ABIYA SYLVANUS EFETOBOR
Publication
The air pollution tolerance indices (APTI) of five plant species randomly sampled from the vicinity of Iron and Steel factory in Ile-Ife Osun State, Nigeria were analyzed. A composite sample of five leaves for each of the plant was used for laboratory analysis. Four physiological and biochemical parameters: leaf relative water content (RWC), ascorbic acid content (AAC), total leaf chlorophyll (TLC) and pH of leaf extract were used to compute the Air pollution tolerance indices (APTI). Results showed order of tolerance as Banana (Musa species) (0.425%) > Sandpaper leaf (Ficus asperifolia) (1.230%) > Elephant grass (Pennisetum purpureum) (3.113%) > Cocoyam (Xanthosom species) (5.828%) > Cassava (Manihot esculenta) (22.019%); indicating that banana was the most tolerant plant while Cassava (Manihot esculenta) was the least tolerant (most sensitive) plant species to air pollution stress in the study area. Therefore, plants with high and low APTI can serve as tolerant and sensitive species for air pollution biomonitor, respectively.
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The contamination of soil by used lubricating oil is rapidly increasing due to global increase in the usage of petroleum products. The effect of spent lubricating oil on the growth and yield response of cowpea Vigna unguiculata (L) Walp was investigated using potted plants in soil contaminated with different concentrations of spent lubricating oil. The 3kg of soil was mixed homogeneously with 50.0mL, 75.0mL and 100.0mL of spent lubricating oil and the control (0.0mL). The growth parameters shows that the application of spent lubricating oil had a significant reduction (p<0.05) on the plant height, leaf area, fresh weight, dry weight and the harvest index of the cowpea seedlings studied. The reductions and morphological effects in the growth characteristics measured shows that there was an increase as the concentration level of the contaminant increases compared to the control. The concentrations of copper, cadmium, iron, lead and nickel in soil contaminated with spent lubricating oil increased with the volume of treatment. Heavy metal concentrations in the shoot and root of treated plants were higher than that of the control. This could be responsible for the retarded growth of the plant, chlorosis of the leaves coupled with dehydration of the plant indicating water deficiency.
The effects of different concentration of spent calcium carbide on the growth indexes (percentage germination, plant height, leaf area, number of leaves, and plant biomass) on okra (Abelmoschus esculentus) were studied at a screen house located beside the academic building of the Federal University Of Technology, Akure, Nigeria. 5kg of soil was polluted with varying concentrations of spent carbide (100g, 200g and 300g) with the control having 0g of spent carbide. Okra seed were introduced and completely randomized design was used. The whole experiment was replicated 4 times. Result indicates that the plants grown in 100g spent carbide polluted soil did better in terms of plant height when compared to other treatments and the control. At 8 weeks after planting (WAP), 100g concentration had the highest possible mean plant height (38.25±1.59) while the control recorded (25.78±1.76). This height was significantly higher (p<0.05) than 300g concentration (8.75±1.53) which was the lowest. Number of leaves was also significantly higher (p<0.05) in 100g plants (5.75±1.18) than 300g plants (1.75±1.18). Dry weight was not significantly different (p<0.05) although 100g plants had the highest of the treatments (5.97±1.11). Other growth indexes show okra plants in 100g polluted soil performing better than other treatments and control. This growth reduces drastically as the concentration of spent calcium carbide increases above 100g concentration level of spent calcium carbide. This shows that okra (Abelmoschus esculentus) grows well in low concentration of spent carbide.
