Effect of pre-sowing and incubation treatment on germination of Garcinia kola (Heckel) seeds. Abstract-Introduction. Garcinia kola, a multipurpose fruit tree, produces fruit, seeds, roots and stem which are extensively used in Nigeria, Ghana and other West African countries for dental care. Cultivation of this fruit tree is limited because of poor seed germination. Our study therefore aimed at improving seed germination properties which will promote cultivation of G. kola by rural farmers. Materials and methods. Seeds taken from a single tree of G. kola were treated with cold water (22°C), hot water (60 °C) and gibberelic acid (0.5 g × L-1) for various lengths of time. They were then put to incubate in sterilized river sand or a thick transparent polyethylene bag to evaluate the capacities of seed to be germinated under such conditions. In addition, the seed moisture content at harvest was also reduced to various levels before incubation in polyethylene bags to determine the critical moisture rate necessary for seeds to germinate. Results. The seeds incubated in the river sand without any treatment before sowing had an average time of germination of 71.2 d and a total percentage of germination of 28% whereas those incubated in polyethylene bags had an average time of germination of 25.8 d and a total percentage of germination of 62%. The cold water treatment, irrespective of the incubation method, did not significantly affect either the mean germination time or the total germination percentage. However, it significantly reduced the spreading out of the seed germination to 5.4 d. The seed pretreatment with gibberelic acid prolonged at the same time the average time of germination and the spreading out of the germination. The seed water content at harvest (50.4%) allowed the best rate of seed germination and the shortest spreading out of the germination period. Conclusion. The pretreatment of freshly harvested seeds with cold water followed by an incubation in a thick transparent polyethylene bag proved most effective in enhancing the germination of G. kola seeds. This procedure has to be recommended to promote the cultivation of this species. Nigeria / Garcinia kola / plant propagation / seed / germination / germinability / seed treatment Effet des traitements avant semis et des techniques d'incubation sur la germination de graines de Garcinia kola (Heckel).

In a bid to diversify the sources of revenue generation in Nigeria, the Government of the Federation has initiated plans to resuscitate coal mining. This study, therefore, assessed the impact of previous mining activities on soil chemical characteristic of the abandoned site. A single factor experiment was conducted in a randomized complete block design (RCBD) with three replications to obtain information on soil status of Iva mined site. Soil samples were collected randomly from ten different sampling points at 0-10, 10-20, and 20-30 cm soil depth in four cardinal points at north (N), south (S), east (E), west (W), and at the centre (c) of crest, middle slope, and valley of Iva mined site. The samples were analysed for heavy metals, macronutrient, soil pH, and organic matter content. The organic matter values ranged from 0.00 ± 0.00 to 1.14 ± 0.02% in dry season and 0.00 ± 0.00 to 1.04 ± 0.06% in wet season, with higher levels of organic matter in the valley (OM ≤ 1.14 %). Soil pH values ranged from 3.98 to 6.00 in wet season and 3.82 to 5.34 in dry season, with higher levels of acidity in the middle slope (pH ≤ 4.37). The range of values of soil macronutrients (K, Mg, N and P) were higher in wet season than in dry season with higher levels of K, Mg, N and P, at middle slope. Similarly, the values of the concentration of heavy metals (Ni and Pb) in soil were higher in wet season than in dry season with higher levels of Ni and Pb at middle slope. The levels of Ni, Pb and Cd in this study are above their allowable limits in Austria, Germany, France, Netherlands, Sweden, and United Kingdom. The high concentrations of Cd and Ni in soils could be taken up in plants via the roots, thus, exposing both man and herbivores to serious health risks.

This study determined the views of respondents in Akwuke and Iva mine communities concerning the impact of coal mining activities on animal and plant species, pattern of settlement, pollution effect and health of people living in these two mined areas in Enugu, Nigeria. Data were generated through sample survey using a well-structured questionnaire and personal observation in the field. Khaya ivorensis (mahogany) was the major tree species that had gone extinct (72% of respondents), and Geochelone sulcata (tortoise) was the major animal species that has gone extinct (80% of respondents) in the two mined areas. Sixty-five percent of the respondents said that water pollution was most severe environmental impact of mining in Akwuke. The major health hazard caused by mining in Akwuke (55% of respondents) and Iva (65% of respondents) was blindness. Indeed, 82.5% of respondents indicated that mining affected the pattern of settlement in the two mined areas. Emphatically, coal mining affected negatively some of the socio-economic activities of the inhabitants of the mined area through removal of vegetation to access coal deposit vis-à-vis blasting, quarrying and crushing of coal.

