This study assessed the effect of crude oil on the emergence and growth of cowpea in two different soil types (wetland/Fadama and upland soils) treated with 0 mL (control), 25, 50 and 75 mL unweathered crude oil per 2 kg soil. The results revealed that emergence day varied between 4-5 days with the exception of the 75 mL treatments which germinated between 6-8 days after planting. Emergence in both soils decreased by 31.25, 37.50 and 87.50% relative to the control for the 25, 50 and 75 mL treatments, respectively. The results obtained on the growth rate of the cowpea also showed a decrease in stem height, leaf number and percentage protein content with increasing crude oil contamination. However, stem height, leaf number and percentage protein content were higher in Fadama soils compared with upland soil while no particular pattern was observed for chlorophyll content in cowpea leaves.
Adewole Michael Gbadebo and Moyinoluwa David Adenuga, 2012. Effect of Crude Oil on the Emergence and Growth of Cowpea in Two Contrasting Soil Types from Abeokuta, Southwestern Nigeria. Asian Journal of Applied Sciences, 5: 232-239.