88 THE CHERRIES OF NEW YORK 



increased demand, for Sour Cherries in particular, brought about by the 

 development of markets ta 1913-14, are most hopeful signs for the future 

 of the cherry industry. 



CHERRY DISEASES 



Cherries, without preventive or remedial intervention, are at the mercy 

 of two or three fimgus diseases and sometimes several others are virulent, 

 depending upon locality, season, weather and variety. One of these 

 diseases, brown-rot, in spite of the great advances in plant pathology of 

 recent years, is almost beyond the control of preventive or remedial 

 measures. Happily, aU the others yield better to treatment. 



Brown-rot^ {Sderotinia fructigena (Persoon) Schroeter), sometimes 

 known as fruit-mold or ripe-rot, very frequently attacks flowers and shoots 

 but is most conspicuous on the ripe or ripening cherries where its presence 

 is quickly detected by a dark discoloration of the skin which is afterwards 

 partly or wholly covered with pustule-like aggregations of gray spores. 

 The decayed fruits usually fall to the ground but sometimes hang to the 

 tree, becoming shriveled mummies, each mixmmy being a storehouse of 

 fungus threads and spores from which infestation spreads to the next 

 crop. The disease, in some seasons, Hke a withering bHght, attacks twigs, 

 flowers and leaves early in the spring doing great damage to the young 

 growth and often wholly preventing the setting of fruit. The rot spreads 

 with surprising rapidity on the fruits in warm, damp weather either before 

 the fruit is picked or in baskets while being shipped or stored. Preventive 

 remedies have so far met with but indifferent success; probably the best 

 method of control is to destroy the mtimmy-like fruits and aU other sources 

 of infection either by picking them from the trees, or much better by 

 plowing them tmder deeply. Varieties of cherries show various degrees 

 of susceptibility to brown-rot. All Sweet Cherries are more subject to 

 the disease than the Sowr sorts. But with either of the two species there 

 are great variations in the susceptibility of the varietal hosts — a matter 

 specially noted in a later chapter in the discussion of varieties. 



Another serious disease of the cherry, and probably the most striking 

 one in appearance, is the black-knot^ (Plowrightia morbosa (Schweinitz) 

 Saccardo), characterized by wart-like excrescences on shoots and branches. 



■Smith, E. F. Peach Rot and Peach Blight, Journ. Myc. 5:123-134. 1889. Quaintance, A. L. 

 The Brown Rot, etc., Ga. Sta. Bui. 50:237-269, figs. 1-9. 1900. 



' Farlow, W. G. The Black Knot, Bulletin Bussey Institution 440-453. 1876. Halsted, B. D. 

 Destroy the Black Knot, etc., N. J. Sta. Bui. 78:1-14. 1891. 



