THE RELATION OF SIZE OF KERNELS IN SWEET CORN 
TO EVENNESS OF MATURITY 1 
By I. C. Hoffman, 2 
Assistant in Vegetable Gardening, Department of Horticulture, Purdue University 
Agricultural Experiment Station 
INTRODUCTION 
Commercial canners have found a wide range in the degree of ma¬ 
turity of sweet-corn ears in the canning season. When the majority 
of the ears are ready to harvest some have already become too hard 
and tough, and others are still too young and watery to give the pack 
the proper consistency. This unevenness of maturity varies with 
the variety and appears to be worst in the small or narrow grain 
types. It is particularly troublesome in the Country Gentleman, 
where the slender “ shoe-peg ” kernel predominates. It causes e 
lack of uniformity in the canning condition of the corn, which results 
in a pack of poor quality unless the ears are properly graded, an 
operation which adds to the expense of handling the crop since the 
grading must be done by hand. In order that these expensive 
variations may be avoided, it is important that as much of the crop 
in each field mature at the same time as possible. 
In 1918 the Indiana Canners 7 Association requested the horticul¬ 
tural department of the Purdue station to study the sweet-corn prob¬ 
lem with a view to developing better strains of the standard canning 
varieties and ones that would be more suitable to Indiana conditions. 
The work reported here is a part of this larger problem. 
For several years, while sweet-corn seed was being tested for ger¬ 
mination and freedom from disease, it was observed that the small 
kernels produced slenderer sprouts with smaller root systems than the 
larger kernels. This was true whether the kernels were picked from 
the same ears or from bulk-shelled samples. The question then arose 
as to whether or not this condition affected the rate of growth and 
time of maturity of the progeny. In the fall of 1920 large and small 
kernels of the same varieties were planted in the greenhouse to de¬ 
termine whether the differences noted in the germinator would be 
found in soil-grown plants. Very striking differences both in size of 
seedlings and in rate of growth developed, and the investigation was 
enlarged and continued for more than two years. During this time 
a large number of observations and experiments were made under 
greenhouse and field conditions, and these will be discussed in the 
following pages. 
1 Received for publication May 2, 1925; issued January, 1926. Contribution from the department of 
horticulture, Purdue University Agricultural Experiment Station. 
2 The writer wishes to thank the Fame Canning Co., of Shelby ville, Ind., for helpful cooperation in some 
of the investigations here reported. 
Journal of Agricultural Research, 
Washington, D. C. 
( 1043 ) 
Vol. XXXI, No. 11 
Dec. 1, 1925 
Key No. Ind.-17 
