NUTRIENT SOLUTIONS FOR WHEAT 
W. E. TOTTINGHAM AND E. J. RANKIN^ 
(Received for publication September 28, 192 1) 
The following brief notes relate to collaborative work of the writers 
upon a project outlined by a special committee of the National Research 
Council (17). Publication in the present rather fragmentary condition 
is ventured in the hope that our observations may be of aid to others 
operating in the same field. Acknowledgment is hereby made of a grant 
from the research funds of the University of Wisconsin in support of this 
investigation. 
Of the six possible three-salt combinations which can supply the six 
essential elements of a nutrient solution, exclusive of iron, as arranged in 
the plan for collaborators. Type VI was chosen for the present investigation. 
This type is composed of KH2PO4, CaS04, and Mg(N03)2. Cultures of 
wheat were conducted in duplicate in the series of solutions of this type, 
following the prescribed plan. The results appear to justify no further 
statement here than that the agreement between duplicate cultures was 
generally very poor. It seemed probable that this condition was due in 
part to the very poor root development of the seedlings employed. The 
roots were short, and usually curved and discolored where they came in 
contact with the nutrient solution. 
Shive's nutrient solution R5C2 (15) diluted to o.i the usual concentra- 
tion is the medium prescribed for germination in this work. The pH of this 
nutrient solution, at the concentration commonly employed, is approxi- 
mately 4.7 (16). It appeared possible that the poor root growth observed 
here was due partly to the acidity of this solution. With this possibility 
in mind, the following tests were undertaken. The seed used throughout 
was w^heat of the Marquis variety, provided for collaborators by the com- 
mittee in charge of the project. In tests other than the comparison of 
continuous with intermittent renewal of the solution, ferric citrate was 
used instead of ferric phosphate, as a source of iron. 
pH in Relation to Germination 
The best solution of the series tested by Livingston and Tottingham 
(9), R8C1, is unfavorable for the germination of wheat when continuously 
renewed at 0.001 the usual concentration of 1.75 atm. osmotic value. This 
solution is still decidedly acid, however, as indicated by the data of table I, 
obtained by the use of Clark and Lubs' method (2) : 
^ Published with permission of the director of the Wisconsin Experiment Station. 
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