Weed Diversity and Infestation in Elaeis Guineensis Agroecosystems of Industrial Plantations in the Grands Ponts Region, Southern Ivory Coast

In oil palm cultivation, weeds are a major obstacle due to their negative effects on crop growth, soil fertility, and agricultural management systems. They compete with crops for the elements necessary for crop development and growth. Therefore, weed control is essential for maintaining yields. However, effective weed control requires knowledge of the weeds specific to palm oil groves and their potential harmfulness to the crop. This study aims to assess the floristic diversity and weed infestation in oil palm plantations within the Integrated Agricultural Unit (IAU) in Irobo, southern part of Côte d'Ivoire. A total of 250 floristic inventories were conducted across 5 localities, based on 2 ecological variables: age groups and toposequence, each with 3 options. Walk-through surveys using the "field walk" method were conducted within each 2500 m 2 plot to identify the weed species, genera, families, and biological types present, and to assess their frequencies, abundance-dominance, and potential harmfulness. As a result, a total of 657 species were identified, comprising 373 genera distributed across 98 botanical families. The most represented families are Fabaceae (65), Poaceae (61), Cyperaceae (37), Rubiaceae (36), Asteraceae (33), Apocynaceae (32), and Malvaceae (25). Dicotyledons and hemicryptophytes were the most common, accounting for 74.58% and 20%, respectively. The infestation diagram highlighted five of the nine groups and showed their infestation levels. Nephrolepis biserrata, Pueraria phaseoloides , and Heterotis rotundifolia are the species in group G1, that could be considered the major general weeds and the most harmful in the study area. In addition, Steinchisma laxum and Croton hirtus are identified as potential general weeds belonging to group G2. This study identified the main classes, families, species, and biological types of weeds present, as well as their potential to be harmful in industrial oil palm plantations. It could help guide the development of sustainable weed management practices in industrial oil palm plantations.