164 
Journal of Agricultural Research voi. xiv, no. 4 
nesium to calcium, and an intermediate range for the ratios magne¬ 
sium to potassium and calcium to potassium, while the group of cultures 
which produced low yields in series B shows a wide range in the values 
for each of the three ratios. 
The individual culture R1C4 giving the lowest dry weight of tops in 
series A shows a low magnesium to calcium ratio value of 2.40 and inter¬ 
mediate values of 6.95 and 2.88 for the ratios magnesium to potassium 
and calcium to potassium, respectively. Culture R1C1, which gave the 
lowest yield of tops in series B, is characterized by the maximum values 
of the ratios magnesium to calcium and magnesium to potassium, and 
by a low value of the ratio calcium to potassium. The values of these 
three ratios are 15.40, 11.10, and 0.76, respectively. Thus, there is no 
agreement between any two corresponding ratio values characterizing 
the individual cultures which produced the minimum yields in their 
respective series. 
From the above considerations it is at once clear that these ion ratio 
values and the dry-weight yields of tops are not at all related in the 
same way in the two series representing the two physiological stages of 
development in the active growth period of the plants. This is still 
further emphasized by the marked differences in the atomic proportions 
characterizing the solutions producing the highest and lowest yields in 
the two series. Thus, for example, the highest yield in series A occurred 
with the solution R4C2, having the ratio values as follows: magnesium to 
calcium, 3.85; magnesium to potassium, 1.39; and calcium to potassium, 
0.36. This indicates that the best solution for tops in this series con¬ 
tains 1.39 atoms of magnesium and 0.36 atoms of calcium for each single 
atom of potassium (by assuming, of course, that the number of atoms 
of an element present in a given mass of it is proportional to the number 
of gram-atoms contained in the mass). The solution (R3C5) which 
produced the highest yield in series B possessed 0.93 atoms of magnesium 
and 1.20 atoms of calcium for each atom of potassium. The difference 
between the atomic proportions characterizing the solutions in the two 
series which produced the pooi^st growth of tops is even more pronounced 
than is that between the atomic proportions characterizing the solutions 
which produced the highest yields. The solution (R1C4) giving the 
lowest yield of tops in series A had the atomic proportions magnesium, 
6.95; calcium, 2.88; and potassium, 1.00, while the solution (R1C1) giv¬ 
ing the lowest yield of tops in series B, possessed the proportions mag¬ 
nesium, 11.10; calcium, 0.76; and potassium, 1.00. It is thus obvious 
that the atomic proportions characterizing the solutions producing the 
beet and also the poorest yields of tops vary markedly with the different 
growth periods here considered. 
I2) DRY WEIGHTS OP ROOTS 
The average relative dry weights of roots are given in Table II in con¬ 
nection with the corresponding data for tops. These relative root yields 
