Impact of adoption of drought-tolerant maize varieties on total maize production in south Eastern Zimbabwe

More bang for your buck: potential gains through optimizing maize breeding schemes in sub-Saharan Africa

Increasing the rate of genetic gain in breeding programs is a critical component of crop genetic improvement strategies to increase yields in smallholder farmers' fields. While a growing array of technologies and tools are being deployed within breeding programs, optimizing resource allocation could provide a simple yet effective way to increase genetic gain, particularly within resource-constrained breeding programs. The objective of this study was to demonstrate that an easy-to-use deterministic model and a breeding costing tool could identify key modifications to improve the efficiency of breeding within the Zimbabwean national maize breeding program. The current program uses pedigree inbreeding, with a 4-1-1 tester scheme, and relatively low selection intensity. The method of inbreeding, test-crossing schemes, and selection intensity were modified within the current program budget. A combination of using doubled haploid lines, a 2-2-1 tester plan, and increased selection intensity improved gain per cycle by 42.8%, gain per year by 161.8%, gain per dollar by 43.1%, and decreased cost of one unit of genetic gain by 28.5% without a change in budget. Our results highlight how a simple deterministic model can identify steps to greatly improve breeding efficiency within resource-constrained breeding programs.

Effects of coupled application of magnetoelectric activated water and amendments on photosynthetic physiological characteristics and yield of maize in arid regions

Seeking effective improvement agent control measures to enhance the photosynthetic physiological traits and yield levels of spring maize is crucial for efficient green agriculture in arid regions. Therefore, this study was conducted to clarify the effects of coupling improvement agents under magnetoelectric activated water irrigation conditions on the photosynthetic physiological traits, grain nutrients, and yield of spring maize in the arid region of northwest China. Field experiments were set up with three concentrations of growth regulators: 400 times (G1), 500 times (G2), and 600 times (G3), and three amounts of Bacillus subtilis: 15 kg/ha (R1), 45 kg/ha (R2), and 75 kg/ha (R3), along with a control group CK, making a total of 10 treatments applied in the field experiment. The results indicate that under magnetoelectric activated water irrigation, coupling improvement agents significantly enhance the photosynthetic traits, grain nutrients, and yield of spring maize in arid areas. With the coupling of improvement agents, the rectangular hyperbola correction model showed a good fit for the light response curve (R2 >0.992). Pnmax was significantly increased (7.37%~37.46%) and was highly correlated with yield (P<0.01). The entropy-weight TOPSIS comprehensive evaluation analysis found that the G2R2 treatment is the optimal improvement agent coupling measure for efficient production of spring maize in arid regions. This treatment yielded 12.68 t/ha and increased 100-kernel weight, grains per spike, and soluble sugar content by 21.3%, 8.22%, and 63.81%, respectively, representing the best balance of quality and high yield. The results of this study provide theoretical references and technical support for the high-quality and efficient production of spring maize in China's arid regions.

Chitosan-fulvic acid nanoparticles enhance drought tolerance in maize via antioxidant defense and transcriptional reprogramming

Nanoparticles are promising alternatives to synthetic fertilizers in the context of climate change and sustainable agriculture. Maize plants were grown under gradient concentrations (50 μM, 100 μM, 200 μM, 500 μM, and 1 mM) of chitosan (Ch), fulvic acid (FA) or chitosan-fulvic acid nanoparticles (Ch-FANPs). Based on the overall phenotypic assessment, 100 μM was selected for downstream experiments. Maize plants grown under this optimized concentration were thereafter subjected to drought stress by water withholding for 14 days. Compared to the individual performances, the combined treatment of Ch-FANPs supported the best plant growth over chitosan, fulvic acid, or sole watered plants and alleviated the adverse effects of drought by enhancing root and shoot growth, and biomass by an average 20%. In addition, Ch-FANPs-treated plants exhibited a significant reduction in hydrogen peroxide (H2O2) content (~10%), with a concomitant increase in ascorbate peroxidase (APX) activity (>100%) while showing a reduced lipid peroxidation level observed by the decrease in malondialdehyde (MDA) content (~100%) and low electrolyte leakage level. Furthermore, chlorophyll content increased significantly (>100%) in maize plants treated with Ch-FANPs compared to Ch or FA and control in response to drought. The expression of drought-induced transcription factors, ZmDREB1A, ZmbZIP1, and ZmNAC28, and the ABA-dependent ZmCIPK3 was upregulated by Ch-FANPs. Owing to the above, Ch-FANPs are proposed as a growth-promoting agent and elicitor of drought tolerance in maize via activation of antioxidant machinery and transcriptional reprogramming of drought-related genes.

