There is no remedy or preventive for this disease.  From the nature of its attack, which is on the inner layer of the tree, it is evident that all applications of fungicides, which must necessarily be applied to the outside of the tree, will not reach the disease.  Injections are impossible and other suggested remedies, such as boring holes in the wood for the purpose of inserting chemicals, are futile.

    The wood of the chestnut tree, within three or four years after its
    death, is still sound and may be used for telephone and telegraph
    poles, posts, railroad ties, lumber and firewood.

Spraying for fungous diseases:  Where a fungous disease is attacking the
    leaves, fruit, or twigs, spraying with Bordeaux mixture may prove
    effective.  The application of Bordeaux mixture is deterrent rather
    than remedial, and should therefore be made immediately before the
    disease appears.  The nature of the disease and the time of treatment
    can be determined without cost, by submitting specimens of affected
    portions of the plant for analysis and advice to the State
    Agricultural Experiment Station or to the United States Department
    of Agriculture.

Bordeaux mixture, the standard fungicide material, consists of a solution of 6 pounds of copper sulphate (blue vitriol) with 4 pounds of slaked lime in 50 gallons of water.  It may be purchased in prepared form in the open market, and when properly made, has a brilliant sky-blue color.  Spraying with Bordeaux mixture should be done in the fall, early spring, or early summer, but never during the period when the trees are in bloom.

STUDY III.  PRUNING TREES

FUNDAMENTAL PRINCIPLES

Trees are very much like human beings in their requirements, mode of life and diseases, and the general principles applicable to the care of one are equally important to the intelligent treatment of the other.  The removal of limbs from trees, as well as from human beings, must be done sparingly and judiciously.  Wounds, in both trees and human beings, must be disinfected and dressed to keep out all fungus or disease germs.  Fungous growths of trees are similar to human cancers, both in the manner of their development and the surgical treatment which they require.  Improper pruning will invite fungi and insects to the tree, hence the importance of a knowledge of fundamental principles in this branch of tree care.

[Illustration:  FIG. 112.—­A Tree Pruned Improperly and too Severely.]

Time:  Too much pruning at one time should never be practiced (Fig. 112),
    and no branch should be removed from a tree without good reason for
    so doing.  Dead and broken branches should be removed as soon as
    observed, regardless of any special pruning season, because they are
    dangerous, unsightly and carry