Effect of Castor Bean (Ricinus communis L.) Aqueous Extracts on the Performance of Root-Knot Nematodes (Meloideogyne spp.) on Tomato (Solanum lycopersicum L.)

The increased concern for environmental and health hazards have called for a reduction in the use of synthetic nematicides for nematode control. Experiments were, therefore, conducted to ascertain the nematicidal potential of castor bean’s crude extract and its five lower concentrations with water as control. In the in vitro studies, crude castor bean aqueous extract and 10, 20, 30 and 40% different concentrations with 100 root-knot nematode eggs or juveniles in separate Petri dishes showed that all the different concentrations had toxic effects on eggs and juveniles of root-knot nematode. Egg hatch inhibition and juvenile mortality increased with increased concentration of the extracts. With an increase in exposure time, juvenile mortality increased. In potted plant studies, crude castor bean aqueous extracts and its lower concentrations of 20, 40 and 60% caused significant improvement in plant growth measures such as height and fresh shoot weight over the water blank control. The crude castor bean extract was nematotoxic to root -knot nematodes in vitro and in potted-tomato plants, but this was not demonstrated in field studies. Further work needs to be done before a firm recommendation can be madeKeywords: Control, juveniles, nematicides, phytochemicals, wate

Variations in the level of resistance to root-knot nematodes (Meloidogyne spp.) infestation among ten cowpeas (Vigna unguiculata L. Walp.) genotypes

The cultivation of cowpea (Vigna unguiculata L. Walp.) cultivars that are tolerant to root-knot nematode attack is among the environmentally safe approach to managing the root-knot nematode menace in cultivated crops. In this study, the tolerance of 10 cowpea genotypes to root-knot nematodes infestation was evaluated in a pot experiment conducted in a Screenhouse, at the University for Development Studies, Nyankpala Campus. The experiment was laid out in a completely randomized design with three replications. The number of second stage juveniles (J2) per 250 cm3 of soil sample were counted while the severity of root-knot nematode damage (root galls) was assessed. The reproduction index (RI) was used to classify the varieties as resistant or susceptible. There was a significant difference (P < 0.05) in the number of second stage juveniles of root-knot nematode (RKN), galling index and RI among the genotypes tested. The study revealed that cowpea genotypes SARI 1-4-90, Padi tuya, Songotra, IT99K-1122, Sanzi and Apagbaala were moderately resistant whereas cowpea genotypes IT86D-610, Zaayura, SARI 5-5-5 and IT07K-299-6 were slightly resistant. Thus, the six moderately resistant cowpea genotypes were suggested to be used as a source of resistance to RKN in future breeding works

Researching African Women and Gender Studies: New Social Science Perspectives

Research on African women and gender studies has grown substantially to a position where African-centered gender theories and praxis contribute to theorizing on global feminist scholarship. Africanist scholars in this field have explored new areas such as transnational and multiracial feminisms, both of which address the complex and interlocking conditions that impact women\u27s lives and produce oppression, opportunity and privilege. In addition, emergent African-centered research on women and gender explores those critical areas of research frequently addressed in the global North which have historically been ignored or marginalized in the African context such as family, work, social and political movements, sexuality, health, technology, migration, and popular Culture. This article examines these developments in African gender studies scholarship and highlights the contributions that new research on understudied linguistic Populations, masculinity, migration, political development and social movements and the virtual world are making to global feminist discourse

Plant-parasitic nematodes associated with sweet potato rhizosphere soil in the Semi- Deciduous Forest and Coastal Savannah Zones of Ghana

A survey was conducted in nine major sweet potato producing districts across the semi-deciduous forest and coastal savannah zones of Ghana to determine the prevalence of plant-parasitic nematodes parasitizing the crop. Soil samples were collected at 90-days after planting from the rhizosphere of sweet potato crop and analysed using Modified Baermann tray method from 100 farms across the study area. Seven plant-parasitic nematode genera were extracted from soil samples collected and morphologically identified under a microscope with four of them, namely Meloidogyne, Pratylenchus, Rotylenchulus, and Helicotylenchus being the most prevalent. Scutellonema sp. occurred in 89% while Tylenchus sp. occurred in 33% of the districts sampled. The ring nematode, Criconemella sp. was found in only two of the nine districts covered; Ketu North and Akatsi South which incidentally recorded 100% of the seven nematodes encountered in the survey. The abundant nematode was Meloidogyne sp. which represented 39% and Criconemella, the least (0.1%) of the total nematodes recovered in the survey. This study has shown that high diversity, incidence and density of economically important plant-parasitic nematodes are associated with sweet potato crop. Development of appropriate management strategies to mitigate the negative effects of plant-parasitic nematodes on sweet potato is recommended. &nbsp

Relationship between land use and groundwater quality in six districts in the eastern region of Ghana

