Peb. 34,1923 
Early Vigor, Yield, and Rot Diseases of Maize 
587 
that reduced early vigor, as a result of artificial inoculation with one of 
the root and stalk rot pathogenes, also is directly correlated with reduced 
yield. The term " inoculated,” as used in the tables, refers to com grown 
from seed inoculated at planting time with Gibberella saubinetii , the inocula 
being prepared by Dickson. The term “ uninoculated ” refers to com in 
contiguous plots of equal size grown from similar seed not inoculated. 
HThe yields from experiments conducted in 1920 and 1921 were sepa¬ 
rated into “marketable” and “unmarketable” grades. The latter 
grade consisted of nubbins, rotted or partly rotted ears, and light chaffy 
ears. Ears that were less than half the length of an average large-sized 
ear of the variety were classed as nubbins. Larger ears also that were 
poorly filled were classed as nubbins. The term “rotted ears” included 
any that showed an appreciable extent of rot due to Diplodia, Fusarium, 
or other causes. The chaffy ears were those with the grains imperfectly 
matured so that the kernels were thin and loose on the cob. Chaffy 
ears that also showed signs of rot were classed as rotted. (See PI. 
2, 3, and 4.) 
The term “infested” soil, as used in this paper, refers to soil known 
to be infested with one or more of the root and stalk rot pathogenes. 
In every case where this term is used the soil had been cropped to com 
or wheat for the previous three years. The wheat had been heavily 
infected with scab {Gibberella saubinetii ), and the com crops were known 
to be badly diseased. 
The term “clean” soil, as used in this paper, refers to soil reasonably 
free from any of the root and stalk rot pathogenes. This soil had not 
been cropped to com or wheat for at least 10 years. 
EXPERIMENTAL DATA 
The experimental data cover numerous and extensive studies on the 
relation of the vigor of com plants in the early stages of their growth 
to their subsequent yield, under different conditions. The variables 
include differences in infection of the seed by rot-producing pathogenes, 
differences in physical character of the kernels, and differences in the 
soil, in character, treatment, and quantity of infestation. 
COMPARISON OF EARLY HEIGHT AND YIELD OF TRANSPLANTED SEEDLINGS 
During the summer of 1918 a number of com seedlings were trans¬ 
planted to the field and studied in order to compare the performance 
of apparently disease-free and diseased seedlings. The seedlings were 
grown on the limestone-sawdust table germinator until the plumules 
were approximately 3 inches long. At this time those selected for 
further study were transferred to small paper boxes containing moist 
soil free from any of the com rot pathogenes. One day later the boxes 
and seedlings were transferred to the field, the healthy and diseased 
seedlings being placed in alternate hills 42 inches apart. Both types of 
seedlings used in these studies had the same height and relative vigor 
when taken from the germinator. These seedlings were so selected 
that they represented adjacent kernels on artificially cross-pollinated 
ears from apparently healthy plants. The field in which these studies 
were carried on had not grown a crop of com for at least 10 years. 
The healthy seedlings suffered no ill effect from transplanting and 
made steady growth in height from the time they were transplanted. 
