THIRTY-SEVENTH ANNUAL REPORT. 39 



"The results which were secured with the sohible oils do not warrant such 

 a flattering report concerning their value as has been given by some ex- 

 perimenters. With one very thorough application of the oils about 90 to 

 95 per cent of the scales were killed. Scalecide was the most satisfactory 

 of the soluble oils. The disadvantage of Kil-o-scale was the heavy brown 

 precipitate which forms in the containing vessel on standing. Scale Destroyer 

 was fairly good, but did not form an emulsion as readily as Scalecide. Scale 

 emulsion was entirely unsatisfactory. Scalespray, while making a fairly 

 good emulsion, fell below all the others in efficiency. As a class the soluble 

 oil sprays have the advantage of easy preparation and solution; they have 

 the disadvantage of being washed off the tree by the first rain. This proves 

 to be a serious drawback only when the application of the spray is succeeded 

 almost immediately by rainfall. Unlike the lime-sulphur wash, the effect 

 of the soluble oils is almost immediate, so fhat a repetition of their applica- 

 tion is unnecessary unless the rainfall occurs within a few hours. 



Of the two ready-made lime-sulphur sprays used, Horicum was more 

 satisfactory than Salimene, because of the greater ease with which it is 

 prepared. The material goes into solution very rapidly, stays in suspension 

 well, is adhesive and conspicuous on the trees. Salimene while apparently 

 similar in composition, is much thicker. About fifteen minutes stirring 

 is required to dissolve it and it settles rapidly. 



The Tobacco-potash-whale-oil soaps have no apparent advantage over the 

 lime-sulphur washes or the soluble oils. On the other hand, they have the 

 disadvantage of requiring a considerable amount of time and hot water 

 in their preparation, and the necessity of making the application while the 

 material is still hot. 



In all of the so-called patent preparations mentioned, the item of cost 

 has been considered, for the reason that these sprays are most suitable 

 for use in a small way, where only a few trees are to be treated. Under 

 such conditions a few cents difference in cost is immaterial. Where a large 

 number of trees are to be treated, the lime-sulphur spray has no superior." 



I would add to his conclusions my belief, from subsequent experience, 

 that while it is safest to recommend the lime-sulphur spray now, the time 

 will soon come when the soluble oil sprays will have been so far perfected 

 and cheapened that they will replace lime-sulphur in most cases. 



DISCUSSION. 



Mr. Post: I would like to ask if you have noticed any bad results on the 

 trees from the oil spray? 



Prof. Fletcher: There is no question but the lime-sulphur is more bene- 

 ficial to the tree than the oil. 



Mr. Post: Yes, but the other way, did the oil sprays actually injure the 

 tree any? 



Prof. Fletcher: We had no trouble with injury from the oil spray. I 

 want you to see, if you are interested, all those sprays. There are samples 

 of them over there; also samples of lime-sulphur, one of which was not 

 boiled long enough, which is one reason why some of you have not gotten 

 good results with lime-sulphur; there is also a sample of it when boiled long 

 enough. 



Q. I would like to ask Prof. Fletcher the results with the Rex lime- 

 sulphur solution. They make great claims for it. Claim it is the same thing 

 as the lime-sulphur we use — got the same strength, only it is chemically 

 prepared so much better. What were the results? 



