Insect and Disease Control 289 



Spraying 



As important as are suitable insecticides and fungicides 

 in the control of peach insects and diseases, they are with- 

 out avail unless properly applied. Perhaps the most com- 

 mon fault is lack of thoroughness. Many growers have 

 virtually thrown away time and money because the trees 

 were not sufficiently well covered with the spray mixture 

 to accomplish the end in view. For instance, the San 

 Jose scale may infest every part of the surface of a tree, 

 excepting, in case of an old tree, the portion of the trunk 

 and larger limbs where the bark is rough and hard. The 

 sprays used in its control kill only by contact and have 

 absolutely no effect on any insects on a sprayed tree which 

 they do not hit. Again, spraying to control brown-rot or 

 scab is a preventive, not a curative, measm-e. Any por- 

 tion of the surface of a fruit not kept completely covered 

 with a thin film of the fungicide is subject to attack. The 

 fungicide on one side of a peach will not give protection 

 against infection on the other side. For obvious reasons, 

 the spores from which these diseases develop are more 

 likely to fall on the upper than on the under surfaces of the 

 fruits. 



To spray thoroughly does not mean the drenching of a 

 tree until the spray mixture is dripping from the branches. 

 Such spraying is wasteful, since what drips off is lost and 

 serves no useful purpose. Thorough spraying means the com- 

 plete covering with a thin film of the spray mixture of every 

 portion of the surface of the tree, foliage, and fruit, depend- 

 ing on the time when, and the object for which, the spraying 

 is being done. It is of course obvious that in the practical 

 application of spray mixtures in orchard work there will 



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