522 
Journal of Agricultural Research 
Vol. XXX, No. 6 
folk, Va. Thirty mild mosaic Bliss 
Triumph tubers and a similar Green 
Mountain lot were represented in 
each place. As previously reported, 20 
observations were made in 1922 by the 
same person, one of the writers, in the 
three localities. The results of these 
observations indicated that mottling 
was less distinct on the foliage at Nor¬ 
folk than in the other localities. It was 
also noted that most of the vines in the 
three localities showed mild mosaic 
symptoms; a few plants plainly dis¬ 
closed mosaic-dwarf or bad mosaic 
symptoms. However, mosaic - dwarf 
appeared on the plants from the same 
tuber in each of the three localities and 
no tuber produced plants having mild 
mosaic in one locality and a different 
stage of mosaic in another locality. 
The tubers from each hill were kept 
separate and in 1923 were planted on 
Aroostook Farm where the results pre¬ 
sented in Table X were obtained. Tuber 
decay in the Green Mountain series 
made comparison possible only in the 
Bliss Triumphs. 
The data in Table X show that rugose- 
mosaic was contracted by 12 of the hills 
in Virginia, by 7 in Long Island, and by 3 
in Maine. Leaf-roll was contracted by 
8 hills in Virginia and by 2 in Long 
Island. Spindle tuber was contracted 
by 21 hills in Virginia and by 4 in Long 
Island and in Maine. Mild mosaic 
probably was present in more hills in 
the Virginia lot than is apparent from 
Table X, because it would be masked, if 
present, in the hills with rugose mosaic. 
EFFECT OF FOUR REGIONS ON THE 
DISSEMINATION OF MOSAIC, LEAF- 
ROLL, AND SPINDLE TUBER IN 
FIVE VARIETIES 
In a previous publication 21 evidence 
was recorded indicating that the dis¬ 
semination of insect-borne diseases both 
differed between localities and varied in 
the same locality, and that such lack of 
uniformity in dissemination apparently 
was due to differences and variations 
in the number, kind, and seasonal 
Table X.— Effect of different climatic conditions in 1922 on mosaic lots from the 
same tubers , as shown by the percentage of disease in the progeny grown in north¬ 
eastern Maine in 1923 
Series 
No.° 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
Mild mosaic 
Rugose mosaic 
Leaf-rolling 
mosaic 
Leaf-roll 
Spindle tuber 
Va. 
L. I. 
Me. 
Va. 
L. I. 
Me. 
Va. 
L. I. 
Me. 
Va. 
L. I. 
Me. 
Va. 
L. I. 
Me. 
100 
100 
50 
12 
50 
75 
100 
100 
ioa 
33 
100 
100 
55 
100 
50 
75 
75 
100 
25 
25 
i 
75 
100 
60 
50 
100 
100 
40 
80 
100 
100 
100 
35 
1 
100 
42 
100 
i 
! 
100 
100 
100 
l 
100 
22 
100 
100 
100 
I 
88 
75 
50 
100 
!_ 
(0 
100 
50 
100 
! 
100 
100 
1 
100 
100 
100 
100 
100 
100 
75 
100 
100 
44 
100 
100 
100 
24 
66 ; 
100 
100 
100 
11 
90 
100 
100 
100 
_ 
100 
100 
36 
100 
100 
100 
100 
100 
100 
100 
100 
18 
.... ; 
100 
100 
; 
18 
100 
100 
81 
_ 
100 
100 
100 
1 
32 
! 
100 
45 
81 
100 
100 
100 
1 J 
50 
100 
100 
1 
16 
100 
100 
100 ; 
100 
n i 
9 
33 
66 
_ 
100 
50 
27 
1 ! 
1 
« Each scries consisted of seed-pieces grown from the same tuber in 1922. 
b Labels in series 1 , 11-17 for Virginia were defaced, but sacks were taken in order of packing. 
c Partly diseased. 
20 Schultz, E. S., and Folsom, D. Op. cit. p. 100. 
21 Schultz, E. S., and Folsom, D. Op. cit. p. 102,109. 
