MANGANESE AND IRON IN GROWTH OF WHEAT 365 



to the high plane of ferric chloride. These amounts of the bi- 

 carbonate were also added to the nutrient solutions containing 

 the corresponding planes of manganous and ferric chlorides.^ 



It can be seen from figure 2 that the roots developed quite 

 uniformly in this series as compared with Series 1. 



The depressing effect of the high plane of ferric chloride pre- 

 viously observed is not evident here. In the appearance of 

 tops, however, the toxic effect of the high plane of sodium bi- 

 carbonate is clearly evident. With regard to color of the tops 

 these cultures suffered far less than those of Series 1. This was 

 probably due to a greater store of reserve iron compounds in 

 the seed here employed, for while chlorosis was noticeable in the 

 control culture of Series 1 before two weeks of growth, symptoms 

 of this condition were not evident in Series 2 until the third week 

 of growth, when appreciable chlorotic effects were apparent only 

 in the cultures receiving the high plane of manganous chloride. 

 It will be noticed that this effect was antagonized by the pres- 

 ence of ferric chloride of the same molecular concentration. 



* The nutrient solutions employed in Series 2 received per liter the following 

 volumes of solutions of various salts of the concentrations indicated: 



M MM 



Control: 13.80 cc. -y Ca(N03)2, 4.90 cc. -^ MgSOi, 3.35 cc. -^ KHoPOj, 5.80. 



M 



cc. -^ KNO3. To the control solution the following additions were made:. 



M 



Low sodium bi-carbonate — 15.0 cc. =7^ NaHCOs 



500 



M M 



Low manganous chloride — 15.0 cc. rrrr NaHCOs, 5 cc. ^th; MnCU. 



Low ferric chloride— 15.0 cc. ~ NaHCOa, 5cc. ~ ^^^^i- 



M 



Low manganous and ferric chlorides 15.0 cc. ^777: NaHCOa 



5U0 



M 



5 cc. CQQ MnCl2 



M 



500 



5 cc. ^^ FeCls. 



High sodium bi-carbonate — 15.0 cc. -=- NaHCOs 



M 

 "5 



High manganous chloride — 15.0 cc. — NaHCOs 5 cc. -r- MnCL 



5 



High ferric chloride— 15.0 cc. -^ NaHCos 5 cc. -=- FeCU 



High manganous and ferric chlorides — 15.0 cc. -5- NaHCOs , 



5 _ M 



j 5 cc. -^ MnClj 



5 cc. -= FeCls. 

 o 