Correlating grain yield with irrigation in a spatio-temporal context on the North China Plain

Irrigation plays a crucial role in enhancing agricultural productivity. The spatiotemporal variability and correlation between historical irrigation and grain yield not only illuminate existing challenges in irrigation, but also offer valuable insights for formulating effective irrigation strategies, which have been previously overlooked. Taking the North China Plain (NCP) as a case study, this study aims to elucidate regional divergence patterns and the dynamic evolution of the spatiotemporal relationship between grain yield and irrigation through time series analysis, GIS spatial analysis, and geographically weighted regression (GWR). The findings reveal that grain yields are higher in the northern regions of NCP compared to the southern regions, with significant variations among prefecture-level cities; maize yields slightly surpass wheat yields. Moreover, there has been a noticeable decrease in irrigation across approximately 49 % of the areas since 2004. Spatial autocorrelation analysis indicates clear spatial aggregation for both grains yields and irrigation. The coupled correlation between wheat yield and effective irrigation has shown a slight increase from 1990 to 2015, while that of maize has significantly decreased. The positive impact of irrigation on grain yield has nearly vanished since 2002. It is recommended to implement sprinkler irrigation in low-yield, low-irrigation areas in the south; deficit irrigation and water-saving technologies may benefit regions with medium yield and negative correlation with irrigation in central parts; maintaining current irrigation strategies is suggested for high-yield and high-irrigation regions. Additionally, relying solely on irrigation to boost yields is unsustainable; it is critical to adopt a combination of agricultural management practices along with planting high water-utilization efficient crop varieties. This study underscores the significance of developing rational irrigational strategies based on a comprehensive understanding of the intricate relationship between irrigation and grain yields-ensuring food security while sustaining agricultural water utilization.

Unveiling Drought-Resilient Latin American Popcorn Lines through Agronomic and Physiological Evaluation

Water stress can lead to physiological and morphological damage, affecting the growth and development of popcorn. The objective of this study was to identify the yield potential of 43 popcorn lines derived from a Latin American germplasm collection, based on agronomic and physiological traits, under full irrigation (WW) and water deficit conditions (WS), aiming to select superior germplasm. The evaluated agronomic traits included the ear length and diameter, number of grains per row (NGR) and rows per ear (NRE), grain yield (GY), popping expansion (EC), volume of expanded popcorn per hectare (VP), grain length (GL), width, and thickness. The physiological traits included the chlorophyll, anthocyanin, and flavonoid content in the leaves. The genetic variability and distinct behavior among the lines for all the agronomic traits under WW and WS conditions were observed. When comparing the water conditions, line L292 had the highest mean for the GY, and line L688 had the highest mean for the EC, highlighting them as the most drought-tolerant lines. A water deficit reduced the leaf greenness but increased the anthocyanin content as an adaptive response. The GY trait showed positive correlations with the VP, NGR, and GL under both water conditions, making the latter useful for indirect selection and thus of great interest for plant breeding targeting the simultaneous improvement of these traits.

The Importance of Philanthropy Foundation for the Future Sustainability of Agriculture and Nutrition: An Opinion Study on Practical Applications, Policies, and Strategies

Food security, food sustainability, and malnutrition represent critical global challenges. Th urgency of comprehensive action is evident in the need for research collaboration between the food industry, agriculture, public health, and nutrition. This article highlights the role of philanthropy, of a non-profit organization, in supporting research and development and filling financial gaps. The article also explores the interplay of nutrition, agriculture, and government and policy, positioning philanthropy as a catalyst for transformative change and advocating for collaborative efforts to comprehensively address global food challenges. In addition, the discussion also underscores the ethical complexities surrounding charitable food aid, especially in terms of the dignity and autonomy of its recipients. The paper concludes by proposing future directions and implications, advocating for diversified intervention portfolios and collaborative efforts involving governments, businesses, and local communities. Apart from that, the importance of answering and alleviating ethical dilemmas related to food charity assistance needs to be a concern for future studies related to philanthropy because of the significant challenges faced by the contemporary food system, which include food security, health, and nutritional sustainability.

Genetic gains in early maturing maize hybrids developed by the International Maize and Wheat Improvement Center in Southern Africa during 2000-2018

Genetic gain estimation in a breeding program provides an opportunity to monitor breeding efficiency and genetic progress over a specific period. The present study was conducted to (i) assess the genetic gains in grain yield of the early maturing maize hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) Southern African breeding program during the period 2000-2018 and (ii) identify key agronomic traits contributing to the yield gains under various management conditions. Seventy-two early maturing hybrids developed by CIMMYT and three commercial checks were assessed under stress and non-stress conditions across 68 environments in seven eastern and southern African countries through the regional on-station trials. Genetic gain was estimated as the slope of the regression of grain yield and other traits against the year of first testing of the hybrid in the regional trial. The results showed highly significant (p< 0.01) annual grain yield gains of 118, 63, 46, and 61 kg ha-1 year-1 under optimum, low N, managed drought, and random stress conditions, respectively. The gains in grain yield realized in this study under both stress and non-stress conditions were associated with improvements in certain agronomic traits and resistance to major maize diseases. The findings of this study clearly demonstrate the significant progress made in developing productive and multiple stress-tolerant maize hybrids together with other desirable agronomic attributes in CIMMYT's hybrid breeding program.

