Arbuscular mycorrhizal fungi reduce root-knot nematode penetration through altered root exudation of their host

Aims: Arbuscular mycorrhizal fungi (AMF) can control root-knot nematode infection, but the mode of action is still unknown. We investigated the effects of AMF and mycorrhizal root exudates on the initial steps of Meloidogyne incognita infection, namely movement towards and penetration of tomato roots. Methods: M. incognita soil migration and root penetration were evaluated in a twin-chamber set-up consisting of a control and mycorrhizal (Glomus mosseae) plant compartment (Solanum lycopersicum cv. Marmande) connected by a bridge. Penetration into control and mycorrhizal roots was also assessed when non-mycorrhizal or mycorrhizal root exudates were applied and nematode motility in the presence of the root exudates was tested in vitro. Results: M. incognita penetration was significantly reduced in mycorrhizal roots compared to control roots. In the twin-chamber set-up, equal numbers of nematodes moved to both compartments, but the majority accumulated in the soil of the mycorrhizal plant compartment, while for the control plants the majority penetrated the roots. Application of mycorrhizal root exudates further reduced nematode penetration in mycorrhizal plants and temporarily paralyzed nematodes, compared with application of water or non-mycorrhizal root exudates. Conclusions: Nematode penetration was reduced in mycorrhizal tomato roots and mycorrhizal root exudates probably contributed at least partially by affecting nematode motility. © 2011 Springer Science+Business Media B.V.status: publishe

Diversity of Fusarium species associated with healthy and malformed Syzygium cordatum inflorescences in South Africa

Syzygium cordatum (Myrtacease) is one of the most common encountered and widely distributed tree species indigenous to South Africa. This tree is often affected by a malformation disease characterized by grossly misshapen inflorescences that do not bear fruit. Because such symptoms have previously been attributed to Fusarium species in other plants, the aim of this study was to determine the diversity of Fusarium species associated with S. cordatum inflorescences. Healthy and malformed S. cordatum inflorescences were collected from Gauteng, Mpumalanga, Western Cape, and KwaZulu-Natal. A total of 118 Fusarium isolates were obtained from healthy (19) and malformed (99) inflorescences and identified using the translation elongation factor 1 alpha (TEF1α) gene region. The results revealed that 39 isolates belonged to the Fusarium fujikuroi species complex (FFSC), 45 isolates to the Fusarium oxysporum species complex (FOSC), 33 to the Fusarium incarnatum-equiseti species complex (FIESC) and one isolate resided in the Fusarium chlamydosporum species complex (FCSC). Phylogenetic analysis separated these isolates into 15 species, of which five (two in the FFSC, three in the FIESC) are new to science. No obvious patterns were found with respect to species recovered in different geographic areas sampled. However, FFSC species, were all recovered only from malformed inflorescences.The Tree Protection Cooperative Programme (TPCP), the Centre of Excellence in Tree Biotechnology (CTHB), Forestry and Agricultural Biotechnology Institute (FABI) and the University of Pretoria.https://link.springer.com/journal/106582023-01-08hj2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

The impact of the COVID-19 pandemic on help-seeking behaviours of Indigenous and Black women experiencing intimate partner violence in the United States

This article is focused on understanding the impact of the COVID-19 pandemic on populations at highest risk for intimate partner violence in its most severe forms. Data Sources Literature sources range from 2010 to 2022. The article is also informed by the experiences of scholars and advocates working with Indigenous and Black women experiencing intimate partner violence in Wisconsin. In our write-up, we draw on Indigenous feminism and Black feminist thought. Implications for Nursing Help seeking is contextual. The context in which help seeking occurs or does not occur for Indigenous and Black women, due to the barriers we discuss is vital for nurses to understand in order to provide efficient and meaningful nursing care. Conclusion Our goal is to center the nursing profession in a leadership position in addressing the complex and unique needs of Indigenous and Black women who experience the highest rates of intimate partner violence and also experience the greatest barriers to care and support. Impact We seek to contribute theory-driven knowledge that informs the work of nurses who are often the first to encounter survivors of intimate partner violence within the clinical setting. Help-seeking is often hindered by factors such as geographic and jurisdictional, economic, and structural response barriers. This knowledge will enhance nurses\u27 ability to lead and advocate for clinical practice and policies that minimize the barriers women experience following intimate partner violence, especially during pandemics, disasters, and other extraordinary circumstances. Public Contributions This article is based on the collaboration of community advocates, nurse scientists, and public health scholars, who work closely with Indigenous and Black survivors of violence and seek to meet their needs and offer them meaningful support

