142 STATE AGRICULTURAL COLLEGE BULLETINS. 



FUNGICIDES. 



For all plants that are not injured by the application of lime to the 

 foliage the Bordeaux mixture will be found the most reliable form. It can 

 be used upon all kinds of jjlants without fear of burning the leaves, but, 

 although the lime itself is' of value in cementing the material upon the 

 plants, its presence is unsightly and not always desirable, particularly if 

 any parts of the plants are to be used as food within four or five weeks. 



As first made, the Bordeaux mixture contained 16 pounds of copper sul- 

 phate and 30 pounds of lime to 22 gallons of water. This made a thick 

 wash that frequently clogged the pump and the nozzle, and was quite 

 expensive. The formula has now been modified so that 4 pounds of cop- 

 per sulphate and 8 pounds of lime added to 22 gallons of water is the most 

 concentrated mixture made. This should be used for the first application, 

 but it may be reduced for the later ones. Four pounds of copper sulphate 

 and '6 pounds of lime for 32 gallons of water seem as efficacious as a 

 stronger mixture for the second application, and if more than this is used 

 the amount of water could, without the mixture losing any of its virtue, be 

 increased to 50 gallons. For the powdery mildews of the grape, goose- 

 berry, and rose, which live entirely upon the exterior of the plants, the 

 weakest mixture seems entirely effectual. 



Two other copper compounds are rather more expensive than the above 

 and are less reliable, but as they are clear solutions they can be used, if 

 necessary, when the fruit or other edible portions are reaching maturity. 

 They are known as modified eau celeste and ammoniacal solution of cop- 

 per carbonate. 



The former is made by dissolving two pounds of copper sulphate in hot 

 water, adding a solution of 1^ pounds of sal soda, and, after all action has 

 ceased, pouring in one quart of ammonia water (26°) and diluting to 32 

 gallons. 



The ammoniacal solution of copi^er carbonate is made by dissolving 

 precipitated copper carbonate (3 oz.) in ammonia water (one quart) and 

 diluting to 32 gallons with water. 



It does not differ from the modified eau celeste, except that the former 

 contains sulphate of soda in solution 'and is somewhat stronger. If, before 

 adding the ammonia to the modified eau celeste, the copijer carbonate 

 formed by the addition of the sal soda to the copper sulphate had been 

 allowed to settle, and, after pouring off the liquid, if the ammonia had 

 then been added, it would be what is known as ammoniacal solution of 

 copper carbonate. 



The powdery mildews may be also kept in check by the use of liver of 

 sulphur (potassium sulphide) dissolved in water, using 3 ounces tp 10 gal- 

 lons of water. For the gooseberry and similar mildews this is entirely 

 eff'ectual, and has the decided advantage of being in no way poisonous and 

 of not staining the fruit; it can therefore be used at any time in the season. 



The copper sulphate ife sold at retail at about 15 cents ]}er pound, but in 

 a pulverized condition can be obtained at about 4 cents per pound f. o. b. 

 New York or Baltimore in barrel lots, and at from 5 to 6 cents for smaller 

 quantities. 



One or two of the wholesale dealers expect to locate distributing depots 

 in Michigan the present season, from which small lots can be sent to cus- 

 tomers with little expense for freight. 



Arrangements have also been made with C. Alsdorf & Son, Lansing, 



