3 86 
Journal of Agricultural Reserach 
Vol. XIV, No. 9 
producing the higher yields of grain to have the greater average height 
of culms and greater average length of spikes. Stated in another way, 
the plants having the greater average height of culms and average 
length of spikes have a tendency toward being the highest yielders. 
The coefficients for yield of kernels correlated with total length of 
spikes per plant are o.636±o.023 in 1914, o.8o8±o.oo9 in 1915, 
o.9io±o.oo4 in 1916, and 0.911 ±0.005 in 1917- Correlation between 
these two characters is high and relatively consistent approaching that 
between yield of kernels and number of kernels. Stated directly, the 
plants with the greatest total length of spikes were generally the highest 
yielders. 
The results for yield of kernels correlated with the several characters 
may be summarized as follows: An increased yield of kernels is very 
closely accompanied by an increase im number of kernels, number of 
culms, and total length of spikes, and somewhat less closely accompanied 
by an increase in average weight of kernels per plant, average height of 
culms, and average length of spikes. 
NUMBER OP CULMS CORRELATED WITH OTHER PLANT CHARACTERS 
For number of culms correlated with average length of spikes per 
plant, the coefficients are 0.061 ±0.038 in 1914, o.o24±o.o28 in 1915, 
o.o39±o.o25 in 1916, and o.236±o.C29 in 1917. In the first three 
years there is practically none, and in the last year a low correlation. 
The conclusion is that these two characters move practically independent 
of each other. 
The coefficients for number of culms correlated with total length of 
spikes per plant are 0.872 ±0.009, 0.839±0.008, 0.958±0.002, and 
o.946±o.oo3, respectively, for the 4-year period. The correlation be¬ 
tween the two characters is somewhat more close and consistent than 
that between yield of kernels and total length of spikes. An increase 
in number of culms is followed by an increase in total length of spikes 
per plant, but not by greater average length of spikes. 
AVERAGE WEIGHT OP KERNELS CORRELATED WITH OTHER PLANT 
CHARACTERS 
The coefficients for average weight of kernels as correlated with num¬ 
ber of kernels per plant are 0.137 ±0.038, 0.192 ±0.027, 0.160±0.024, 
and 0.160 ±0.030, respectively, for the four years. The coefficients are 
uniformly low but positive in each instance with the lowest 3.6 times 
its probable error. To a limited extent, an increase in number of ker¬ 
nels is accompanied by a greater average weight of the kernels. 
Average weight of kernels correlated with number of culms per plant 
gave coefficients of —0.071 ±0.038 in 1914, o.i37±o.027 in 1915, 
— o.o54±o.o25 in 1916, and —o.oo9±o.o3o in 1917. The low coeffi¬ 
cients as judged by their probable errors and the variation from year 
shows slight or no correlation between these characters. 
