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Studies have shown that despite the positive response of maize to nitrogen (N), phosphorus (P), and potassium (K), actual yields in the savanna agroecological zones (AEZs) of northern Ghana remain well below the potential even wit...
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Studies have shown that despite the positive response of maize to nitrogen (N), phosphorus (P), and potassium (K), actual yields in the savanna agroecological zones (AEZs) of northern Ghana remain well below the potential even with N-P-K fertilizer application. In a two-year nutrient omission trial in 12 locations within the Sudan savanna and Guinea savanna AEZs of northern Ghana, we quantified maize yield increases resulting from addition of secondary and micronutrients from the NPK-only fertilization practice for maize production in the two AEZs. In both years, applying only NPK fertilizer resulted in average yields of 3.6 t ha - 1 and 2.5 t ha - 1 in the Guinea savanna and Sudan savanna AEZs, respectively. However, addition of sulfur (S), zinc (Zn), and boron (B) to the NPK fertilizers ("balanced" fertilization) resulted in an average of 60% and 64% yield increases over those of the NPK-only treatment in the Sudan savanna and Guinea savanna AEZs, respectively. Compared to balanced fertilization, omission of S, Zn, and B reduced grain yield by an average of ～34%, ～28%, and ～14%, respectively. The combined data suggest that, even though secondary- and micronutrients are needed in small quantities by plants relative to N, P, and K, they have an enormous effect on crop productivity. Therefore, to ensure sustainably increased maize productivity in the savanna agroecological zones of northern Ghana, fertilizer recommendations should not be restricted to only NPK fertilizers but all limiting secondary- and micronutrients must be accounted for in a holistic and balanced fertilizer recommendation.
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Council for Scientific and Industrial Research - Savanna Agricultural Research Institute (CSIR-SARI) in collaboration with University of California, Riverside phenotyped 300 Recombinant Inbred Lines (RILs) of Multi - parent Advanc...
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Council for Scientific and Industrial Research - Savanna Agricultural Research Institute (CSIR-SARI) in collaboration with University of California, Riverside phenotyped 300 Recombinant Inbred Lines (RILs) of Multi - parent Advanced Generation Inter-Cross (MAGIC) cowpea population from eight elite cowpea cultivars in Northern Ghana. Among the traits targeted in the phenotyping is extra early maturity suitable for Sudan Savanna agro ecological zone of Ghana. Ten selected extra early genotypes from the MAGIC population were intercropped with maize to identify genotype(s) that can maintain agronomic performances and grain yield. A field experiment was carried out at the Manga Station of SARI, Ghana during the 2018 and 2019 growing season to evaluate the ten extra-early cowpea genotypes in maize/cowpea intercrop. The experimental design used was split plot with three replications. The cropping patterns (row, strip and sole cropping) were assigned to the main plot. Ten cowpea genotypes (MAGIC 008, MAGIC 043, MAGIC 048, MAGIC 055, MAGIC 076, MAGIC 118, MAGIC 154, MAGIC 176, CB27, and SARC 1-57-2) were assigned to sub-plots. The results indicated that the number of seed per pod of the cowpea was not affected by cowpea genotype and intercrop pattern interaction; however, the interaction influenced grain yield, pod per plant, plant height, 50% flowering and 100 seed weight of cowpea. MAGIC genotypes, M008, M048, M055, M154, recorded higher grain yield under both strip intercropping and sole cropping. SARC1-57-2 also recorded the highest grain yield under row intercropping. M048, M055, M076, M176 and SARI’s collection SARC1-57-2 were the top five genotypes in fodder production. Intercropping advantage was compared with sole cropping. Land equivalent ratio greater than 1 was observed for all the genotypes with MAGIC 048 recording the highest LER at strip intercrop. Benefit Cost Ratio also showed that there is advantage of intercropping than sole cropping.
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Agricultural intensification has resulted in severe soil nutrient depletion in Africa.? Alternative agricultural practices have been promoted to restore and sustain soil fertility. Use of mineral fertilizer alongside different cro...
