Impact of positive selection technology on seed yam productivity.

Positive Selection (PS) technique has been shown to reduce virus infection and increase yields, however there is insufficient empirical evidence on how this technology affects seed yam farm productivity. This study employed Propensity Score Matching (PSM) technique to evaluate the impact of PS on seed yam yields of 368 farmers randomly selected from Ghana and Nigeria. The findings showed that educational attainment, distance from the farm to the nearest market, cropping patterns, and other factors influenced farmers' adoption of PS. Furthermore, the adoption of PS technology resulted in a 16.98 % boost in farm productivity for PS seed yam farmers compared to their productivity without the technology. It is of the utmost importance that PS adoption be supported by developing tailored training materials for farmers to improve their use of the PS technology.

Evaluation and phenotypic plasticity of taro [Colocasia esculenta (l.) Schott.] genotypes for nutrient and anti-nutrient composition.

The study was carried out to determine the nutritional and anti-nutritional composition of taro genotypes and also determine the phenotypic plasticity of the genotypes in two agro ecological zones in Ghana. The towns and zones were Bunso in the semi deciduous forest (an upland) and Tano Dumasi in the forest savannah transition agro-ecological (a waterlogged area) zone in the Eastern and Ashanti regions respectively.Two (2) freshly harvested corms of each genotype from each location were assessed for their nutritional (moisture, protein, carbohydrate, ash and fat) and anti-nutritional (phytate, oxalate and tannin) composition Data collected were subjected to analysis of variance and AMMI analysis using GenStat 12 edition to assess the effect of genotype, environment and their interaction on the traits studied. Phenotypic plasticity for the genotypes and the traits studied was also calculated. Pearson correlation was also conducted to assess the relationship between the traits studied. There were significant differences among the genotypes for nutrient and anti-nutrient composition except for percentage fat, indicating enough genetic variability among the genotypes, giving room for good selection progress for development of taro varieties. A higher magnitude of the environment over genotype and genotype by environment interaction observed indicates the influence of environment in the expression of the nutritional and anti-nutritional traits. Observed varied phenotypic plasticity among the genotypes for the nutrient and anti-nutrients composition also indicates varied adaptation of the genotypes to the environment. Genotypes BL/SM/115, CE/MAL/32 and CE/IND/16 and hybrids KAO19 × CE/MAL/32 and CE/IND/16×KAO19, CE/IND/16 × BL/SM/10, and CE/IND/16 × BL/SM/115 which recorded high nutrients and low anti-nutrients content and were stable across the environments can be released to farmers for cultivation. They could also be included in breeding programs for the development of enhanced nutritional quality of taro in Ghana.

Genotype by Phytophthora colocasiae isolate interaction in breeding for resistance to taro [Colocasia esculenta var esculenta (L.) Schott] leaf blight disease in Ghana.

Two experiments were undertaken to evaluate the resistance of 5 parents and 20 hybrids of dasheen taro (n = 25) developed through the diallel method to Phytophthora leaf blight disease which is also known as taro leaf blight disease (TLBD). The field experiment which was laid out in Randomized Complete Block Design with 3 replications assessed the disease incidence (%) and disease severity index (DSI%) among the genotypes planted in three (3) agro-ecological zones in Ghana. In the laboratory the parents and hybrids were inoculated with three (3) Phytophthora colocasiae isolates from Dormaa Ahenekro, Tano Dumasi and Bunso in the Bono, Ashanti and Eastern regions of Ghana respectively and the diameter of lesions formed on the leaves after five days of inoculation were measured. Significant differences (p < 0.05) among the parents and hybrids for resistance to the Phytophthora colocasiae isolates, TLBD incidence (%) and DSI (%) in the field were observed making room for selection for further breeding for resistant varieties of dasheen taro. The isolate effect and genotype by isolate interaction effect were not significant (p > 0.05) indicating the similarity of the isolates' virulence and pathogenicity and therefore any of the isolates identified can be used to screen for resistance to TLBD in Ghana. Hybrids BL/SM/115 × BL/SM/10, BL/SM/115 × CE/MAL/32, CE/MAL/32 × BL/SM/10, CE/MAL/32 × CE/IND/16 and CE/IND/16 × BL/SM/115 and parent CE/IND/16 were observed to have no disease incidence with corresponding zero DSI (%) making them highly resistant and therefore can further be field evaluated and be recommended to farmers for cultivation. The highly significant and positive predictive value for TLBD incidence and DSI (%) based on the lesion area on leaf discs suggests that resistant genotypes of TLBD can be selected at the laboratory without spending long periods of time and money for evaluating genotypes in the field.

