360 



AMERICAN FORESTRY 



INJECTING CURATIVE CHEMICAL SOLUTIONS 



Another view of the apparatus used in injecting solutions into a tree. 

 A glass jar containing the chemical solution was hung in the branches 

 ana connected by rubber tubing with a glars tube inserted in a small hole 

 made through the bark of the trunk. This hole in the bark had to be 

 made under cover of a liquid, otherwise air clogged the vessels of the 

 wood and the solution would not be drawn into the tree. A clamp held 

 the glass tube tightly against the tree. 



it would kill the cells of the tree near the injection hole 

 and would not reach other parts. This is one of the 

 reasons why horing a hole in the trunk and filling it with 

 strong chemical in either solid or liquid form is not likely 

 to benefit a tree. 



It was found to be essential to make the holes through 

 the bark for injection purposes under cover of a liquid. 

 I f air enters before injection or with the solution, air- 

 bubbles will clog the small tubes or vessels in the vascular 

 bundles and prevent the solution's being absorbed by the 

 tree. The reader will probably ask at this point if a 

 tree whose trunk is peppered with injection holes is not 

 seriously injured by such treatment. As a matter of 

 fact, the trees with which the experiments were made 

 did not suffer from this cause. The injections were 

 made under sanitary conditions and only small holes 

 were made. These were afterward filled with clean 

 grafting wax, and a callus growth quickly closed up the 

 wound, forcing out the wax plug. By the end of three 

 years, there was not even a scar to show where the in- 

 jection had been made. 



The idea of introducing chemical substances into plants 

 is more than two centuries old. The first report on tree 

 injection for purposes of medication was published by a 



Russian scientist in 1894. This was followed by scattered 

 work in America, France, Germany and Russia. Some 

 successful results were reported, but in the main the 

 effect of injected solutions were not beneficial or the 

 results were inconclusive. The most practical method 

 was contained in the Russian publications, and the Rus- 

 sion method of introducing solutions was used in the 

 beginning of the chestnut experiments. Very soon how- 

 ever an easier and less expensive method was developed, 

 in which the apparatus cou'.d be quickly adjusted to the 

 trunk and left for twelve hours or more without further 

 attention. On small trees, a glass container holding the 

 solution to be injected was hung on a branch of the tree. 

 The solution was led to the point of injection by a rubber 

 tube in the end of which was a piece of small glass tubing 

 which was inserted into the injection hole. The glass 

 tube was held in place by means of a perforated rubber 



CHESTNUT TREE IN WHICH LITHIUM CARBONATE HAS BEEN 

 INJECTED 



This shows the drying up of the chestnut blight canker. The dead hark 

 was easily lifted out because the fungus was killed by the chemical. 



cork, which in turn was pressed tightly against the tree 

 trunk by a clamp, thus preventing leakage. This appa- 

 ratus is shown in the accompanying illustration. A varia- 

 tion of this method was used on large trees. In place 

 of the clamp, a link chain was placed around the trunk. 

 It was tightened by turnbuckles and held the perforated 

 rubber corks against the tree. The corks were protected 

 from the metal chain by iron washers. A glass "T" tube, 

 thrust through the cork, introduced the solution into the 

 injection hole. The rubber tube leading from the reser- 

 voirs higher in the tree was attached to the vertical end 



