Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


A 3-fold difference (P < 0.05) was found in a 5-replication split plot comparison of % yield loss due to ratoon stunting disease (RSD) alone in contrast to that due to the disease in combination with sugarcane borer (SCB), Diatraea saccharalis (F.), damage in 1st stubble sugarcane. The research plan utilized differential levels of SCB damage as whole plots and a factorial combination of 2 levels of RSD (0 vs 63%) and 2 types of seed cane ( 35% SCB bored internodes) as subplots. Based on the plant cane data, a highly significant negative correlation r = -0.82, was found between SCB damage and cane weight. Loss in sugar production due to 55% SCB bored internodes was 24.4%. The association of simulated or actual SCB injury with stalk rots, particularly Colletotrichum falcatum Went, caused from 9.2-34.1% reduction in germination, and as much as 2.5 metric tons/ha loss in sugar production. Excepting SCB control, a survey spanning 2 years of sugarcane management practices among producers in 3 geographic areas of Louisiana showed substantial variability in the efficacy of control tactics applied against weeds and RSD, with effective suppression of weeds in sugarcane being the most inconsistent and difficult to achieve. These results indicate the need for an integrated approach to managing several components of pest complexes, disease, weeds, and insects in Louisiana sugarcane.