58 
Journal of Agricultural Research 
Vol. XXIX, No. 2 
bacterial blight, and he furthermore 
expresses the opinion that the disease 
in Manchuria is the same as that found 
in America. He also records the occur¬ 
rence of this bacteriosis in other parts 
of China and Japan. 
In 1921 another Japanese investi¬ 
gator, Takimoto (14), published a 
comprehensive account of his investi¬ 
gations on a bacterial disease of soy¬ 
beans which he had had under observa¬ 
tion since 1914. This disease mani¬ 
fests itself by the formation of nu¬ 
merous small, angular, dark-brown leaf- 
spots with chlorotic intervening tissues. 
Lesions may also form along the veins 
and extend along them making dark 
streaks. Black, sunken areas form 
upon both petioles and stems. These 
symptoms, as he points out, are quite 
different from bacterial blight in 
America. The organism which he iso¬ 
lated was proved to be pathogenic not 
only to soybean in all stages of its 
growth, but also to Adzuki bean, Pha - 
seolus angularis Willd. Takimoto does 
not assign a name to the bacterium 
which he had under observation, but 
does compare it morphologically and 
physiologically with published accounts 
of Bacterium glycineum, as described 
by Miss Coerper, Bad. sojae, as de¬ 
scribed by the writer, and Pesudomonas 
glycineum, as described by Nakano, 3 
who isolated the organism in 1916 from 
collections made in Kumamoto pre¬ 
fecture. He concludes that it is most 
like Bad. sojae, but differs from it in 
the absence of a capsule, in its failure 
to effect a change in milk, and in its 
growth in the closed arm of fermenta¬ 
tion tubes containing dextrose, sac¬ 
charose, and mannite. It is doubtful 
whether these differences would be con¬ 
firmed were both forms in the hands of 
one investigator; and it remains for 
subsequent investigation to determine 
the identity of the organism of Taki¬ 
moto and Bacterium sojae and whether 
either or both are identical with Pseu¬ 
domonas glycineum Nakano. 4 Cer¬ 
tainly none of these are like the soy¬ 
bean bacterial pustule, as will become 
apparent when they are compared 
with the description of the appearance 
of this disease and with the cultural 
characters of the causal organism. 
Bacterial pustule is known to occur 
in Texas, Virginia, Kansas, South 
Carolina, and Louisiana (3, 4 )• It 
has been collected from a sufficient 
number of localities in North Carolina 
to warrant the belief that it is generally 
prevalent throughout the State. 
APPEARANCE OF THE DISEASE 
Soybean pustule has not been 
observed upon the stems and pods, but 
upon the foliage only. Soybeans in 
all stages of growth varying from the 
seedling stage to mature plants are 
subject to infection. The disease may 
appear upon the foliage in any stage 
of maturity, but reaches its most de¬ 
structive stage of development at the 
time when the plants have reached 
their maximum vegetative growth. 
The first indication of the disease is 
the presence of minute elevations on 
either or both leaf surfaces (figs. 1 
and 2). These elevations themselves 
are light green in color. Soon a yel¬ 
lowish-green halo forms as a border at 
the base of each elevation. At this 
stage the lesions are easily distin¬ 
guished from those produced by Bac¬ 
terium glycineum and Bad. sojae, 
neither of which causes the formation 
of pustules, and each of which, espe¬ 
cially in the early stages, causes the 
invaded tissues to be translucent. 
This is followed by the enlargement 
of the elevations to very prominent 
pustular outgrowths often extending 
above the leaf about twice as high as 
the thickness of the leaf (fig. 3). 
These raised portions soon collapse and, 
together with a portion of the sur¬ 
rounding invaded tissues, become brown. 
Ultimately, the lesions become angular 
to irregular reddish-brown areas which 
vary in size from minute specks to 
large irregular spots. These large 
areas arise by the fusion of lesions in 
case initial lesions are abundant. 
Lesions in all stages of development 
occur on the same leaflet. This indi¬ 
cates that the initial infections serve 
as the source of inoculum for secondary 
infections. 
The general aspect of the pustule 
disease in the late stages (Pis. 1, 2) is 
like that produced by the rust fungi, 
whereas bacterial blight lesions are 
dark brown to brownish-black in 
color and tend to break out and fall 
away, thus making perforations or 
notches in the leaves. 
Nakano’s original paper has not been seen by the writer, nor does he have a complete reference to it. 
These papers were translated by Mr. S. Yonemachu, a special student of textile manufacture at the 
North Carolina State College of Agriculture and Engineering. Grateful acknowledgment is herewith 
made of his kindness and courtesy in rendering this service. 
