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Water deficit and heat are the primary abiotic stresses affecting plants. We conducted in vitro experiments to investigate how citron watermelon seedlings respond to water deficit and heat, focusing on growth, water status, reserve mobilization, hydrolase activity, and metabolite partitioning, including non-structural carbohydrate availability, during the vulnerable stage of seedling establishment crucial for crop production. To reveal the involvement of phytosterols (stigmasterol, sitosterol, and campesterol) in combined stress tolerance, four citron watermelon genotypes were investigated under varying osmotic potential [−0.05 MPa, −0.09 MPa and −0.19 MPa] and temperature (26 °C and 38 °C). Phytosterols were analyzed by gas chromatography–mass spectrometry (GC–MS). Seedlings subjected to osmotic stress from polyethylene glycol (PEG) exhibited reduced growth, linked to relative water content (RWC) changes, delayed starch mobilization in cotyle-dons, and decreased non-structural carbohydrate availability in roots. High temperature retarded the photosynthetic apparatus's establishment and compromised photosynthetic pigment activity and dry matter production. The results suggest that inherent stress tolerance in citron watermelon is characterized by the increased accumulation of lipids, mainly sterols, especially in heat/drought-stressed plants. This study provides valuable information about the metabolic response of citron watermelon to combined stress and metabolites identified, which will encourage further study in transcriptome and proteomics to improve drought tolerance. [ABSTRACT FROM AUTHOR]

Wetlands are critical ecological infrastructures that improve water quality, serve as habitat for fish and other aquatic life, accumulate floodwaters, and maintain surface water flow during dry periods. However, the health of wetlands has been compromised by anthropogenic activities that affect the constant supply of ecosystem services. This study assessed the impact of anthropogenically modified land use on wetland health in the Witbank Dam Catchment in South Africa, whose land use has been severely modified for agriculture and mining purposes. The study developed a model linking surface runoff generated in the catchment with land use and wetland typology to comprehend diffuse pollution from pollution-source land uses. Runoff data and related wetland spatial information were processed and analysed in a Geographic Information System (GIS) to estimate pollutants (agricultural nutrients and acid mine drainage) from runoff detained and released by wetlands. The analysis facilitated the assessment of the value of wetlands in enhancing water quality, as well as human and environmental health. The runoff volume from pollution-source land uses (urban areas, farmlands, and mining) was used to evaluate annual pollution levels. Wetland types are ranked according to their efficiency levels to filter pollutants. The assumption is that the difference between filtered and unfiltered runoff is the quantity of polluted runoff water discharged into the river system. The analysis has shown that 85% of polluted runoff generated in the catchment ends up in the river system. An important observation is that although wetlands have a substantial ability to absorb excess pollutants, they have finite boundaries. Once they reach their full holding capacity, they can no longer absorb any further pollutants. The excess is discharged into the river system, risking human and environmental health. This explains why the Limpopo River is heavily polluted resulting in the death of fish, crocodiles and other aquatic life. [ABSTRACT FROM AUTHOR]

There is growing interest in promoting neglected and underutilized crop species to enhance agrobiodiversity and contribute to food systems transformation under climate change. A lack of available measured data has hindered the mainstreaming of these crops and limited the ability of agricultural databases to be used for calibrating and validating crop models. This study conducts a systematic scoping review and bibliometric analysis to assess the use of agricultural databases for crop modeling. The Biblioshiny App v4.1.2 and VOSviewer software v1.6.20 were used to analyze 51 peer-reviewed articles from Scopus and Web of Science. Key findings from this review were that agricultural databases have been used for estimating crop yield, assessing soil conditions, and fertilizer management and are invaluable for developing decision support tools. The main challenges include the need for high-quality datasets for developing agricultural databases and more expertise and financial resources to develop and apply crop and machine learning models. From the bibliometric dataset, only one study used modeled data to develop a crop database despite such data having a level of uncertainty. This presents an opportunity for future research to improve models to minimize their uncertainty level and provide reliable data for crop database development. [ABSTRACT FROM AUTHOR]

