JOURNAL OF AGRICULTURAL RESE ARCH 
Vol. XXI Washington, D. C., July i, 1921 No. 7 
STUDY OF THE RELATION OF THE LENGTH OF KERNEL 
TO THE YIELD OF CORN. (ZEA MAYS INDENTATA).‘ 
C. C. Cunningham 
Formerly Assistant Professor of Agronomy, Kansas Agricultural Experiment Station 
Among com growers there is a prevalent opinion that length or depth 
of kernel is a very desirable character in com {Zea mays indenlala) and 
that short kernels indicate deterioration. Rough, dented kernels are 
usually long and, therefore, this type is given preference by most growers 
in selecting seed com, while smoothly dented ears are avoided. 
Apparently, the relation of the length of kernel to the yield of com 
has not been investigated directly. Some data on this subject, however, 
have been secured indirectly. 
Montgomery 2 compared smooth and rough types of Reid Yellow Dent 
continuously selected for five years. Comparative yield data were 
secured for three seasons. The smooth-dented type outyielded the 
rough-dented type two out of three seasons and averaged 4.4 bushels 
more per acre. Although no data were presented to show the relative 
length of the kernels for the two lots of com, it is probably safe to assume 
that those of the rough-dented type were the longer because of the cor¬ 
relation between indentation and length of kernels. 
The writer 3 reported that smooth- or wrinkle-dented ears outyielded 
rough ears in ear-to-row tests of several varieties of corn conducted at 
the Kansas Agricultural Experiment Station. 
Williams 4 compared smooth- and rough-dented strains of Clarage corn 
continuously selected for six years at the Ohio Agricultural Experiment 
Station and secured an average difference of 1.76 bushels per acre in 
favor of the smooth type. 
Hutcheson and Wolfe 3 compared characters of a group each of high- 
yielding and low-yielding ears of Boone County White grown in ear-to-row 
1 Contribution No. 19 from Department of Agronomy, Agricultural Experiment Station of Kansas State 
Agricultural College. 
* Montgomery, E. G. experiments with corn. Nebr. Agr. Exp. Sta. Bui. 112, p. 23. 1909. 
* Cunningham, C. C. the relation op ear characters op corn to yield. In Jour. Amer. Soc. 
Agron., v. 8, no. 3, p. 193. 1916. 
4 Williams, C. G., and Welton, R. A. corn experiments. Ohio Agr. Exp. Sta. Bui. 282, p. 87. 1915 
6 Hutcheson, T. B., and Wolpe, T. K. relation between yield and ear characters in corn. 
In Jour. Amer. Soc. Agron., v. 10, no. 6, p. 253. 1918. 
Journal of Agricultural Research, 
Washington, D. C. 
yf 
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Vol. XXI, No. 7 
July 1, 1921 
Key No. Kans.-25 
