Jan. 26,1924 
The Black-Bundle Disease of Corn 
197 
The plats were hand-planted in hills 42 inches apart each way at the 
rate of 3 kernels per hill. Great care was exercised throughout the season 
to avoid mechanical injury of the plants during cultivation, and to guard 
against insect pests and rodents, but no attempt was made either to thin 
to a uniform stand or to correct for differences in stand. 
Acre yields have been reduced to a uniform moisture basis of 14 per 
cent and reported as “Total yield'* and “Yield of marketable corn," 
the latter obtained from the former by excluding small nubbins, rotten 
ears, and light chaffy ears as described by Holbert et al ( 22 ). 
Table XI gives the field and harvest data on the influence of inocu¬ 
lating various strains of Yellow Dent corn with Cephalosporium 
acremonium isolated from dent com. The inoculum was in the form of a 
spore suspension in sterile water, enough spores from potato-dextrose 
agar cultures being used to produce a moderate cloudiness in the water. 
The seed was soaked in the inoculum not to exceed one-half hour and then 
planted. 
As was noted above under life cycle of the organism, Table XI is a pre¬ 
sentation of data on seed inoculation. The effects in this case are almost 
negative. 
Table XII gives the results of inoculations with Cephalosporium acre¬ 
monium with all conditions similar to those in Table XI except that the 
inoculations were made by means of a hypodermic syringe when the 
plants were about 12 inches in height. Approximately 0.2 cc. of the sus¬ 
pension of the organism was injected into the central portion of each stalk 
at about 2 inches above the crown of the plant. Control plants were 
injected with corresponding amounts of sterile water. The difference in 
final field stands of the inoculated plats and the control plats averaged 
less than one-half per cent. 
Table XIII .—Summary of data presented in Table XII 
Points of comparison. 
Control. 
Inocu¬ 
lated. 
Per cent 
increase 
following 
inocula¬ 
tion. 
Per cent 
decrease 
following 
inocula¬ 
tion. 
Odds. 
Mean percentage final field stand. 
Mean number of suckers per plat. 
Mean number of purple stalks per plat.. 
Mean number of prolific stalks per plat. 
Mean number of barren stalks per plat.. 
Mean number of nubbin ears per plat... 
Mean total yield (bushel) per plat. 
Mean yield of marketable corn (bushel) 
ner olat. 
93-6 
14-5 
2.0 
2.1 
8.9 
5-9 
84.8 
S 9 - 6 
93 -i 
35-5 
3 -i 
45 
13.8 
8.4 
75 -i 
47*7 
144.8 
55 -o 
ii 4-3 
55 -i 
42.4 
0-5 
II.4 
20.0 
> 999:* 
74:1 
> 999:1 
> 999:1 
> 999:1 
> 999:1 
> 999:1 
It will be noted from Table XIII, which gives a summary of the data 
in Table XII, that there was a 144.8 per cent increase in number of suckers, 
55 percent increase in purple stalks, 114.3 percent increase in prolific stalks, 
55.1 per cent increase in number of barren stalks, 42.4 per cent increase 
in number of nubbins, 11.4 per cent decrease in total yield, and 20.0 per 
cent decrease in yield of marketable com in the plats inoculated with 
Cephalosporium acremonium. The increase in the number of suckers on 
the inoculated plants was the most apparent symptom in the plats. This 
