Com Investigations 
137 
Fig. 30. — The field in which 475 plats were devoted to a study of root-rot 
diseases in relation to yield in 1921. (See Table 57.) 
In these experiments it was thought that failure to produce a 
plant due to disease should be charged up against the affected 
seed. The corn was, therefore, planted definitely at the stand- 
ard rate of three kernels per hill and the yield determined for 
the entire plat, rather than to plant thick and reduce to a per- 
fect stand. Only ears were used which showed 100 per cent 
germination in the viability tests. This reduced the complica- 
tion resulting from lack of vitality due to other causes than 
disease. 
Extensive detailed notes were taken on each field plat regard- 
ing stand and growth characteristics which might prove of in- 
terest in interpreting results. These are summarized in Tables 
57 and 58, to which the reader is referred for comparisons. It 
is apparent that the disease free, diseased, and original corn 
were almost identical in (1) the number of plants coming up in 
the spring, (2) plant survival till harvest, (3) number of weak 
plants in the spring, (4) date tasseling, (5) date ripe, (6) plant 
height, (7) suckers per 100 plants, (8) barrenness, (9) per cent 
lodging, (10) shrinkage of ear corn, (11) shelling percentage, 
and (12) yield of grain per acre. 
