A 3-months ecological study was conducted to determine the effects of crude oil on vegetation growth in the Niger Delta region of Nigeria. Crude oil had significant (p ≤ 0.05) adverse effects on water infiltration, vegetation regeneration, root length and the accumulation of plant biomass. The vegetation heights at the polluted sites were 44 ± 5cm against 136 ± 20cm and 3.9 ± 0.4cm and 13.9 ± 2.8cm for Sphenostylis stenocarpa and Vigna subterranea respectively in comparison to the unpolluted sites. Up to 641 mg/kg total petroleum hydrocarbons, TPH were seen in the shoot tissues and 22mg/kg in V. subterranea and S. stenocarpa respectively while good percentages of hydrocarbon degradation were recorded for V. subterranea . Stress responses by the leaf tissue were measured by the leaf area, LA. Other growth indices monitored presented V. subterranea as more tolerant specie. Phytotoxic responses were observed and recorded. The implications of these results for the enhancement of environmental quality and Agriculture within the study area are discussed.
