Pomaceous Fruits 



37 



badly affected fruits. Scabby fruits are much more sus- 

 ceptible to storage rots than are clean fruits (p. 49). 



Upon the leaves and more rarely upon twigs the fungus 

 forms a thick velvety coat, varying from dark olive-green to 

 black, in spots at first circular in outline, later irregular and 

 coalescing. The irritation and retardation of growth caused 

 by the presence of the fungus often induces the leaves to curl 

 and wrinkle in a characteristic manner. The fungus winters 

 on fallen leaves, and wind-borne spores from them give rise to 

 spring infection. Cf. pp. 58, GO. 



The injuries by this disease may be enumerated as fol- 

 lows: lessened leaf value, retarded twig and wood growth, 

 premature fall of fruit, 

 retardation of full de- 

 velopment of fruit, and 

 injury to sale and keep- 

 ing quality of fruit. 



Baldwin, Golden Rus- 

 set, and Hubbardston 

 are among the most re- 

 sistant varieties, though 

 scab-resistance seems to 

 vary geographically and 

 even seasonally. Cf. 

 p. 60. 



Bordeaux mixture and 

 lime-sulfur are effective 

 sprays. It is especially 

 important to apply the 

 mixture immediately l)e- 

 fore the blossoms open, again just after the petals fall, fol- 

 lowed by one or two later sprayings. Cf. p. 57. Dusting is 

 discussed on page 446. Burning of infected, fallen leaves is 

 a good sanitary measure. 



OBlotch ^^-^^' ^-^ {Phyllostida solitaria E. & E.). — In some 

 sections of the country this disease of bark, leaf, and fruit is 

 even more troublesome than any of the preceding, though its 



Fig. 13. 



Apple blotch, 

 and Rorer. 



After Scott 



