138 The Connecticut Pomological Society 



spray when they are in bud, and just after they are in blossom. 

 Whether that is best is a question which has been discussed a 

 good deal. As a matter of fact, it is hardly going to make 

 much difiference whether it is just before or just after, but 

 after that it is put on at intervals of ten days. The black rot 

 is not always easy to prevent. It is sometimes aflfected by the 

 weather. About five sprayings, at intervals of ten days or two 

 weeks when the vines are in blossom, is usually very helpful. 

 The grape is not hurt by the normal Bordeaux." 



A Member: ''Do you have any trouble in making the 

 Bordeaux adhere ? " 



Professor Waite: "There should not be any trouble 

 with the right kind of spraying. If any of you do have any 

 trouble with pear leaves, for example, I will give you a sim- 

 ple remedy for that trouble. Use a high pressure pump, make 

 the solution thin, and go through the orchard very rapidly, 

 just giving it the finest kind of spray. Let it dry, and then 

 go back and spray over it again. Where the particles have 

 failed to go the first time it will stick the second time. 

 When you wish to make a really good job of it, try double 

 spraying." 



Secretary Miles: "Has anything been found superior to 

 Bordeaux mixture for spraying ? " 



Professor Waite: "In a general way, I should say not. 

 The efficiency of the Bordeaux mixture, however, depends on 

 a number of different factors, — on the copper compound that 

 is in it, and it also depends on the cementing power of the 

 gypsum which remains in the solution as a residual product 

 of the decomposition. When you mix copper hydrate with 

 lime the soda which is in the lime makes lime sulphate. Sul- 

 phate of lime is different. Now, a part of that remains in 

 the solution, and the mixture is a saturated solution of gypsum. 

 Now when we spray that on the trees, that saturated solution 

 of gypsum becomes a cement which fixes the Bordeaux on 

 the leaf, becomes insoluble in water, and this sticking power 

 of the Bordeaux depends on the cementing action of the 

 gypsum solution." 



Mr. Ives : " In your observation, where Bordeaux was 

 applied very thoroughly to apple trees, did it rust the fruit 



