Varietal response of four cowpea cultivars (Vigna unguiculata L. Walp) to different densities of guinea grass (Panicum maximum)

Two field experiments were conducted in 2007 and 2008 to evaluate the performance of four cowpea varieties to different densities (0, 5, 20 and 35 m-2) of guinea grass at the Experimental Garden of the Ambrose Alli University, Ekpoma. The experimental design was a 4 x 4 factorial scheme. Weed densities did not significantly (P>0.05) affect plant height at 3, 6 and 9 weeks after planting (WAP) but the varieties did. However, the interaction between weed densities and varieties was not significant throughout the study. Dry matter yield by the different cowpea varieties significantly (

Simulated flooding and drought effects on germination, growth, and yield parameters of sesame (Sesamum indicum L.)

The effects of drought on germination of sesame seeds (Sesamum indicum L.) also known as benniseed were simulated in the laboratory using varying concentrations of sodium chloride, glucose and polyethylene glycol at 0 – 0.50 MPa water potential. Higher osmotic conditions (0.25 – 0.50 MPa) significantly reduced the percentage germination, radical and shoot development. The ability of the three chemicals to reduce germination and seedling development in sesame was of the order: polyethylene glycol < glucose < sodium chloride. Different irrigation regimes of water were used toinduce flooding and drought effects on plants cultivated in pots in a green house. Both flooding and drought resulted in stunted growth, reduced dry matter, number of leaves per plant and seed yield per plant. Prolonged flooding reduced maturity time, and induced chlorosis and floral abortion. The growth and seed yield of sesame are adversely affected by continuous flooding and severe drough

The effects of sodium azide and colchicine treatments on morphological and yield traits of sesame seed (Sesame indicum L.)

Seeds of Sesame (Sesame indicum L.) were exposed to varying concentrations of sodium azide and colchicine solutions ranging from 0 - 0.250% (w/v). Variations in the percentage germination and survival,number of days to maturity, plant heights, total leaf area/plant, chlorophyll content, pollen sterility, dry matter and fruit size were recorded in the C1 and C2 generations. The frequency of mutation/injury increased with increasing concentrations of the mutagens. The LC50 values based on survival percentages in the M1 generation were fixed at 0.0776 and 0.0473% for sodium azide and colchicine respectively. There were dose related effects of the mutagenic treatments on quantitative traits resulting in reductions in traits such as germination and survival percentages, plant height, number of fruit/plant, but increases in leaf area, maturity time and fruit size. Colchicine treatment produced shortened internodes, deformed leaves, and chlorophyll mutants. Low doses of both mutagens

Potentials of leaves of Aspilia africana (Compositae) in wound care: an experimental evaluation

<p>Abstract</p> <p>Background</p> <p>The potentials of the leaves of the haemorrhage plant, <it>Aspilia africana </it>C. D Adams (Compositae) in wound care was evaluated using experimental models. <it>A. africana</it>, which is widespread in Africa, is used in traditional medicine to stop bleeding from wounds, clean the surfaces of sores, in the treatment of rheumatic pains, bee and scorpion stings and for removal of opacities and foreign bodies from the eyes. The present study was undertaken to evaluate the potentials for use of leaves of this plant in wound care.</p> <p>Methods</p> <p>The effect of the methanol extract (ME) and the hexane (HF) and methanol (MF) fractions (obtained by cold maceration and graded solvent extraction respectively) on bleeding/clotting time of fresh experimentally-induced wounds in rats, coagulation time of whole rat blood, growth of microbial wound contaminants and rate of healing of experimentally-induced wounds in rats were studied as well as the acute toxicity and lethality (LD₅₀) of the methanol extract and phytochemical analysis of the extract and fractions.</p> <p>Results</p> <p>The extract and fractions significantly (<it>P </it>< 0.05) reduced bleeding/clotting time in rats and decreased coagulation time of whole rat blood in order of magnitude of effect: MF>ME>HF. Also, the extract and fractions caused varying degrees of inhibition of the growth of clinical isolates of <it>Pseudomonas fluorescens </it>and <it>Staphylococcus aureus</it>, as well as typed strains of <it>Ps. aeruginosa </it>(ATCC 10145) and <it>Staph. aureus </it>(ATCC 12600), and reduced epithelialisation period of wounds experimentally-induced in rats. Acute toxicity and lethality (LD₅₀) test in mice established an i.p LD₅₀of 894 mg/kg for the methanol extract (ME). Phytochemical analysis revealed the presence of alkaloids, saponins, tannins, flavonoids, resins, sterols, terpenoids and carbohydrates.</p> <p>Conclusion</p> <p>The leaves of <it>A. africana </it>possess constituents capable of arresting wound bleeding, inhibiting the growth of microbial wound contaminants and accelerating wound healing which suggest good potentials for use in wound care.</p