Impact of adoption of heat-stress tolerant maize hybrid on yield and profitability: Evidence from Terai region of Nepal

Abiotic stresses (drought, heat) are one of the major impediments to enhancing the maize productivity of marginal farmers in the facet of climate change. The present study attempts to investigate the impact of heat-tolerant maize hybrid on yield and income in the Terai region of Nepal. This study uses cross-sectional farm household-level data collected in August 2021 from a randomly selected sample of 404 rural households. We used a doubly robust inverse probability weighted regression adjustment method to obtain reliable impact estimates. Adoption of heat-tolerant hybrid increases yields by 16% and income by 44% in the spring season (a stress condition). Overall, yield increases by 12%, net income by 31%, saving of 40% in seed costs, and per capita food expenditure increases by 8.50%. Hence a conducive environment must be created for scaling up heat-tolerant maize varieties to increase productivity, minimize risk, and transform of the maize sector.

Impact of CGIAR maize germplasm in Sub-Saharan Africa

This study reports on the adoption and impacts of CGIAR-related maize varieties in 18 major maize-producing countries in sub-Saharan Africa (SSA) during 1995-2015. Of the 1345 maize varieties released during this timeframe, approximately 60% had a known CGIAR parentage. About 34% (9.5 million ha) of the total maize area in 2015 was cultivated with 'new' CGIAR-related maize varieties released between 1995 and 2015. In the same year, an additional 13% of the maize area was cultivated with 'old' CGIAR-related maize varieties released before 1995. The aggregate annual economic benefit of using new CGIAR-related maize germplasm for yield increase in SSA was estimated at US$1.1-1.6 billion in 2015, which we attributed equally to co-investments by CGIAR funders, public-sector national research and extension programs, and private sector partners. Given that the annual global investment in CGIAR maize breeding at its maximum was US$30 million, the benefit-cost ratios for the CGIAR investment and CGIAR-attributable portion of economic benefits varied from 12:1-17:1, under the assumption of a 5-year lag in the research investment to yield returns. The study also discusses the methodological challenges involved in large-scale impact assessments. Post-2015 CGIAR tropical maize breeding efforts have had a strong emphasis on stress tolerance.

Effectiveness of vegetation indices and UAV-multispectral imageries in assessing the response of hybrid maize (Zea mays L.) to water deficit stress under field environment

Unmanned aerial vehicles (UAVs) equipped with multi-sensors are one of the most innovative technologies for measuring plant health and predicting final yield in field conditions, especially in the water deficit situation in rain-deprived regions. The objective of this investigation was to evaluate the individual plant and canopy-level measurements using UAV imageries in three different genotypes, Suwan4452 (drought-tolerant), Pac339, and S7328 (drought-sensitive) of maize (Zea mays L.) at vegetative and reproductive stages under WW (well-watered) and WD (water deficit) conditions. At the vegetative stage, only CWSI (crop water stress index) of Pac339 and S7328 under WD increased significantly by 1.86- and 1.69-fold over WW, whereas the vegetation indices (EVI2 (Enhanced Vegetation Index 2), OSAVI (Optimized Soil-Adjusted Vegetation Index), GNDVI (Green Normalized Difference Vegetation Index), NDRE (Normalized Difference Red Edge Index), and NDVI (Normalized Difference Vegetation Index)) derived from UAV multi-sensors did not vary. At the reproductive stage, CWSI in drought-sensitive genotype (S7328) under WD increased by 1.92-fold over WW. All the vegetation indices (EVI2, OSAVI, GNDVI, NDRE, and NDVI) of Pac339 and S7328 under WD decreased when compared with those of Suwan4452. NDVI derived from GreenSeeker^® handheld and NDVI from UAV data was closely related (R² = 0.5924). An increase in leaf temperature (T_leaf) and reduction in NDVI of WD stressed maize plants was observed (R² = 0.5829) leading to yield loss (R² = 0.5198). In summary, a close correlation was observed between the physiological data of individual plants and vegetation indices of canopy level (collected using a UAV platform) in drought-sensitive genotypes of maize crops under WD conditions, thus indicating its effectiveness in the classification of drought-tolerant genotypes.

Improving drought tolerance in maize: Tools and techniques

Drought is an important constraint to agricultural productivity worldwide and is expected to worsen with climate change. To assist farmers, especially in sub-Saharan Africa (SSA), to adapt to climate change, continuous generation of stress-tolerant and farmer-preferred crop varieties, and their adoption by farmers, is critical to curb food insecurity. Maize is the most widely grown staple crop in SSA and plays a significant role in food security. The aim of this review is to present an overview of a broad range of tools and techniques used to improve drought tolerance in maize. We also present a summary of progress in breeding for maize drought tolerance, while incorporating research findings from disciplines such as physiology, molecular biology, and systems modeling. The review is expected to complement existing knowledge about breeding maize for climate resilience. Collaborative maize drought tolerance breeding projects in SSA emphasize the value of public-private partnerships in increasing access to genomic techniques and useful transgenes. To sustain the impact of maize drought tolerance projects in SSA, there must be complementary efforts to train the next generation of plant breeders and crop scientists.

