SUCROSE CONTENT OF SUGARCANE AS AFFECTED BY MOTH-BORER, DIATRAEA SACCHARALIS (FABRICIUS), INFESTATION

Abstract

More than 1,000 samples of stalks of sugarcane were milled and their juices analyzed in attempting to obtain a more accurate estimate of the losses caused by infestation of sugarcane in Puerto Rico by the moth stalk-borer, Diatraea saccharalis (Fabricius). The samples were divided into (1) whole-canes unbored, (2) whole-canes bored, (3) tops unbored, (4) tops bored, (5) central portions unbored, (6) central portions bored, (7) bases unbored, and (8) bases bored. The statistical analyses showed that the highest percentage of sucrose in cane is found in the central portion, less is found at the base, and the least in the top joints. By using a factor of 0.03549 (as determined by the junior author), which represents the loss of available sucrose per 1 percent of joint infestation, one can calculate the losses of sucrose caused by moth-borer damage in any given area. Thus it was found that Colonia Juana Díaz, near Santa Isabel, P. R. had an estimated total loss of $49,326 in the 3 years 1950, 1951, and 1952, from borer injury. It is estimated that the average annual losses in Puerto Rico amounted to approximately $2,500,000 in the 12-year period from 1940 to 1951.