Preponderance of vaccine-preventable diseases hotspots in northern Ghana: a spatial and space-time clustering analysis from 2010 to 2014.

BACKGROUND: Vaccine-preventable diseases (VPDs) persist globally with a disproportionately high burden in Low and Middle-Income Countries (LMICs). Although this might be partly due to the failure to sustain vaccination coverage above 90% in some WHO regions, a more nuanced understanding of VPD transmission beyond vaccination coverage may unveil other important factors in VPD transmission and control. This study identified VPDs hotspots and explored their relationships with ecology, urbanicity and land-use variations (Artisanal and Small-scale Gold Mining (ASGM) activities) in Ghana. METHODS: District-level disease count data from 2010 to 2014 from the Ghana Health Service (GHS) and population data from the Ghana Population and Housing Census (PHC) were used to determine clustering patterns of six VPDs (Measles, Meningitis, Mumps, Otitis media, Pneumonia and Tetanus). Spatial and space-time cluster analyses were implemented in SaTScan using the discrete Poisson model. P-values were estimated using a combination of sequential Monte Carlo, standard Monte Carlo, and Gumbel approximations. RESULTS: The study found a preponderance for VPD hotspots in the northern parts of Ghana and northernmost ecological zones (Sudan Savannah and Guinea Savannah). Incidence of meningitis was higher in the Sudan Savannah ecological zone relative to: Tropical Rain Forest (p = 0.001); Semi Deciduous Forest (p < 0.0001); Transitional Zone (p < 0.0001); Coastal Savannah (p < 0.0001) and Guinea Savannah (p = 0.033). Except for mumps, which recorded a higher incidence in urban districts (p = 0.045), incidence of the other five VPDs did not differ across the urban-rural divide. Whereas spatial analysis suggested that some VPD hotspots (tetanus and otitis media) occur more frequently in mining districts in the southern part of the country, a Mann-Whitney U test revealed a higher incidence of meningitis in non-mining districts (p = 0.019). Pneumonia and meningitis recorded the highest (722.8 per 100,000) and least (0.8 per 100,000) incidence rates respectively during the study period. CONCLUSION: This study shows a preponderance of VPD hotspots in the northern parts of Ghana and in semi-arid ecoclimates. The relationship between ASGM activities and VPD transmission in Ghana remains blurred and requires further studies with better spatial resolution to clarify.

Corrigendum: bla CTX-M-1/IncI1-Iγ Plasmids Circulating in Escherichia coli From Norwegian Broiler Production Are Related, but Distinguishable.

[This corrects the article DOI: 10.3389/fmicb.2020.00333.].

Corrigendum: bla CTX-M-1 /IncI1-Iγ Plasmids Circulating in Escherichia coli From Norwegian Broiler Production Are Related, but Distinguishable.

[This corrects the article DOI: 10.3389/fmicb.2020.00333.].

blaCTX-M-1/IncI1-Iγ Plasmids Circulating in Escherichia coli From Norwegian Broiler Production Are Related, but Distinguishable.

Escherichia coli carrying blaCTX-M-1 mediating resistance to extended-spectrum cephalosporins was recently described as a new genotype in Norwegian broiler production. The aim of this study was to characterize these isolates (n = 31) in order to determine whether the emergence of the genotype was caused by clonal expansion or horizontal dissemination of blaCTX-M-1-carrying plasmids. All included isolates were subjected to whole genome sequencing. Plasmid transferability was determined by conjugation, and plasmid replicons in the transconjugants were described using PCR-based replicon typing. Plasmid sizes were determined using S1 nuclease digestion. Plasmids in a subset of strains were reconstructed and compared to plasmids from broiler production in other European countries. The isolates belonged to nine different sequence types (STs), with the largest group being ST57 (n = 12). The vast majority of blaCTX-M-1-carrying plasmids were conjugative. All transconjugants were positive for the IncI1-Iγ replicon, and several also harbored the IncFIB replicon. Highly similar plasmids were present in different E. coli STs. Additionally, high similarity to previously published plasmids was detected. A reconstructed plasmid from an ST57 isolate harbored both IncI1-Iγ and IncFIB replicons and was considered to be co-integrated. The presence of one large plasmid was confirmed by S1 nuclease digestion. Our results show that dissemination of blaCTX-M-1 in Norwegian broiler production is due to both clonal expansion and horizontal transfer of plasmids carrying blaCTX-M-1. The blaCTX-M-1/IncI1-Iγ plasmids grouped into two main lineages, namely clonal complex (CC)-3 and CC-7. The genetic diversity at both strain and plasmid level indicates multiple introductions to Norway. We also show that the blaCTX-M-1 plasmids circulating in Norwegian broiler production are highly similar to plasmids previously described in other countries.

