Feb. 34,1933 
Early Vigor , Yield , and AW Diseases of Maize 
617 
field stands and constitutes an important loss to the corn crop. This 
is especially true with com planted early when weather and soil con¬ 
ditions are more or less unfavorable for germination and growth. How¬ 
ever, a good field stand grown from diseased or disease-susceptible seed 
is no insurance against reduction in total yield. This fact is brought out 
in Table XXVI where the difference in field stand is only 3.0 per cent 
and the difference in total yield is 10.4 bushels per acre. It also occurs in 
Table XXIV where there is a difference of 3.4 per cent in field stand and 
7.0 bushels in total yield. Moreover, in view of the results obtained by 
Kiesselbach and Ratcliff (25), it does not appear probable that the reduc¬ 
tions in total field stand are an adequate explanation for all the reductions 
Fig. 16 —Graphic presentation of the percentage of marketable com (by weight) produced by the two 
lots of seed at different dates of planting. The heavy line represents the nearly disease-free seed, the 
light line moderately diseased seed. (Taken from Tables XXI to XXIV, inclusive.) 
in total yield in the experiments herein reported. An analysis of all the 
data shows that reduced stands may be considered, in a great majority 
of instances, an indication that a considerable portion of the com popula¬ 
tion in question has grown from infected or susceptible seed which in 
turn is responsible for much of the reductions in total yield. The fact 
remains, however, that reductions in total yield herein reported can be 
traced to the use of infected seed and represent losses encountered in 
actual farm practice. r , * 
The reductions in early vigor in the corn grown from moderately 
diseased seed were well marked, with a very few exceptions, throughout 
all the experiments reported for 1921. The differences of 24.4±2.14, 
26.2±2.38, 23.6±2.46 and ii.o±2.2i in percentage of vigorous plants 