The reliance on rainfed agriculture exposes southern Africa to low agricultural productivity and food and nutritional insecurity; yet, the region is endowed with vast irrigation potential. Extreme weather events including drought, floods, and heatwaves exacerbate the existing challenges, underscoring the need to improve agricultural water management as a climate change adaptation strategy. This mixed-methods review followed the Search, Appraisal, Synthesis, and Analysis (SALSA) framework to explore the irrigation opportunities and challenges in southern Africa by critically analysing the drivers and constraints of irrigation systems in southern Africa. The premise is to understand the reasons behind the abandonment of some of the areas equipped for irrigation. In cases where irrigation systems are present, the study assesses whether such technologies are effectively being used to generate the expected agricultural productivity gains, and what factors, in cases where that is not the case, constrain farmers from fully using the existing infrastructure. The review further discusses the enabling environment supporting irrigated agriculture and the role of gender in irrigation development. An assessment of the role of women in agriculture on the share of land equipped for irrigation to total cultivated land area, as well as on the proportion of the area equipped for irrigation versus the area that is actually irrigated is conducted. The review found a divergence between countries' land areas equipped for irrigation and actually irrigated areas. Specific to irrigation expansion, the review rebuts the notion that increasing the irrigated area increases crop production and ensures food security. This may not always be true as irrigation development needs to consider the impacts on other closely linked water and energy sectors through transformative approaches like the water–energy–food (WEF) nexus and scenario planning. If well-planned and implemented, sustainable irrigated agriculture could be catalytic to transforming southern Africa's food system to be inclusive, equitable, socially just, and resilient, benefiting people and the planet. [ABSTRACT FROM AUTHOR]

Water, energy, and food are intricately interlinked, as is evident in many developing countries that plan to increase their irrigated area to ensure that their agricultural production meets the food [...]

Food environments are rapidly changing globally, both in developed and developing contexts, contributing to poor dietary habits and environmental concerns. As a result, more than 80% of countries in the world face different forms of malnutrition, while the environment faces further degradation due to unsustainable production and consumption patterns. Understanding food environments in diverse settings via a global lens is critical for facilitating the global transition to sustainable and healthy food environments. A virtual workshop was held with stakeholders from five nations (Germany, Ghana, Malaysia, South Africa, and Tanzania) representing varying levels of development to interrogate global food environment concerns and propose cross cutting thematic areas that may be explored and addressed through policy change and intervention. The workshop initiated a transdisciplinary project to shape food environments for sustainable and healthy diets. The Reference Manual for Convenors of Food Systems Summit Dialogues for United Nations Food Systems Summit (UNFSS) (United Nations, 2020) was used as guidance to ensure that an inclusive mix of stakeholders were invited. The stakeholders included key players from public and private sectors in disciplines of agriculture, agro-forestry, environment and ecology, education, food retail and market, trade and commerce, health care and nutrition. Following the workshop discussion, the findings were analyzed using a general inductive approach. Through triangulation of findings, we identified the common challenges and opportunities for achieving collective nutritional, social and environmental sustainability in the modern food environments, which have become more universal globally. It is evident that research and data are essential for sustainable development of food systems, while Sustainable Development Goal (SDG) 17 - Partnership for the Goals - should be placed at the core of the transformative process. We proposed several research-driven transdisciplinary interventions to facilitate a paradigm shift from the profit logic model over everything else, and to counter the existing policy fragmentation and systemic challenges to making food environments nutrition-sensitive and socially and environmentally sustainable. [ABSTRACT FROM AUTHOR]

The influence of water regimes on plants is crucial for integrating bush tea (Athrixia phylicoides DC.) into strategies in Sub-Saharan Africa to tackle food and nutritional insecurity by considering physiological aspects, nutritional yield, nutritional water productivity, and metabolite composition. The objective of the study was to determine the physiological aspects, including leaf gas exchange and chlorophyll fluorescence, nutritional yield, nutritional water productivity, and metabolite composition of bush tea under varying water regimes. The tunnel experiment was laid out in a randomized complete block design (RCBD) with treatments consisting of three water regimes: 100% of crop water requirement (ETa), 30% of ETa, and a control (no irrigation), all replicated three times. The morphological aspects were recorded on a weekly basis. However, yield, nutrient content, nutritional water productivity (NWP), and phytochemical composition were determined at harvest. The phytochemical analysis by liquid chromatography mass spectrometry (LC-MS), coupled with visualization of the detected chemical spaces through molecular networking, indicated Athrixia phylicoides DC. to be rich in various bioactive compound derivatives, including methyl chlorogenate, flavonoids, tartaric acid, caffeoylquinic acid, and glutinane. The results showed that 30% ETa enhanced plant growth, nutrient content, and nutritional water productivity compared to other water treatments. Nevertheless, 100% ETa yielded more (95.62 kg ha−1) than 30% ETa (60.61 kg ha−1) and control (12.12 kg ha−1). The accumulation of chlorogenic acids was higher under 30% ETa compared to 100% ETa and control. Therefore, this study is the first to determine the accumulation of various bioactive compounds in bush tea leaf extracts under varying water regimes. This confirms that in areas with low water availability, bush tea is well adapted for production without limiting nutrients. [ABSTRACT FROM AUTHOR]

