Fungicides, for Plant- Diseases. 41 



Blight-powder, Sulphated sulphur.— Prepared by thoroughly 

 mixing from 3 to 8 pounds of anhydrous sulphate of copper 

 with 90 to 100 pounds of flowers of sulphur. For simulta- 

 neous treatment of downy mildew, tomato and potato-blight 

 and rot. Little used. 



Bordeaux mixture (Copper mixture of Gironde). — 1. Dissolve 6 

 pounds of sulphate of copper in 16 gallons of water. In an- 

 other vessel slake 4 pounds of fresh lime in 6 gallons of 

 water. When the latter mixture has cooled, it is slowly 

 poured into the copper solution, care being taken to mix the 

 fluids thoroughly by constant stirring. Prepare some days 

 before use. Stir before applying. Stronger mixtures were 

 at first recommended, but they are not now used. 



2. Powdered sulphate of copper, 12 pounds in 15-20 gal- 

 lons water ; lime, 8 pounds in 10-12 gallons of water. When 

 the materials are thoroughly incorporated with the water, 

 add the two mixtures. 



For do\vn3'^-mildew and black-rot of the grape, blight and 

 rot of the tomato and potato, blights of fruits, and many other 

 diseases. 



Sometimes the mixture is not washed off the grapes by the 

 rains. In this case, add one quart of strong cider-vinegar to 

 5 gallons of water, and dip the grapes, allowing them to re- 

 main a few minutes, then rinse once or twice. Dip the 

 grapes by placing them in a wire basket. 



Carbolic acid (Phenic acid). — 1. Ha If -pint to 10 gallons of water. 

 For powdery mildew of the vine. 



2. Soap-suds, 10 gallons ; glycerine, 1 pound ; carbolic 

 acid, }4 pint. Mix thoroughly to form an emulsion. For 

 orange-leaf scab. 



Chloride of iron. — A very dilute solution of chloride of iron has 

 been used with success in combating the coffee disease due 

 to Hemileia vastatrix. The solution is applied to the under 

 surface of the leaves by means of a pulverizator or spraying- 

 apparatus. Its sticky nature causes it to adhere for two 

 months. It is suggestive in connection with some of our 

 plant-diseases. 



Copper, Precipitated carbonate of. — Dissolve 2 pounds of sulphate 

 of copper in hot water, and in another vessel 2.5 pounds of 

 sal soda in hot water ; when cool, the two are added together 

 with constant stirring. The mixture is then diluted to 25 

 gallons. For diseases of the gi'ape. 



