SIXTEENTH ANNUAL MEETING. 107 



places. If it is liberally but not forcibly applied it may roll 

 over without penetrating places partly sheltered or covered 

 with plant hairs and the amount of oil is not sufficient to give 

 its penetrating powers a chance to act. If we remember that 

 in using the "k.-l." or mechanical mixtures we recommend 

 from 15 to 20 per cent of actual oil we must not be surprised 

 if 2)V-2 per cent, sometimes fails, nor deem the requirement of 

 5 per cent, unreasonable. 



And now some words on the mechanical problem. Neither 

 the lime-sulphur nor the oil mixtures kill anything that they 

 do not touch : — all are truly and strictly contact insecticides. 

 Given a peach tree, with smooth or slightly roughened 

 bark, there are few sheltered places where a scale is 

 protected. Spraying with lime and sulphur it is easy to cover 

 completely, and whenever everything is white the work is thor- 

 oughly done. The trees are not so large as to make it difficult 

 to get to all parts of them with considerable force and the 

 scales get the full benefit of the application. Under ordinary 

 circumstances, assuming the material to be well prepared the 

 scales are pretty well killed ofT. 



Apply the "Scalecide" 1 to 15 in the same way and you get 

 no better results; but it takes only half as much material to 

 do the work because the wash is thin, can be sprayed with a 

 finer nozzle and greater force, and will spread and get under 

 scales more easily. The cost is a little in favor of the lime, 

 wash, but this is counterbalanced by having a material nuich 

 less offensive to handle, not so hard on the apparatus and 

 ready for application at a few minutes notice. 



In favor of the lime-sulphur, however, is its effect against 

 some of the peach diseases and its almost specific tendency to 

 improve the vigor and appearance of the tree, and this advan- 

 tage is so great that I usually recommend for peach orchards 

 the lime and sulphur wash. 



I might digress here for a moment to say that there can 

 be no cumulative efYect on trees from the application of "scale- 

 cide" and soluble oils containing no vaseline. The material 

 being completely soluble in water is washed off and nothing 

 remains to be added to by later sprayings. 



Given an apple tree of bearing age and considerable size 



