876 
Journal of Agricultural Research voi. xxvn, n 0 . h 
Tabijs IX .—Summary of data given in Table VIII o n the relation of previous cropping to 
the yield of corn grown from disease-resistant and disease-susceptible seed at Blooming¬ 
ton, III., in 1921 
Previous crop. 
Acre yield of 
corn grown 
from disease- 
resistant seed. 
Acre yield of 
corn grown from 
disease-sus¬ 
ceptible seed. 
Virgin bluegrass sod (clean soil). 
Scabbed wheat (infested soil).. 
Bushels. 
56. 7±i. 0 
54. o±i. 2 
Bushels. 
52. 8±o. 7 
43 - 4 ±i. 0 
Difference. 
2. 7 dh 1. 6 
9 - 4 ±i* 2 
The plats were located on a uniform piece of virgin, bluegrass sod with 
good drainage. The size of these plats was 4 rows wide by 10 hills long. 
Alternate with every plat planted with inoculated seed was a plat planted 
with uninoculated seed. As shown in Table X, these plats were replicated 
a number of times for both the disease-resistant and disease-susceptible 
selections. All the hills were 42 inches apart each way and were planted 
at the rate of 3 kernels per hill. As in all the other corn experiments, the 
plantings were made by hand to insure accuracy. Field stand and yield 
were taken on the entire plat 4 rows wide by 10 hills long, a total of 40 
hills with a perfect stand of 120 plants. 
RESUi/rs 
The field stand, the number of vigorous plants, and the acre yield were 
reduced in every instance by the inoculations, as shown in Table X. The 
reductions in yield were small, averaging 3 per cent, when seed of disease- 
resistant corn was used. A large decrease in yield, averaging 18 per cent, 
resulted from inoculating seed of disease-susceptible corn, which is repre¬ 
sentative of the corn in most general commercial use. By following the 
recommendations given by Holbert and Hoffer (ro), and Holbert et al., 8 
seed corn that is disease-resistant to a considerable degree can be obtained 
by the average farmer, and thus at least part of the loss due to this organ¬ 
ism can be avoided. In fact, disease-resistant seed is already being used, 
and is gaining in favor very rapidly in many parts of the Corn Belt. 
The reductions in yield from susceptible corn were greater than the 
reductions in stand and were more comparable to the reduction in per¬ 
centage of vigorous plants. This relationship in respect to vigorous 
plants has been previously pointed out by Holbert et al. ( 12 ). These 
experiments, as well as others previously reported, show that Gibberella 
saubinetvi, isolated from infected wheat, is an active parasite on corn. 
The organism has not been found to go up through the stalk during the 
active growing period, but apparently confines its attack to the under¬ 
ground parts of the seedling, thus decreasing stand and plant vigor. 
This results in reduced resistance to later invasions by other parasites and 
in low yields of corn of poor quality. 
9 Holbert, J. R. and others. Op. cit. 
