CITRUS scab: its CAUSE AND CONTROL. 5 



REVIEW OF THE LITERATURE,- 



« 



It is generally recognized in Japan that citrus scab is a native dis- 

 ease of oranges. Scabby oranges were first called by the native 

 names "abata mikan" (smallpox orange), "kasakaki mikan," and 

 "kasa mikan" (both meaning syphilis-scab orange), according to 

 Nishida (13)^ and Ideta (9). The disease is now called "s6kaby6" 

 (Fig. 1, a, scab disease), first proposed by Nishida (14) 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 sdkabyo" (Fig. 1, &, round scab 

 disease) and " kankitsu kwaiyobyo" (Fig. 1, c, canker disease of citrus) 

 (29, 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 "shitokan" (Fig. 1, d, shih t'ou kan, lion- « IS ^ ^ 

 head orange) and ''reishikitsu" (Fig. 1, e, li chih 7 ffl] Rp g^ BJjj] |s^ 

 chu, lychee orange) , the latter bearing the popu- 

 lar name "kasa mikan." These two were illus- c SBSP^I^^ 

 trated in the "Honzo Dzufu" of Tsunemasa Bfra Fn sin 



Iwasaki, completed in 1828 (10, book 62, fol. 7 <a? ISeHHIJ 

 and 11). In these early works scabby oranges ^SP^PS^ 



are treated as particular kinds and not as dis- ^ EZaiLifllUiu 

 eased fruits. It was first proved by Onda (15) fig. i.— Japanese charac 

 that the disease was controlled under Japan con- and their hosts: a, soka- 

 ditions by spraying with Bordeaux mixture, but 1^^°- &. marugata soka- 



"^ TT • / \ T T ■'y^' '^^ kankitsu kwaiyo- 



according to Hon (8, p. 281-282) the disease was byo; d, shitokan; c, reis- 

 given no particular attention by citrus growers ^^^itsu. 

 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 (som") oranges, fre- 

 quently on grapefruit and lemon trees, and rarely on sweet-orange 

 trees. 



2 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. 



3 Serial numbers (italic) in parentheses refer to " Literature cited " at the end of this bulletin. 



