 





h 



46 



48 































...do 



...do 



...do 



1 





1 1 



47 



47 































...do 



...do 



...do 



1 



."i Tninntes 



\ 2 



■6H 



38 































...do 



...do 



...do 



^HV. 





u 



4tt 



46 































...do 



...do 



...do 



1 





( i 



48 



49 















. 















...do 



...do 



...do 



1 



10 minutes 



\ 2 



51 



■49 































...do 



...do 



...do 



^HV. 





Is 



55 



65 































...do 



...do 



...do 



1 



Check (im- 



( 1 



37 



33 



23 



4 



6 



33 



100 



30 



91 



Several.. 



Some 



I* to 2... 





mersed i n 



1 2 



38 



33 



17 



10 



6 



33 



100 



33 



100 



...do 



4 



2 



isY. 



cold water). 



b 



25 



lo 



14 







1 



15 



100 



15 



100 







5 



li 





Soil B: 































Immersed i n 































boiling 































water— 

































1^ 



51 



49 































None.... 



None 



4to5i... 





2i minutes 



70 



70 































...do 



...do 



...do 



Ihv. 





l3 



71 



67 































...do 



...do 



5J 





■ 4 



( 1 



51 



51 























2 



4 



...do 



...do 



4to5J... 





5 minutes. 



2 



55 



57 































...do 



...do 



...do 



[hv. 





|3 



37 



34 































...do 



...do 



...do 







1 1 



58 



.50 























2 



4 



...do 



...do 



...do 



1 



10 minutes 



\ 2 



88 



38 























1 



3 



...do 



...do 



...do 



mv. 





Is 



50 



50 























1 



2 



...do 



...do 



...do 



1 





f 1 



47 



40 











6 



6 



15 



35 



87 



1 



2 



1* 





Check (im- 

 mersed i n 

 cold water). 



2 

 3 

 4 



22 

 36 

 20 



23 

 34 

 21 





 

 





 

 



7 

 8 

 11 



7 

 8 

 11 



30 

 23 

 52 



3 



18 

 16 



13 

 70 



76 



























2 



2 



14 to 2... 



(2) 



h 



23 



24 











12 



12 



oO 



10 



41 



2 



4 



2i 







I 6 



19 



17 











1 



1 



6 



6 



35 







2 



2 





1 Abbreviations used: HV=Healthy and vigorous; SY=Stunted and yellow. 



2 Much smaller than in treated soil. 



DISCUSSION OF RESULTS. 



A close study of Table III reveals a striking confirmation of the 

 results secured in the 4-inch pot treatments of Experiment Series I. 

 All treatments completely eliminated nematode infection and damp- 

 ing-ofl, almost eliminated Rhizoctonia, greatly increased the percent- 

 age of germination, and markedly stimulated the growth of the 