Physio-morphological traits and osmoregulation strategies of hybrid maize (Zea mays) at the seedling stage in response to water-deficit stress

Drought has been identified as a major factor restricting maize productivity worldwide, especially in the rainfed areas. The objective of the present study was to investigate the physiological adaptation strategies and sugar-related gene expression levels in three maize (Zea mays L.) genotypes with different drought tolerance abilities (Suwan4452, drought tolerant as a positive check; S7328, drought susceptible as a negative check; Pac339, drought susceptible) at the seedling stage. Ten-day old seedlings of maize genotypes were subjected to (i) well-watered (WW) or control and (ii) water-deficit (WD) conditions. Leaf osmotic potential of cv. S7328 under WD was significantly decreased by 1.35-1.45 folds compared with cv. Pac339 under WW, whereas it was retained in cv. Suwan4452, which utilized total soluble sugars as the major osmolytes for maintaining leaf greenness, F_v/F_m, Φ_PSII, and stomatal function (P_n, net photosynthetic rate; g_s, stomatal conductance; and E, transpiration rate). Interestingly, sucrose degradation (65% over the control) in cv. Pac339 under WD was evident in relation to the downregulation of the ZmSPS1 level, whereas glucose enrichment (1.65 folds over the control) was observed in relation to the upregulation of ZmSPS1 and ZmSUS1. Moreover, CWSI (crop water stress index), calculated from leaf temperature of stressed plants, was negatively correlated with E, g_s, and P_n. Overall, growth characteristics, aboveground and belowground parts, in the drought-susceptible cv. Pac339 and cv. S7328, were significantly decreased (> 25% over the control), whereas these parameters in the drought-tolerant cv. Suwan4452 were unaffected. The study validates the use of leaf temperature, CWSI, P_n, g_s, and E as sensitive parameters and overall growth characters as effective indices for drought tolerance screening in maize genotypes at the seedling stage. However, further experiments are required to validate the results observed in this study under field conditions.

Welfare impact of climate change on capture fisheries in Vietnam

Fisheries are forecasted to shrink in the tropics due to climate change. In Vietnam, fisheries are a pro-poor economic sector and essential nutrition source; however, welfares of producers and consumers in the climate change context are not well understood. While most studies focus on the gains or losses of total products and revenues, this paper pays additional attention to the changes in surpluses of market players in the long run. A combination of the production function, demand and supply functions, and partial equilibrium analysis is employed to measure the production and welfare impacts based on time series data from 1976 to 2018 and a Vietnam household living standards survey in 2018. The results show that relative to the present, catch yield is likely to reduce 35%-45% by mid-century and 45%-80% by the end of the century. Consumers may lose their surplus of 7-9 billion USD (PPP, 2018) by 2035 and 10-18 billion USD by 2065 due to supply reduction, while producers may gain additional profit of 3.5-4.5 billion USD by 2035 and 5-9 billion USD by 2065 owing to a price increase. The research findings suggest that Vietnam could impose measures to limit capture effort, as set out in the Law of Fisheries 2017, without harming fisher welfare. The expansion of aquaculture could reduce the gap between supply and demand of wild fish to mitigate consumer welfare loss; however, this impact is still ambiguous.

Variation in Maize Grain Yield Indices When Exposed to Combined Heat and Water Stress Conditions under Different Soil Amendments

Increased yield can be achieved by optimising the growth environment, improving the plant gene pool, or a combination of the two. This study’s objective was to evaluate the effect of combined heat and water stress (CHWS) on maize yield, grown in various soil conditions. The experimental design was a four-replicated 3 × 3 × 2 × 3 factorial in a completely randomized design. Three water stress levels, three soil amendments, two soil textural types, and three drought-tolerant maize varieties were combined to create 54 treatment interactions. The result showed that as the severity of the water stress increased, the yield decreased. The near terminal water stress reduced cob weight, grain weight, and grain number by 96, 97, and 97%, respectively. The maize varieties were ranked WE5323 ≥ ZM1523 > WE3128 in terms of average performance and stability. Under heat and moderate water stress, the poultry manure amendment performed well for WE5323 and ZM1523, while the mineral fertilizer amendment performed best for WE3128. Compared to the inorganic amendment, the organic had a greater ameliorative capacity for grain yield under CHWS. For improved grain yield under CHWS, farmers are advised to grow WE5323 and ZM1523 with organic amendments. The findings in this study could improve food security strategies for low-income households living in high-stress environments.

