SPRAYING 317 



Bordeaux mixture leaves a light blue deposit upon the plant 

 tissue, and when this deposit is undesirable, or would injure 

 the sale of the products, as with flowers or ripening fruits, 

 a colorless compound known as the ammoniacal solution of 

 copper carbonate is used. This solution is prepared by dissolv- 

 ing three ounces of copper carbonate in one quart of strong 

 ammonia and diluting this with twenty-five gallons of water. 



FIG. 159. Gasoline power sprayers and the owners who will use them 



An orchard demonstration of spraying by the state agricultural college in this locality 



through three years has taught the farmers that " a little science is a dangerous thing " 



to insects and fungi 



409. Apparatus for spraying. Outdoor work requires a good 

 pump, with sufficient power to reduce the mixture to very fine 

 particles through a nozzle that distributes it evenly. The amount 

 of power required varies with the operation and the mixture to 

 be applied. In applying washes for the control of scale or for 

 aphids mixtures that are not likely to injure the tissues of the 

 plant a nozzle with a larger aperture and a lower power may 

 be used. In applying fungicides and insecticides that are likely 

 to injure the plant tissues, it is essential that the surface be 

 covered with a very thin coating. 



