162 



M. M. McCooL 



TABLE 30. 



Experiment with Canada Field Pea. 

 FOR Ten Plants 



Duration, Thirty Days. Data 



Composition of solution 



N/10CaCl2+N/50SrCl2, 

 N/10 CaCU+N/lOO SrCh 

 N/10 CaCl2+N/500 SrCh 

 N/100 CaClo+N/50 SrCU 

 N/50SrCl2 



N/100 SrCl2 



N/500 SrCl2 



N/10CaCl2 



Distilled water 



Full nutrient solution 



Green 

 weight 

 of tops 

 (grams) 



7.50 

 9.00 

 7.64 

 5.36 

 Dead, weight 



not given 



Dead, weight 



not given 



5.50 



9.75 



5.40 



10.40 



Green 

 weight 

 of roots 

 (grams) 



7.30 

 5.90 

 5.75 

 4.45 



4.45 



5.60 

 4.27 

 6.00 

 3.55 

 8.65 



Total 



green 



weight 



(grams) 



14.80 



14.90 



13.39 



9.81 



9.77 

 15.75 



8.95 

 19.05 



Average 

 length 

 of tops 

 (centi- 

 meters) 



15 

 15 

 16 

 12 



7 

 11 

 17 

 10 

 15 



Average 

 length 

 of roots 

 (centi- 

 meters) 



9 



8 

 7 

 8 



11 



11 



8 



7 



6 



10 



Calcium and ammonium 



Seedlings that have been grown for ten days in full nutrient solutions are 

 also more resistant to ammonium than are those taken from the germi- 

 nating pan and placed directly in the solutions. N/100 NH4CI is the 

 weakest solution that is toxic in the former case and N/3000 to N/4000 

 in the latter. The toxicity of either N/25 or N/100 NH4CI is reduced by 

 the presence of N/10 CaCl2. The results obtained appear in the following 

 table : 



TABLE 31. 



Experiment with Canada Field Pea. 

 FOR Ten Plants 



Duration, Thirty Days. Data 



Composition of solution 



Total 



green weight 



(grams) 



Average length 



of tops 

 (centimeters) 



Average length 



of roots 



(centimeters) 



N/10 CaCl2+N/25 NH4CI . 



N/10 CaCl2-hN/100 NH4CI 

 N/10 CaCl2-^N/500 NH4CI 



N/lOCaCU 



N/25NH4CI 



N/100 NH4CI 



Distilled water 



Weight not 

 taken 

 12.21 

 16.35 



18.85 



13.35 

 11.95 



13 



18 



22 

 24 

 Dead 

 12 

 14 



Dead after ten 

 days 



8 



7 



11 