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Agricultural intensification has resulted in severe soil nutrient depletion in Africa.? Alternative agricultural practices have been promoted to restore and sustain soil fertility. Use of mineral fertilizer alongside different cropping systems has been particularly promising. This study was conducted in the Guinea savannah zone of Ghana during the 2015 and 2016 cropping season (July to November) to assess the performance of soybean and maize in a rotation system. In season one, using randomized complete block design the treatments were, soybean (without treatment), inoculated soybean, soybean with phosphorus application, inoculated soybean with phosphorus application and maize. During the second season, the first season experimental plots served as main-plots and divided into four sub-plots on which maize planted and treated with four nitrogen rates in a split plot design. The results show that soybean production leads to significant increase in residual soil nitrogen content of about 16kg/ha to 55kg/ha, which is about 28 folds higher than that observed in maize fields. The level of Residual N was enhanced with inoculation. Phosphorus application during the first season of maize cultivation led to increases in residual P levels, which had a positive impact on yield of soybean in the second season. Grain yield of maize that followed soybean in a rotation system performed better than maize that followed maize at various fertilizer rates. This shows that, the residual N and P helps maize and soybean respectively in a rotation system which makes it highly economical.
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Secondary somatic embryos (SSEs) of cocoa, a recalcitrant tropical, seed-producing species, were cryopreserved using a vitrification approach and Differential Scanning Calorimetry (DSC) was employed to optimise sucrose preculture ...
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Secondary somatic embryos (SSEs) of cocoa, a recalcitrant tropical, seed-producing species, were cryopreserved using a vitrification approach and Differential Scanning Calorimetry (DSC) was employed to optimise sucrose preculture and Plant Vitrification Solution 2 (PVS2) incubation. The objective of the study was to evaluate the influence of sucrose preculture and PVS2 dehydration on water content of SSE that will enable it to survive cryostorage. SSEs were precultured for 3 or 5 days on media containing 0.5 M or 0.75 M sucrose and cryoprotected in loading solution (2 M glycerol and 0.4 M sucrose in medium) for 20 min before they were dehydrated with cold PVS2 for 0 - 90 min. Thermal analysis revealed the occurrence of ice crystallization in the SSEs with the extent declining with increasing PVS2 exposure. Maximal survival of SSEs was promoted by preculture on 0.5 M sucrose medium and dehydration with PVS2 for 45 - 60 min, which was characterised by small ice crystallization. Exposure of SSEs beyond 60 min leads to excessive dehydration as characterized by no change in the thermograms. Based on these findings, preculture of SSEs on 0.5 M sucrose medium and dehydration with cold PVS2 for 60 min has been adopted for the successful cryopreservation of cocoa germplasm.
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摘要 :
Secondary somatic embryos (SSEs) of cocoa, a recalcitrant tropical, seed-producing species, were cryopreserved using a vitrification approach and Differential Scanning Calorimetry (DSC) was employed to optimise sucrose preculture ...
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Secondary somatic embryos (SSEs) of cocoa, a recalcitrant tropical, seed-producing species, were cryopreserved using a vitrification approach and Differential Scanning Calorimetry (DSC) was employed to optimise sucrose preculture and Plant Vitrification Solution 2 (PVS2) incubation. The objective of the study was to evaluate the influence of sucrose preculture and PVS2 dehydration on water content of SSE that will enable it to survive cryostorage. SSEs were precultured for 3 or 5 days on media containing 0.5 M or 0.75 M sucrose and cryoprotected in loading solution (2 M glycerol and 0.4 M sucrose in medium) for 20 min before they were dehydrated with cold PVS2 for 0 - 90 min. Thermal analysis revealed the occurrence of ice crystallization in the SSEs with the extent declining with increasing PVS2 exposure. Maximal survival of SSEs was promoted by preculture on 0.5 M sucrose medium and dehydration with PVS2 for 45 - 60 min, which was characterised by small ice crystallization. Exposure of SSEs beyond 60 min leads to excessive dehydration as characterized by no change in the thermograms. Based on these findings, preculture of SSEs on 0.5 M sucrose medium and dehydration with cold PVS2 for 60 min has been adopted for the successful cryopreservation of cocoa germplasm.
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Of the 37 million people estimated to be living with HIV globally in 2017, about 24.7 million were in the sub-Saharan Africa region, which has been and remains worst affected by the epidemic. Enrolment of newly diagnosed individua...
