i8 The Colorado Experiment Station. 
or in formalin, one pound in thirty gallons. 
The removal of sick leaves in the early stages of the disease is 
practiced by some growers with success. Others have tried this 
preventative and found it to be a complete failure. The investiga¬ 
tions of Stewart* and Harding condemn this practice and prove 
quite conclusively that the method is not only harmful to the plants, 
but also worthless. The treatment fails, they say, because, 
“The removal of so many leaves checks the growth of the 
plants; infection occurs by way of the roots as well us through the 
leaves; infection may occur at the base of the leaf close to the stem 
and get into the stem unobserved; the germs of the disease are so 
widely and so abundantly distributed that it is useless to try to 
stamp out the disease by the removal of diseased material.” 
Warm days, cool nights and frequent showers seem to accel¬ 
erate the rot. Smithf is inclined to think that cabbage planted late 
is less susceptible than that which is planted early. In selecting 
cabbage for producing seed the following season, care should be 
taken to pick out only those plants which are absolutely free from 
. the infection. 
When cabbage is to be stored over winter, the heads should be 
examined critically and any diseased ones rejected or kept by them¬ 
selves. The room or store house must be kept cool, below 40° F., 
and must have uniform ventilation. 
It is a matter of common observation in the Eastern States 
that when cabbage is grown year after year on the same piece of 
land, there is a notable increase in the amount of rot. In the first 
place, such a method is not to be recommended from an agricultural 
standpoint, since it violates the important principle of crop rotation, 
and further, if it becomes necessary, because of limited space, to 
continue using this land, our only hope of getting rid of the disease 
is to grow crops other than members of the cabbage family for five 
or ten years and longer. During this interim the land must be kept 
free from all cruciferous weeds which harbor the bacteria, especial¬ 
ly the common wild mustard. 
If possible, cabbage should be set each year on ground which 
has not been planted to it for some time, or which has been in sod 
several seasons, or else cultivated to crops which are not affected by 
the rot. The one important thing for the gardener to observe if he 
would be a successful cabbage grower, is to take the utmost care to 
keep his field from becoming infected, and if once infected not to 
spread the malady over his whole farm. 
*Bull. 232, N. Y. Expt. Sta. 
fFarmers’ Bull. 63, U. S. Dept. Ag. 
