Some Bacterial Diseases of Plants. 13 
the cut surface should be protected from wound rots by. painting. 
Either lead and oil paint, or shellac wash, or grafting wax may be 
used for this, but the lead and oil paint is cheaper and less liable to 
crack than the others when exposed to the sun. The question may 
be asked, “When is the proper time to do the cutting?” The writer 
would answer, “Whenever the blight appears.” Trimming out the 
diseased parts may be done at any time in the late fall, winter and 
spring. The most favorable time, however, is in the autumn after 
the leaves have fallen, for then the blighted twigs become very con¬ 
spicuous by the dead leaves still hanging to them. It is not advis¬ 
able to postpone the cutting until the growing season, for at that 
time there is great danger of overlooking new cases which are con¬ 
stantly occurring owing to the lack of development so early in the 
season. If the entire tree is affected, there is little hope of saving 
it and the best procedure is to grub it out and burn the whole tree. 
Too much stress cannot be laid upon the complete destruction of 
the diseased wood, for our only hope of stamping out the blight lies 
in removing the source of the infection. A single twig left on the 
ground unburned may mean the loss of the whole orchard. 
The knife and the saw used must be sterilized after each cut 
in order that the disease germs clinging to the instrument may not 
be carried to the healthy parts of the tree. This can be done by 
passing the knife several times through a flame, or it may be dipped 
into either a 5 per cent, solution of carbolic acid or a 1-1000 solution 
of mercuric chlorid, made by dissolving 1 part by weight of mer¬ 
curic chloride in 1,000 parts of water to which 2 parts of hydro¬ 
chloric acid have been added. 
A careful inspection of the orchard should be made in the 
winter and spring before the blossom season, in order to destroy 
any new cases that may have developed since the previous examina¬ 
tion. 
The greater part of the blight will be eradicated by one careful 
winter and spring cutting, and if this be done and done thoroughly, 
the disease can be entirely controlled. 
Susceptibility of Different Varities. —So far as we know 
at the present time there are no varieties that are entirely immune 
to the disease. Mr. O. B. Whipple, in charge of the fruit investi¬ 
gations of the Colorado Experiment Station on the Western Slope, 
state that among the pears grown in that locality, the Bartlett, 
Easter, Flemish Beauty, Clapp’s Favorite, Clairgeau, Howell, and 
Sheldon suffer worst from the blight, and among the more resistant 
varieties may be mentioned the Anjou, Kieffer, Seckel, Mt. Ver¬ 
non, Garber and Suduth. The most susceptible apples found in this 
same region are the Tolman Sweet, Peewaukee, Transcendent 
(Crab), Jonathan, Red Mountain, and Winter Banana. 