The study assessed heavy metals in the soil and subsequent accumulation in plants at an industrial site at Enyimba city, Abia State, Nigeria. Soil and medicinal plant samples were analyzed for zinc (Zn), lead (Pb) and cadmium (Cd). The highest concentration of Zn (142.06 ± 2.91 mg/kg), Pb (18.06 ± 1.30 mg/kg) and Cd (27.055 ± 2.468 mg/kg) were obtained at the sampling points of 2, 7 and 5, respectively. The highest concentrations of Zn (27.09 ± 1.44 mg/kg) and Cd (2.000 ± 0.156 mg/kg) were accumulated by Azadiractha indica while the highest concentration of Pb (4.58 ± 0.51 mg/kg) was accumulated by Mangifera indica. The levels of Zn and Cd in soil were 13.77 ± 1.35 to 142.06 ± 2.91 and 0.695 ± 0.106 to 27.055 ± 2.468, and their concentrations in Azadiractha indica were 5.06 ± 0.35 to 27.09 ± 1.44 and 0.002 ± 0.001 to 2.000 ± 0.156 mg/kg, respectively. The concentrations of Zn and Cd in soil and Cd in Azadiractha indica reflected a state of pollution relative to Dutch criteria for soil and the FAO/WHO Codex Alimentarius Commission for soil and herbal plants.

The on-going action and plan to revive old coal mines in Nigeria necessitated a study on the soil chemical characteristics at abandoned coal mine in Akwuke, Enugu State, Nigeria. A single factor experiment was conducted in a randomized complete block design (RCBD) with three replications to obtain information on soil status of Akwuke mined site. Soil samples were collected randomly from ten different sampling points at 0-10, 10-20, and 20-30 cm soil depth in four cardinal points at north (N), south (S), east (E), west (W), and at the center (c) of crest, middle slope, and valley of Akwuke mined site. The samples were analyzed for heavy metals, macronutrient, soil pH, and organic matter content. Soil pH (4.29-6.14) in wet season is higher than 4.14-5.58 in dry season at Akwuke mine site. The values of N, P, K, Ca, and Mg in soil at Akwuke mine were higher in dry season than in wet season. The highest soil organic matter content (0.96±0.04%) at Akwuke mine is obtained in dry season at 0-10 cm valley. The concentrations of Ni, Pb, and Cd in soil at mined site ranged from 4.15±0.07 to 19.81±1.29, 6.11±0.13 to 21.10±0.85, and 0.01±0.00 to 3.06±0.08 mg/kg. Mg (89.60±1.41 to 251.9±1.41 cmol/kg). Cd and Ni in soil at the mined site was higher than their allowable limits in Sweden, and United Kingdom. The high concentrations of these metals (Cd and Ni) in soils could expose both animals and local inhabitants to high levels of Cd and Ni, thus, posing a serious health risks to the local people.

Human health challenges in recent times have been attributed to consumption of food contaminated with heavy metals. Coal mining is an anthropogenic activity that releases heavy metals into the environment. This study, therefore, assessed accumulation of heavy metals (lead (Pb), cadmium (Cd), nickel (Ni), arsenic (As) and iron (Fe)) in plant species in the vicinity of Akwuke and Iva coal mine in Coal city, Enugu State. The results indicate that the highest concentration of Ni (9.02 ± 0.03 mg/kg), As (0.005 ± 0.001 mg/kg) and Cd (2.16 ± 0.07 mg/kg) was accumulated in Alchornea cordifolia while the concentration of Pb (10.37 ± 0.52 mg/kg) was highest in Andropogon gayanus and Fe (231.00 ± 1.41 mg/kg) was highest in Irvingia gabonensis. The values of Ni (9.02 ± 0.03 mg/kg), As (0.005 ± 0.00 mg/kg), Pb (10.37 ± 0.32 mg/kg), Cd (2.02 ± 0.03 mg/kg), and Fe (46.00 ± 1.41 mg/kg) accumulated in A. cordifolia, A. gayanus, D. guinense, and M. indica in wet season were significantly (P < 0.05) higher than their corresponding values (5.04 ± 0.07, 8.96 ± 0.01 and 0.003 ± 0.001 mg/kg, 1.87 ± 0.07 mg/kg, and 33.45 ± 0.21 mg/kg) in dry season, respectively. Alchornea cordifolia, Andropogon gayanus and Irvingia gabonensis consumed by animals and local inhabitants in the vicinity of the two mined sites could expose them to high levels of Pb, Ni and Cd, thus posing a serious health risk to the local people.

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