Diversidade de plantas daninhas em cultivos de mandioca: um estudo florístico na várzea do Alto Solimões, Amazonas

Abstract

Inadequate weed management in Amazonian floodplain areas is a limiting factor for cassava (Manihot esculenta) production, especially in the Upper Solimões region, where there is a lack of studies. In this context, the objective of this study was to evaluate the floristic composition of weeds in cassava crops in the floodplain ecosystem of the Solimões River in Benjamin Constant, Amazonas. The methodology comprised a survey of weeds in 11 crops in the São José community over two agricultural years (2020/2021 and 2021/2022) and phytosociological analysis. The study identified two classes, 18 families, and 41 species. The Dicotyledonous class was predominant in the family, and the Monocotyledonous class had the largest number of species. Most weeds are perennial and reproduce by seeds. In the first year, the species with the highest IVI were Panicum trichoides, Veronica filiformis, and Brachiaria mutica. In the second year, the species with the highest IVI were Persicaria sp., Panicum laxum, and Digitaria horizontales. The higher occurrence of grasses suggests that they are more competitive species and adapted to the floodplain environment. It is concluded that weed management should prioritize dominant species to reduce competition and negative impacts on cassava production.