82 



Journal of Agricultural Research 



Vol. XIX, No. 3 



growth were maintained: wheat, i8 days; soybeans, i6 days; corn, 8 

 days; alfalfa, 20 days. In Table IV are given the green weights 

 of seedlings at time of harvesting and the average reaction of 

 each culture as shown by the determinations of hydrogen-ion concen- 

 tration made at the beginning and end of the 4-day periods on the cultures 

 of the wheat series only. In figure 4 the relative total green weights, based 

 upon the highest weight taken as 100 in each instance, are shown plotted 

 against the average Ph of the cultures. Plate 15, C, shows the appear- 

 ance of the wheat plants at the time of harvesting. 



Table IV. — Average reactions of cidhires of series B and green weights of seedlings at 



time of harvesting 



WHEAT 



Culture No. 



3 

 4 

 5 

 6 



7 



Reaction. 



Ph- 



2. 17 



2. 96 



4. II 

 5-16 



5-94 

 6.97 

 7.71 



Green weight of lo plants. 



Tops. 



Gm. 

 o. 230 



1-730 



2. 548 



3- 581 



3. 620 

 2. 421 

 2. 103 



Roots. 



Gm. 

 "■ o. 067 



• 143 



• 149 



• 372 



• 356 



• 324 

 . 141 



Entire 



plants 



exclusive 



of seeds. 



Gm. 

 O. 297 



873 

 697 



953 

 976 



745 

 244 



SOYBEANS 



o Seedlings dead at time of harvesting. 



* Because of the uniformity of reaction of successive cultures made up to to represent a given reaction 

 and the relatively small changes in reaction produced by growth of seedlings it is assumed tbat the 

 average reactions found in the wheat series apply to the cultures of the soybean, corn, and alfalfa series. 

 Occasional determinations on cultures of the latter series showed this to be true. 