Does the Adoption of Climate-Smart Agricultural Practices Impact Farmers' Income? Evidence from Ghana

People's lives, particularly farmers', have been affected by extreme weather conditions that have reduced the yield of numerous crops due to climate change. Climate-smart agriculture practices can reduce or eliminate greenhouse gas emissions and have the propensity to increase farm income and productivity. Therefore, the purpose of this study is to ascertain whether CSA practices impact farmers' income. This study includes all cocoa farmers in the selected districts in the Ashanti Region. The population includes those who live in the six cocoa production villages. The multistage sampling procedure was considered based on the dominants of literature. The study used an endogenous switching regression framework to examine the effects of the adoption of climate-smart agricultural practices (CSAPs) on farmers' income. While estimating treatment effects, telasso uses lasso techniques to select the appropriate variable sets. The results revealed that gender, farm experience, age, household size, and farm size do not significantly influence the adoption of irrigation and crop insurance. The study revealed a significant positive impact of access to credit on adopting irrigation and crop insurance. The adoption of climate-smart practices has a positive coefficient. This indicates that if all respondents in each region adopts these practices, their income would increase significantly. This study shows that adopting irrigation practices leads to an increase in household income of 8.6% and 11.1%, respectively, for cocoa farmers. Crop insurance has a positive coefficient and is statistically significant on household income, on-farm, and off-farm. This paper shows that climate-smart practices such as crop insurance can positively influence farmers' income in Ghana. We also conjecture that crop insurance is the most effective and efficient climate-smart practice among the various agricultural practices. The study suggests that access to credit and mass awareness should be compulsory modules coupled with the consistent training of farmers on new technologies for effective policy implementation. Expanding access to extension officers could enhance farmers' adaptive capacity and warrant the efficiency of implemented practices.

Maize varietal replacement in Eastern and Southern Africa: Bottlenecks, drivers and strategies for improvement

Seed security is vital for food security. Rapid-cycle, climate-adaptive breeding programs and seed systems that deliver new, elite varieties to farmers to replace obsolete ones can greatly improve the productivity of maize-based cropping systems in sub-Saharan Africa (SSA). Despite the importance and benefits of accelerated varietal turnover to climate change adaptation and food security, the rate of maize varietal replacement in SSA is slow. This review outlines the major bottlenecks, drivers, risks, and benefits of active replacement of maize varieties in eastern and southern Africa (ESA) and highlights strategies that are critical to varietal turnover. Although there is an upsurge of new seed companies in ESA and introduction of new varieties with better genetics in the market, some established seed companies continue to sell old (over 15-year-old) varieties. Several recently developed maize hybrids in ESA have shown significant genetic gains under farmers' conditions. Empirical evidence also shows that timely replacement of old products results in better business success as it helps seed companies maintain or improve market share and brand relevance. Therefore, proactive management of product life cycles by seed companies benefits both the farmers and businesses alike, contributing to improved food security and adaptation to the changing climate.

The Role and Perspective of Climate Smart Agriculture in Africa: A Scientific Review

Climate-smart agriculture (CSA) is gaining a wide acceptance as a laudable approach that can assist farmers to maximize the potential of the farming systems in Africa. A number of practices have been identified as CSA practices, and successful outcomes of CSA technologies are being reported. However, CSA uptake among African farmers remains low despite its proven potential. The aim of this paper is to analyse the state of CSA in Africa and identify the constraints to the uptake of the practices among smallholder farmers. This paper synthesizes a subset of literature between 2010 and 2020. The key findings are that the response to climate change and the pattern and extent of adoption of CSAs differs from one macro-area to another. Factors such as resource constraints, institutional instruments, climate and ecological settings, and farmers’ characteristics, such as farmers’ experience and access to extension services, are significant determinants of CSA adoption. Socioeconomic constraints, poor availability of data and mastery of CSA approach, inadequate labour, and the wide diversity of the farming systems in Africa are challenges militating CSA uptake in the system This paper argues that it is crucial to ensure that limited resources available are systematically harnessed to achieve the triple-win benefits of CSA. Furthermore, there is the need to identify and prioritize locally suitable CSA practices and provide an enabling environment needed for CSA uptake and sustenance in the African farming systems.

Genome-Wide Association Study Reveals Genetic Architecture and Candidate Genes for Yield and Related Traits under Terminal Drought, Combined Heat and Drought in Tropical Maize Germplasm

Maize (Zea mays L.) production is constrained by drought and heat stresses. The combination of these two stresses is likely to be more detrimental. To breed for maize cultivars tolerant of these stresses, 162 tropical maize inbred lines were evaluated under combined heat and drought (CHD) and terminal drought (TD) conditions. The mixed linear model was employed for the genome-wide association study using 7834 SNP markers and several phenotypic data including, days to 50% anthesis (AD) and silking (SD), husk cover (HUSKC), and grain yield (GY). In total, 66, 27, and 24 SNPs were associated with the traits evaluated under CHD, TD, and their combined effects, respectively. Of these, four single nucleotide polymorphism (SNP) markers (SNP_161703060 on Chr01, SNP_196800695 on Chr02, SNP_195454836 on Chr05, and SNP_51772182 on Chr07) had pleiotropic effects on both AD and SD under CHD conditions. Four SNPs (SNP_138825271 (Chr03), SNP_244895453 (Chr04), SNP_168561609 (Chr05), and SNP_62970998 (Chr06)) were associated with AD, SD, and HUSKC under TD. Twelve candidate genes containing phytohormone cis-acting regulating elements were implicated in the regulation of plant responses to multiple stress conditions including heat and drought. The SNPs and candidate genes identified in the study will provide invaluable information for breeding climate smart maize varieties under tropical conditions following validation of the SNP markers.

