PROCEEDINGS, 1918 57 



the experimental use of such formulae as the foregoing and at 

 the same time laid out an extensive series of experiments to de- 

 termine the most suitable proportions of lime and copper sul- 

 phate necessary to eliminate foliage injury and russetting of the 

 fruit, and also to test the fungicidal value of the various mix- 

 tures under different conditions and their value as"carriers" for 

 arsenical poisons. 



It is not our purpose to give the details of our experiments 

 on these points. At a later date we hope to prepare a more ex- 

 tended and detailed account, with full and complete data re- 

 garding the course of these and subsequent experiments. It 

 will suffice for the present, to record only the general nature 

 of the results obtained. All of the different mixtures were 

 used four times, i. e., at each of the regular spraying periods. 



When the various kinds of Bordeaux were tested against 

 each other for leaf injury, it was found that with all those in 

 which lime was used barely to the point of alkalinity, the maxi- 

 mum amount of foliage yellowing was apparent, often accom- 

 panied by a scorching of the leaves and subsequent partial de- 

 foliation. When equal parts of copper sulphate and lime were 

 used, serious yellowing and defoliation sometimes occurred, 

 though not so serious as with the foregoing. The differences 

 between 1-1-40, 2-2-40, 3-3-40, 4-4-40 and 5-5-40 Bordeaux 

 were very slight. In fact the difference between them scarce- 

 ly exceeded those between duplicates of the same treatment. 

 As these formulae were modified by adding a higher proportion 

 of lime, the amount of yellowing decreased. This decrease 

 was not strongly marked up to two parts of lime to one of cop- 

 per sulphate, but from two to three parts of lime to one of cop- 

 per sulphate, the change was very marked as each additional 

 quantity of lime was used. At three parts of lime to one of 

 copper sulphate, the yellowing was reduced to a minimum and 

 in many cases, it was not greater than in the check plots. Great- 

 er proportions of lime than the foregoing had no apparent ef- 

 fect. Judging from this year's work, therefore, it is unsafe 

 to use less than three parts of lime to one of copper sulphate in 

 making Bordeaux for repeated applications to the apple. From 

 our own results and observations, we cannot see any advantage 

 in using a greater proportion than 1 to 5 and the correct propor- 

 tion probably lies somewhere between 1 to 3 and 1 to 5. 



It is of interest to note here that the yellowing of foliage 

 due to sprays of the lime sulphur-arsenate combination, differs 

 from Bordeaux yellowing in the manner of its appearance. The 

 latter is usually gradual in its onset, beginning earlier and last- 



