6i6 
Journal of Agricultural Research 
Vol. XXIII, No. 8 
As the season advanced and conditions became more favorable for the 
growth of the weaker plants the difference in field stand became less, 
being only 3.0 per cent in the last planting (fig. 14). 
Table XXV .—Summary of data in Tables XXI to XXIV inclusive, showing percent¬ 
age increases in favor of nearly disease-free seed over moderately diseased seed 
Date of planting. 
Percentage increase in favor of nearly disease-free seed. 
Total 
stand. 
Vigorous 
plants. 
Total 
yield. 
Yield of 
marketable 
com. 
Market¬ 
able ears. 
May 7 
I 5* 0 
S3-4 
17. 2 
49-3 
31.6 
14 
9 - 7 
56.8 
14- 5 
5 °. 0 
35* 0 
21 
7-7 
49.8 
io-S 
35* 8 
33* 0 
30 
3-4 
17. 2 
15 -1 
79-4 
67.4 
/=>£/9A/r//V<? 
Fig. is.— Graphic presentation of the percentage of kernels in the two lots of seed which produced vigorous 
plants when planted at different dates. The heavy line represents the nearly disease : free seed, the light 
light line the moderately diseased seed. (Taken from Tables XXI to XXIV, inclusive.) 
From all these data it will be seen that reduction in percentage of 
field stand, due to the use of infected or susceptible seed, depends on 
several factors, among which are the extent of infection and the general 
condition of the soil in which the seed is planted. There seems to be 
little doubt that the planting of seed infected with or susceptible to the 
root and stalk rot pathogenes is responsible for many unsatisfactory 
