ITie (anadian tjorticoltdrist 



OCTOBER, 1904 



Volume XXVII 



mm 



Number 10 



SPRAYING TESTS AGAINST THE SCALE 



PROP. R. HARCOURT, OXT. AGRI. COLLEGE, GUELPH. 



LAST spring a ,coij,siderabile quantity 

 of the lime and sulphur mixture was 

 used in the Niagara district in combating 

 the San Jose scale. It is gratifying to 

 note that wherever it has been thoroughly 

 applied the results have been most satis- 

 factory. 



About the middle of July and again one 

 month later, in company with Prof. Loch- 

 head, P. Hodgetts, Secretary Fruit Growers' 

 Association, J. Fred. Smith, Glanford, 

 Chief San Jose Scale Inspector, and Robt. 

 Thompson, St. Catherines, I visited a 

 number of peach, plum, and pear orchards 

 in the St. Catherines district which had been 

 more or less badly infested with the scale. 

 In every instance where trees were sprayed 

 with the lime and sulphur mixture the scale 

 was checked, just in proportion to the 

 thoroughness with which the spraying was 

 done. 



From what was seen in the orchards and 

 from the statements of many of the fruit 

 growers, there seems to be no doubt that 

 this mixture will destroy the scale, but to 

 do so it must come in direct contact with 

 the scale, as any parts left uncovered in the 

 spraying, act as a seed bed for the reinfest- 

 ment of the whole tree. As it is practically 

 impossible to cover every crutch and crevice 

 on the tree, the use of the lime and sulphur 



spray may not exterminate the scale, but it 

 has been clearly demonstrated that the pest 

 can be controlled, provided the spraying is 

 carefully done. 



One very .pleasing feature in connection 

 with this matter is that, while the cost and 

 labor entailed in preparing and applying 

 the lime and sulphur mixture is consider- 

 able, it is not so great as was anticipated, 

 and is not regarded as an insurmountable 

 difficulty. Further, its application has ap- 

 parently greatly reduced the amount of leaf 

 curl. 



In the June number of the Horticulturist 

 (page 240) it was announced that several 

 barrels of lime-sulphur and sal soda, and 

 lime-sulphur and caustic soda mixtures had 

 been prepared and applied. It will be 

 remembered that the advantage of these 

 mixtures over the ordinary lime and sul- 

 phur is that they do not require boiling 

 and thus this tedious part of the manufac- 

 turing process is saved. A thorough in- 

 spection of the trees sprayed with these 

 preparations shows that they have been 

 about as successful in destroying the scale 

 as that made by boiling. More experiment- 

 ing will have to be done before it can be 

 said definitely that it will always give as 

 good results, but enough has been done to 

 demonstrate that this method of preparation 



