544 Journal of Agricultural Research voi. xii, N0.9 



Industry. Okra is susceptible to inoculation with V. albo-arttim from 

 okra, snapdragon, eggplant, and potato; and to F. vasinjectum from 

 okra. Eggplant is susceptible to V. alho-atrum from eggplant, okra, 

 and snapdragon. Cotton is susceptible to the strains of this fungus 

 from okra and to F. vasinjectum from okra and cotton. 



Thus, it is apparent that the species of Fusarium causing the wilt 

 disease of okra is identical with F. vasinjectum. Likewise it is evident 

 that V. alho-atrum is a serious vascular parasite of a number of different 

 economic plants. In view of the fact that the genus Acrostalagmus 

 should be combined with the earlier genus Verticillium, it seems probable 

 that V . alho-atrum is the fungus described by Van Hook under the name 

 ''Acrostalagmus alhus," the cause of ginseng-wilt; by Lawrence as A. 

 caulophagus, the cause of the bluestem disease of black raspberry; and 

 by Gueguen as A. vilmorinii, the cause of a wilt disease of China aster 

 and associated with a disease of cacao fruits. 



V . alho-atrum and F. vasinjectum are readily cultivated artificially, 

 indicating that both are capable of persisting saprophytically in the soil 

 for an indefinite period in the absence of the preferred host. There 

 was no indication that either fimgus is carried from field to field or from 

 year to year by the seed or from plant to plant by the cutting knives. . 



As a control measure it may be suggested that seed be selected only 

 from healthy plants. If extreme precaution is to be taken, the seed 

 may be disinfected in a formalin solution (i to 240) for two hours. 



Since okra, eggplant, potato, cotton, snapdragon, and the weeds 

 Xanthium spp. and Abuiilon spp. are all susceptible to the Verticillium- 

 wilt, as well as ginseng, China aster, and black raspberry, as seems 

 probable, these plants should be taken into consideration in planning 

 a rotation to eliminate wilt diseases. Similarly, okra and cotton are 

 hosts of F. vasinjectum and should not follow each other in rotation if 

 best results are expected. 



LITERATURE CITED 

 (i) Aderhold, Rudolf. 



1907. UBER EINE THROMBOSE DES JOHANNIS- UND STACHELBEERE. In Mitt. 



K. Biol. Anst. Land- u. Forstw., Heft 4, p. 26-27. 



(2) Appei<, Otto. 



1909. EiNiGES UBER DIE BI.ATTR0LLKRANKHE1T DER KARTOFPEL. /n Jahresbcr. 



Ver. Angew. Bot., Jahrg. 6, 1908, p. 259-265. 



(3) Atkinson, G. F. 



1892. SOME DISEASES OP COTTON. Ala. Agf. Exp. Sta. Bui. 41, 65 p., 25 fig. 



(4) Brown, Nelue A. 



1914. A SNAPDRAGON WILT DUE TO VERTiciLUUM. In Phytopathology, V. 4, 

 no. 3, p. 217. 



(5) Butler, E. J. 



1910. THE WILT DISEASE OP PIGEON-PEA AND THE PARASITISM OP NEOCOSMOS- 



PORA VASINFECTA SMITH. Mem. Dept. Agr. India, Bot. Ser., v. 2, 

 no. 9, 64 p., 6 pi. (part col.). Bibliography, p. 63-64. 



