40 

 APPLYING THE SPRAY. 



Sprays are preventive and not curative, and must therefore be 

 applied before the injury becomes apparent. After a fungus has 

 gained entrance to the foHage or fruit, it can not be reached and the 

 diseased parts made sound again ; but the infection may be prevented 

 by coating the parts with a fungicide, such as Bordeaux mixture, 

 which prevents the germination of the spores. Similarlj^, the codling 

 moth may not be poisoned after it has burrowed into the fruit, but if 

 the poison has been put in the calyx cavities before the calyx lobes 

 close and has been sprayed on the foliage and fruit before the latter is 

 entered by the larvae, the destruction of the latter in large numbers is 

 insured. Successful spraying, therefore, must be based on a knowledge 

 of the diseases and insects to be controlled. With all of the affections 

 here considered the work should be done in advance of their expected 

 appearance in the orchard. There are two principal reasons why 

 spraying in the hands of some is unsatisfactory, namely, failure to 

 make the applications at the proper time and failure to thoroughly 

 coat the trees and fruit with the mixture. In order to overcome the 

 former difficulty the orchardist must be informed as to the nature of 

 the malady or insect to be treated, and the latter may be overcome 

 by maintaining proper equipment and by giving the necessary atten- 

 tion to thoroughness in spraying. 



In the operation of spraying the liquid should be broken into a very 

 fine mist. The nozzles should be so manipulated that every part of 

 the foliage and fruit shall be uniformly covered with fine dots of the 

 spray. It is not necessary that the foliage and fruit should be 

 actually coated with the spray, but every portion should be thickly 

 peppered with it. The higher and inner portions of the tree are com- 

 monly insufficiently sprayed, and while the lic{uid may actually be 

 dripping from the lov/er branches, the upper parts of the tr^e may 

 show but little of the spray. 



The desired mist-like spray can ordinarily be secured only with 

 high pressure at the pump. This pressure should be not less than 100 

 pounds, though this is not ordinarily obtained except with gasoline 

 or other power outfits, wliich should supply a pressure of 125 pounds 

 to 150 pounds. When hand pumps are used the pressure should be 

 maintained as liigh as practicable, and never less than 75 pounds, in 

 which case good nozzles become more essential for perfect work. 

 To maintain this pressure wall require constant hard work, and 

 the tendency Avill be to allow the pressure to lighten. Except in 

 spraying the tops of trees the nozzle men should never ride in the 

 wagon, even wliile spraying the smallest trees. In order to reach the 

 inner branches and the underside of the fruit and foliage the operator 



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