Pomaceous Fruits 57 



riu7n corticolum Edg. is superficial on Ijoth apples and pears 

 and of little importance; the Fmit-spot/^' ''^ {Phonia pomi 

 Pass.), occurs in the northeastern United States, the spots 

 are small, sunken, brown or black; Rough-bark"'- is caused 

 by Phomopsis mali Rob. The Septobasidium canker is 

 due to Septobasidium pedicillatum (Schw.) Pat. Phytophthora 

 cadorum (L. & C.) Schr. causes a fruit rot. Black-mold, 

 due to Fumago vagans, is superficial, while black-mold due 

 to Alternaria sps. produces a core rot. Plenodomus can- 

 ker ^'° (Plenodomus fusco-maculans (Sacc.) Coons) kills the 

 cortex, which eventually flakes off in long strips leaving 

 the wood bare. Die-back canker ^^^ (see peach) is occa- 

 sionally present, also Fruit rots due to Endomyces and 

 Rhizopus. Rosette, which resembles peach rosette, has 

 been noted in three states. 



Conditions Infi,uencing the Spraying Schedule for 

 Apple Disease * 



A spraying schedule which may give the best result in one 

 part of the country when used in spraying a certain variety 

 may be unsatisfactory in another part of the country, or 

 for another variety or in another season, or in another 

 orchard in the same part of the country. No attempt is 

 made, therefore, to present definite spraying schedules, al- 

 though an attempt is made to present briefly the considera- 

 tions which govern them. 



Primarily, sprays are applied commercially to control 

 apple scab, apple blotch, and bitter-rot. The control of other 

 fungi with the exception of apple rust is usually incidental to 

 the control of these three. 



To secure the best results it is necessary to make the first 

 application of fungicide before the first infections take place, 

 and to repeat at sufficient intervals to give protection from 

 this time on. In general, it may be said that the first apple- 



* Prepared by W. A. Ruth. 