Functionality and resilience of hand-pumped boreholes in sub-Saharan Africa

In sub-Saharan Africa as many as 184 million people rely on hand-pumps. Thus, hand-pumps are, and will remain, a crucial water source in a changing climate, although as many as one in three are non-functional at any time. Drawing on the results of three studies we demonstrate that hand-pumps are resilient and safe, and we examine the physical factors that determine hand-pump functionality. In the first study we analysed the performance of 5196 water points (hand-pumps, motorized boreholes, springs, open-sources) and the success of a proactive maintenance programme during the 2015-16 drought in Ethiopia. Water sources were visited every week for 12 weeks to gather data on access and functionality. The second study, again in Ethiopia, involved monitoring 51 groundwater points (hand-pumps, springs, hand-dug wells) over an 18-month period in 2016. Water sources were equipped with water level loggers and were tested monthly for thermo-tolerant coliforms. All sources were put under considerable strain during the drought. Most demand was placed on motorised boreholes in lowland areas. However, increases in functionality of motorised boreholes, as a result of the maintenance programme, lagged behind those of hand-pumps. Functionality was low for both sources at the on-set of the drought (65% and 75% respectively). Motorised boreholes had longer downtimes due to a lack of appropriate and/or accessible maintenance skills. Water level monitoring showed that hand-pumped boreholes recovered most quickly from daily abstractions. All sources were contaminated with thermo-tolerant coliforms during the rains marking drought cessation but hand-pumped boreholes were least affected. Our results show that hand-pumped boreholes are resilient and less prone to contamination than springs and hand-dug wells. However, like the other sources we studied, hand-pumps had low levels of functionality at the onset of the drought. To better understand the factors affecting functionality we systematically dismantled 150 hand-pumped boreholes in Ethiopia, Uganda and Malawi in 2017. We conducted detailed inspections of hand-pump components and borehole design. Water levels were measured and a pumping test was conducted to measure aquifer yield (transmissivity). In each country specific contextual factors influence functionality. In Ethiopia deep water levels (>60 m) strongly influence functionality. Many hand-pumps operate beyond lift limits (45 m). Aquifer yield is an order of magnitude larger for fully functional hand-pumps than partially functional hand-pumps in Ethiopia. In Uganda many hand-pumps are installed in aquifers with transmissivities close to the minimum required to sustain a hand-pump (c.1 m2/d). The use of galvanized steel components, along with corrosive groundwater, results in high rates of corrosion in Uganda. In all three countries hydrogeology, borehole design and pump condition interact to determine functionality outcomes. Our results reinforce the importance of appropriate borehole siting and design, on-going operation and maintenance and use of appropriate and good quality materials. When supported by responsive and proactive maintenance hand-pumped boreholes, which are less prone to contamination than other shallow groundwater sources, are a resilient water source in a changing climate and are capable of providing water continuously during drought

Biological control interventions reduce pest abundance and crop damage while maintaining natural enemies in sub-Saharan Africa:a meta-analysis

