662 INSECTS AFFECTING VEGETATION 



general use, and wherever liquid spraying is practicable it should by 

 all means be used. 



FORMULAS FOR OTHER COPPER SOLUTIONS. 



Copper SulpJiate Solution. The formula for copper sulphate 

 solution is as follows: 



Copper sulphate (-bluestone) 3 pounds 



Water 50 gallons 



Dissolve the bluestone in the water in the same manner as for 

 the preparation of Bordeaux mixture (p. 657). A more dilute solu- 

 tion (2 pounds to 50 gallons) is sometimes used on foliage. 



Caution. This solution is severely injurious to plants in foliage, 

 and should therefore be applied only during the dormant period. 

 Even the more dilute solution is usually injurious to leaves and 

 flowers. 



Copper Acetate Solution. The following formula is used for 

 copper acetate solution: 



Dibasic acetate of copper 6 ounces 



Water 50 gallons 



Copper acetate is readily soluble in water, and the solution may 

 be effected by simply adding the salt to the water and stirring thor- 

 oughly. Its use is much the same as that of ammoniacal copper car- 

 bonate, and it is recommended for application to ripening fruit when 

 it is desired to avoid the staining effect of Bordeaux mixture, though 

 it is much inferior to the latter as a fungicide. 



Caution. The injurious effect of acetate of copper on foliage 

 is somewhat greater than that of Bordeaux mixture, and to such sus- 

 ceptible foliage as that of the peach it should be applied sparingly, 

 if at all. 



Ammoniacal Copper Carbonate. The formula for ammoniacal 

 copper carbonate is as follows : 



Copper carbonate 5 ounces 



Strong ammonia (26 Baume) 2 to 3 pints 



Water to make 50 gallons 



Dilute the ammonia with about 2 gallons of water, as it has been 

 found (Penny, Del. Exp. Sta. Bui. 22) that ammonia diluted seven 

 or eight times is a greater solvent for copper carbonate than the con- 

 centrated liquid. Add water to the carbonate to make a thin paste, 

 pour on about half of the diluted ammonia, and stir vigorously for 

 several minutes ; allow it to settle and pour off the solution, leaving 

 the undissolved salt behind. Repeat this operation, using small por- 

 tions of the remaining ammonia water until all the carbonate is 

 dissolved, being careful to use no more ammonia than is necessary 

 to complete the solution. Then, after adding the remainder of the 

 required quantity of water, the solution is ready for application. 



Ammoniacal copper carbonate is a clear, light-blue solution, 

 which upon drying leaves little or no stain. As a fungicide it is in- 

 ferior to Bordeaux mixture, and should be used only as a substitute 

 for the latter when the stain of Bordeaux mixture upon ornamental 

 plants and maturing fruits is objectionable, 



