Journal of Agricultural Research 
Vol. XIV, No. 4 
162 
all nearly alike when the series was begun, the average yield values may 
be considered to approximate very closely the values which would have 
obtained if all the plants had been exactly alike at the beginning of the 
second 4-week growth period. 
(b) Comparison of the ranges of the ion ratio vaeues for high 
and for eow yieeds of Tops —The ion ratio values of the 3-salt solu¬ 
tions here employed have been discussed in detail in previous publica¬ 
tions (6, 7) in connection with the study of the growth of young wheat 
and buckwheat plants in these solutions, in an endeavor to determine 
the relation of these ratio values to the physiological properties of the 
various salt combinations as they affect the growth of the plants. These 
ion ratio values have also been considered by McCall (3) in his study 
of young wheat plants in sand cultures. 
In Table III are presented the cation ratio values of the nine cultures 
of each of the two series here considered, giving the highest dry weights 
of tops and of the nine cultures giving the lowest corresponding weights. 
The cultures are in every case arranged in the descending order of the 
values of the magnesium to calcium ratio. These cultures are the ones 
included in the areas of high and of low yields outlined on the triangular 
diagrams of figure 1. The table is divided into two vertical sections; 
the first section gives the culture numbers and the three cation ratio 
values of each of the nine cultures which produced high yields and the 
nine which gave low yields of tops in series A and also the total range 
in the magnitude of these ratio values. The second section presents 
the corresponding data for series B. At the bottom of the table are 
given the maximum and minimum ratio values and the total ranges of 
these for the entire series. The ratio values of the culture giving the 
highest yield in each series are indicated in bold-face type, while those 
of the culture giving the lowest dry weight appear in italics. 
It will be observed that the ion-ratio values characterizing the cul¬ 
tures in each of the two series giving high and low yields of tops are lim¬ 
ited to certain ranges of these ratio values, which are less extensive than 
the total ranges for the entire series. 
From a comparison of the ratio values for the group of cultures pro¬ 
ducing high yields in series A with those of the corresponding group in 
series B, it may be seen that there is substantial agreement between 
the two series with respect to the ranges of the magnesium to potassium 
ratio values. This group of cultures in each of the two series is char¬ 
acterized by a relatively low range of values for this ratio, the range 
being 3.93 for series A and 3.71 for series B. There is, however, no such 
agreement between the two series with respect to the range of the values 
for the magnesium to calcium and calcium to potassium ratios. The range 
of the former is high (12.69) m series A and relatively low (5.53) in 
series B, while the range of the latter is relatively low (1.30) in series 
A and high (5.22) in series B. 
