Diversity, structure, and dynamics of weeds in rainfed rice cultivation at badiatte and essyl, ziguinchor (senegal)

Abstract

Over the past decades, human and natural changes had led to an increase in the diversity and abundance of weeds in cultivated lands of not only Senegal, but also across the world. However, weed structure and dynamics were not well-known by local populations. This research intended to study some cultural practices and some factors that can influence the weeds presence in rice crops. Therefore, a survey and inventory were carried out at Badiatte and Essyl. Interviews by using a questionnaire were done on cultural practices and perceptions of local populations. To study the dynamics and structure of weeds, the quadrant point method was used. Abiotic factors that can influence the weeds presence, such as soil texture and pH were determined. In total, 31 species belonging to 25 genera and 11 families were inventoried in the two villages. The Cyperaceae (Cyperus rotundus L., Cyperus esculentus L., Killinga pumila Michx., Cyperus amabilis Vahl, Fimbristylis littoralis Gaudich, Pycreus macrostachyos Lam., Schoenoplectus senegalensis Steud., Fimbristylis hispidula (Vahl) Kunth followed by Fabaceae (Desmodium triflorum L.), and Amaranthaceae (Amaranthus viridis L.) were most abundant in terms of individuals. The specific diversity was higher in Badiatte. The structure and dynamics of weeds changed over time due to the agricultural practices and management. They differed from one site to another depending on maintenance practices, soil preparation, and environmental conditions. The weeds evolution was influenced by soil proprieties and cultural practices (ploughing, varieties cultivated, weeding, and fertilization).