6i8 
Journal of Agricultural Research 
Vol. xxm. No. s 
presented in Tables XXI to XXIV, and figures 9 to 12 and figure 15 
are very significant. (PI. 7.) Inasmuch as the majority of weak plants 
are either barren or nubbin producers, the differences in percentage of 
weak plants probably contributed to the wide differences in yield at the 
end of the season. 
ML/9/VT/A/G 
Fig. x 7. —Graphic presentation of the total number of rotted ears (continuous lines) and the total number of 
chaffy ears (broken lines) produced by the two lots of seed at different dates of planting. The heavy 
lines represent the nearly disease-free seed, the light lines moderately diseased seed. (Taken from Tables 
XXI to XXIV, inclusive.) 
especially true in seasons like 1921 when conditions were so favorable for 
the development of ear rots. The differences in the yield of marketable 
corn presented in Tables XXI, XXII, XXIII, and XXIV and figures 
9, 10, and 11 are similar to those reported for 1920 and are well correlated 
with differences in early vigor (fig. 13). However, the results from the 
fourth planting that are presented in Table XXIV require some addi¬ 
tional explanation. Although the difference in early vigor was the least 
in the last planting, yet the difference in yield of sound com in this same 
planting was the greatest (Table XXV and fig. 12). The late-planted 
