citrus scab: its cause and control. 5 
review of the uteratur1 
ll i^ generally re :oijmzed in Japan thai citrus scab is a native dis- 
ease of oranges. Scabby oranges were first called by the native 
names "abata mikan" (smallpox orange), "kasakaki mikan. v and 
"kasa mikan" (both meaning syphilis-scab orange), according to 
Nishida (13) 3 and Ideta (9). The disease is now called "sdkabyd" 
(Fig. 1, a, scab disease), first proposed by Nishida (J4) in accordance 
with the American name "citrus scab."' This name, however, in- 
cluded not only citrus scab but also citrus canker until the latter was 
separated by the terms "marugata sokabyo" (Fig. 1, &, round scab 
disease) and " kankitsu kwaiyobyo" Fig. 1. c. canker disease of citrus) 
p. 7-9). 
Probably the earliest mention of citrus scab in Japanese litera- 
ture is in a manuscript work called "Nankai Hofu" (oranges of the 
South Sea district) written by Yoshiyuki Murase in 1818. Two 
kinds of scabby orange were given, with the Chinese 
names "shitdkan" (Fig. 1, d, shih t'ou kan, lion- « M M 09 
head orange) and - reishikitsu" (Fig. 1. e li chili & H B B gjH ffl 
ehu,lychee orange), the latter bearing the popu- 
lar name "kasa mikan." These two were illus- c S3 S3 83 ES 111 
trated in the 'Honzo Dzufu" of Tsunemasa 
Iwasaki, completed in 1828 (10, book 62, fob 7 d IM \M SO 
and 11). In these early works scabby oranges SesSFwIf 3 ^ 
are treated as particular kinds and not as dis- ^ *^ "^ ™ 
eased fruits. It was first proved by Onda (15) fig. i.— Japanese charac- 
,i ,,i I- n j j t ters * or citrus diseases 
that the disease was controlled under Japan con- a nd their hosts: a, soka- 
ditions bv spraying with Bordeaux mixture, but by6; b > m^gata s6ka - 
.. ' Tx " . 7 ,. byo; c, kankitsu kwaiyo- 
accordmg to Hon (8, p. 281-282) the disease was byo: d, shitdkan; e,reis- 
given no particular attention by citrus growers hlkuo; - 
until about 1905, when they recognized its disadvantage in connection 
with the exportation of the Satsuma orange. 
The first report on citrus scab in America was made by Scribner 
(19) , who stated that the disease first made its appearance in America 
in 1885 on sour-orange stock in a citrus nursery near Ocala, Fla. In 
1886 it was attacking lemon trees. In a later publication (20) on the 
subject, accompanied by a colored plate of gross and microscopic 
features, he attributes the disease to a species of Cladosporium, with- 
out describing it. 
Underwood (30, p. 34) confirmed Scribner ? s findings and reported 
the disease as occurring very commonly on wild (sour) oranges, fre- 
quently on grapefruit and lemon trees, and rarely on sweet-orange 
trees. 
- The abstracts of the Japanese literature on citrus scab were made by Dr. Tyozaburo Tanaka, of the 
Office of Crop Physiology and Breeding Investigations, Bureau of Plant Industry, 
^rial numbers (italic) in parentheses refer to " Literature cited '"' at the end of this bulletin. 
