i 
4 BULLETIN 395, TJ. S. DEPARTMENT OF AGRICULTURE. 
than in the United States, the disease has received only minor atten- 
tion from foreign writers. Von Thiimen (1877) reported its occur- 
rence in Austria; Cobb (1894, p. 385-386), in Australia; Craig (1898, 
p. 40), in Canada; Oudemans (1901, p. 388), in Holland; Sorauer 
(1908, p. 252), in southern Europe; and Evans (1911, p. 696), in South 
Africa. 
ECONOMIC IMPORTANCE.i 
Badly scabbed fruit is seriously reduced in market value (1) by 
its unsightly appearance (PL I, figs. 1 and 2) ; (2) by its lack of uni- 
formity in size, shape, and evenness of ripening; (3) by the cracking 
of individual or of confluent lesions (PL I, fig. 1, and PL II) and the 
consequent increment in destructive fungal and bacterial invasions — 
notably brown-rot (Sclerotinia cinerea (Bon.) Schrot.) (PL II, upper 
figure) ; and (4), in severe cases, by its impaired flavor. Further loss 
may be occasioned by the premature shedding or shriveling of fruits 
which are badly scabbed about the attachment of the peduncle. 
Many writers have reported severe economic losses from peach scab. 
Selby (1904, p. 63) recorded heavy losses in Ohio. Rolfs (1909, p. 66) 
states — 
At least 60 per cent of the Elberta fruit on the station ground during the season 
of 1906 was ruined by this organism [Cladosporium carpophilum]. The loss was even 
greater on a number of other varieties. 
Scott and Ayres (1910, p. 14) write — 
The damage done by this disease is apparently not fully realized by peach growers. 
Scab spots are so common on the peach that most of the eastern growers have come to 
take the disease as a matter of course and scarcely realize that their fruit is bringing 
25 per cent less in the market than the same fruit free from scab would bring. * * * 
In many localities it practically prohibits the growing of certain, varieties * * * 
and the growers have been obliged to confine their plantings of such late varieties as 
Bilyeu and Sal way to the high ridges in order to avoid scab. 
Scott and Quaintance (1911, p. 10-11) say — 
If the loss in the orchard and the reduction in market value are both considered, it 
seems evident that a loss of 10 per cent of the total value of the peach crop in the eastern 
United States is caused by peach scab . 
In order to supplement the data from published records and per- 
sonal observations, an inquiry concerning the economic importance 
of the disease in the various States was included in the questionnaire 
referred to on the preceding page. The answers showed a consensus 
of opinion that, unless controlled, the disease may occasion serious 
losses in practically every important peach-producing State east of 
the Rocky Mountains. 
In formulating a more concrete conception of the economic impor- 
tance of the disease, it is of interest to refer to the estimates of the 
latest census report 2 from which the data in Table I are taken. 
1 See estimates and notes by Mr. M. B. Waite, p. 45-46. 
2 Thirteenth Census of the United States ... v. 5, Agriculture, 1909-10, p. 711, tab. 133, 1913. 
