APPLE DISEASES 71 



few and highly valued on account of their ornamental qualities. 

 In any case the value of the operation is as yet uncertain. 

 Spraying apples to protect them against sporidial infection is 

 unreliable. This is because effectiveness is so dependent upon 

 the time of the application. A delay of one day after telial gelat- 

 inization makes spraying the apple of no value. The time in 

 which effective spraying may be done is not long enough to allow 

 for covering a large orchard efficaciously without undue outlay 

 for machinery and labor. Where orchards are far enough from 

 the cedars to escape severe infection and where only moder- 

 ately susceptible varieties exist, the application of a fungicide 

 may prove effective. Under such conditions spray the leaves 

 as soon as they unfold and keep them protected until the first 

 week in June. Subsequent applications should be made often 

 enough to protect the new leaves as they appear. Lime-sulfur 

 1-40 may be used. Wherever cedars occur and it is not feasible 

 to destroy them, the young orchards should be set to resistant 

 varieties, avoiding particularly the York Imperial, Rome and 

 Wealthy. 



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22 : 105-120. 1909. 

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American Journ. Bot. 2 : 402-417. 1915. 



