264 
Journal of Agricultural Research 
Vol. XXV, No. 6 
Table IV.— Showing relation between distribution of sprouts and foliage condition of 
progeny plants 
Dot No. 
Number of 
tubers. 
Distribution of sprouts. 
Number of 
plants. 
1 
Clustered at apex. 
4 
. 
1 
.do. 
A 
. . . 
x 
, do . 
*T 
2 
. 
1 
.do. 
4 
). 
>. 
i 
. ..do. 
T 
T . 
1 1 
....do . 
J 
4 
5 . 
1 
. do . 
T 
A 
>. . . . 
! T 
.do. 
*T 
7 
j. I 1 
. do . 
O 
4 
J . ! X 
Scattered. 
6 
5 . 1 
. ...do. 
tr 
1 
i. 1 
. ...do. 
D 
2 
).i 1 
...do . 
0 
2 
1 l 
. ...do. 
O 
e 
i.! i 
.do. 
6 
1.! 1 
.do. 
>.! 1 
.do. 
4 
c./EMflLr i 
.do. 
r 
8 
l. I 
.do. 
< 
. . 
.do. 
4 
1 . ... 
I 
.do. 
T 
4 
3 . 
T 
.do. 
T 
2 
I 
90. 
Condition of plants. 
Medium mosaic. 
Healthy. 
Do. 
Extreme mosaic. 
Do. 
Do. 
Do. 
Healthy. 
Do. 
Medium mosaic. 
Mild mosaic. 
Medium mosaic. 
Extreme mosaic. 
Mild mosaic. 
Medium mosaic. 
Healthy. 
Mild mosaic. 
Healthy. 
Mild mosaic. 
Healthy. 
Medium mosaic. 
Extreme mosaic. 
The results of these limited observations do not show either apical 
dominance or the lack of it in the tubers to be consistently correlated 
with any condition as to health or disease in the resulting plants. Tubers 
with sprouts clustered at the apex produced both healthy and mosaic 
plants and the same results were observed in the case of tubers with 
sprouts not confined to the bud end or apex. In Plate 5, B, 78, 79, 80, 
are shown tubers with normal sprouts clustered at the apex, and in 
C, 81, 83, and D, 84, of the same plate are shown tubers without this 
apical dominance. By referring to Table I it will be seen that of the 
tubers showing apical dominance, No. 78 produced mosaic plants, while 
No. 79 and 80 gave healthy plants, also, that of the tubers not exhib¬ 
iting this dominance, No. 81 gave healthy plants while No. 83 and 84 
gave mosaic plants. 
In agreement with the statement of Appleman referred to above, the 
present observations indicate that apical dominance may be suppressed 
when basal eyes are situated more favorably for germination than ter¬ 
minal ones, so as an index of vigor in tubers this characteristic would be 
subject to limitations. Moreover, as an index of vigor it is subject to 
the further limitation that tubers with distinct apical dominance may 
develop mosaic and even mosaic of the extreme type, as in tubers 65, 
66, 67, and 78 in Table IV. 
Referring again to the data in Table IV, the records show that in the 
germination of tubers 61, 62, and 63 the plants from bud-end seed pieces 
started more promptly and grew better than the plants from the stem 
end of the tubers. The records further show in a limited number of 
cases examined that, regardless of disease condition, when there is 
marked apical dominance of sprouts, the plants from the apex grow 
more vigorously and those from the stem end less so, while in cases of 
