54 



N. S. ENTOMOLOGICAL SOCIETY 



deaux without lime particles; and for the- immediate protection 

 of the sprayed plant it is quite as good." 



In general it may be stated that the experience of plant 

 pathologists, horticulturists and practical farmers in this coun- 

 try is against the use of neutral Bordeaux and in favor of the 

 ordinary Bordeaux containing an excess of lime. Not only 

 has the application of the latter proved effective in protecting 

 the plants so treated from cryptogamic parasites, but the 

 injury to foliage and fruit has proved to be much less. 



Sturgis (2) discussing the use of a mixture with a further 

 excess of lime on peach foliage says,/ 'Bordeaux mixture of the 

 2-4-50 formula cannot be unconditionally recommended for 

 use upon peach trees. Although somewhat less injurious to the 

 foliage and decidedly less so to the fruit of certain varieties 

 than the stronger mixtures, it, nevertheless, causes in some 

 cases, marked deterioration both in the quality and the quan- 

 tity of the fruit." The reader is reminded that, in this case, 

 the excess of lime is only in the proportion of two to one and 

 that the peach not the apple is the tree referred to. 



Waite (3) discussing the use of Bordeaux mixture on the 

 fruit states- "The form of Bordeaux mixture most harmless to 

 foliage is made up by the formula 3-9-50, having a considerable 

 excess of lime. This may be known as "Peach Bordeaux Mix- 

 ture" and contains as follows: 



Copper Sulphate lbs. 3. 



Lime lbs - 9 ; 



Water, to make g a l s - £0. 



This preparation approximates the mixture with a low cop- 

 per content and high excess of lime that we will later have occa- 

 sion to discuss. 



Hedrick (5) cites numerous answers to enquiries in regard to 

 Bordeaux injury in which several contradictory views are put 

 forward, some claiming that excess of lime safens the mixture 

 while others report no advantage from its use. In order to test 

 out this point, Hedrick, who is chiefly interested in decreasing 

 the russetting of the fruit rather than injury to the foliage con- 

 ducted a number of experiments. He sums up his results in 

 these words: "Excess of lime investigations in this state, in- 

 formation from the apple regions and the seasons experiments 

 prove conclusively that an excess of lime will not prevent Bor- 

 deaux injury or greatly lessen it. Therefore a formula con- 

 taining no greater excess of lime than one part to one ol copper 

 sulphate is advised." Later on in the same bulletin Hedrick 



