Impacts of weed control methods on weed dynamics in rainfed rice cultivation in the Niakara Department in northern Côte d'Ivoire

Introduction: Rice accounts for approximately 10% of national food production and has become the staple food for the majority of Ivorians. Unfortunately, the proliferation of weeds in the fields is one of the main factors limiting its production. This study aims to identify the main weeds and evaluate the effectiveness of two weeding methods on weed management in rain-fed rice cultivation. 

Methods: A survey was conducted among 70 producers to identify problematic weeds. A trial was then set up on 14 plots belonging to producers. This enabled the effect of chemical weed control and the combination of chemical and manual weed control on weed growth dynamics and the agronomic importance of major weeds to be assessed.

Results: The study identified 22 problematic weeds. The most common family is Poaceae. Therophytes (63.64%) and grasses (81.82%) are the most problematic biomorphological types. Rottboellia cochinchinensis (Poaceae) and Setaria pumila (Poaceae) are the most frequently cited invasive species. The results on weed management methods reveal that chemical weed control and the combination of chemical and manual weed control significantly reduced weed flora. Major weed flora decreased significantly.

Conclusion: This study highlights the need to implement more effective and efficient integrated weed management strategies for sustainable agriculture.