218 Minnesota Plant Diseases. 



lime to four or three pounds of copper sulphate. The tests 

 given above should be applied and the need of strong or weak 

 solutions constantly kept in mind. Bordeaux can be very ad- 

 vantageously combined with insecticides so that the two appli- 

 cations can be made by one spraying. (For such combinations 

 the reader is referred to the Eighth Annual Report of the State 

 Entomologist of Minnesota, 1903.) 



Dry bordeaux. (See under Powders.) 



The following formulae are, in general, used only under spe- 

 cial conditions, for instance, where the spotting of the foliage 

 or other features of bordeaux are undesirable. 



Bordeaux resin mixture. 



"Resin 5 pounds. 



Potash lime : . . . I pound. 



Fish oil I pint. 



Water 5 gallons." 



[N. Y. (Geneva) Bull. No. 188, 1900.] 



Add to bordeaux as directed below. 



To prepare a stock resin solution proceed as follows : 



"Place the oil and resin in the kettle, heating them until 

 the resin is dissolved, then remove the kettle from the fire and 

 allow the mass to cool slightly, after which the solution of lye 

 is added slowly, the whole being stirred while adding the lye. 

 After adding the lye the kettle should be again placed over 

 the fire and the required amount of water added. The whole 

 should be boiled until the solution will mix with cold water 

 forming an amber-colored solution. Care should always be 

 taken to have the resin and oil cool enough so that when the 

 solution of lye or the water is added the whole mass will not 

 boil over and catch fire. 



"Dilute this stock resin solution with eight parts of water 

 before adding to the bordeaux mixture, that is, in preparing a 

 fifty-gallon barrel of the mixture, the copper sulphate and lime 

 are diluted enough to make forty gallons after which two gal- 

 lons of stock resin solution are diluted to ten gallons, then 

 added to the bordeaux." [N. Y. Ex. Sta. (Geneva) Bull. No. 

 1881900.] 



This solution exceeds ordinary bordeaux in adhesive prop- 

 erties and has been highly recommended for asparagus rust. 



