Spring deadhearts (number and total stand in two 0.002 ha samples per field) and end-ofseason
percent bored internodes (50 stalks sampled with bored internodes counted by position
from four locations in each field) were collected (hand cut) to determine the level of sugarcane
borer injury. The majority of the cane in 2000 and 2001 was severely lodged at the time of
harvest. Insecticide application information (application frequency per year) was obtained from
either the grower or consultant. Rainfall information was obtained for 2000 and 2001 from the
Louisiana Office of State Climatology.
A sucrose analysis was conducted on each sample at the USDA-ARS Sugarcane
Research Unit at Houma, Louisiana. Fiber was determined by shredding of the stalk with a prebreaker
manufactured by Cameco Industries prior to juice extraction. The method used was
similar to the one reported by Gravois and Milligan 1992 with the exception that a 1000g fiber
sample was used for juice extraction. Brix and pol reading were used to determine theoretical
recoverable sugar (TRS, g/kg) (Gravois et al.1991). A significant amount of the sucrose and
fiber data for 2000 and 2001 was lost due to an unfortunate computer malfunction. Therefore,
the sucrose and fiber data for this study were not reported.
Results
During 2000, a total of 5,350 stalks yielding a total of 65,081 internodes were collected
from the eight sugarcane growing regions. The total number of internodes bored was 1,331, for
an average of 2.05% bored internodes. Spring sugarcane borer deadhearts averaged 665 per
hectare for the 2000-growing season and ranged from a high of 1,620 deadhearts in the Central
region to a low of 271 in the Lower Lafourche region (Table 2.1).
In 2000, a long period of low rainfall occurred in all of the sugarcane growing regions
except in the Central Louisiana region where high early rainfall occurred (Table 2.2). The
rainfall in the spring of 2000 ranged from 2.2cm in the Lower Lafourche region to a high of