PROCEEDINGS, 1918 55 



states: "However, I am extremely doubtful if it (i. e. excess of 

 lime) has any practical value in preventing injury on the foliage 

 of apples." It should be borne in mind that in this investiga- 

 tion, the greatest excess of lime used by Hedrick was two parts 

 of lime to one of copper sulphate and not the greater excess 

 which will be discussed later on in this article. 



Crandall (6) holds that there is a decided advantage in 

 maintaining an excess of lime, over and above that contained 

 in the 4-4-40 formula upon the foliage, but states that the 

 excess must be provided by subsequent applications and not by 

 increasing the amount in the original mixture, as this injures 

 its adhesiveness. 



With the introduction of lime sulphur in 1910, the use of 

 Bordeaux for orchard spraying rapidly decreased, though this 

 mixture was still used exclusively on potatoes, and grapes. It 

 was known that the repeated applications of ordinary Bor- 

 deaux to apple trees often resulted in serious russetting of the 

 fruit and also to serious yellowing of the leaves accompanied by 

 a greater or less degree of defoliation. The amount of dam- 

 age varied greatly, depending upon the variety, the season and 

 the method of manufacture. This explains the sudden rise in 

 popularity of the lime sulphur wash, which did not cause rus- 

 setting of the fruit, nor such noticeably yellowing as resulted 

 from the repeated applications of 4-4-40 Bordeaux. 



With the increase of high power spraying and greater ca- 

 pacity nozzles in Nova Scotia, it soon became apparent that 

 lime sulphur as ordinarily used was causing damage, different 

 in kind, but even more serious in effect than the old Bordeaux 

 mixture. The climate of Nova Scotia being unusually moist, 

 it is usually necessary to apply four sprays each season to 

 check the ravages of apple scab and it was found that the fourth 

 spray was particularly injurious under certain conditions and 

 with certain varieties,in injuring the foliage and causing serious 

 drop of fruit, as has already been shown by the writers else- 

 where (12, 14 & 15) and also by Murphy (16) and others. Ex- 

 periments were conducted using weaker mixtures of lime sul- 

 phur, but though this was of considerable benefit, it did not by 

 any means eliminate the injury referred to under all conditions. 

 A Bordeaux made up to the formula of 7-7-100 was then sub- 

 stituted for lime sulphur in the fourth spray. This was gener- 

 ally of material benefit as far as preventing dropping of the 

 fruit was concerned, but in most cases, it gave rise to a large 

 percentage of the old familiar "yellow leaf'so characteristic of 

 Bordeaux injury. Indeed in a series of experiments conducted 



