92 
Journal of Agricultural Research 
Vol. XXVII, No. 2 
parallel plots of three rows each on May 26, 1921, and the occurrence of 
a very small percentage of seed-borne mosaic in 9 of the 15 varieties was 
determined by a careful examination of the seedlings on June 26 as shown 
in Table I. The secondary spread of infection as shown by the records 
of August 16 w T ill be referred to later. 
Table I .—Mosaic in variety plot, IQ 2 I 
Variety. 
Number 
of plants. 
Mosaic 
seedlings 
June 26. 
Mosaic plants, Aug. 16. 
Number. 
Per cent. 
Midwest. 
272 
O 
79 
29 
Elton. 
2 53 
2 
24 
9 
36847. 
236 
O 
1 
0.4 
Haberlandt. 
255 
5 
57 
22 
Wea. 
294 
0 
28 
9 
Lexington. 
352 
1 
8 
2 
Soysota. 
221 
0 
0 
0 
A. K. 
205 
1 
17 
8 
Black Eyebrow. 
l6o 
1 
21 
*3 
Pinpu. 
209 
0 
7 
3 
Feldun. 
270 
1 
7 
2 
Dunfield. 
2 59 
2 
14 
5 
Ito San. 
250 
0 
4 
2 
Arlington. 
301 
2 
18 
6 
Manchu. 
l66 
1 
12 
7 
In a small plot of Midwest soybeans planted in 1921 with seed from 
a field in which the disease occurred in 1920, 17 out of 423 seedlings, or 
4 per cent, developed mosaic. A number of volunteer seedlings came up 
in 1921 in the field used in 1920 and one of these showed mosaic, indicat¬ 
ing that the disease persisted over winter in the seed lying in the field. 
Two rows were planted in 1921 with seed saved from mosaic Midwest 
plants in 1920 and out of the 156 seedlings, 14, or 9 per cent, showed 
mosaic. Among the progenies of six mosaic plants, 12 out of 65 seed¬ 
lings, or 18 per cent, were mosaic. 
In a plot planted in 1922 with seed saved from mosaic Midwest plants 
in 1921, 172 out of 993 seedlings, or 17 per cent, showed mosaic, while 
in another plot planted with seed from healthy plants, 590 seedlings came 
up and none were mosaic. 
These results with seed from mosaic plants corroborate the writers’ pre¬ 
vious conclusion that a varying and usually rather low percentage of such 
seed carries the disease. Dickson (3, p . 83-86) obtained similar results 
in connection with the seed transmission of mosaic in Trifolium pralense 
L. and Melilotus alba Desr. Reddick and Stewart (8) found a varying 
but much higher percentage of transmission of bean mosaic through the 
seed, and Archibald (r, p . 62) found that 43 per cent of the seed from 
mosaic bean plants transmitted the disease. Doolittle and Gilbert (4) 
found that a low percentage of the seed from mosaic wild cucumber 
transmitted cucurbit mosaic, and Newhall (6) likewise found in the case 
of lettuce mosaic that a very low percentage of the seed transmitted the 
disease. 
Seed saved from mosaic soybean plants of a number of varieties in 
the fall of 1921 were planted in the greenhouse the following winter 
with results as shown in Table II. The results of a similar test made 
with seed selected from mosaic plants in 1922 are shown in Table III. 
