Aug. 26,1918 
Variation and Correlation in Wheat 
39i 
number of kernels. When the kernels developed normally, lower yield 
was accompanied by a higher average weight per kernel. 
(2) In general, a reduction in the magnitude of the means is accompa¬ 
nied by less variability. A number of exceptions to this general tendency 
occurred. 
(3) Correlation between weight of seed sown and resultant plant char¬ 
acters at maturity is not high in any instance and may be so modified 
by environmental conditions that the relation may be slight or obliterated 
entirely. 
(4) Correlation between plant characters is modified by environment, 
the degree of modification from this cause varying with the characters 
considered. 
(5) An increased yield of kernels is very closely accompanied by an 
increase in 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. 
(6) A larger number of culms per plant is accompanied by a greater 
total length of spikes but not by a greater average length of spikes. 
(7) Average weight of kernels is substantially and fairly consistently 
correlated with yield of kernels, and, subject to radical change due to 
environment, moderately correlated with average length of spikes. 
With number of kernels the correlation is rather low but always con¬ 
sistent. Average weight of kernels is practically independent of average 
length of spikes. 
(8) There is a distinct tendency for greater average height of culms to 
be accompanied by greater average length of spikes, number of kernels, 
and higher yield of kernels. Average length of spikes is moderately 
correlated with average weight of kernels three years out of four. The 
correlation between average height of culms and number of culms is 
always low. 
(9) There is a distinct tendency for plants of varying height at second 
leaf to maintain the same relative heights at six weeks, but there is a 
lesser tendency for this relation to be maintained at maturity. 
LITERATURE CITED 
Atkinson, Alfred. 
1912. a study or the CORRELATION oe characters oe wheat. Presented as a 
thesis for the degree of M. S. in Agriculture, Cornell University, 1912. 
(Not printed.) 
Davenport, Eugene. 
1907. principles OE breeding. 727 p., illus. Boston, New York. 
Georgeson, C. C., Burtis, F. C. } and Otis, D. H. 
1896. experiments with wheat. Kan. Agr. Exp. Sta. Bui. 59, p. 89-105. 
1897. experiments with oats. Kan. Agr. Exp. Sta. Bui. 74, p. 195-211. 
