34 



WHEAT RESISTANCE TO TOXIC SALTS. 



SUMMARY OF TABLES. 



In order to make more easily comparable the differences of resist- 

 ance of the several varieties to the various salts, the results as a whole 

 have been brought together in the following table. At the bottom of 

 the columns is given the average, for each salt, of the toxic limits of 

 all the varieties; so it requires only a glance to see which varieties 

 are aboxo or below the average in their resistance to the toxic effect 

 of each salt. 



A glance at the above table shows that the Zimmerman variety is 

 much the most resistant. This, however, does not necessarily mean that 

 it is most resistant to every salt. On the contrary, Zimmerman is 

 Jess resistant to magnesium sulphate than Budapest and Turkey, less 

 resistant to sodium carbonate than Turkey and Kharkof, and less 

 resistant to sodium bicarbonate than Kharkof. This same variety, 

 however, is very resistant to the influence of sodium chlorid, sodium 

 sulphate, and sodium carbonate, which brings uj) its average to a 

 considerable extent. The least resistant variety is Chul, which runs 

 low for all salts except sodium carbonate, in which its resistance is 

 slightly above the average of the varieties with which experiments 

 were made. The low resistance of this variety was unexpected, in 

 view^' of the character of the country from which it came. 



A further consideration of this table show^s how nearly equal the 

 Padiii and Kubanka varieties are in their resistance. A comparison 

 of the two varieties for the same salts shows but a slight variation. 

 Taking into consideration the original habitat of the two varieties, 

 we would expect very little difference. Both are Russian varieties 

 and subjected to very similar climatic and soil conditions. Both 

 varieties are ver}^ resistant to salt solutions, and in view of the fact 

 that they both come from regions containing much saline soil their 

 similarity in this respect is not surprising. 



Good examples for contrast to Padui and Kubanka are furnished 

 in Budapest and Preston, Budaf)est is a naturalized Michigan vari- 



