37 2 
Journal of Agricultural Research 
Voi. XIV, No. 9 
COEFFICIENTS OF VARIABILITY 
With few exceptions the coefficients were higher in 1914 than in the 
three other years. This corresponds to the generally lower means for that 
year. 
As is indicated by the coefficients, number of days to second leaf and 
average weight of kernels in 1917 varied least, but each character was 
highly variable from year to year. Height at six weeks, height at matur¬ 
ity, average height of culms, and average length of spikes were compara¬ 
tively low in variability each year and from year to year. This confirms 
similar indications by the standard deviations. 
As indicated by the coefficients of variability, the greatest variation in 
the 4-year period occurred in 1914 for total weight per plant, yield of 
of straw, and yield of kernels. 
CORRELATIONS 
Correlation coefficients were determined for weight of seed used and 
each of the resultant plant characters listed in Table III. The assembled 
data also offered the opportunity to study the interrelation of plant charac¬ 
ters for which the coefficients of correlation are presented in Table XIII. 
Since it was not considered feasible to present all the correlation tables, 
the selection for presentation was confined to those likely to be of most 
value and interest. (See Tables IV-XI; XIV-XXI.) 
Table III .—Coefficients of correlation between weight of seed and characters of the resultant 
plants 
Characters studied. 
Number of days from planting to second 
leaf.. 
Height of plants at appearance of second 
leaf..an.. 
Height of plants at six weeks....cm.. 
Height of tallest culm at maturity...cm.. 
Average height of culms at maturity, cm.. 
Average length of spikes per plant.. .cm.. 
Total length of culms per plant.cm.. 
Total length of spikes per plant.cm.. 
Number of culms per plant. 
Total weight per plant ..dgm.. 
Yield of straw per plant.dgm.. 
Yield of kernels per plant.dgm.. 
Number of kernels per plant... 
Average weight of kernels per plant, 
mgm... 
1914 
o. i46±o. 038 
. 356± • 040 
. ig6± . 037 
. 093 ± *038 
. oe>7± .038 
. 251 i -036 
• 259± .036 
. 232± . 036 
. 229± * 036 
.226± • 036 
. 143± ■ 05S 
. 246± . 036 
— .o62± .038 
19 IS 
o. 114^0. 027 
. 445 i .022 
— . 03 7± .028 
— . 099± .028 
— . I 93 ± *027 
. o66± . 028 
— . oi8± . 028 
. ii6± . 027 
. o64± . 028 
. <m 6± . 028 
. o8S± . 028 
. o?6± • 028 
. o86± .028 
1916 
—0.484^0.019 
. 169± . 024 
. 649 ± . 014 
. 311 ± .023 
. i92± . 024 
. I26± . 025 
. 46 o± . 020 
• 442± .020 
• 420± .021 
.423d: .021 
. 407 ± .021 
• 445 i -020 
• 458dh .020 
. 055 ± . 02 S 
1917 
—o. 634 ±o. 018 
. 259± . 028 
. 7i2± . 015 
• o74± .030 
. n8± . 030 
.202 rfc . 029 
• 395 ± -026 
• 4 i 7 :L * 025 
• 398 ± .025 
• 435 =t -024 
, 40 id; .025 
• 4?8± .024 
. 465 ± .023 
. I4id: . 030 