Spatial assessment of sugarcane (Saccharurn spp. L.) production to feed the Komenda Sugar Factory, Ghana.

Ghana imports about US$ 2 million worth of sugar annually. To address this huge import bill and to take advantage of a growing demand for sugar in the West African sub-region, the Government of Ghana initiated a Sugar Policy. The Government of Ghana, therefore, re-constructed and commissioned the Komenda Sugar Factory in 2016 at a reported cost of US$ 35 million. The Komenda Sugar Factory can process 1,250 tons of sugarcane per day (or 225,000 tons per annum), but was shut down soon after the test run and commissioning. This raised considerable public outcry. Among the numerous reasons that were given, it was widely believed that the factory faced feedstock deficits. This study therefore applied satellite remote sensing and Geographic Information Systems to quantify the potential feedstock supply from current production within the immediate catchment of the factory. Supervised classification was applied to Landsat 8 images, using QGIS, to quantify sugarcane production in the study area and at specified buffer distances from the factory. The results showed that the factory could mobilize only 7% of its feedstock requirement within the industrially recommended radius of 40 miles and 13% within the entire catchment area in the 2016/2017 season. Thus, under current scale of production and production conditions, the Komenda Sugar Factory faces large deficits in feedstock supply. National production data suggests that total national sugarcane production in 2016 would only meet 68% of the factory's requirement if it were operational. The results suggest an urgent need to establish a plantation for the factory and to commit out-growers to production to support and sustain the factory if it is to become operational soon. There is also a need for high-yielding, high-brix, and early maturing varieties, coupled with good agronomic practices, to bridge the quantity and (potentially) quality gaps.

Potential of Leguminous Cover Crops in Management of a Mixed Population of Root-knot Nematodes (Meloidogyne spp.).

Root-knot nematode is an important pest in agricultural production worldwide. Crop rotation is the only management strategy in some production systems, especially for resource poor farmers in developing countries. A series of experiments was conducted in the laboratory with several leguminous cover crops to investigate their potential for managing a mixture of root-knot nematodes (Meloidogyne arenaria, M. incognita, M. javanica). The root-knot nematode mixture failed to multiply on Mucuna pruriens and Crotalaria spectabilis but on Dolichos lablab the population increased more than 2- fold when inoculated with 500 and 1,000 nematodes per plant. There was no root-galling on M. pruriens and C. spectabilis but the gall rating was noted on D. lablab. Greater mortality of juvenile root-knot nematodes occurred when exposed to eluants of roots and leaves of leguminous crops than those of tomato; 48.7% of juveniles died after 72 h exposure to root eluant of C. spectabilis. The leaf eluant of D. lablab was toxic to nematodes but the root eluant was not. Thus, different parts of a botanical contain different active ingredients or different concentrations of the same active ingredient. The numbers of root-knot nematode eggs that hatched in root exudates of M. pruriens and C. spectabilis were significantly lower (20% and 26%) than in distilled water, tomato and P. vulgaris root exudates (83%, 72% and 89%) respectively. Tomato lacks nematotoxic compounds found in M. pruriens and C. spectabilis. Three months after inoculating plants with 1,000 root-knot nematode juveniles the populations in pots with M. pruriens, C. spectabilis and C. retusa had been reduced by approximately 79%, 85% and 86% respectively; compared with an increase of 262% nematodes in pots with Phaseolus vulgaris. There was significant reduction of 90% nematodes in fallow pots with no growing plant. The results from this study demonstrate that some leguminous species contain compounds that either kill root-knot nematodes or interfere with hatching and affect their capacity to invade and develop within their roots. M. pruriens, C. spectabilis and C. retusa could be used with effect to decrease a mixed field populations of root-knot nematodes.