66 Report OF THE BACTERIOLOGIST OF THE 
BLACK ROT GHRMS PASS THH WINTER IN CABBAGE PLANTS. 
As has been stated, cabbages intended for raising seed the 
following season are placed in shallow trenches at the approach 
of freezing weather and covered with six to twelve inches of soil. 
Here they are frozen in and remain until spring. 
At the time of opening the trenches in the spring we have on 
a number of occasions collected plants showing black bundles and 
taken them to the laboratory for study. From these plants by 
culture methods we have obtained P. campestris, it often being 
the only organism present in the darkened bundles. In order 
to avoid possible errors in recognizing the germ, cultures have 
been inoculated into healthy young cabbage and cauliflower 
plants with all precautions necessary to prevent contamination. 
After such inoculation black rot has appeared in two to three 
weeks. Check plants treated in the same manner except that 
they were punctured with a sterile needle have always remained 
healthy. 
From this it is evident that the black rot germs are present in 
some of the plants at the time they are set out in the spring and 
that they are in condition to continue their attack upon the 
plants: 
OBSERVATIONS IN THE FIELD. 
May 26, 1899, six fields of seed cabbage just in bloom near 
Cutchogue were examined. In all the fields many plants showed 
the characteristic blackening of the fine veins of the leaves and 
in some cases so many of the bundles in the stem were affected 
as to cause the plant to wilt. Soft rot was sometimes present 
in the plants suffering from black rot. 
Although it is possible to recognize the disease in the field 
with great certainty, in order to settle the matter beyond question 
plants were taken to the laboratory and cultures made from 
the blackened bundles. P. campestris was isolated from four 
such plants and the identity of the cultures was further strength- 
ened by ioculating in each case into healthy cabbage plants. 
Each culture produced the characteristic black rot when thus 
inoculated into healthy cabbage plants while other healthy plants 
grown along side and treated as controls did not take the 
disease. 
‘0 Harding, H. A. & Stewart, F.C. A Bacterial Soft Rot of Certain Cruci- 
ferous Plants and Amorphophallus simlense. Science, N. 8., 16: 314-315. Aug. 
22, 1902. 
