20 



of the destruction of the plum curculio. The application of this 

 remech' was made with the Field pump as upon the apple and pear trees. 



ROTTING OF THE FRUIT. 



In the above experiments no special application was made to pre- 

 vent the rotting of the fruit, but a close comparison of the fruit of 

 trees treated with the Bordeaux mixture, with those untreated, would 

 indicate that the application of the above mixture was decidedly 

 beneficial. 



EXPERIMENT No. 5. 



BORDEAUX MIXTURE FOR GRAPE MILDEW AND ROT. 



In the station plots are planted two vines each, of about 100 varie- 

 ties of grapes. Of these vines one of each variety was treated with 

 the above mixture and the other left as a check vine by whicli to 

 judge of the effects of the application. vSome of these varieties have 

 not fruited but those that produced fruit m sufficient quantity for 

 comparison are given in the table below^. 



To destroy all germs that might be adhering to the canes before 

 the leaves unfolded, all parts were thoroughly painted with a strong 

 solution of sulphate of copper, April 2d and 3d. 



As soon as the foliage was fully developed an application of sul- 

 phate of copper, one pound to twenty-two gallons of water, was 

 made. This was on May 29th. Soon after this application it was 

 found that the foliage was seriously injured and the next application 

 made June 20th, was of the Bordeaux mixture. As the rose bugs 

 were beginning to work, one pound of Paris green to 500 gallons of the 

 mixture was added to this and other applications made July I9th 

 and 28th. 



The Paris green had no effect upon the rose bug, and hand picking 

 was resorted to, to save the crop, but the effect of the Bordeaux 

 mixture was so marked that at a long distance it was visible, not 

 only preventing the mildew on the leaf but the rot of the berry, to 

 which some varieties are almost invariably subject. The last appli- 

 cation of this mixture was made July 28th, and yet at the time of 

 ripening more or less of it was plainly visible on the foliage and the 

 berry. In some cases enough remained on the berries to injure them 

 somewhat for market 



