Characterization of the weed flora in maize (Zea mays L.) farms in the Adamawa region of Cameroon

Abstract

In the Adamawa region of Cameroon, maize as the predominant crop, faces significant challenges, including weed management, which substantially compromises yields. This study aimed to characterize the weed flora of maize farms in the Vina division. The modified Braun-Blanquet phytosociological method was applied to 40 maize farms, with three 25 m² surveys per site, chosen according to vegetation homogeneity. A total of 74 weed species were recorded, distributed across 58 genera and 17 botanical families. Poaceae (27.02 %), Fabaceae (14.86 %), and Asteraceae (13.51 %) are the most represented families, accounting for 55.39% of the overall observed weed flora. Dicotyledons dominate, representing 62.2 % of the species, while the biological spectrum reveals a strong presence of Therophytes (50 %), indicating a high proportion of short-cycle annual species. High diversity indices (Shannon: 3.81; Simpson: 0.97) and low intersite similarity coefficients (< 50 %), reflect significant high floristic richness and marked heterogeneity between sites. The combined analysis of the infestation diagram and hierarchical classification made it possible to identify three groups of weeds according to their harmfulness. The group of major species, the most problematic for maize cultivation, notably includes Spermacoce latifolia, Ageratum conyzoides, Eleusine indica, Galinsoga quadriradiata, Setaria barbata, Bidens pilosa, Commelina benghalensis, Mimosa pudica, Sida rhombifolia, Kyllinga squamulata, and Euphorbia hirta. These results constitute an essential basis for implementing targeted management strategies adapted to the local agro-ecological context. However, their effective application in integrated weed management needs comprehensive complementary research on species ecology, their interactions with cropping practices, and their sensitivity to control methods.