Larvaecidal effects of aqueous extracts of Azadirachta indica (neem) on the larvae of Anopheles mosquito

The effect of crude aqueous extracts of Azadirachta indica (neem) against the larvae of Anopheles mosquito was investigated. Exposure of the larvae to undiluted extracts of seed oil, leaf and bark for 12 hours led to 100, 98, and 48% mortality, respectively. Dilution of these extracts also resulted in mortality of the larvae. We suggest that the seed oil and leaf extract of neem contain properties that could be developed and used in the control of mosquitoes in the tropics. Key words: Anopheles mosquito, neem, Azadirachta indica. African Journal of Biotechnology Vol.2(9) 2003: 325-32

Effects of sulphuric acid, mechanical scarification and wet heat treatments on germination of seeds of African locust bean tree, Parkia biglobosa

Effects of different treatment methods on the germination of seeds of Parkia biglobosa (mimosaceae) were carried out. Prior treatment of seeds with sulphuric acid, wet heat and mechanical scarification were found to induce germination of the dormant seeds. These methods could be applied to raise seedlings of the plant for field propagation. African Journal of Biotechnology Vol.3(3) 2004: 179-18

Phytochemical and Antibacterial Properties of Root and Leaf Extracts of Calotropis procera

Phytochemical and antibacterial properties of water, methanol and ethanol extracts obtained from root and leaf of Calotropis procera were investigated. Antibacterial growth inhibition was determined using Ditch method against Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Streptococcus pyrogenes. The phytochemical screening reveals the presence of alkaloids, flavonoids, tannins, saponins, and cardiac glycosides, balsams and volatile oil and steroids with higher amount in water extracts. The concentration of the phytochemical constituents were in the order of water > methanol > ethanol. Water extracts showed broad spectrum activity against the tested organisms at concentrations of 30, 60, 90 and 120 mg/ml. Methanol and ethanol extracts did not show a significant effect against the tested organisms at 120 mg/ml as compared with those of tetracycline. The result of this study validates the use of water extract of this species in ethnomedicine and could provide a lead in the isolation of antibacterial agents from water extracts of Calotropis procera

Effects of soaking duration on germination and seedling growth of tomato (Lycopersicum esculentum Mill)

The effects of soaking duration on germination and seedling growth of tomato (Lycopersicum esculentum Mill) Roma VF, UC82B and Xina varieties were investigated. The treatments consisted of three soaking durations (12, 24, 36 h) and control replicated four times in a latin square design. Results indicated significant enhancement of germination by all soaking durations except for Xina variety where 36 h treatment showed no significant difference from the control. Maximum total germination (%) was obtained under 24 h treatment for all the seed varieties. Soaking durations of 12 and 24 h enhanced growth and dry matter accumulation for both Roma VF and UC82 B. The study has demonstrated the advantages of soaking seeds in water for about 24 h prior to sowing them in the field. Key Words: Seed, tomato, soaking duration, varieties, germination, seedling, growth. African Journal of Biotechnology Vol.3(1) 2004: 47-5

Utilisation of Environmental Impact Assessment (EIA) Technique in assessment of impact of human interference on natural ecology of estuaries : a case study of Mersey estuary

A Conceptual study of the impacts of human activities on thenatural ecology of estuaries was carried out. The Mersey Estuarywas used as a case study. Environmental Impact AssessmentTechniques (EIA) was used to identify and evaluate impactsgenerated by various activities of Man on estuaries.The study was conducted with materials and data gatheredfrom scientific papers, documents, reports and other relatedliterature sources.The findings of the research reveal that estuaries exist inseveral forms and shape. They are characterised by gradedsalinity ranging from marine condition (3.5%) to fresh water(0.05%) and periodic and spontaneous tidal movements. Estuariesare highly productive ecosystems and support large wildlife andfish.For many years Man has exploited estuarine resources.However, in the last two hundred years, the advent of theindustrial revolution led to dramatic growth of navigation andestablishment of industries close to estuarine waters.Consequently estuaries attracted large human populations whichdischarged sewage along with industrial effluent direct intotheir waters causing rapid deterioration in water quality andsevere distress of the biota.The Mersey Estuary is typical of such industrializedestuaries. The level of engineering modification and the extentof pollution witnessed in the Estuary is possibly unparalleledby any other estuary in the U. K. These activities havesignificantly affected the ecosystem of the Mersey and the socioeconomiclif e of people living within its catchment boundary andbeyond.EIA has become an important tool in environmental planningand management. I have used its principles and techniques in theidentification and analysis of impacts caused by activities ofMan on the Mersey Estuary.Analysis of results indicate that the construction oftraining wall along the sea channels and the building of theManchester Ship Canal were most important, reducing estuarinecapacity and the stabilization of the inner estuary navigationchannel. The heavy organic load from sewage and industrydischarged directly into the estuary caused severe deficiency ofdissolved oxygen and consequent loss of fish and wildlife. Thedrive to clean up the Estuary started in the 1970s and so farpositive changes are being recorded showing improved wildlifewhich reflect general improvement in the whole Estuary

Interaction Effect of Season, Habitat and Leaf Age on Proximate Composition of Senna occidentalis and Senna obtusifolia Leaves Grown in Fadama and Upland Locations in Sokoto, Nigeria

This study was aimed to assess the effect of season, habitat and leaf age on proximate composition of leaves of Senna occidentalis L. and S. obtusifolia L. Leaves samples were collected from stands of Fadama Research Farm and Upland (Biological garden) at Permanent Site, Usmanu Danfodiyo University Sokoto and analyzed for nutrient contents using oven drying, muffle furnace ashing, soxhlet extraction, distillation and ashing, micro Kjeldahl method, and difference (NFE) methods. Data was subjected to ANOVA and LSD at 0.05% for means separation. The results for interaction effect were all statistically significant (P<0.05) in the leaves of the two Senna species and were influenced variedly by the treatment factors. Specifically, rainy subseason, fadama and upland habitats, young and matured leaves treatments favoured most of the nutrient contents (e.g. moisture, ash, crude fibre and NFE) in the following ranges : Moisture (31.37 - 81.07%), Ash (3..50 - 80.00%), Crude Fibre (1.00 – 12.50%), Ether Extract (1.07–5.47 %), Crude Protein (7.13 – 18.94 %) and NFE (60.49 - 83.66%). This indicates that season, habitat and leaf age are important factors affecting plant growth and development. The results suggest that the species may be sources of the nutrients studied and could enrich the dietary intake of individuals.Keywords: Interaction effect, Season, Habitat, Leaf age, Proximate composition, Senn