BULLETIN 146, U. S. DEPARTMENT OF AGRICULTURE. 



Table I. — Analysis of sugar cane (D. 7.'t) to determine effect on sugar content of 

 the borer injury to cane — Continued. 



RESULTS OF ABOVE 



ANALYSIS 



FIGURED ON A BASIS OF 1 TON OF CANE TO 



THE 











SAMPLE. 









a> 





6 



o 



<~ o 





"3 ° 



ri 



as 



h 



-^ u " 



3 



CD 



3 o 



ft 



a 



ca 



to 



Nature of 



a 

 o 



o 



•g 

 "3 



go 



a 3 



3tJ 



ft 



w 



? =1 



3 

 X) 



o 

 o 



ft 



MO 



3 . 

 w 3 



.S B J 



o 



CD 



ft 



t. 3 



3 o 



CO ^2 



CD 



-H CD 





sample. 



£ 





<IT u 



w ° 



"""■a 3 



a> 



§ 3 



3 v. 



£ m 3 



3 



CD 

 O 

 O 



3 



.35 



m O fc. 



c 





bo 



'3 



bD 



"3 

 IS 



s s s 



C3 



o 



"'"3 2 



O Mi" 



1-5 



o 



3 



3 



■3° 



T3 ft 



m 



£3" 



3 ° fe 







Lbs. 



Lbs. 



Z&s. 



Z&s. 



Z&s. 



Lbs. 



Z&s. 



Lbs. 



Lbs. 



ibs. 



£6s. 



P. e/. 



1 



Borer-free 



Medium in- 



2,000 



1,222 





20S.96 





19.55 





13.44 





175.97 







2 









fested 



2,000 



1,216 



6 



195. 77 



13.19 



20.67 



1.12 



14.59 



1.15 



160.51 



15.46 



8.78 



3 



Heavilv in- 





























fested 



2,000 



1,176 



46 



161. 11 



47.85 



24.69 



5.14 



21.17 



7.73 



115.25 



60.72 



34.51 



He summarizes his results as follows : 



The sugar-cane borer damages cane in the field by destroying a considerable 

 percentage of the eyes, thus reducing the stand of plant cane ; by stunting the 

 growth of the cane, owing to the physical injury of the stem ; by admitting 

 fungous diseases through the wounds in the stem ; and is the main cause of 

 injury by the wind, owing to the weakening of the stalk due to the tunnels 

 and burrows. These classes of injury have been appreciated by planters. It 

 now develops that there is another and very important class of injury which 

 has been overlooked. This is the reduction of both the quantity and quality 

 of the juice, which is dealt with specially in this circular. It becomes evident 

 that both the planters and the manufacturers are vitally interested in the work 

 of the sugar-cane borer. 



Mr. Van Dine states : 



'There is a direct loss in sugar and a decided reduction in the purity of the 

 juice of cane infested by the moth stalkborer. This loss in Porto Rico exceeds 

 670 pounds of sugar per acre of cane in which the infestation was not apparent 

 except upon examination, the yield averaging 41 tons of cane per acre and the 

 stalks being normal and healthy in appearance. The loss increases in direct 

 proportion to the number of joints of the cane stalks infested by the borer. 

 There is more fiber and less juice in borer-infested cane. The actual weight of 

 borer-infested cane is less than that of sound cane, and it is considered that 

 the juice deteriorates more rapidly in infested cane when cane is allowed to 

 stand without being crushed for any length of time after harvest. 



In the early bulletin on the moth borer by Dr. W. C. Stubbs and 

 Prof. H. A. Morgan (152) it is found that after the borer became 

 established on Belle Alliance Plantation, in Louisiana, there was 

 " a falling off of 4.98 tons per acre and about 25 pounds of sugar per 

 ton." From the figures given in that bulletin it is calculated that an 

 average yield of 3,455 pounds of sugar per acre accrued on Belle 

 Alliance Plantation before the borer made its appearance, whereas 

 the average yield thereafter was only 2,393 pounds per acre. The 

 loss in sugar from these figures would be 1,061 pounds per acre. 

 At 4.35 cents per pound, which is given as the average price of 

 (white) sugar for three years, the annual money loss per acre due to 

 the moth borer would be $16.15. At the present ruling prices the 

 loss would be correspondingly greater. 



