84 N. S. ENTOMOLOGICAL SOCIETY 



Sta. on, "An Investigation of Lime Sulphur Injury its Causes and Prevention" shows 

 that the polysulphides, particularly the tetra and penta sulphides are responsible for 

 most of the lime sulphur injury, that the hydrometer tests do not accurately indicate 

 the strength of the solution or the varying amounts of the different constituents in the 

 solution and on that account one might draw a gallon of concentrate from the bottom of 

 a barrel which when diluted to a given strength will not burn, while a gallon from the 

 top of the same barrel even though it tests the same according to the hydrometer will, 

 when diluted to the same extent, cause burning. While we have not noticed injury from 

 this cause in Nova Scotia, all solutions, both home made and concentrated, both from 

 the top and the bottom of the barrel, giving approximately the same result when used 

 in the same manner, yet there is every probability that this may in many cases be a de- 

 termining factor in burning in Nova Scotia. 



In 1917 an enquiry was sent to various manufacturers of lime and sulphur to de- 

 termine if there was any difference between their product of 1910 and 1914 and their 

 product of 1915-16-17. All gave practically the same answer, "That the analysis has 

 not varied or has varied only slightly." This we think is correct as the home made con- 

 centrate has given the same injury as the commercial concentrate, when used in the 

 same strength. 



It will be seen from what evidence we have that the question of lime sulphur is an 

 extremely local problem. In dry, bright localities where such varieties as Mcintosh are 

 grown, and where only one spray is applied after the blossoms, injury may be entirely 

 absent. On other varieties and in other localities, such as the Annapolis Valley, lime 

 sulphur when used for four or five sprays may, and in many seasons does, reduce the 

 crop by from 20 to 50 per cent, and in some cases even more than that. 



By following the various leads now in hand, and possibly developing others^it 

 would seem possible in one or two years more to determine from meteorological records, 

 from a knowledge of the varieties grown, and from the methods followed in any locality, 

 whether and to what extent lime sulphur can with safety be used. 



