APPLE DISEASES 59 
Davis. About the margin of older, sunken spots is sometimes 
seen a reddish border. On very young apples the points of 
infection show as small water-soaked areas, and in wet weather 
there may be a yellowish, gummy exudate. On some varieties 
at least, like the Ben Davis, the skin ultimately cracks (Fig. 15). 
The crevices, although usually about one-half of an inch long, 
may girdle the fruit and extend to the core. Often these 
cracks intersect, forming a cross (Fig. 15). Within a few days 
after the blotches become 
visible, black pimples are 
developed on the lesions 
(shown in Fig. 15). These 
are the fruiting bodies of the 
pathogene and they may 
number from three to sev- 
eral on each diseased area. 
They are cither scattered 
promiscuously over the 
lesion, or are arranged 
aroundthemargin. A large 
percentage of affected fruit 
drops prematurely. Fic. 15. — Apple-blotch, late stage. 
Apple-blotch also affects 
the fruit spurs, twigs and rapidly growing shoots, showing 
itself in the form of characteristic cankers (Fig. 16). Larger 
limbs are not commonly attacked. On the fruit-spurs the 
cankers are at first purplish or blackish. The center turns 
‘brown with age, the margin remaining unchanged in color. 
The resulting legion is small and rather inconspicuous, with 
a crack along the margin. On water sprouts, and on 
other rapidly growing shoots, the cankers have much the same 
appearance as just described, but are longer, often measur- 
ing an inch or more in length, and sometimes girdling the 
stem. Longitudinal cracks appear not only along the edge 
