UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 829 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
s&r&ju 
Washington, D. C. 
PROFESSIONAL PAPER 
October 29, 1919 
THE MOSAIC DISEASE OF SUGAR CANE 
AND OTHER GRASSES. 
By E. W. Brandes, 
Pathologist, Sugar-Plant Investigations; formerly Pathologist, Porto Rico Agricultural 
Experiment Station, Mayaguez, P. R. 
CONTENTS. 
History of the disease 1 
Distribution in the United States 4 
Losses in the United States 7 
Primary symptoms : , 8 
Secondary symptoms 10 
Injuries resembling mosaic 12 
Varietal susceptibility 12 
Varieties attacked 12 
Immune varieties 14 
Other hosts 15 
Nature of the disease 16 
Infection phenomena 16 
Transmission of mosaic in diseased seed 
pieces 18 
Page. 
Nature of the disease — Continued. 
Transmission of the disease by carriers 18 
Soil relations 19 
Relation to disinfectants 20 
Relation to fertilizers 20 
Control 20 
Elimination by roguing 21 
Elimination by grinding all cane and secur- 
ing clean seed 22 
Exclusion. 22 
Eradication 23 
Elimination by planting immune varieties. 24 
HISTORY OF THE DISEASE. 
The mosaic disease of sugar cane, the presence of which has 
recently been discovered in Louisiana and other Southern States, 
is the malady that in epidemic form has occasioned severe losses in 
parts of Porto Eico during the past four years. There it has been 
variously called matizado, "mottlings;" ray as amarillas, "yellow 
stripe;" morida de perro, "dog bite;" la enfermadad de Arecibo, 
"disease of Arecibo;" la enfermadad nueva, "new disease;" etc. 
The disease was first noticed in Porto Rico about the middle of 
1916. 
Starting from some point near Arecibo, on the north coast of 
Porto Rico, it spread rapidly over the cane fields to the west, down 
the west coast to the south coast, and up into the valleys and hills 
