4 BULLETIN 829, U. S. DEPARTMENT OE AGRICULTURE. 



of transmission was not present or at least not abundant in this 

 region, it has spread very little. At Santiago de las Vegas it was 

 found on plants recently imported from Louisiana and from Tucuman, 

 Argentina. The latter plants had come originally from Java. The 

 . disease had spread from these plants to an adjoining field of the native 

 Crystalina cane. In view of this demonstration of its ability to 

 spread at Santiago, it is very fortunate that the diseased plants were 

 early observed and destroyed. A slight infection has been found at 

 Mercedes, also as the result of a recent importation. 



Infected cuttings have been received in both Porto Rico and Cuba 

 from Tucuman, Argentina, but to what extent the disease is prevalent 

 in Argentina has not been learned. 



Last year the mosaic disease was found in abundance at La Romana 

 and the city of Santo Domingo, Santo Domingo, and less plentifully 

 at Samana, La Vega, Monte Cristi, and Bonao. 1 Lastly it was dis- 

 covered at St. Croix, Virgin Islands, on cane imported from Porto 



Rico. 1 



DISTRIBUTION IN THE UNITED STATES. 2 



The presence of the mosaic disease in the United States was first 

 suspected when an agent of the Office of Sugar-Plant Investigations 

 of the United States Department of Agriculture discovered young 

 diseased cane in Porto Rico from seed cane imported from Louisiana. 

 The plants were so young at the time that secondary infection seemed 

 improbable, and it was assumed that the seed pieces were diseased 

 when shipped from Louisiana. Accordingly another agent of the 

 same office visited Louisiana and on July 7, 1919, confirmed the 

 presence of mosaic there. The State authorities were apprised of this 

 important disclosure, and the Government agent made a hurried 

 reconnoissance of the Gulf States, which revealed the fact that the 

 disease was already quite widely distributed there. 



On account of the infectious nature of the malady and the fact that 

 it has caused severe losses in other cane countries, a complete sur- 

 vey of the Southern States was immediately instituted to determine 

 the location of all infested areas and, if possible, to trace the original 

 importation of the disease and the course of its subsequent spread. 

 Infested areas have been well delimited. The disease has been found 

 by inspectors of the United States Department of Agriculture in 

 Louisiana, Florida, Georgia, Alabama, and Mississippi (fig. 1). It 

 is most abundant in Louisiana, as would be expected. There the 

 river district is already badly infested. As far north as Angola, in 

 West Feliciana Parish, several fields in a large plantation were found 



1 Stevenson, John A. The mottling disease of sugar cane. In Jour. Dept. Agr. and Labor, Porto Rico 

 in press). 



2 Thanks are due to Mr. W. G. Taggart, vice director of the University of Louisiana Sugar Cane Experi- 

 ment Station, and to Dr. C W. Edgerton, pathologist, Louisiana Experiment Station, for courtesies 

 extended to the writer and suggestions facilitating the survey in Louisiana. 



