SOYBEAN MOSAIC: SEED TRANSMISSION AND EFFECT 
ON YIELD 1 
By James B. Kendrick, Assistant in Botany, and Max W. Gardner, Associate in 
Botany, Indiana Agricultural Experiment Station 2 
INTRODUCTION 
Rather extensive inoculation tests in field and greenhouse have failed 
to reveal any host for soybean mosaic other than the soybean itself. 
Cross inoculations from mosaic red clover and garden bean to soybean 
were unsuccessful, and cross inoculations from soybean to sixty varieties 
of garden beans and seven other species of Phaseolus, to two species of 
Dolichos, to field peas, and to cowpeas gave only negative results. 
Mosaic has been noted On the following varieties of soybeans at La 
Fayette, Ind.: Midwest or Medium Yellow, Haberlandt, Manchu, Ito 
San, Mongol, Hurrelbrinks, Mammoth Black, Habara, A. K., Arlington, 
Hoosier, Elton, Wea, Lexington, Black Eyebrow, Pinpu, 36847, Feldun 
Dunfield, Soysota, Wilson Black, Mammoth Yellow, Brown, Virg inia ’ 
and Tar Heel Black. The disease seems to be most prevalent in the 
Midwest, Haberlandt, and Black Eyebrow varieties and the symptoms 
seem to be most conspicuous in the Midwest variety. The Midwest or 
Medium Yellow variety has been erroneously known locally as Holly- 
brook, according to Wiancko and Mulvey (9), 3 and it was in this variety 
that we (5) first noted the disease. 
As yet the mosaic disease does not seem to have become seriously 
prevalent in Indiana. F. E. Robbins found the disease in only 4 out 
of 27 soybean fields inspected in 1923. With the exception of one field 
of the Midwest variety, only a very low percentage of infection has been 
found in commercial fields. 
In addition to the typical mosaic symptoms described in a previous 
account by the authors (5), other symptoms have been found associated 
with the disease, but these have not been relied upon as criteria of mosaic 
in the following work. Among these symptoms are a bronzing of the 
young, leaves produced by a brown discoloration of short segments of 
the veins and large splotches on the older leaves produced by a lacelike 
yellowing or browning of the veins. In the Lexington variety severe 
symptoms were evinced in 1923. The mosaic plants were extremely 
stunted, the growing tips were killed outright, and brown necrotic 
streaks developed on the stems and petioles. 
SEED TRANSMISSION 
In the previous account (5) it was recorded that about 13 per cent of 
the seed from mosaic plants transmitted the disease. Subsequent tests 
have given similar results with a number of varieties and with older seed. 
The presence of the disease in ordinary commercial seed one year old 
was shown in 1921. Fifteen varieties and selections were planted in 
tui^KxpwimenfStation ° n N ° V ' I923 ’ Contribution from the Botanical Department, Indiana Agricul- 
* The writers wish to acknowledge their indebtedness to Prof. H. S. Jackson for helpful suggestions. 
* Reference is made by number (italic) to ‘ * Literature cited, ” p. 98. ** 
Journal of Agricultural Research, 
Washington, D. C. 
Vol. XXVII, No. a 
