Fig. 1

TPH degradation percentage of soil treated with different levels of crude oil of 0% (control), 1%, 3%, 5%, and 7% and planted with Vinca rosea compared to unplanted polluted soil after a 5-month experimental period. Different uppercase letters indicate significant differences between the planted and unplanted treatments at each oil concentration, and different lowercase letters indicate significant differences among different soil treatments at p ≤ 0.05. Values are expressed as the mean ± SE, n = 3