56 



N. S. ENTOMOLOGICAL SOCIETY 



during the past. season, an application of 7-7-100 Bordeaux 

 mixture following three sprayings of lime sulphur, caused more 

 leaf yellowing than three applications of the same mixture. 

 This is explained on the ground that repeated applications of 

 lime sulphur injure the chlorophyll of the leaf,as has already 

 been shown by one of us (4) and thus renders the leaves more 

 susceptible to this form of Bordeaux injury or the cause may 

 be at least partly chemical. It should be noted that numer- 

 ous single applications of 7-7-100 Bordeaux applied at any of the 

 the four spraying seasons, and not preceeded or followed by 

 other sprays, gave little if any leaf yellowing this season. While 

 this does not always hold good,it goes far to prove the conten- 

 tion, that the yellowing of foliage from Bordeaux is largely 

 cumulative, i. e. is the effect of repeated applications. 



While the question of finding some harmless and efficient 

 substitute for lime sulphur was thus becoming acute, the at- 

 tention of the writers was drawn to experiments conducted by 

 a practical orchardist, viz. Mr. G.L. Thompson, on his own farm 

 at Berwick, N. S. In 1913, Mr. Thompson, becoming dissat- 

 isfied with lime sulphur as an apple spray, began experimenting 

 with a heavy lime wash. Finding this deficient in fungicidal 

 value, he then began adding small quantities of copper sulphate 

 to the lime with, on the whole, excellent results. Following 

 his lead, Mr. John Buchanan of Waterville, N. S., tried a sim- 

 ilar mixture, using formulae varying from one to four pounds 

 of copper sulphate to twenty-five pounds of lime added to one 

 hundred gallons of water. Brief mention of the results of his 

 work from the standpoint of pest control, has been made by 

 one of us (13) in a former article. Both Mr. Thompson and 

 Mr. Buchanan have been using a Bordeaux containing a very 

 high excess of lime, and with results known to the writers to be 

 generally better than those obtained by other growers, or by 

 the writers experimentally, with other compounds. These 

 men have obtained large crops of good fruit, accompanied, it is 

 true, by a certain amount of slight russetting and possibly a 

 slight paling of the fruit in some cases, but with no indication 

 of drop of the apples and with good healthy foliage, showing 

 little evidence of leaf yellowing or other injury. 



In 1917, the writers first used this excess of lime Bordeaux 

 or "Thompson Bordeaux" as it is called, and found that the 

 use of formulae as 2-10-40 and 3-10-40, reduced the amount of 

 leaf yellowing to a minimum as compared with formulae calling 

 for equal parts of lime and copper sulphate. Accordingly, for 

 1918. we recommended to the growers of the Annapolis Valley, 



