Sept. 1, 1924 
235 
Bacterial Pustule of Soybean 
in the same manner with the same 
culture, which, furthermore, produced 
good typical infections on soybean. 
When previously passed through Pha¬ 
seolus the soybean organism produced 
infections on bush string bean leaves 
and pods (PI. 1, H, I; PI. 4, B) in no 
way distinguishable from those caused 
by Bad. phaseoli EFS. (PI. 1, J, to L). 
INOCULATIONS WITH BACTERIUM 
PHASEOLI SOJENSE AFTER PAS¬ 
SAGE THROUGH PHASEOLUS 
As it had occurred to the writer 
that the pathogenicity of Bad. phaseoli 
sojense for Phaseolus might be in¬ 
creased by its passage through members 
of that genus, parallel inoculations were 
made September 30, 1919, on King of 
the Garden Lima (3 weeks old), dwarf 
bush string bean (2 weeks old) and 
Hahto soybean (3 weeks old) with two 
cultures of Bad. phaseoli sojense , one 
(colony 3) plated May 26, 1919, from 
soybean, the other (colony 1) plated 
July 19,1919, from a Lima leaf, but both 
descended originally from the same 
colony plated from the Texas material 
received in 1916. 5 The inoculations 
were made by spraying in inoculating 
cages in which the plants were kept 
moist for 72 hours. In addition to the 
above, six King of the Garden Limas 
(3 weeks old) were sprayed, three with 
each organism, and covered with 
paraffined bags for 72 hours. The 
results were as follows: 
BACT. PHASEOLI SOJENSE 
Inoculation experiment showing the effect of previous p issue through Phaseolus 
9th day 
COLONY 3 (FROM SOYBEAN) 
Lima bean (cage): Infection doubtful. 
Tiny red spots and distorted leaflets but 
no bacteria found in either on microscopic 
examination. 
Lima bean (bags): Infection doubtful. 
Dwarf bush string bean: Peppered with water- 
soaked spots. 
Soybean: Typical infection, pustule stage. 
| COLONY 1 (FROM LIMA BEAN) 
Lima bean (cage): Good infection, water- 
soaked spots. 
Lima bean (bags): Water-soaked spots. Bac¬ 
teria in abundance. 
Dwarf bush string bean: Water-soaked spots. 
Soybean: Infection doubtful. 
llth day 
Lima bean (cage): Still doubtful. Found no 
bacteria. 
Lima bean (bags): A few tiny suspicious- 
looking spots. 
Dwarf bush string bean: Centers of spots 
becoming discolored. 
Soybean: Center of pustules becoming brown. 
Lima bean (cage): Excellent infection. Spots 
becoming discolored. 
Lima bean (bags): Excellent infection. Some 
of infected leaves are wilting and shrivelling. 
Dwarf bush string bean: Excellent infection 
on a few leaves—discoloration beginning. 
Soybean: Infection doubtful. 
15th day 
Lima bean (cage): No typical spots. 
Lima bean (bags): Infection doubtful. 
“ Dwarf bush string bean: Spots have increased 
little, if any, in size. 
Soybean: Typical infection. 
Lima bean (cage): Spots increasing in size. 
Lima bean (bags): Spots increasing in size 
and surrounding tissue becoming yellow. 
Some shrivelling. 
Dwarf bush string bean: Conspicuous spots, 
increased in size; distortion of leaf due to 
infection of veins, shrivelling. 
Soybean: Infection doubtful. 
18th day 
Lima bean (cage): No typical spots but 
found bacteria in the distorted leaflets and 
pale green spots with tiny red centers and 
isolated the parasite from both. 
Dwarf bush string bean: Some wilt also. 
Isolated parasite from petiole of wilted leaf. 
27th day 
Lima bean (cage and bags): No change. 
Dwarf bush string bean: No enlargement of 
spots which are still small and red. No i 
yellowing. Small red spots full of bac- i 
teria. Parasite isolated. Photographed ; 
leaf. (PI. 4, A). j 
Soybean: Typical infection j 
Lima bean (cage and bags): Excellent infec¬ 
tion in all. Shrivelled leaves. 
Dwarf bush string bean: Some leaves shriv¬ 
elled. Some have dropped off. Multitude 
of bacteria. Parasite isolated. Photographed 
leaf. (PI. 4, B). 
Soybean: No signs of infection 
5 These two colonies had passed through the following series of inoculations: 
From Texas soybean: Colony e, Sept. 23,1916>soybean> Lima pod>soybean>{g^.^J 1 1 ^j^^.polony 1 