Indigenous crops have been proposed as part of a solution for household food security and sustainable farming systems. However, they have been overlooked and underutilised by households and farmers despite their potential contribution to household food security. The objective of this paper was to determine the association of socio-economic factors and indigenous crops with the household food security of farming households. About 260 farming households were selected using a simple random sampling procedure. The food security status was measured through the use of the Household Food Insecurity Access Scale (HFIAS). The Chi-square test and extended ordered probit regression model assessed the relationship of socio-economic factors and indigenous crops with household food security status. The results from the HFIAS showed that farming households were largely in the mildly and moderately food-insecure categories, with 34.2% and 36.2% of the sampled farmers found in these categories, respectively. The Chi-square test showed a statistically significant relationship between food security status and socio-economic factors. Young men and everyone were perceived to be the ones likely to consume indigenous crops. Consumption of indigenous crops was perceived to be associated with food security. The results also showed that farming experience is likely to positively contribute to the food security status of the farming households. Selling indigenous crops in a formal market is perceived to be associated with food security compared to selling in an informal market. This study concludes that consuming indigenous crops is likely associated with improved food security. Identifying an appropriate market for sales of indigenous crops is imperative. Government, extension officers, and nutritionists must conduct training workshops to encourage households to grow, market and buy indigenous crops. Government and policymakers need to include indigenous crops in the national food and nutrition security policy and create formal markets for indigenous crops. [ABSTRACT FROM AUTHOR]

Early warning systems (EWS) facilitate societies' preparedness and effective response capabilities to climate risks. Climate risks embody hazards, exposure, and vulnerability associated with a particular geographical area. Building an effective EWS requires consideration of the factors above to help people with coping mechanisms. The objective of this paper is to propose an approach that can enhance EWSs and ensure an effective climate risk resilience development. The paper focuses on the Southern African Development Community (SADC) region and highlights the issues with EWS, identifying weaknesses and characteristics of EWS to help in climate risk adaptation strategies. The SADC region was chosen as the context because it is a climate variability and change hotspot with many vulnerable populations residing in rural communities. Trending themes on building climate risk resilience were uncovered through scientific mapping and network analysis of published articles from 2008 to 2022. This paper contributes to on-going research on building climate risks resilience through early warning systems to identify hidden trends and emerging technologies from articles in order to enhance the operationalization and design of EWS. This review provides insight into technological interventions for assessing climate risks to build preparedness and resilience. From the review analysis, it is determined that there exists a plethora of evidence to support the argument that involving communities in the co-designing of EWS would improve risk knowledge, anticipation, and preparedness. Additionally, Fourth Industrial Revolution (4IR) technologies provide effective tools to address existing EWS' weaknesses, such as lack of real-time data collection and automation. However, 4IR technology is still at a nascent stage in EWS applications in Africa. Furthermore, policy across societies, institutions, and technology industries ought to be coordinated and integrated to develop a strategy toward implementing climate resilient-based EWS to facilitate the operations of disaster risk managers. The Social, Institutional, and Technology model can potentially increase communities' resilience; therefore, it is recommended to develop EWS. [ABSTRACT FROM AUTHOR]

Irrigation is widely considered a potential means to improve agricultural productivity, nutrition, and income, as farmers can carry out farming and production year-round. However, the feasibility of irrigation technologies is highly dependent on the long-term economic return farmers achieve. Solar-based irrigation could address the challenges of underinvestment in irrigation within Africa. Evidence on the economic viability of the adopted solar pumps such as MajiPump is very scant and focused on ex post evaluation. This study evaluated the income and nutritional feasibility of solar-powered irrigation using the MajiPump in sub-humid Ethiopian highlands using the farm simulation (FARMSIM) model and compared it with the manual pulley system. Results from the FARMSIM model show that farmers' adoption of Maji solar pump technology to grow vegetables is economically feasible with financial support such as credit or loan for initial and capital investment to acquire the pump. The average profit under the solar MajiPump, drip irrigation, and conservation agriculture was 3.6 times higher than that of the baseline scenario. While the pulley technology provides the same amount of irrigation water to grow vegetables, its feasibility is limited due to high labor costs and time, estimated to be more than seven times the baseline. The simulation results show that the alternative scenarios' nutrition level has improved relative to other scenarios and met the minimum daily average nutrition requirement level for proteins, iron, and vitamin A but fell short in fat, calcium, and calories. The results suggest that farmers who adopt improved small-scale irrigation technologies (solar MajiPump and drip system) have a higher potential to increase production and income from irrigated crops and improve their nutrition if part of the income generated is used to purchase supplemental food for their nutrition. [ABSTRACT FROM AUTHOR]