Feb. 34 .is»3 Early Vigor, Yield, and Rot Diseases of Maize 
59i 
Table IV. —Correlation of early height (36 days after planting) and yield in Funk 
Ninety-Day corn grown on clean soil from relatively disease-free and diseased seed, at 
Bloomington , III., in igig 
Condition of seed. 
Number of 
plants. 
Average 
height. 
Average 
yield per 
plant. 
Correlation 
coefficient. 
Probable 
error. 
Disease-free. 
354 
Cm. 
150.4 
Gfti. 
191. 0 
+0.359 
±0. 031 
Diseased. 
331 
146.3 
179.4 
+ • 435 
± .030 
Seed selected from normally rip¬ 
ened plants. 
243 
156-3 
212. 6 
+ -305 
± .039 
Seed selected from prematurely 
ripened plants. 
244 
154.0 
197.0 
+ -307 
± • °39 
The experimental plots represented in Table IV were not planted until 
the latter part of the normal com planting season. The soil in these 
plots had not grown com during the previous io years. These facts 
probably account for the correlation coefficients being lower than those 
given in Table II. Yet it seems that, even under these conditions, the 
correlation between early height and yield is significant. 
Tabus V .—Correlation of height and yield in Bloody Butcher corn grown from artificially 
pollinated ears . Seed planted May 30 in infested soil at Bloomington, III., in igig 
Group 
No. 
Condition of parent 
plant. 
Treatment of seed. 
Num¬ 
ber of 
plants. 
Days 
after 
plant¬ 
ing. 
Aver¬ 
age 
height. 
Aver- 
yiefd 
&. 
Correla¬ 
tion co¬ 
efficient. 
Prob¬ 
able 
error. 
Cm. 
Gm. 
I 
Diseased plants 
f Uninoculated... 
265 
30 
67 
132 
+0. 167 
±0. 040 
selfed. 
^Inoculated. . . . 
200 
30 
57 
123 
4 - .360 
± .041 
II 
Apparently dis- 
’Uninoculated... 
240 
30 
75 
218 
+ -405 
± -037 
ease-free 
Inoculated. ... 
208 
3 ° 
72 
240 
+ .366 
± *045 
plants crossed 
Uninoculated... 
240 
52 
213 
218 
+ -569 
± .029 
Inoculated. . . . 
208 
52 
211 
240 
+ .429 
± .038 
III 
Apparently dis- 
Uninoculated... 
72 
30 
56 
254 
+ -432 
± . 064 
ease-free 
Inoculated.... 
57 
30 
43 
233 
+ *537 
± .063 
plants selfed. 
Uninoculated... 
72 
52 
210 
254 
+ • 600 
± .051 
Inoculated.... 
57 
52 
199 
233 
+ .680 
db . 048 
IV 
Diseased plants 
Uninoculated... 
65 
30 
92 
155 
+ .447 
± .067 
crossed. 
Inoculated.... 
50 
30 
93 
”3 
+ *007 
± .095 
Uninoculated... 
65 
52 
211 
*55 
+ *650 
rb • 048 
Inoculated.... 
50 
52 
204 
IJ 3 
+ .205 
± .085 
In each group shown in Table V, series of plantings of seed inoculated 
with Gibberella saubinetU were made along with corresponding series with 
uninoculated seed. 
There seems to be no special relation between the correlation coeffi¬ 
cients and inoculation in the four different groups. However, there is 
in most cases a strong correlation between early height arid yield. The 
correlation coefficients are higher for the measurements taken 52 days 
after planting than for those taken 30 days after planting. This can be 
accounted for by the fact that weak plants make slower gains in height 
during that period of their development (Tables VIII and IX). It will 
be noted that the inoculation (Gibberella saubinetU) materially reduced 
