to evaluate the efficacy of using organic fertilizer as bioremediant for spent engine oil polluted soils.Three concentrations of spent engine oil (0, 5 and 10 % w/w, spent engine oil in soil) and three application rates of organic fertilize (0, 5 and 10 t ha-1) were utilized in a 3 x 3 factorial arrangement and laid out as a completely randomized design with three replication. Soil pH, available P and exchangeable cations were significantly reduced by spent engine oil except organic C compared to control. Heavy metals (Va and Pb) concentration increased with increasing concentration of spent engine oil. Amendment of spent engine oil polluted soil with organic fertilizer significantly remediated the degraded soil and decreases the heavy metal concentration. In addition, 10 t ha-1 organic fertilizer showed superiority over 5tha-1 organic fertilizer in amending spent engine oil degraded soil for pH, total N, available P, exchangeable Ca 2+ and reduced heavy metal concentration. Soil pollution adversely affected number of leaves, dry vine weight, dry leaf weight and herbage yield. Growth and herbage yield were much higher in organic fertilizer amended spent engine oil polluted soil. the highest herbage yield (9.23 t ha-1) was obtained from unpolluted soil treated with 10 t ha-1 organic fertilizer which was statistically comparable with soil polluted with 5 % spent engine oil and amended with 10 t ha-1 organic fertilizer (7.10 t ha-1). Soils polluted with 5 % spent engine oil had higher bacteria population compared to control, while organic fertilizer had depressing effect on soil without spent oil pollution.However, unpolluted soiltreated with 10 t ha-1 organic fertilizer had the fungi (0.77 x 10 6 cfu g-1) population which was statistically compared to 5 t ha-1 organically treated soil without spent engine oil pollution (0.76 x 10 6 cfu g-1). Soil polluted with spent engine oil has been bioremediated with organic fertilizer and hence put into productive use.

A nursery trial was conducted in the screen house of the Teaching and Research Farm, Faculty of Agriculture, University of Benin, Benin City, Nigeria in 2011 to investigate the effect of different potting media and watering frequencies on the growth of Dennetia tripetala seedlings. Three different growing media: Rice husks (Rh), pig dung (Pd) and cocoa husk (Ch) were used as sources of growth. They were combined in a 1:1 ratio to make seven media combinations with four watering frequencies at once daily (D 1 ), twice daily (D 2 ), once every other day (D 3 ) and twice every other day (D 4 ). The trial was laid out in a 7 x 4 factorial design fitted into a Completely Randomized Design (CRD) with three replications. Data were collected on plant height, leaf number, and canopy diameter, stem girth, dry weight of root and shoot. Results obtained revealed that potting medium with sole pig dung significantly produced the best seedling attributes in terms of plant height (11.46cm), stem girth (1.01cm), canopy diameter (9.58cm) while, leaf number (11.16), dry weight of shoots (0.51g) and roots (0.19g) were best with sole rice husk and rice husk plus pig dung (1:1) respectively. Watering twice every other day had a significant (p<0.05) influence on plant height, canopy diameter, stem girth and root dry matter. There were significant interaction effects between sole pig dung and watering once, twice daily and twice every other. However, in order to save labour, money and time spent in watering, watering twice every other day plus pig dung sole may be adequate for raising D. tripelata seedlings.

The present investigation was conducted to enhance seedling production of Black Velvet Tamarind (Dialium guineense). Three different types (sets) of experiments were designed. The results showed no sprouting of the stem cuttings in the first type of experiment ( stem cuttings treated with Naphthalene Acetic Acid (NAA) and coconut milk). The second type of experiment (seeds subjected to some pre-sowing treatments using NAA, coconut milk, manual scarification and seeds soaked in water for 24 hrs) showed highly significant treatment effects for seed treatments and days after planting, DAP (p < 0.001), while time or duration of treatment was not significant. There were highly significant interaction effects for Treatment duration x Seed treatments and Treatment duration x Days after planting (DAP). Mean percentage germination was best at 2000ppm NAA (43.85%), but was not significantly different from 1000ppm, (40.28%), water soaked (40.28%) and manual scarification (38.88%). Lower germination rates were observed for 500ppm (34.72%), normal or untreated seeds (30.75%), and coconut milk (28.38%). There were highly significant treatment effects (p < 0.001) between the control (normal seeds) with 11.2% mean germination, cold treatment (stratification), 21.1% and manual scarification 33.7%. DAP was also highly significant with the highest mean germination of 34.1% at 56DAP. Treatments x DAP was highly significant (p < 0.01) in the third experiment (stratification, a cold temperature pre-sowing treatment). Soaking seeds for 24 hrs before planting was adjudged the best treatment for enhancing seedling production in Dialium guineense in this study. It was the easiest and cheapest of all other treatments considered.

:The response in growth and development of seedlings of Dialium guineense to different potting media was studied in the screen house. Five potting media: River sand (Rs), Top soil (Ts), Poultry manure (Pm), Rice husk (Rh) and Oil palm refuse bunch (OPRB) were used. They were evaluated as sole treatments and in combination with river sand (Rs) in different ratios (1:1, 1:2, 2:5 and 5:2) respectively. All together, twenty -one (21) potting media types were evaluated. The experiment was laid out in a completely randomized design (CRD) in three replications. Data were collected on monthly basis for plant growth parameters, while shoot and root dry weight were measured at the end of the experiment. On the average the seedlings of D. guineense responded best on the Rs + Ts 1:2 growth medium in number of leaves (16.67), stem girth (0.31 cm), number of nodes (11.67), shoot dry weight (1.24 g) and root dry weight (0.50 g). Rs + Ts 1:2 was followed by Rs + Pm 1:1 and Ts sole respectively with respect to the growth parameters evaluated and were not significantly (p 0.05) from one another, but were significantly (p < 0.05) different from other media and their combinations with river sand.

A preliminary pot trial was conducted in a greenhouse to determine the effects of rubber effluent on some soil chemical properties as well as early growth and nutrient uptake by maize plant. The levels of rubber effluent used were 0, 50, 100, 150, 200, 250 ml per 2 kg soil. The trial was arranged in a completely randomized design and replicated three times. Results showed that the soil pH, organic carbon, N, P, K, Mg, Ca Na, ECEC, Fe, Mn and Zn were significantly higher (P<0.05) in rubber effluent treated soils than the control, while the control was significantly higher in exchangeable acidity. Except Zn, the N, P, K, Mg, Ca, Na, Fe, Mn content and their uptake by the plant were significantly higher (P<0.05) in rubber effluent treated plant than the control. The plant height, leaf area and number of leaves were also significantly higher in effluent treated plants than the control. The N, P, K, Mg, Ca, Na content and their uptake and the growth parameters however declined at 200 ml treatment while in Fe, Mn and Zn content and their uptake, there was no definite pattern of increase with increasing effluent levels. Conclusively, rubber effluent contained vital plant nutrients which may be favorable to soil fertility improvement and maize growth at the application rates.