1907.] PUBLIC DOCUMENT No. 73. 147 



tant that all orchard trees should be so trimmed as to leave the 

 least possible shelter for the moths at egg-laying time ; and that 

 in all trimming operations the removal of branches should be so 

 accomplished that no cavities may result. To this end a gen- 

 eral opening up of the tree is advised, and this is the practice of 

 the best fruit growers of the country. It is important that the 

 cuts made in removing the branches should be smooth and close 

 to the trunk, in order to insure a proper healing of the wound. 

 Where large branches are cut off, the first incision should be 

 made from below and the second and main cut from above, so 

 that as the branch falls there shall be no tearing down of the 

 sap wood. Usually a cut of from one-half to one and one-half 

 inches on the lower side, dependent upon the size of the limb, 

 will suffice. Then the branch may be sawed off from above in 

 the usual manner, care being taken to make the cut close to and 

 parallel with the main trunk or branch. (See Plate, Fig. 1.) 

 Next, an application of coal tar or paint should be made over 

 the entire surface of the cut, and for this purpose an ordinary 

 stencil brush will be found very useful. This treatment has a 

 double effect. It excludes air from the wound, and also pre- 

 vents the admission of fungous growths which cause decay. 

 For the latter reason, coal tar, containing as it does a large 

 percentage of carbolic acid and naphthaline substances of high 

 germicidal powers, is especially effective. 



There are to-day in Middlesex Fells numbers of white oaks 

 which were so trimmed and treated in the process of removing 

 large limbs in 1895 that no decay has occurred. At the present 

 writing the scars caused by the removal of these large limbs 

 have closed over in an entirely satisfactory manner. On the 

 other hand, there may be seen in every town improperly pruned 

 fruit and shade trees, where proper precautions were not taken, 

 and where cavities often extending to the heart of the tree have 

 resulted. (See Plate, Figs. 2-6.) Thus, by constantly keep- 

 ing in view the future effect of pruning operations on the tree, 

 it is possible to do this necessary preliminary work in such a 

 way as to prevent the formation of hiding places for the motli, 

 and at the same time materially benefit the tree. 



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