156 



M. M. McCooL 



Sodium and strontium. — With these bases also, as with potassium and 

 strontium, is shown a clear case of mutual antagonism. By combining 

 a solution of sodium with one of strontium, each of which, when alone 

 in solution, is detrimental to wheat plants, no detrimental action results. 

 Sodium is not so effective as potassium in overcoming the harmful prop- 

 erties of strontium. For example, an N/500 NaCl solution does not 

 reduce the toxicit}^ of N/1000 SrCl2 to any greater extent than does a 

 solution of N/1000 KCl. A comparison of the data in Table 23 with 

 those in Table 24 discloses the fact that the growth of wheat seedlings is 

 less when placed in cultures containing sodium and strontium than when 

 placed in solutions of similar composition of potassium and strontium. 



TABLE 24. Experiment -with Wheat. Duration, Twenty-five days. Data for Ten 



Plants 



Composition of solution 



Total 



?reen weight 



of plants 



(grams) 



Average length 



of tops 



(centimeters) 



Average length 



of roots 



(centimeters) 



N/50 NaCl 



N/50 NaCl+N/100 SrCh . . 

 N/50 NaCl+N/500 SrCh. . 

 N/50 NaCl+N/2,000 SrCh. 

 N/500 NaCl+N/1,000 SrCl 



N/2,000 SrCl2 



Distilled water 



0.51 

 0.71 

 1.05 

 1.10 

 1.10 

 0.75 

 0.68 



4.0 

 6.0 

 8.5 

 9.0 

 7.0 

 7.5 

 7.0 







5.0 



9.0 



8.0 



2.0 



1.5 



6.0 



Fig. 7. — Antidotal relations hetiveen sodium and strontium; distilled water as the solvent 



81. N/20 NaNOs 



82. N/50 NaNOs 



83. N/100 NaNOs 



84. N/50 NaNOs +N/.500 Sr(N0s)2 



85. N/50 NaNOs +N/1000 Sr(NOs)2 



86. N/50 NaNOs +N/3000 Sr(N03)2 



93. Distilledjwater 



SY. N/500 NaNOs +N/500 SrCNOs)!"' 

 88 X'500 XaXOs+N/lOOO Sr(N03)2 



89. N'oOO XaXOs+N/3000 Sr(N03)2 



90. X 'ino 8r(X03)2 i 



91. X/500 Sr(N03)2 ] 



92. N/5000 Sr(N03)2 