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Of the 37 million people estimated to be living with HIV globally in 2017, about 24.7 million were in the sub-Saharan Africa region, which has been and remains worst affected by the epidemic. Enrolment of newly diagnosed individuals into care in the region, however, remains poor with up to 54% not being linked to care. Linkage to care is a very important step in the HIV cascade as it is the precursor to initiating antiretroviral therapy (ART), retention in care, and viral suppression. A systematic review was conducted to gather information regarding the strategies that have been documented to increase linkage to care of Persons living with HIV(PLHIV) in urban areas of sub-Saharan Africa. An electronic search was conducted on Scopus, Cochrane central, CINAHL Plus, PubMed and OpenGrey for linkage strategies implemented from 2006. A total of 189 potentially relevant citations were identified, of which 7 were eligible for inclusion. The identified strategies were categorized using themes from literature. The most common strategies included: health system interventions (i.e. comprehensive care, task shifting); patient convenience and accessibility (i.e. immediate CD4 count testing, immediate ART initiation, community HIV testing); behavior interventions and peer support (i.e. assisted partner services, care facilitation, mobile phone appointment reminders, health education) and incentives (i.e. non-cash financial incentives and transport reimbursement). Several strategies showed favorable outcomes: comprehensive care, immediate CD4 count testing, immediate ART initiation, and assisted partner services. Assisted partner services, same day home-based ART initiation, combination intervention strategies and point-of-care CD4 testing significantly improved linkage to care in urban settings of sub-Saharan African region. They can be delivered either in a health facility or in the community but should be facilitated by health workers. There is, however, the need to conduct more linkage-specific studies in the sub-region.
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Amaranthus species is an important leafy vegetable in Ghana; however, foliar diseases of the crop reduce the marketable and edible portions as well as income to farmers. To facilitate the development of disease management strategy...
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Amaranthus species is an important leafy vegetable in Ghana; however, foliar diseases of the crop reduce the marketable and edible portions as well as income to farmers. To facilitate the development of disease management strategy, there is the need to document various diseases limiting amaranth production. In view of this, surveys were carried out in forty-three peri-urban vegetable farms in the Kumasi and Tamale Metropolis of Ghana to assess the prevalence and severity of fungal diseases associated with amaranth. Farms were selected using snowball pattern and on each farm, disease incidence and severity were assessed on 45 plants. Disease incidence for any particular fungal disease was calculated as number of plants showing symptoms compared to total number of plants selected whilst disease severity was rated as extent of tissue damage using a severity scale of 1-5. Survey results revealed anthracnose; stems cankers, wilting and wet rot as most prevalent diseases on amaranth. Wilting was the most frequent disease observed; occurring in 95% of farms visited whilst anthracnose, wet rot and stem canker were observed in 91%, 40 and 47% respectively of farms visited. Similarly, wilting disease incidence ranged from 13.3 to 51% across all locations compared to 13.3 to 58.3% for anthracnose, 11.9 to 61.7% for wet rot and 18.3 to 51.7% for stem canker. This work is among few investigations that had been made into diseases affecting the production of Amaranth in Ghana.
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In Ghana, sesame is cultivated in some districts of northern Ghana. Genotypes cultivated are land races that are low yielding leading to decline in production. There is the need for improvement of these land races to generate high...
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In Ghana, sesame is cultivated in some districts of northern Ghana. Genotypes cultivated are land races that are low yielding leading to decline in production. There is the need for improvement of these land races to generate high yielding cultivars. Characterization of genetic diversity of the sesame land races will be of great value in assisting in parental lines selection for sesame breeding programmes in Ghana. Twenty-five sesame land races were collected from five districts in northern Ghana noted for sesame cultivation. Seeds collected were planted in three replicates in randomized complete block design and were evaluated for a number of morphological characters. Data collected were subjected to Principal Component Analysis (PCA) and a dendrogram showing similarity between the accessions were drawn. Data on number of capsules per plant, number of seeds per capsule, and plant height at flowering were subjected to analysis of variance using GenStat Discovery Edition 4. Molecular genetic diversity was assessed by using thirty eight SSR markers widely distributed across sesame genome to characterize the materials. Twenty-one out of the 38 primers were polymorphic. Cluster analyses using the Euclidean similarity test and a complete link clustering method were used to make a dendrogram out of the morphological data. Analysis of variance showed that capsule number was significantly different; a range of 54.9 and 146.7 was produced. The number of seeds per capsule varied significantly and the variation between highest and lowest accession in seed production was 33%. Plant height was also significantly different ranging from 60.6 to 94.1?cm. Using morphological traits the accessions clustered into two major groups and two minor groups and variation among accessions were 10-61%. On the other hand, SSR marker-based dendrogram revealed five major and two minor groups. It showed that variation among the accessions was low, 10-20%. Heterozygosity was 0.52, total alleles produced were 410, and average allele per locus was 19.52. Six accessions, C3, C4, S5, W1, W3, and W5 fell in five different clusters in the SSR dendrogram and in six clusters in the morphomolecular based dendrogram. These accessions were noted for high capsule number per plant and seeds number per capsule and are recommended for consideration as potential parental lines for breeding programme for high yield.
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