Reduction of nematicide and insecticide use on banana plantations in the french west indies

Due to economic constraints on export markets, banana producers of the French West Indies have to adopt intensive production systems. In the last decade, these systems were mostly based on the utilization of large quantities of pesticides against nematodes and weevils. The development of soil sanitation (fallow and/or crop rotations) combined with the use of micropropagated plants has reduced the number of these applications (ca. 30% between 1996 and 1999) and thus reduced the cost of treatments (from 13 to 7%). Therefore, pesticide use leads to numerous drawbacks, less and less accepted by the community (water and soil pollution) and European market (residues in fruits, demand for "safe" certified and organic products). In order to limit the nematicide use vs. #Radopholus similis#, two complementary means were investigated: i) the improvement of fallow efficiency (through banana destruction technique, research of #R. similis# reservoir plants) and ii) the evaluation of the value of rotation crops (pineapple, sugarcane, dasheen, tomato). As a consequence of the past prevalence of #R. similis#, data of damage induced by other nematodes are still lacking to justify treatments. Research is also ongoing to determine the pathogenicity in these new banana production systems (using micropropagated plants) of these presumed second ary parasites which remain after fallow or rotation, e.g., #Meloidogyne# spp., #Pratylenchus# spp., and #Hoplolaimus seinhorstii#. With regard to the black weevil, #Cosmopolites sordidus#, pheromone traps can be used as a basis of forecasting to reduce insecticide application. Mass trapping may also control black weevil when infestation levels are low to average. Present investigations are designed to increase mass trapping efficiency (by modifying sordidine spreaders) and to combine pheromone traps with entomopathogens such as #Steinernema carpocapsae#. (Texte intégral)