Phytochemical studies and antioxidant activity of two South African medicinal plants traditionally used for the management of opportunistic fungal infections in HIV/AIDS patients

<p>Abstract</p> <p>Background</p> <p>It has been observed that perturbations in the antioxidant defense systems, and consequently redox imbalance, are present in many tissues of HIV-infected patients. Hence, the exogenous supply of antioxidants, as natural compounds that scavenge free radicals, might represent an important additional strategy for the treatment of HIV infection. The aim of this study was therefore to analyse the phytochemical constituents and antioxidant potential of <it>Gasteria bicolor </it>Haw and <it>Pittosporum viridiflorum </it>Sims., two South African plants traditionally used for the management of opportunistic fungal infections (OFIs) in AIDS patients.</p> <p>Methods</p> <p>The <it>in vitro </it>antioxidant properties of the two plants were screened through DPPH (1,1-diphenyl-2-picrylhydrazyl), NO (nitric oxide), H₂O₂(hydrogen peroxide) radical scavenging effects and reducing power assays. Phytochemical studies were done by spectrophotometric techniques.</p> <p>Results</p> <p>There were no significant differences in the flavonoid and proanthocyanidins contents between the leaves and bark extracts of <it>Gasteria bicolor </it>and <it>Pittosporum viridiflorum </it>respectively, while the total phenolic content of the bark extract of <it>P. viridiflorum </it>was significantly higher than that of <it>G. bicolor </it>leaf. The acetone extracts of both plants indicated strong antioxidant activities.</p> <p>Conclusion</p> <p>The results from this study indicate that the leaves and stem extracts of <it>Gasteria bicolor </it>and <it>Pittosporum viridiflorum </it>respectively possess antioxidant properties and could serve as free radical inhibitors, acting possibly as primary antioxidants. Since reactive oxygen species are thought to be associated with the pathogenesis of AIDS, and HIV-infected individuals often have impaired antioxidant defenses, the inhibitory effect of the extracts on free radicals may partially justify the traditional use of these plants in the management of OFIs in HIV patients in South Africa.</p

Effects of different NaCl Concentrations on germination and seedling growth of Amaranthus hybridus and Celosia argentea

Salinity refers to the salt content of any given system. By nature, arid soils are naturally saline. Soils could also acquire salinity due to some agricultural practices like irrigation. There is need therefore for search on halophytes that could adapt to such soils and be used to reclaim soils contaminated with salts. Thus, this present study focused on investigating Amaranthus hybridus and Celosia argentea with respect to their potentials and suitability for use in saline environments. This study was conducted in two phases; germination (laboratory-based) and seedling tests (field-based). Shoot length, root length, root/shoot ratio, total length, fresh weight, dry weight, dry matter content, leaf area index, leaf number as well as relative water content were parameters used for assessing results for the field-based test. Germination results showed that only the control (0 mM) showed 100 % germination in both species. Germination percentages decreased steadily with increasing NaCl concentrations in both species. Growth was steadily stimulated in both species at lower NaCl levels with best growth stimulation at 50 mM NaCl but was adversely affected by higher NaCl concentration levels (75, 100 and 150 mM). Both species showed almost the same phenomenon for fresh weight, dry weight, dry matter, leaf area index, number of leaves as well as relative water concentration. These show that both species would best be cultivated under moderate than low or high saline concentration. The findings in this study showed that it is best for seedlings of both species of plants to be raised in nurseries free of NaCl to attain 100% germination and after which, the seedlings could then be transplanted to moderately saline soils for maximum growth and development. This has strong implications for maximizing food productivity and ensuring food security. Key words: Germination, early seedling growth, NaCl, salinity, Amaranthus hybridus, Celosia argentea

Germination Biology Of Mariacus longibracteatus Cherm And Oryza barthii A. Chev.

The germination biology of two most abundant and frequent weeds of lowland rice in Edo state was studied. The two species varied in their temperature requirements for germination: the optimum temperature for the germination of M. longibracteatus 40oC while O. barthii was 32oC. M. longibracteatus did not germinate at temperatures below 25oC but O. barthii germinated at 20oC. Optimum seedling emergence was recorded at a depth of 0.5cm in M. longibracteatus whereas O. barthii emerged most at depths of 2.0 and 3.0cm. Both species showed controlled seed germination as a survival mechanism. Simulated moisture stress and hydrogen ion activity adversely affected the germination of seeds of both species indicating high sensitivity to moisture stress and solute concentrations. Treatments that would increase the soil pH would limit the spread of both species. Key Words: Germination biology, weeds, lowland rice Global Journal of Agricultural Sciences Vol.3(1&2) 2004: 15-1