Nouvelles variétés de canne à sucre (Saccharum officinarum L.) adaptées aux conditions pluviales dans les périmètres sucriers de Ferké au Nord Côte d'Ivoire
Sugarcane is an important cash crop in Ivory Coast with a total production of about 2 million tons of cane/annum and 200,000 tons of sugar/annum. It contributes to about 1.2% of total country DGP and 3.3% of agricultural GDP. However, stem borer (Eldana saccharina W) infestations in Ferké sugarcane plantations have significantly impacted both cane and sugar yields over the last three cropping seasons with total sugar losses estimated to 5,000 tons in 2016-17. That pest damage outbreak was hypothesized to be linked to higher fertilizer rates applied to sugarcane plantations over 2014-15 and 2015-16 cropping seasons. The study aimed to determine the optimum Nfertilizer rate in sugarcane that could maintain stem borer infestations under control (BIN ≤ 5%). It was carried out on a commercial plantation of Ferké 2 sugar mill in northern Ivory Coast. That field which was cultivated with SP70-1006 variety was sprinkler irrigated with a center pivot and the experimental design was a randomized complete block with 11 N-fertilizer rates in four replications. Results obtained over two successive cropping seasons showed that, in plant cane, yield performance, cane juice quality and stem borer infestations were not significantly influenced by fertilizer treatments indicating that nitrogen was not a limiting factor in the soil profile to crop growth and development probably due to the decay of organic matter as a result of soil tillage. In contrast, in first ratoon, cane yields and stem borer infestations in terms of per cent of bored cane and bored internode percentage were significantly influenced by N-fertilizer treatments with an optimum rate of 100 to 110 kg N/ha. Cane yield increase resulting from additional N-fertilizer applications to that optimum rate was very little compared to the return cost of fertilizer with higher levels of stem borer infestations (> 8% BIN).
Heavy stalk borer infestations broke out over the last three cropping seasons in sugarcane plantations of both Ferké sugar mills of Northern Ivory Coast. The study objective was to determine the cause of heavy infestation observed on cane and sugar yields in order to implement a proper pest management strategy. The study which covers from 2006-06 to 2017-18 cropping seasons was based on sampling of all sugarcane plantations at harvest for cane juice analyses and assessment of stalk borer damages in terms of percentage of internodes bored. This allowed to cluster harvested lands depending on the intensity of infested canes and assess the amount of sugar production losses due to E. saccharina. It came out that 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 variety SP71-8210, all main sugarcane varieties grown were only heavily infested in Ferké 1. Although infestations were of concern on plantations no matter their water status, they seemed to be much more severe on 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 importantly in 2016-17 for both sites with, respectively, a loss of 2600 and 2300 tons of sugar. Significant reduction in sugar production as a result of the limitation in 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 involving the application of silicone fertilizer, the growing of resistant or tolerant cane varieties and cropping practices preserving natural enemies such as mechanized green harvesting and growing service plants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.