Climate change adaptation strategies and production efficiency: The case of citrus farmers in the Limpopo province, South Africa

Climate change adaptation policies and strategies have inevitably become an integral component of agricultural production on a global scale. The evaluative extent to which these adaptation techniques have influenced agricultural productivity is inherently exiguous. Citrus production in tropical regions such as South Africa, is more vulnerable to climate change as the region already experience hot and dry climate, hence the need to implement different strategies for climate change adaption in these regions. This study was designed to assess the effect of adopting the following climate change adaptation measures: planting drought resistant varieties, rainwater harvesting, planting early maturing varieties, integrated pest management (IPM) , changing fertiliser type, and applying drip irrigation to manage climate challenges on the production efficiency of citrus farmers in the Limpopo province of South Africa. The stochastic frontier production function with Cobb Douglas production functional form was used to analyse the productivity of farmers’ vis-à-vis adopted climate change strategies. A survey was conducted and data were collected through a semi-structured questionnaire administered to respondents from 235 production units in the five district municipalities of Limpopo. The likelihood ratio tests for profit models showed that farmers were profit efficient considering the identified adaptation strategies. The variables that influenced profit efficiency was price of fertiliser (p < 0.010) and water cost (p < 0.010). The inefficiency model showed that besides changing fertiliser as an adaptation measure, the other adaptation strategies including IPM, water harvesting and planting drought resistant varieties did not change the profit efficiency of farmers. Therefore, the results indicate that citrus farmers can still adapt to climate change and remain profit efficient.

Non-attitudinal and non-knowledge based factors constrain households from translating good nutritional knowledge and attitude to achieve the WHO recommended minimum intake level for fruits and vegetables in a developing country setting: evidence from Gulu district, Uganda

BACKGROUND

The high level of incidence of mortality attributed to non-communicable diseases such as cancer, diabetes and hypertension being experienced in developing countries requires concerted effort on investment in strategies that can reduce the risks of development of such diseases. Fruits and vegetables (FV) contain natural bioactive compounds, and if consumed at or above 400 g per day (RDMIL) as recommended by World Health Organization (WHO) is believed to contribute to reduced risk of development of such diseases. The objective of this study was to determine in a developing country set-up, the extent to which rural and urban households conform to RDMIL, the status of nutritional attitude (NA) and knowledge (NK) associated with consumption of FV, and to delineate non-attitudinal and non-knowledge-based factors (NANK) that hinder achievement of RDMIL.

METHOD

A cross-sectional survey of 400 randomly selected households and 16 focus group discussions (FGD) were conducted using Gulu district of Uganda as a microcosm for a developing country setting. Level of consumption of FV was assessed using 24-h dietary recall and compared to RDMIL as a fraction (%). The status of NK and NA were determined using sets of closed-ended questions anchored on a three-point Likert scale. Further quantitative statistical analyses were conducted using t-test, chi-square, Pearson's correlation and multiple linear regression. FGD provided data on NANK factors and were analysed using qualitative content analysis procedure.

RESULTS

Urban and rural inhabitants met up to 72.0 and 62.4% of the RMDIL, respectively, with absolute intake being higher among urban than rural households by 37.54 g. NK and NA were good but the intensity of NK was higher among urban respondents by 11%. RDMIL was positively correlated with NA while socio-demographic predictors of RDMIL varied with household location. FGD revealed that primary agricultural production constraints, market limitations, postharvest management limitations, health concerns, social discomfort and environmental policy restrictions were the major NANK factors that hindered achievement of the RDMIL.

CONCLUSIONS

These results indicate that NANK factors constrain households from translating good NA and NK to achieve the RMDIL.

Climate-resilient strategies for sustainable management of water resources and agriculture

Warming of the earth is considered as the major adverse effect of climate change along with other abnormalities such as non-availability of water resources, decreased agriculture production, food security, rise in seawater level, glaciers melting, and loss of biodiversity. Over the years, decreased agriculture production and water quality degradation have been observed due to climatic abnormalities. Crop production is highly sensitive to climate. It gets affected by long-term trends in average rainfall and temperature, annual climate variations, shocks during different stages of growth, and extreme weather events. Globally, the areas sown for the major crops of barley, maize, rice, sorghum, soya bean, and wheat have all seen an increase in the percentage of area affected by drought as defined in terms of the Palmer Drought Severity Index since the 1960s, from approximately 5-10% to approximately 15-25%. Increase in temperature will be observed in terms of wheat yield losses - 5.5 ± 4.4% per degree Celsius for the United States, - 9.1 ± 5.4% per degree Celsius for India, and - 7.8 ± 6.3% per degree Celsius for Russia as these countries are more vulnerable to temperature increase. Water management through increasing storage capacity (or rainwater storage), fair policies for water supply and distribution, river health, and watershed management can reduce the negative effects of climate change on water resource availability. Similarly, climate change-resistant crop development, water management in irrigation, adapting climate-smart agriculture approach, and promoting indigenous knowledge can ensure the food security via increasing agricultural yield. Technical intervention can equip the farmers with the scientific analyses of the climatic parameters required for the sustainable agriculture management. These technologies may include application of software, nutrient management, water management practices, instruments for temperature measurement and soil health analysis etc. Holistic efforts of the stakeholders (farmers, local society, academia, scientists, policy makers, NGOs etc.) can provide better results to reduce the risks of climate change on agriculture and water resources as discussed in this paper. Graphical abstract.

