Relations of Manganese and Other Cations 



177 



Sulfate of aluminium and manganese were used in the above experi- 

 ments. The results were similar, however, when either chlorids, nitrates, 

 or sulfates were employed. 



McCallum (1909) reports that the treatment of seed potatoes with 

 manganese chlorid before planting accelerates the formation of tubers. 

 The foliage is not influenced by this treatment. 



Brenchley (1910) grew barley to maturity in nutrient solutions to 

 which varying amounts of manganese sulfate were added. The full 

 nutrient solution was made up as follows: 



KNO3 0.50 gram 



KH2PO4 0.25 gram 



MgS04, . 25 gram 



CaS04 0.25 gram 



NaCl 0.10 gram 



FeClg Trace 



Distilled water 1,000 cubic centimeters 



The cultures employed and the dry weights obtained are given in the 

 following table : 



Culture 



Relation of MnS04 to 

 amount of solution 



Weight 



Weight 



Weight 



of 



of 



of 



shoots 



roots 



gram 



(grams) 



(grams) 



(grams) 



26.7 



4.4 



3.8 



37.1 



5.0 



6.0 



40.5 



5.9 



1.7 



47.9 



5.8 



4.6 



45.9 



6.6 



6.4 



39.1 



6.3 



7.4 



Total 

 weight 



(grams) 



1 

 2 

 3 

 4 

 5 

 6 



Ito 1,000 



1 to 100,000 . . . 

 1 to 1.000,000. 

 1 to 5,000,000. 

 1 to 10,000,000 

 Control 



34.9 



48.1 

 48.1 

 58.3 

 58.9 



52.8 



At the time of harvest the seeds were ripe in culture 3. In culture 2 

 some seeds were ripe, others were partially ripe, and some were green. 

 Brenchley's conclusions from these experiments are: 



" 1. The higher concentrations of manganese sulphate have a decided 

 retarding effect upon the ripening of the grain. 



