Feb. 24 ,1933 Early Vigor , Yield , and Diseases of Maize 
601 
/2S*fc2 €A'7 r /?&£0/ c / ! Vj9A/7& 
O /O 20 30 <40 SO 60 7 V 90 /OO 
or caw 
Fig. 6.—Graphic presentation of Table XVI, showing the relation of moderately diseased and nearly 
disease-free seed to the percentage of vigorous, semi vigorous, and weak plants produced, and to yield of 
marketable and unmarketable com in bushels per acre. 
TABbF XVII. —Influence of moderately diseased and nearly disease-free seed on early vigor 
and yield of marketable corn of McKieghan strain of Reid Yellow Dent on soil of 
average fertility on which clover hid been grown for the previous two years but which had 
previously never been limed nor phosphated (22), at Yates City, III., in IQ20 
Points considered. 
Number of plants in experiment.. 
Early vigor: 
Percentage of kernels producing plants. 
Percentage of kernels producing vigorous 
plants. 
Percentage of kernels producing weak plants. 
Yield: 
Total acre yield (in bushels). 
Acre yield of marketable com (in bushels).. 
Moder¬ 
ately dis¬ 
eased 
Nearly 
disease- 
free 
In favor of disease- 
free seed. 
com¬ 
posite. 
com¬ 
posite. 
Increase. 
Decrease. 
I, 082 
1,251 
Percent. 
Percent. 
75 -i 
86.8 
IS-6 
29.4 
39 * 1 
33-0 
16. 2 
13 -1 
19. I 
67.0 
72.4 
8.1 
44-5 
52.4 
17.8 
The increase in yield of marketable corn shown in Table XVII and 
figure 7 is not so marked as in previous tables, but it is large enough to 
be significant. 
