wly planted, bark injuries of any kind
should be guarded against. Extreme care is necessary in the training of
the scaffold branches, as the tree grows, in order that the mature tree
shall be well formed with as few large wounds as possible through the
removal of large branches.
The application of fungicidal sprays, such as Bordeaux, at intervals
throughout the growing season, may be helpful. The trunk and the main
branches, especially, of young trees should be protected from sun scald.
Borers and other insects must be kept out. Injury from tools used about
the trees must be guarded against. Any break in the bark offers easy
entrance to the fungus spores. Wrapping the trunk with burlap or paper
may be very helpful in preventing such injuries. Probably the best time
of year to make necessary pruning cuts is in early spring. Pruning
should be followed by the painting of the wounds with shellac, later
covering this with a good grade of paint. The tree should be well fed to
aid in the growth of callus formation to cover the wound quickly.
Other methods of attack in solving the problem include the immunization
of the chestnut against the blight and the breeding of resistant
varieties. Experimental work along these lines is being carried on by
individuals and Federal and State agencies, but the work has not as yet
progressed sufficiently to give results of commercial value.
If careful cultural methods are followed in every locality, with special
emphasis on the prompt and thorough disposal of diseased material, by
removal and burning, we can look forward to a number of years of
profitable chestnut production in Illinois.
DR. DEMING:
Is the Riehl orchard free from blight?
DR. COLBY:
One of the same gentlemen who visited Ithaca the other day, by
authority, is making a very careful survey for disease of the nut trees
in the eastern and northern United States. The Riehl orchard that we
visited last year about this time had considerably over 100 trees badly
diseased. We'll have to do the best we can with the old trees but watch
the young ones carefully.
DR. DEMING:
Don't you think that one of the commonest causes of the blight of
chestnut trees is through the wounds and the inoculations made by the
claws of squirrels?
DR. COLBY:
Yes, and also woodpeckers. The old trees can be preserved for a longer
or shorter time, depending on the care that is given to them. We found
the disease down in the Endicott orch
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