Perception de la Dégradation des Terres et Adoption des Technologies de Conservation des Eaux et des Sols au Nord du Burkina Faso : le cas du Zaï et des Cordons Pierreux

This study is based on data collected from 141 family-type farms in the Yatenga province in Burkina Faso. A probit approach is used to analyze the effect of perception of land degradation and other factors on the adoption of zaï and stone rows. The results of the estimation show that the availability of organic matter from small ruminants is determinant for the adoption of both zaï and stone rows. Although most of farmers are aware of the causes and consequences of land degradation, this factor does not significantly impact on farmers’ decision to invest in SWC measures. Opportunities do exist for making more efficient use of local sources of nutrients, such as small ruminants’ organic matter in combination with locally accepted SWC measures. This may increase farmers’ willingness to go beyond SWC measures, to invest in nutrient supply in their soils which are characterized by poor fertility. The study shows that combining training on SWC and the development of small-scale animal breeding could contribute to reach this goal in a degraded area.Land degradation, technology adoption, stone rows, Zai, Yatenga, Community/Rural/Urban Development, Consumer/Household Economics, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Labor and Human Capital, Land Economics/Use, Marketing, Research and Development/Tech Change/Emerging Technologies,

Spread of bacterial wilt disease of potato in the highlands of Fouta Djalon, Republic of Guinea

Bacterial wilt in potato (Solanum tuberosum) is caused by Ralstonia solanacearum in the highlands of Fouta Djalon in Guinea. The disease causes 50-70% loss of potato in Guinea. The bacterium is transmitted either by imported tuber seeds or through seed exchanges between the farmers themselves from a contaminated area to bacteria-free areas or through irrigation waters along the fields. This is mainly a consequence of the informal potato seed system that prevails in Guinea. Because of the high price of seeds, farmers use several sources of supply. However, potato is an attractive cash crop in Guinea and the most important economic crop in Fouta Djalon. Most populations in the middle Guinea utilizes potato. The potato farmer's organization in Guinea, FPFD (Fédération des Producteurs du Fouta Djalon), is a model in West African sub-region because of its dynamism and organization with its 500 groups, 25 unions and more than 25,000 members. Training of potato growers in certified seed production techniques remains a major problem in Guinea that needed to be solved. This information is important for developing bacterial wilt disease management strategies through the training of farmers and state support for research

Influence of plant growth regulators on somatic embryogenesis induction from inner teguments of rubber (Hevea brasiliensis) seeds

Generating somatic embryos from the inner teguments of hevea seeds is difficult. Like other ligneous plants, the rubber-tree is generally considered to be recalcitrant with regard to somatic embryogenesis. In this study, the ability of callus from inner integument explants to develop embryogenic callus lines was highlighted. Combination of 2,4-dichlorophenoxyacetic acid (2,4-D/KT) (9 μM/3.375 μM) revealed the positive effect of the 2,4-D on callogenesis and somatic embryogenesis from the inner integument of the seed of immature fruit. The rate of embryogenic calli of about 50% obtained, suggested that 2,4-D has a similar effect as 3,4-dichlorophenoxy acetic acid (3,4-D). So, although 2,4-D is rarely used as a hormone in biotechnology of rubber, its positive influence on callus induction and somatic embryo development shows that it is an alternative to 3,4-D which is commonly used. Optimal combinations of 2,4-D/thidiazuron (TDZ) (9 μM/34.2 nM) produced abnormal embryos at lower rates (approximately 5%) than the optimal combination of 2,4-D/KT.Keywords: Callus, culture medium, Hevea brasiliensis, hormones, rubber-tree, somatic embryogenesisAfrican Journal of Biotechnology Vol. 12(16), pp. 1972-197

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa.

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century