MOSAIC OF SUGAR CA3^E AIsTD OTHER GRASSES. 5 



in which 75 per cent or more of the plants had the mosaic disease. 

 From this point south to Donaldsonville, however, the amount of 

 infection is not heavy. Many plantations are entirely free from 

 mosaic, so far as can be determined by inspection. From Donaldson- 

 ville to New Orleans an increasing amount of infection was recorded 

 by the inspectors. Between Lutcher and Reserve, about 75 per cent 

 of the plants in every plantation were infected. This is by far the 

 most heavily infested large area in the United States. From this 

 region to New Orleans and from New Orleans to the lower extremity 

 of the river district the amount of infection ranges from 4 to 30 per 

 cent. Just a few fields were visited where no mosaic was found. 



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Fig. 1. — Map showing the location of diseased areas of sugar cane in the United States. 



In the Bayou Lafourche district mosaic was found in only about one 

 out of four fields visited and where present amounted to only 1 to 8 per 

 cent of the plants. In the Bayou Teche district no mosaic was 

 found on plantation cane, although nearly 500 fields were carefully 

 inspected. A few cases were found in this region on cane recently 

 distributed by the State Sugar Experiment Station. The imme- 

 diate destruction of these few sources of infection is a matter of great 

 importance. No mosaic whatever was found west of Bayou Teche 

 or in Avoyelles and Rapides Parishes to the north. Thus, a very 

 considerable part of the sugar-cane lands of Louisiana is still free 

 from the disease, and every effort should be made to keep it free. 



In Georgia the worst infested region is in the vicinity of Cairo, 

 Grady County. There the proportion of infection ranges from less 

 than 1 to 75 per cent or more in fields where the disease is present, 



