THE SUGAR-CANE MOTH BORER. 



55 



NOT BURNING CANE TKASH. 



To protect the egg parasite the senior author some years ago began 

 experimenting in disposing of cane trash by plowing it under and 

 by raking it to the headland. 



On one plat at the Sugar Experiment Station, Audubon Park, 

 New Orleans, the cane trash was burned in the fall of 1912 as usual, 

 while on another plat of about the same size the trash was raked to 

 the headlands in the spring before cultivation. Through the grow- 

 ing season of 1913 careful examinations were made to ascertain the 

 infestation in the two plats, and even in the spring and early summer 

 the results were promising. For a long time no borers were found in 

 the unburned plat, whereas borers and " dead hearts " were found in 

 the burned-over plat, but when the cane was cut in October, the 

 difference was most striking. In the burned-over plat 67.5 per cent 

 of the canes were infested by the borer, while in the unburned plat 

 only 15.5 per cent were infested. 



On a plantation in the lower Rio Grande Valley of Texas no cane 

 trash was burned in the fall and winter of 1912-13, while on neigh- 

 boring plantations under the same management the trash was burned 

 in the fall as usual. When examinations were made in the fall of 

 1913 the difference in infestation was easily discernible. The aver- 

 age infestation of the unburned fields was 30.6 per cent, while the 

 average infestation of the burned-over fields was 76 per cent. In 

 1912 the average infestation of these plantations was 50.5 per cent 

 and in a field a few miles away it was 86 per cent. 



In 1914 various experiments were conducted at Audubon Park. 

 Trash was burned in the fall, burned in the spring, raked to the head- 

 land in the spring, and plowed under in the spring. The results of 

 these experiments are recorded in Table XII. 



Table XII. — Nonburning experiments, Audubon Park, New Orleans, La., 1914- 



Kind of treatment. 



Number of 

 plants in- 

 fested by 

 borer, May 

 29 to June 

 2, 1914. 



Number of 



plants 



killed by 



borer, Oct. 



28 to Nov. 



2, 1914. 



Per cent 



of canes 



infested by 



borer, Nov. 



2 to 5, 1914. 





3 



6 



5 



20 



3 

 12 

 38 



6 



45. 73 



Trash left on field in winter and raked to headland in spring 



63.31 

 83.79 



Trash left on held in winter and burned as soon as possible in spring. . 



69.44 



Note. — The plants infested May 29 to June 2 ("dead hearts") were cut out and 

 destroyed about June 10, so that the plants killed by October 28 to November 2 were 

 different plants which had been infested later in the season. The dates refer to the times 

 examinations were made. 



In each of these plats there were about 20 rows of cane. Three 

 plats were in one field, not separated in any way, while the plat 

 on which the trash was burned in the spring was separated from 



