2 BULLETIN 395, U. S. DEPARTMENT OF AGRICULTUEE. 



losses in practically aU of tlie important peach-producing districts in 

 this area. 



The disease was first reported from Klostemeuberg, Austria, by 

 Von Thiimen (1877),^ who observed its occurrence upon the fruit of 

 the peach and briefly described the associated fungus as Cladosporium 

 carpopMlum sp. nov. The same author (1879, p. 13-15) emended 

 his original description of the fungus and published notes concerning 

 the occurrence, description, and economic importance of the malady. 

 The disease received little further attention until its occurrence in 

 America was reported by Arthur (1889, p. 5-8), who noted its 

 prevalence in Indiana and described the fruit lesions and the asso- 

 ciated fungus, citing the work of Von Thiimen. Peach scab, how- 

 ever, was not unknown to American mycologists prior to this time, 

 since the herbarium of the New York Botanical Garden and the 

 Pathological Collections ^ of the Bureau of Plant Industry contain 

 specimens collected by F. S. Earle, Cobden, 111., 1881 ^ (on fruit) and 

 1887^'^ (oh leaves), and by A. B. Langlois, Mississippi, 1886^-^ (on 

 fruit). Pammel (1892, p. 100) reported that Galloway, in unpub- 

 lished notes, had recorded the occurrence of the "peach fungus" 

 (Cladosporium carpopMlum) on peach leaves. Halsted (1895, p. 

 329-330) described what he considered to be scab injury upon peach 

 leaves. A study of his description and illustrations, however, makes 

 it appear conclusive that he failed to differentiate true scab injury 

 from other foliage troubles. Taft (1894, p. 57) reported the scab 

 fungus as attacking fruits, leaves, and tender shoots of the peach. 

 He gave no details, however, concerning the injury on twigs and leaves. 

 Sturgis (1897) noted a fungus, which he reported as conforming 

 morphologically to the description of C. carpopMlum, associated with 

 twig injuries of the peach, almond, and apricot. He concluded that 

 the fungus was C. carpopMlum and that it was the causal agent of 

 the trouble. He reported, however, no cultural studies or infection 

 experiments. Chnton (1904, p. 340-341) briefly described scab 

 injuries on peach fruit, twigs, and leaves. 



Selby (1898 and 1904), beginning in 1895, conducted an extensive 

 series of peach-spraying experiments, from which he concluded that 

 scab may be controlled by the use of Bordeaux mixture. A large 

 number of similar tests have been made with Bordeaux mixture of 

 various formulas and methods of preparation, but the toxicity of this 

 fungicide to the foUage has prevented its coming into general use in 

 the United States as a summer spray for peaches. Scott (1907 and 



I Bibliographic notations in parentheses refer to ".Literature cited," pp. 64-66. 



- The writer wishes to express his indebtedness to the curators of these herbaria for their kindness in 

 making these records available and in sending him material which enabled him to verify the identification 

 of each of these collections. 



? In the herbarium of the New York Botanical Garden, New York- 



^ In the Pathological Collections of the Bureau of Plant Industry, United States Department of 

 Agriculture. 



