Diversité floristique et déterminants de l’enherbement des bananeraies industrielles de Dabou au sud de la Côte d’ivoire

Objectifs : L’étude de la flore adventice des bananeraies de Dabou répond à la recherche de la compétitivité de la banane de Côte d’Ivoire. L’objectif est de connaître les déterminants de l’enherbement pour une production durable de la banane sans herbicides.Méthodes et résultats : Des paramètres phytosociologiques et agronomiques ont été conjointement suivis dans 4 bananeraies industrielles. Les données obtenues ont été analysées. La flore adventice est très diversifiée et dominée par huit espèces héliophiles majeures. Le non respect du calendrier de désherbage chimique, la nature des sols, la position topographique des parcelles, la faible densité des bananiers et leur faible recouvrement sont les causes de l’enherbement.Conclusions : Les facteurs phytoécologiques sont les principaux responsables de l’enherbement. La lutte chimique est limitée. La lutte biologique par les Légumineuses de couverture peut être envisagée.Mots clés : Adventice, Bananier Grande Naine, Côte d’Ivoire, Phytosociologie

Can Land Managers Control Japanese Knotweed? Lessons from Control Tests in Belgium

Japanese knotweed Fallopia japonica is an extremely abundant invasive plant in Belgium and surrounding countries. To date, no eradication method is available for land managers facing the invasion of this rhizomatous plant. We tested different chemical herbicides with two application methods (spraying and stem injection), as well as mechanical treatments, on knotweed clones throughout southern Belgium. The tested control methods were selected to be potentially usable by managers, e.g., using legally accepted rates for herbicides. Stem volume, height and density reduction were assessed after one or two years, depending on the control method. Labor estimations were made for each control method. No tested control method completely eradicated the clones. Stem injection with glyphosate-based herbicide (3.6 kg ha-1 of acid equivalent glyphosate) caused the most damage, i.e., no sprouting shoots were observed the year following the injection. The following year, though, stunted shoots appeared. Among the mechanical control methods, repeated cuts combined with native tree transplanting most appreciably reduced knotweed development. The most efficient methods we tested could curb knotweed invasion, but are not likely to be effective in eradicating the species. As such, they should be included in a more integrated restoration strategy, together with prevention and public awareness campaigns

Perception and understanding of invasive alien species issues by nature conservation and horticulture professionals in Belgium

We conducted a survey to determine how two professional sectors in Belgium, horticulture professionals and nature reserve managers (those directly involved in conservation), view the issues associated with invasive plant species. We developed and utilized a questionnaire that addressed the themes of awareness, concept and use of language, availability of information, impacts and, finally, control and available solutions. Using co-inertia analyses, we tested to what extent the perception of invasive alien species (IAS) was dependent upon the perception of Nature in general. Only forty-two percent of respondent horticulture professionals and eighty-two percent of nature reserve managers had a general knowledge of IAS. Many individuals in both target groups nonetheless had an accurate understanding of the scientific issues. Our results therefore suggest that the manner in which individuals within the two groups view, or perceive, the IAS issue was more the result of lack of information than simply biased perceptions of target groups. Though IAS perceptions by the two groups diverged, they were on par with how they viewed Nature in general. The descriptions of IAS by participants converged with the ideas and concepts frequently found in the scientific literature. Both managers and horticulture professionals expressed a strong willingness to participate in programs designed to prevent the spread of, and damage caused by, IAS. Despite this, the continued commercial availability of many invasive species highlighted the necessity to use both mandatory and voluntary approaches to reduce their re-introduction and spread. The results of this study provide stakeholders and conservation managers with practical information on which communication and management strategies can be based