260 NEBRASKA STATE HORTICULTURAL SOCIETY 



(perhaps 25 per cent on an average) to do work on a tree when 

 these are used instead of climbing spurs, and this is one reason why- 

 many firms who value remuneration more than reputation use the 

 spurs. 



To Minimize Unreliability. 



The U. S. department of agriculture is suggesting a plan that may 

 help put commercial tree surgery on a better basis. Owners are urged 

 to have a definite written contract with the tree surgeons they employ, 

 and the following is suggested as a model for such contract. 



(1) No climbing spurs shall be used on any part of a tree. 



(2) The shoes worn by the workmen shall have soft rubber 

 bottoms. 



(3) Ordinary commercial orange shellac shall be applied to 

 cover the cut edges of sapwood and cambium (which is the soft form- 

 ative tissue from which the new wood and bark originate) within five 

 minutes after the final trimming cut is made. 



(4) All cut or shellaced surfaces shall be painted with com- 

 mercial creosote, followed by thick coal tar. 



(5) All diseased, rotteA, discolored, water-soaked, or insect 

 eaten wood shall be removed in cavity work and the cavity inspected 

 by the owner or his agent before it is filled. 



(6) Only a good grade of Portland cement and clean, sharp 

 sand in no weaker mixture than 1 to 3 shall be used to fill cavities. 



(7) The contractor shall repair free or expense any defects that 

 may appear in the work within one year. 



If the ovvner prefers to have a cavity filled with asphalt or other 

 material instead of cement, the contract can be altered accordingly. 

 If it is desireable to substitute some other preparation for shellac, 

 this can be done. Similarly, under certain conditions, various other 

 modifications may be made, althougli alterations in Nos. 1, 2, 5, and 

 7 should be made with caution. It may so happen that if all insect- 

 eaten wood is removed, the tree may be dangerously weakened; under 

 such conditions the diseased matter can be removed to solid wood and 

 the cavity fumigated. Other suggestions along these lines may bo 

 found in the pamphlet issued by the department. 



Invitation to Cooperate. 



The department realizes that this science is comparatively new 

 and that methods in the near future may be developed that will prove 

 far superior to some now in common use. It therefore invite\5 corres- 

 pondence either from individuals or firms concerning new methods 

 of treatment and is prepared to advise regarding any particular 

 method so far as experimental results will permit. The cooperation 

 of all who are interested is necessary for this work. All interested 

 are urged to write for the new bulletin. — U. S. Dept. of Agriculture. 



