Outbreaks of the African sugarcane stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae) in sugarcane plantations of the northern Ivory Coast: management strategies under implementation

Heavy infestations of the stalk borer Eldana saccharina broke out over the last three cropping seasons in sugarcane plantations of both Ferké sugar mills of the northern Ivory Coast. The study objective was to determine the cause of heavy infestations observed on cane and the impact on sugar yields to implement a proper pest-management strategy. The study, which covered 10 years of cropping seasons from 2006-07 to 2017-18, was based on sampling of all sugarcane fields at harvest for cane juice analysis and assessment of borer damage in terms of percentage of internodes bored. This allowed us to cluster harvested fields depending on the intensity of infested canes and assess the amount of sugar production lost due to E. saccharina. Infestations of this borer, observed at harvest, broke out only three years ago in Ferké 1 and two years ago in Ferké 2. Heavy infestations occurred over 45-55% of the sugarcane area in Ferké 1, as opposed to 25-35% in Ferké 2. Except for the variety SP71-8210, all main sugarcane varieties grown were heavily infested in Ferké 1. Although infestations were of concern in fields no matter what their water status was, they seemed to be much more severe in rainfed and semi-irrigated crops compared to irrigated ones. Sugar-production loss due to E. saccharina occurred over the last three years in Ferké 1, as opposed to the last two years in Ferké 2, but more significantly in 2016-17 at both sites with, respectively, a loss of 2600 and 2300 t of sugar. Significant reductions in sugar losses due to the borer as a result of limiting nitrogen fertilizer rates was achieved in 2017-18 compared to 20116-17, by 62 and 50%, respectively, in Ferké 1 and Ferké 2. This was one aspect of an integrated stalk borer management strategy to be implemented that also included the application of silicon fertilizers, the growing of resistant or tolerant cane varieties and cropping practices preserving natural enemies such as mechanized green harvesting and growing food plants for parasites.

Bibliographic Details

Main Authors:	Boua, Mélanie, Coulibaly-Ouattara, Yah, Goebel, François-Régis
Format:	conference_item biblioteca
Language:	eng
Published:	ISSCT
Online Access:	http://agritrop.cirad.fr/593477/ http://agritrop.cirad.fr/593477/1/Boua%2C%20Coulibaly-Ouattara%2C%20Goebel.pdf
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