JOURNAL OF AGMQKTORAL RESEARCH 
Voi,. XXIII Washington, D. C., February 24,1923 No. 8 
EARLY VIGOR OF MAIZE PLANTS AND YIELD OF 
GRAIN AS INFLUENCED BY THE CORN ROOT, 
STALK, AND EAR ROT DISEASES 1 
By James R. Holbert, Agronomist, Office of Cereal Investigations, Bureau of Plant 
Industry, United States Department of Agriculture; W. L. Burlison, Head of DeparU 
ment of Agronomy and Chief of Division of Crop Production, Illinois Agricultural 
Experiment Station; H. Howard Biggar, formerly Scientific Assistant, Office of Cereal 
Investigations, Bureau of Plant Industry, United States Department of Agriculture; 
Benjamin Koehler, Assistant Pathologist, Office of Cereal Investigations, Bureau of 
Plant Industry, United States Department of Agriculture; George H. Dungan, Associate 
in Crop Production, Illinois Agricultural Experiment Station; and MERLE T. Jenkins, 
Scientific Assistant, Office of Cereal Investigations, Bureau of Plant Industry, United 
States Department of Agriculture 2 
PURPOSE OF THE PAPER 
The purpose of this paper is (i) to emphasize the important relation 
existing between early vigor and yield of dent (Zea mays indentata), 
(2) to call attention to the reduction in early vigor of corn plants grown 
from seed infected with one or more of the corn root and stalk rot patho- 
genes or seed susceptible to the root and stalk rots, and (3) to present 
data bearing directly on the correlation between this reduced early vigor 
and reduced yield, with special reference to reduced yield of marketable 
com. 
A study of any field of com, especially during the first few weeks after 
the plants have appeared above the ground, reveals striking differences 
in plant vigor. These differences in early vigor may be caused by many 
factors and may express themselves in both the size and appearance of 
the plants. 
REVlEW^OFiElTERATURE 
Darwin (7) 8 found that maize plants grown from self-fertilized seed 
were slower growing and less vigorous than plants grown from cross- 
fertilized seed. Beal, of the Michigan Agricultural Experiment Station 
( 28 ), in 1877-1882 reported an increase in both vigor and yield in first- 
generation hybrids when certain unrelated varieties were crossed. He 
urged the commercial utilization of this increased vigor as a method of 
increasing yields. The results of the early experiments of Beal were 
confirmed by other workers. Collins (5, 6) found that many crosses 
between diverse types of maize resulted in greatly increased vigor, a 
wider range of adaptability, and increased productivity. 
1 Accepted for publication May *7,192s. 
* The authors are indebted to Messrs. C. E. Podge. A. T. Evans, E. H. Toole, R. W. Stark, D. F. 
Bracken, W. M. Winters, G. J. Burt, J. K. Reiley, and E. M. D. Bracker for valuable assistance during 
the investigations and the preparation of the manuscript. 
1 Reference is made by number ( italic ) to “ Literature cited,” p. 638-629. 
Journal of Agricultural Research, 
Washington, D. C. 
aaw 
<S*3) 
Vol. XXIII, No. 8 
Feb. 34. Z 933 
Key No. G—282 
28651—23-1 