Water Use Efficiency in Popcorn (Zea mays L. var. everta): Which Physiological Traits Would Be Useful for Breeding?

To ensure genetic gains in popcorn breeding programs carried out under drought conditions knowledge about the response of morphophysiological traits of plants to water stress for the selection of key traits is required. Therefore, the objective was to evaluate popcorn inbred lines with agronomically efficient (P2 and P3) and inefficient (L61 and L63) water use and two hybrids (P2xL61 and P3xL63) derived from these contrasting parents, cultivated under two water regimes (WW watered-WW; and water-stressed-WS) in a greenhouse, replicated five times, where each experimental unit consisted of one plant in a PVC tube. Irrigation was applied until stage V6 and suspended thereafter. Individual and combined analyses of variance were performed and the genotypic correlations and relative heteroses estimated. The water use efficient inbred lines were superior in root length (RL), root dry weight (RDW), and net CO2 assimilation rate (A), which were the characteristics that differentiated the studied genotypes most clearly. High heterosis estimates were observed for RL, SDW, leaf width (LW), leaf midrib length (LL), and agronomic water use efficiency (AWUE). The existence of a synergistic association between root angle and length for the characteristics A, stomatal conductance (gs), and chlorophyll concentration (SPAD index) proved most important for the identification and phenotyping of superior genotypes. Based on the study of these characteristics, the higher AWUE of the previously selected inbred lines could be explained. The results reinforced the importance of root physiological and morphological traits to explain AWUE and the possibility of advances by exploiting heterosis, given the morphophysiological superiority of hybrids in relation to parents.

Local Perceptions on the Impact of Drought on Wetland Ecosystem Services and Associated Household Livelihood Benefits: The Case of the Driefontein Ramsar Site in Zimbabwe

The paper assesses local people’s perceptions on the impact of drought on wetland ecosystem services and the associated household livelihood benefits, focusing on the Driefontein Ramsar site in Chirumanzu district, Zimbabwe. Field data were obtained using a questionnaire from 159 randomly selected households, key informant interviews and transect walks. The study findings show that provisioning, regulating and supporting services are severely affected by a high frequency of drought, occurring at least once every two years, compared to cultural services. There is a reduction in water for domestic use and crop farming, pasture for livestock, fish, thatch grass and ground water recharge. Although cultural services such as traditional rain-making ceremonies and spiritual enhancement are largely unaffected by drought, the wetland’s aesthetic value was reported to be diminishing. The habitat and breeding areas of endangered crane bird species were perceived to be dwindling, affecting their reproduction. All the household heads are not formally employed and largely depend on the wetland resources for food and income. However, drought is adversely affecting wetland-based agricultural activities that are key pillars of the households’ economy. Therefore, there is a need for alternative livelihood strategies that enable local communities to adapt to drought impacts without exerting more pressure on the declining wetland resources.

A scoping review of adoption of climate-resilient crops by small-scale producers in low- and middle-income countries

Climate-resilient crops and crop varieties have been recommended as a way for farmers to cope with or adapt to climate change, but despite the apparent benefits, rates of adoption by smallholder farmers are highly variable. Here we present a scoping review, using PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols), examining the conditions that have led to the adoption of climate-resilient crops over the past 30 years in lower- and middle-income countries. The descriptive analysis performed on 202 papers shows that small-scale producers adopted climate-resilient crops and varieties to cope with abiotic stresses such as drought, heat, flooding and salinity. The most prevalent trait in our dataset was drought tolerance, followed by water-use efficiency. Our analysis found that the most important determinants of adoption of climate-resilient crops were the availability and effectiveness of extension services and outreach, followed by education levels of heads of households, farmers' access to inputs-especially seeds and fertilizers-and socio-economic status of farming families. About 53% of studies reported that social differences such as sex, age, marital status and ethnicity affected the adoption of varieties or crops as climate change-adaptation strategies. On the basis of the collected evidence, this study presents a series of pathways and interventions that could contribute to higher adoption rates of climate-resilient crops and reduce dis-adoption.

What explains the gender differences in the adoption of multiple maize varieties? Empirical evidence from Uganda and Tanzania

Understanding the process that underpins the effective and equitable adoption of modern crop varieties remains an imperative for agricultural development in Africa. This study examines gender differences in adoption rates and determinants of the decision to adopt drought-tolerant (DT) and non-drought-tolerant (ND) maize varieties, based on analysis of maize production data from Tanzania and Uganda. Applying a switching regression with multinomial logit models, we exploit plot level adoption decisions by women and men individually or jointly with in the household, controlling for gender dimension of resource ownership along with other covariates. We find gender differences in the adoption rates for both DT and ND. The results suggest substitution effects noticeable in the decision to use one maize variety rather than another. As the size of the area about which both spouses are jointly owned increases, so does the likelihood that they will adopt DT. Furthermore, DT adoption is also more likely if farmers have experienced frequent climate shocks and dry spells in the past growing seasons. The differences in adoption behavior between men and women jointly or individually are attributable to a combination of the levels and returns of physical- and social-capital factors, as well as to structural issues. One important policy implication of the results is the need for targeted and disaggregated strategies for scaling modern maize varieties, instead of one-size-fits-all approaches.

