HOW FAR TO GO IN CAVITY FILLING 



101 



an incomplete removal of diseased wood, to the cement 

 being flushed out to the surface of the outer bark, or to 

 the want of tar on the outer surface of the filling. 



Cavity filling to a limited extent, when properly done, 

 is very useful and conducive of much good. When im- 

 properly done or done unnecessarily, it is wasteful and 

 often injurious. Here are a few instances of the unneces- 

 sary and improper kind often met with : 



One often sees diseased cavities covered with sheets 

 of tin. This allows all decayed wood and fungous growth 

 to remain undisturbed within. Now, no one would think 

 of filling a cavity in a tooth without first removing all 

 decayed matter from the interior of the cavity and then 

 washing it with some antiseptic solution. Still, here were 

 similar operations tolerated on trees with utter disregard 

 for these fundamental principles. The tin coverings did 

 more harm than good, because they merely shut out the 

 sun and wind and added more dampness to the interior, 

 thereby favoring every possible development of disease. 



Another instance which came under my observation 

 was an attempt to replace bruised bark with cement. 

 This was repeated on hundreds of trees at a vast cost and 

 with utter failure. The person responsible for this work 

 did not understand the purpose of filling a cavity, for, 

 had he known that the filling should be put there to pre- 

 vent moisture from lodging within the cavity or to fur- 

 nish a support for the growing tissue to roll over, he might 

 easily have seen that in this instance there was no chance 

 for moisture to lodge on the perpendicular smooth 

 surface, and that the exposed wood furnished ample sup- 

 port for the growing tissue to roll upon. The application 

 of a little coal-tar to the exposed wood would have 

 been all that was necessary The cement covering, however, 

 merely favored decay, and when the growing tissue 

 on each side of the wound began to extend, it pushed 

 out the cement. 



On still another occasion the owner was investing a 

 large sum in filling cavities in chestnut trees that were at 

 the time badly afflicted with the chestnut disease. The 



THE COMPLETED FILLING 



Here the tree cavity is properly filled. The interior, cleansed of all foreign 

 substances, is studded with nails and solidly filled with bricks, stones and cement, 

 the outer edge is interlaced with wire to assist in holding the material in place 

 and the outer layer of cement is covered with coal-tar. 



operator should have recognized the presence of the dis- 

 ease; he should have known that there is no remedy for 

 it. and that the speedy death of these trees was inevitable. 

 As it happened, the trees soon began to die, and the im- 

 practicability of the treatment became evident. 



ADVICE FOR FEBRUARY 



1. Continue removing and burning trees previously 

 marked during the fall. 



2. Clean up the heavy brush in the woodlands and 

 burn the superfluous parts while the snow is on the ground. 



3. Work on wounds and cavities, confining yourself 

 to digging out all decayed wood, chiseling out old stubs 

 so as to drain water and covering all exposed wounds with 

 coal-tar in mixture with creosote. 



4. Collect and burn cocoons and egg masses of insects. 



5. Commence pruning fruit trees. Remove dead and 

 superfluous branches from apple trees and cut the crowns 

 back so as to form low compact heads. 



6. Inspect all pear trees for fire blight and cut out all 



cankers from main branches and trunks and tar the wounds. 

 Also cut out black knot from plum and cherry. 



7. Spray fruit trees for sucking insects and canker. 

 Determine beforehand what you are spraying for by com- 

 municating with your local agricultural experiment station 

 or by submitting samples and details to this Department 

 of American Forestry. Then use chemicals and methods 

 especially prescribed for the particular pest you are spray- 

 ing for. Choose a mild day for spraying work. 



8. Prune and tie up grape vines by the end of this 

 month. 



9. Turn over the manure pile or leaf mold compost pre- 

 pared last fall and see that the liquid manure is not wasted. 



QUESTIONS AND ANSWERS 



Q. I wish to rig up a wagon for moving large deciduous 

 trees from a caliper of eight to fourteen inches. 



Can you give me any advice or suggestions concerning the 



most successful outfits used in your section, or the names of any 

 parties who manufacture for sale outfits for this work? 



I H. F. B., Minneapolis, Minnesota. . 



