214 



M. M. McCooL 



TABLE 10— (concluded) 



Experiment with MgCU 



Composition of solution 



Length 



of tops 



(centimeters) 



Length 



of roots 



(centimeters) 



Notes on condition 

 of roots 



N/3MgCl2 



N/5 MgCl2 . 





 Shght 

 1.25 

 2.50 







Slight 

 5.00 

 8.75 



Lateral roots very short 

 Few short lateral branches 

 No injury 



N/10 MgCU 



N/20MgCl2 





Experiment with KCl 



Composition of solution 



Length 



of tops 



(centimeters) 



Length 



of roots 



(centimeters) 



Notes on condition 

 of roots 



N/1 KCl 



N/3 KCl 





 



1.25 

 1 25 





 



2.50 

 5.00 





N/5 KCl 



Great injury 



N/10 KCl 



Slight injury 









Experiment with XHiCl 



Composition of solution 



Length 



of tops 



(centimeters) 



Length 



of roots 



(centimeters) 



Notes on condition 

 of roots 



N/3 NH,C1 





 



1.85 

 2.50 





 



5.00 

 5.25 





N/5 NHiCl 





N/10 NHiCl 



Slight injury 



N/20 NHiCl 



No injury 







CONCLUSIONS 



Barium, strontium, ammonium, magnesium, sodium, and potassium, 

 in the order given, when present in pure solution are verj^ toxic to seed- 

 lings. This toxicity is greatly reduced by either full nutrient solutions 

 or soil cultures. 