Insect pests are a major challenge to smallholder crop production in sub-Saharan Africa (SSA), where access to synthetic pesticides, which are linked to environmental and health risks, is often limited. Biological control interventions could offer a sustainable solution, yet an understanding of their effectiveness is lacking. We used a meta-analysis approach to investigate the effectiveness of commonly used biocontrol interventions and botanical pesticides on pest abundance (PA), crop damage (CD), crop yield (Y) and natural enemy abundance (NEA) when compared with controls with no biocontrol and with synthetic pesticides. We also evaluated whether the magnitude of biocontrol effectiveness was affected by type of biocontrol intervention, crop type, pest taxon, farm type and landscape configuration. Overall, from 99 studies on 31 crops, we found that compared to no biocontrol, biocontrol interventions reduced PA by 63%, CD by over 50% and increased Y by over 60%. Compared to synthetic pesticides, biocontrol resulted in comparable PA and Y, while NEA was 43% greater. Our results also highlighted that the potential for biocontrol to be modulated by landscape configuration is a critical knowledge gap in SSA. We show that biocontrol represents an effective tool for smallholder farmers, which can maintain yields without associated negative pesticide effects. Furthermore, the evidence presented here advocates strongly for including biocontrol practices in national and regional agricultural policies

Biological control interventions and botanical pesticides for insect pests of crops in sub-Saharan Africa:A mapping review

Agricultural productivity can be increased sustainably in sub-Saharan Africa (SSA) by reducing crop losses due to insect pest damage. As an alternative to environmentally-damaging chemical pesticides, biological control interventions and botanical pesticides show potential to achieve both high yields and profits. However, synthesized information of their performance and understanding of their adoption among smallholder farmers is limited. Here, 173 studies of biological control interventions and botanical pesticides of insect pests for 35 crops from 20 sub-Saharan countries from 2005 to 2021 were systematically reviewed. Drawing on published datasets, we found that cereals, particularly maize, were the most studied crop (59%). Research on botanical pesticides constituted 32% of the studies, followed by augmentation/introduction biocontrol (29%), and push-pull (21%). Studies evaluating the technical performance of biocontrol interventions dominated (73%), with a regional clustering of push-pull studies in Kenya. Few studies investigated each intervention on each crop type, across different farming contexts and scales, highlighting an urgent need for landscape-scale studies to elucidate land-use impacts on biocontrol effectiveness. Limited evidence also exists on the synergistic effects of biocontrol on multiple ecosystem services and on non-target/beneficial organisms. We found an absence of interdisciplinary studies that addressed the wider indirect benefits of not using chemical pesticides, the social-economic outcomes, and barriers to adoption by farmers, which we argue are necessary to identify pathways to greater adoption and to support policy advocacy of biocontrol interventions in SSA

Biological control interventions and botanical pesticides for insect pests of crops in sub-Saharan Africa: A Mapping Review

Agricultural productivity can be increased sustainably in sub-Saharan Africa (SSA) by reducing crop losses due to insect pest damage. As an alternative to environmentally-damaging chemical pesticides, biological control interventions and botanical pesticides show potential to achieve both high yields and profits. However, synthesized information of their performance and understanding of their adoption among smallholder farmers is limited. Here, 173 studies of biological control interventions and botanical pesticides of insect pests for 35 crops from 20 sub-Saharan countries from 2005 to 2021 were systematically reviewed. Drawing on published datasets, we found that cereals, particularly maize, were the most studied crop (59%). Research on botanical pesticides constituted 32% of the studies, followed by augmentation/introduction biocontrol (29%), and push-pull (21%). Studies evaluating the technical performance of biocontrol interventions dominated (73%), with a regional clustering of push-pull studies in Kenya. Few studies investigated each intervention on each crop type, across different farming contexts and scales, highlighting an urgent need for landscape-scale studies to elucidate land-use impacts on biocontrol effectiveness. Limited evidence also exists on the synergistic effects of biocontrol on multiple ecosystem services and on non-target/beneficial organisms. We found an absence of interdisciplinary studies that addressed the wider indirect benefits of not using chemical pesticides, the social-economic outcomes, and barriers to adoption by farmers, which we argue are necessary to identify pathways to greater adoption and to support policy advocacy of biocontrol interventions in SSA