ABSTRACT ‘

The effect of diesel on germination, grow th performance and anatomy of Pigeon pea ' (Cajanus cajan}. African Yam bean (Sphenosty/is stenocarpa) and Bambara groundnut (Vigna subterranean} was investigated. Seeds of the plants were cultivated on soil contaminated with diesel. Five kilogram (5kg) of the soil was treated with 50ml, lOOmL 150ml. and 200ml of diesel to obtain 1%, 2%, 3%. and 4% level of contamination while untreated soil (0%) served as the control. The experiment was designed using a factorial arrangement (5x3) in a completely randomized design and replicated three times. Germination was observed as the emergence of the plumule from the soil surface. The various grow th parameters measured were done two weeks after germination occurred and this continued every two w'eeks for eight weeks (2 weeks after germination. 4WAG. 6WAG and 8WAG). The germination results showed that control of C. cajan had the highest germination rate of 1.71 and a percentage germination of 83.33 ± 11.55%. while 4% had the low'est germination rate of 0.71 and a percentage germination of 36.67 ± 5.77% respectively. Control of S', stenocarpa had the highest germination rate of 1.79 and percentage germination of 76.70± 5.577%, while 4% had the lowest germination rate of 0.79 and a percentage germination of 33.33 ± 5.77% respectively. Control of V. subterranean had the highest germination rate of 2.00 and a percentage germination of 93.33 ± 5.77%, while 4% had the low'est gennination rate of 0.86 and a percentage germination of 40.00 ± 0.00% respectively. Results of the plant height showed that the heights ofthe plants significantly reduced (P<0.05) at 4% pollution level as C. cajan stood at 3.45 ± 0.25cm as at 2WAG, and 22.35 ± 1.38cm as at 8WAG, S’, stenocarpa stood at 4.07 ± 0.31cm as at 2WAG, and 14.05 ± 0.40cm as at 8WAG, V. subterranean stood at 2.87 ± 0.50 cm as at 2WAG, and 13.06 ± 1.06cm as at 8WAG respectively compared to the control with corresponding values 17.37 ± 0.98cm at 2WAG,and 53.93 ± 0.18cm at 8WAG for C. cajan, \3>.3>1 ± 0.75cm at 2WAG, and 32.35 ± 0.55cm at 8WAG for S', stenocarpa, and 6.40 ± 0.43cm at 2WAG. and 34.00 ± 1.15cm for V. subterranean respectively. The number of leaves, leaf area and stem girth of the plants w'ere significantly reduced at P<0.05 in 4% polluted soils compared with the control. It was observed that diesel pollution caused reduction in the number of stomata and distortions in the epidermal cells ofthe leaf, destruction of the vascular tissues, mid-rib and reduction of air spaces in the stem and root of the plants as the concentration of the diesel in the soil increased. From the results of this study, it was clear that diesel contamination had deleterious effect on the germination, growth and general anatomy of the plants. Researches in the area of plant biotechnology should focus towards developing varieties of these plants that can tolerate this stress condition