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

Intrinsic multiplication rate variation and plasticity of human blood stage malaria parasites.

Pathogen multiplication rate is theoretically an important determinant of virulence, although often poorly understood and difficult to measure accurately. We show intrinsic asexual blood stage multiplication rate variation of the major human malaria parasite Plasmodium falciparum to be associated with blood-stage infection intensity in patients. A panel of clinical isolates from a highly endemic West African population was analysed repeatedly during five months of continuous laboratory culture, showing a range of exponential multiplication rates at all timepoints tested, mean rates increasing over time. All isolates had different genome sequences, many containing within-isolate diversity that decreased over time in culture, but increases in multiplication rates were not primarily attributable to genomic selection. New mutants, including premature stop codons emerging in a few isolates, did not attain sufficiently high frequencies to substantially affect overall multiplication rates. Significantly, multiplication rate variation among the isolates at each of the assayed culture timepoints robustly correlated with parasite levels seen in patients at clinical presentation, indicating innate parasite control of multiplication rate that contributes to virulence

Exploring barriers to the use of formal maternal health services and priority areas for action in Sidama zone, southern Ethiopia.

In 2015 the maternal mortality ratio for Ethiopia was 353 per 100,000 live births. Large numbers of women do not use maternal health services. This study aimed to identify factors influencing the use of maternal health services at the primary health care unit (PHCU) level in rural communities in Sidama zone, south Ethiopia in order to design quality improvement interventions. We conducted a qualitative study in six woredas in 2013: 14 focus group discussions (FGDs) and 44 in-depth interviews with purposefully selected community members (women, male, traditional birth attendants, local kebele administrators), health professionals and health extension workers (HEWs) at PHCUs. We digitally recorded, transcribed and thematically analysed the interviews and FGDs using Nvivo. The 'three delay model' informed the analytical process and discussion of barriers to the use of maternal health services. Lack of knowledge on danger signs and benefits of maternal health services; cultural and traditional beliefs; trust in TBAs; lack of decision making power of women, previous negative experiences with health facilities; fear of going to an unfamiliar setting; lack of privacy and perceived costs of maternal health services were the main factors causing the first delay in deciding to seek care. Transport problems in inaccessible areas were the main contributing factor for the second delay on reaching care facilities. Lack of logistic supplies and equipment, insufficient knowledge and skills and unprofessional behaviour of health workers were key factors for the third delay in accessing quality care. Use of maternal health services at the PHCU level in Sidama zone is influenced by complex factors within the community and health system. PHCUs should continue to implement awareness creation activities to improve knowledge of the community on complications of pregnancy and benefits of maternal health services. The health system has to be responsive to community's cultural norms and practices. The mangers of the woreda health office and health centres should take into account the available budgets; work on ensuring the necessary logistics and supplies to be in place at PHCU

Plant Parasitic Nematodes Associated with Okra in the Forest Savanna Transition and Semi-Deciduous Forest Agro-Ecologies of Ghana

Okra is an important vegetable crop in Ghana. Plant-parasitic nematodes infect okra, reducing the quality and quantity of fresh immature and dry fruits. This study was carried out to determine diversity, density and distribution of plant parasitic nematodes attacking okra in the Forest savanna transition and Semi-deciduous forest agro-ecologies of Ghana. In each agro-ecology, soils from okra rhizosphere were sampled from 15 farms for plant-parasitic nematodes assessment. Nematodes were extracted using the modified Baermann nematodes extraction method. Six nematode genera were identified; Meloidogyne, Pratylenchus, Xiphinema, Helicotylenchus, Rotylenchulus and Scutellonema. Meloidogyne occurred with 64.9% relative abundance and 100% frequency. Rotylenchulus, Pratylenchus, and Helicotylencus nematodes also occurred with 100% frequency. Xiphinema were the least abundant (0.05%) and the least frequent (15%). The findings have shown that a large number of nematodes exist on okra plants and therefore there is the need for educational campaigns to be stepped up by Agricultural Extension Services of the Ministry of Food and Agriculture on plant parasitic nematode infections in okra production

Looking out for a better mitigation strategy: smallholder farmers’ willingness to pay for drought-index crop insurance premium in the Northern Region of Ghana