The chemical quality of groundwater in six district of the eastern region beneath the different types of land use areas of Ghana was examined to evaluate the effects of human activities on groundwater. Analyses indicate that groundwater in the studied area is fresh and generally suitable for most uses. The groundwater is generally characterised by a chemical facies of Ca-HCO3−, Na-Cl and mixed Na–Ca-HCO3 types and is weakly mineralised. Anthropogenic disturbances have had and continue to have an impact on the aquatic ecosystem of Ghana. High concentration of Cl− and TDS were found in wells in high residential areas while the highest levels of Na, Ca, SO42− and NO3− were found in agricultural and high density residential areas. About 50% of boreholes sampled have elevated level of NO3−-N emanating from agricultural runoff

Occurrence of entomopathogenic nematodes (Steinernematidae, heterorhabditidae) as potential biocontrol agents against Spodoptera frugiperda infesting Zea mays

Synthetic insecticides are used worldwide to manage invasive fall armyworm (Spodoptera frugiperda) in cereals, in spite of the chemical’s prohibitive cost and threats to environmental health. In Ghana, little attention has been given to entomopathogenic nematodes as insect pest biocontrol agents, due to the existence of dismal expertise in the field. This study evaluated maize (Zea mays L.) farms for endemic entomopathogenic nematodes as potential biological control agents against fall armyworms infesting maize in Ghana. Entomopathogenic nematode juveniles were extracted using an insect baiting technique, White traps. These Rhabditid nematodes (Heterorhabditis; Steinernema) were found in 75% of 200 soil samples; and 92.5% of 40 districts targeted by this study. The Greater Accra region recorded the greatest population density (1,820 juveniles per 5 fall armyworm larvae cadavers); while; the Central region recorded the lowest density (81 juveniles per 5 fall armyworm larvae cadavers). There was high presence of entomopathogenic nematodes across the study areas. Therefore, entomopathogenic nematodes offer a promising alternative strategy for managing fall armyworm infestation of maize in Ghana to minimise over-reliance on synthetic insecticides. &nbsp

Big Data Analytics and Business Failures in Data-Rich Environments: An Organizing Framework

In view of the burgeoning scholarly works on big data and big data analytical capabilities, there remains limited research on how different access to big data and different big data analytic capabilities possessed by firms can generate diverse conditions leading to business failure. To fill this gap in the existing literature, an integrated framework was developed that entailed two approaches to big data as an asset (i.e. threshold resource and distinctive resource) and two types of competences in big data analytics (i.e. threshold competence and distinctive/core competence). The analysis provides insights into how ordinary big data analytic capability and mere possession of big data are more likely to create conditions for business failure. The study extends the existing streams of research by shedding light on decisions and processes in facilitating or hampering firms’ ability to harness big data to mitigate the cause of business failures. The analysis led to the categorisation of a number of fruitful avenues for research on data-driven approaches to business failure

How and when does founder polychronicity affect new venture performance? The roles of entrepreneurial orientation and firm age

This paper proposes a moderated mediation model to examine the relationship between polychronicity and venture performance. We argue that entrepreneurial orientation (EO) mediates the positive relationship between polychronicity and venture performance. The hypotheses were tested using time-lagged data from a sample of 249 ventures from Vietnam. Using structural equation modeling, our findings indicate that EO mediates the relationship between polychronicity and venture performance. Additionally, the results reveal the relationship between polychronicity and EO is moderated by firm age, and that this interaction effect is stronger for younger firms than older firms. Our theory-based arguments and findings help extend and provide support to the polychronicity-venture performance relationship, which highlights the significance of the effect polychronicity has on venture performance through founders polychronic proclivities

Sustainability orientation, CSR implementation and new venture growth

Purpose: Building on the upper echelons theory and sustainability orientation (SO) literature, we examined the possibility that the relationship between chief executive officers’ (CEOs’) SO and venture growth might be mediated by levels of CSR implementation. Design/methodology/approach: We used data obtained from from 211 new ventures operating in Ghana. Multiple regression analysis was used to test the hypotheses. Findings: We found that CSR implementation mediates the relationship between SO and venture growth. In addition, we found that, at higher levels of financial slack, the effect of SO on CSR implementation is attenuated. However, our results show that, at higher levels of CEO power, the influence of SO on CSR implementation is amplified. Originality: To the best of our knowledge, this study is among the first to examine mediating role of CSR implementation in the relationship between SO and venture growth, and also, examines two internal contingency factors (i.e., CEO power and financial slack) on this association. Theoretical/Academic Implications: This study builds on prior scholarly works by articulating a key managerial characteristic that shapes the implementation of environmental and social policies. Specifically, we show that SO influences venture growth through CSR implementation. We also provide insights on the connection of CSR implementation to growth of new business ventures. Practitioner/Policy Implications: Our study encourages CEOs to voluntarily adopt CSR and sustainability initiatives. The analysis also reinforces the need that higher levels of CEO power have a major impact in amplifying the effects of sustainability orientation on degree of CSR implementation. There is a need for government to create forums where organizational decisionmakers, i.e., CEOs, exchange not only the best knowledge about CSR implementation and sustainability, but also best practices to provide opportunities for cross fertilization of ideas and increased innovations