Drought Risk to Agricultural Systems in Zimbabwe: A Spatial Analysis of Hazard, Exposure, and Vulnerability

The devastating impacts of drought are fast becoming a global concern. Zimbabwe is among the countries more severely affected, where drought impacts have led to water shortages, declining yields, and periods of food insecurity, accompanied by economic downturns. In particular, the country’s agricultural sector, mostly comprised of smallholder rainfed systems, is at great risk of drought. In this study, a multimethod approach is applied, including a remote sensing-based analysis of vegetation health data from 1989–2019 to assess the drought hazard, as well as a spatial analysis combined with expert consultations to determine drought vulnerability and exposure of agricultural systems. The results show that droughts frequently occur with changing patterns across Zimbabwe. Every district has been affected by drought during the past thirty years, with varying levels of severity and frequency. Severe drought episodes have been observed in 1991–1992, 1994–1995, 2002–2003, 2015–2016, and 2018–2019. Drought vulnerability and exposure vary substantially in the country, with the south-western provinces of Matabeleland North and South showing particularly high levels. Assessments of high-risk areas, combined with an analysis of the drivers of risk, set the path towards tailor-made adaptation strategies that consider drought frequency and severity, exposure, and vulnerability.

Determinants of Food Security and Technical Efficiency among Agricultural Households in Nigeria

The challenge of food security in Nigeria hinges on several factors of which poor technical efficiency is key. Using a stochastic frontier framework, we estimated the technical efficiency of agricultural households in Nigeria and tested for the significance of mean technical efficiency of food-secure and food-insecure agricultural households. We further assessed the determinants of agricultural households’ inefficiencies within the stochastic frontier model and adopted a standard probit model to assess the determinants of households’ food security status. The results of our analyses revealed that; on the overall, the agricultural households had a mean technical efficiency of 52%, suggesting that agricultural households have the tendency of improving their technical efficiency by 48% using the available resource more efficiently. We found that households that are food-secure are more technically efficient than food in-secure households and this was significant at one-percent. Our results provide useful insights into the role of land size and number of assets as determinants of agricultural households’ food security and technical efficiency status.

Perception of weather and seasonal drought forecasts and its impact on livelihood in East Nusa Tenggara, Indonesia

A cross-sectional study was conducted in 2018 to assess the perception of households on drought forecasts and its impact on crop and livestock losses. A total of 300 households from seven districts in East Nusa Tenggara Indonesia were considered. The study indicated that the majority of the households are poor families with low education background. They sold poultry for income generation during drought events. The survey revealed that only small percentage of the households usied forecast to support their livelihood management. The statistical test confirmed that the use of forecast did not necessarily impacted the crop loss. However, the crops were significantly affected by the response to drought forecast. Households that changed their agricultural practice experienced significantly different losses than households that did not do anything differently to their crops. The households argued that the accuracy of the forecasts issued by the government was very low. Therefore, it is recommended that policymakers and government authorities provide more accurate forecasts and a better strategy to increase household awareness of using drought forecasts.

Using Biotechnology-Led Approaches to Uplift Cereal and Food Legume Yields in Dryland Environments

Drought and heat in dryland agriculture challenge the enhancement of crop productivity and threaten global food security. This review is centered on harnessing genetic variation through biotechnology-led approaches to select for increased productivity and stress tolerance that will enhance crop adaptation in dryland environments. Peer-reviewed literature, mostly from the last decade and involving experiments with at least two seasons' data, form the basis of this review. It begins by highlighting the adverse impact of the increasing intensity and duration of drought and heat stress due to global warming on crop productivity and its impact on food and nutritional security in dryland environments. This is followed by (1) an overview of the physiological and molecular basis of plant adaptation to elevated CO2 (eCO2), drought, and heat stress; (2) the critical role of high-throughput phenotyping platforms to study phenomes and genomes to increase breeding efficiency; (3) opportunities to enhance stress tolerance and productivity in food crops (cereals and grain legumes) by deploying biotechnology-led approaches [pyramiding quantitative trait loci (QTL), genomic selection, marker-assisted recurrent selection, epigenetic variation, genome editing, and transgene) and inducing flowering independent of environmental clues to match the length of growing season; (4) opportunities to increase productivity in C3 crops by harnessing novel variations (genes and network) in crops' (C3, C4) germplasm pools associated with increased photosynthesis; and (5) the adoption, impact, risk assessment, and enabling policy environments to scale up the adoption of seed-technology to enhance food and nutritional security. This synthesis of technological innovations and insights in seed-based technology offers crop genetic enhancers further opportunities to increase crop productivity in dryland environments.