BACKGROUND: The impact of climate change and variability on livelihoods of smallholder farmers in Northern Ghana has become severer than ever before. As a result, crop insurance has been advocated as one of the recommended risk transfer mechanisms to support farmers in coping with production risks. We used a multistage sampling procedure to select a sample of 315 farmers from 15 farming communities in the Northern Region of Ghana and obtained from this sample the data needed for the analysis. We then applied the contingent valuation method to the data and evaluated the premium amount maize farmers in the study area are willing to pay for crop insurance under a hypothetical market-based drought-index insurance regime. In addition, we used the binary probit model to identify the drivers of farmers’ willingness to pay (WTP). RESULTS: The results revealed that the premium a maize farmer is willing to pay for crop drought-index insurance is GHS175.25/ha (circa USD39/ha). And while variables such as sex, level of education and perception index unexpectedly reduce farmers’ WTP for weather-index crop insurance, others such as women’s contributions to agriculture, previous farm income and landownership are significant drivers that enhance farmers’ WTP. CONCLUSION: It is concluded that the premium that maize farmers in the northern region are willing to pay annually per ha of a maize farm is GHS175.25 (USD). The results of the binary probit model revealed that sex, age, education, insurance awareness, regular payment of insurance premium, land ownership, farming methods, farm risk level, the nature of damage caused by an event, women contribution, income and mean perception index of crop insurance are factors that significantly influence the WTP amount for crop drought-index insurance

Analysis of Erythrocyte Invasion Mechanisms of Plasmodium falciparum Clinical Isolates Across 3 Malaria-Endemic Areas in Ghana.

BACKGROUND: Plasmodium falciparum invades human erythrocytes by using an array of ligands that interact with several receptors, including sialic acid (SA), complement receptor 1 (CR1), and basigin. We hypothesized that in malaria-endemic areas, parasites vary invasion pathways under immune pressure. Therefore, invasion mechanisms of clinical isolates collected from 3 zones of Ghana with different levels of endemicity (from lowest to highest, Accra, Navrongo, and Kintampo) were compared using standardized methods. METHODS: Blood samples were collected from children aged 2-14 years in whom malaria was diagnosed, and erythrocyte invasion phenotypes were determined using the enzymes neuraminidase, chymotrypsin, and trypsin, which differentially cleave receptors from the erythrocyte surface. In addition, antibodies against CR1 and basigin were used to determine the contributions of these receptors to invasion. Gene expression levels of P. falciparum invasion ligands were also examined. RESULTS: The parasites generally expressed SA-independent invasion phenotypes across the malaria-endemic areas, with parasites from Kintampo showing the highest invasion rates in neuraminidase-treated erythrocytes. CR1 was a major mediator of SA-independent invasion, while basigin was essential for both SA-dependent and SA-independent invasion mechanisms. Furthermore, expression of the basigin ligand PfRh5 was the best predictor of donor parasitemia. CONCLUSIONS: Erythrocyte invasion phenotypes expressed by P. falciparum are influenced by endemicity levels, and the PfRh5-basigin pathway is a potential vaccine target

Evaluation of nematode suppression and yield improvement potential of organic substances in sweet potato crop

Objective: To investigate nematode suppression and yield improvement potential of two organic materials; poultry manure and chopped neem leaves in sweet potato production.Methodology and results: A factorial experiment mounted on Randomized Complete Block Design was conducted in 2014 and 2015 at Atebubu and Wenchi, prominent farming communities in the Brong Ahafo region of Ghana. The organic materials were applied on two sweet potato varieties; Apomuden and Santom pona. Poultry manure and neem leaves weighing 100g and 30g respectively were applied per stand. Plant population, nematodes population per 200-cm3 soil at planting and harvest, tuber galls, vine dry matter weight at harvest and yield were analyzed. Significantly, higher (P < 0.05) plant population was recorded at Wenchi compared to Atebubu in 2015. Control plots recorded significantly highest plant parasitic nematodes compared with the poultry manure and neem leaf treatments. Consistently, neem leaf amended plots recorded lowest population levels (67, 68 and 33) % and (84 and 84) % less Meloidogyne spp., P. brachyurus and H. multicintus and Meloidogyne spp., and P. brachyurus were extracted from neem leaf amended Santom pona plots compared with the control of Santom pona at Atebubu and Wenchi respectively. Poultry manure on Santom pona recorded the highest gall index, which was 78.8% more than observed on Santom pona treated with neem leaves. Neem leaf correlated positively with Apomuden and recorded the highest yield in 2014 at Atebubu, which was approximately 93% higher than the control of Santom pona, which yielded 0.9t/ha. The yield of neem leaf on Apomuden was significantly higher (35% and 41%) than neem leaf on Santom pona in 2014 and 2015 at Atebubu and Wenchi respectively.Conclusion and application of findings: Nematode management with synthetic products must be discouraged on grounds of mammalian toxicity and environmental degradation. The use of organic amendments should be encouraged for suppression of nematode population densities, improvement in yield and environmental friendliness. The latter option is sustainable and more importantly, tuber crops produced with organic amendments would be free from chemical residues.Keywords: Neem leaves, nematodes, poultry manure, sweet potato varietie