72 APPLE GROWING IN CALIFORNIA. 



purple apple aphis. This pest always leaves the apples small and mis- 

 shapen, but well-formed seeds are present. Fig. 46 shows the same two 

 apples as in Fig. 45, which have been cut open. A well-developed seed 

 is shown in the core of the typical-shaped apple, while the other one has 

 none. 



Another form of injury is the so-called frost russet illustrated in 

 Fig. 47. The russeting very frequently shapes itself in a band about the 

 fruit, but in some cases may occur in the calyx and stem cavities. This 

 injury is very commonly confused with that resulting from scab, 

 Bordeaux injury and various other things. The presence of the charac- 

 teristic bands as illustrated is a sure indication of frost injury. 



Fig. 47 Frost russet band on apples. (Original) 

 LEAF INJURY. 



A peculiar crumpling or blistering of the leaves of certain varieties 

 usually follows severe spring freezes. The epidermis of the leaf may 

 separate from the inside portion wherever these blisters occur. Such 

 leaves are apt to turn yellow and drop very early in the season. This 

 form of injury is not serious. 



SUSCEPTIBILIT%Y OF VARIETIES. 



Some varieties of apples will stand much more freezing than others. 

 Again, some varieties will blossom much later than others, thus escaping 

 a frost that would injure earlier blossoming varieties. It is. therefore, 

 wise for the orchardist who lives in sections of killing spring frosts 

 to select the hardiest, and in some cases preference should be given to 

 late blooming varieties. As an illustration of this fact the Rome Beauty 

 and Rails apples blossom much later than the Ben Davis and Jona- 

 than, consequently often escape injury when the latter named varieties 

 are killed by a freeze coming about blossoming time. 



