30 STATE HORTICULTURAL SOCIETY. 



feet away from the trunk. Each of these ten trees, therefore, received 

 three fluid ounces of the carbon bisulphide. Five more trees each 

 received one fluid ounce of the liquid injected one foot away from the 

 trunk on two sides, and five other trees each received the same treat- 

 ment, except the injection was made two feet away from the trunk. 

 Each of these ten trees, therefore, received two fluid ounces of carbon 

 bisulphide. Still another group of five trees received one fluid ounce 

 €ach injected one foot away from the trunk on only one side, and another 

 ive trees each received the same treatment, except tbe injection was 

 made two feet away from the trunk. Each of these ten trees, there- 

 fore, received one fluid ounce of the carbon bisulphide. 



On the 24th of October these trees treated with the carbon bisul- 

 phide were also inspected and examined by Col. J. C. Evans, two other 

 gentlemen and myself. We could find no aphids on tbe roots of any 

 of these trees, except those that were injected on one side of the 

 trunk only. On all such we found living aphids on the untreated side. 

 There was no apparent difference in the results between those treated 

 with two or with three injections, nor between those injected one or 

 two feet away from the trunk. In no case could any injury to the 

 trees be observed. This being the case, I should advise one to always 

 make the application two feet away from the trunk and on but two 

 sides. 



The injector used was very convenient, and enabled us to place a 

 known quantity of the carbon bisulphide in the earth near the roots 

 without wasting the liquid and with considerable rapidity. The Mc- 

 Gowen injector was merely modified to adapt it to orchard work. 



From the above experiments it is evident that there is great danger 

 of injuring the trees in using carbon bisulphide unless one is careful 

 to make the injection at least one and preferably two feet away from 

 the trunk. However, by the use of an injector that will inject one 

 fluid ounce, and by injecting two feet from the trunk on two sides of 

 the tree one can readily kill the wooly-aphis and not injure the tree. 

 The injection should always be made when the earth is dry. If it be 

 at all wet the fumes of the carbon bisulphide will not penetrate the 

 earth to any extent, but will be lost. Carbon bisulphide evaporates 

 very rapidly and the fumes are heavier than the air, and in a dry soil 

 they will penetrate and kill all the aphis for a considerable distance 

 from the point of injection. In inserting the injector it will occasion- 

 ally strike a large root just below the surface of the ground. In such 

 cases remove it and make the injection to the right or left so as not 

 to^allow the liquid to touch a main root. The depth to inject varies 



