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Combining ability for grain yield and other agronomic traits of early tropical maize lines under optimal, drought, and suboptimal soil nitrogen conditions
No full textMaize (Zea mays L.) is crucial for food security and industrial use in Sub-Saharan Africa. However, its production is limited by drought and low soil nitrogen. Therefore, developing stress-tolerant maize hybrids is essential for enhancing productivity in the region. Effective selection of these hybrids depends on understanding the mode of inheritance of new maize lines under stress conditions. The objectives of this study were thus to assess the general combining ability (GCA) and specific combining ability (SCA) effects of new maize lines under optimal, drought, and suboptimal soil nitrogen conditions. A total of 320 testcrosses, 32 lines, and 10 testers were evaluated under these conditions. Significant differences (P ≤ 0.05) were found between lines, testers, and line-by-tester interactions for most traits. Seven lines (L2, L6, L10, L18, L20, L25, and L31) and four testers (T2, T5, T9, and T10) had positive GCA effects for yield across the three growing conditions, highlighting favorable additive genetic effects under stress conditions. In addition, specific crosses including L1 × T2 and L5 × T3 (optimal conditions) and L9 × T9 and L32 × T6 (suboptimal soil nitrogen) showed positive SCA effects for yield. These lines and testers with positive GCA and SCA represent valuable genetic resources for the development of high-yielding, drought and suboptimal soil nitrogen-tolerant maize varieties
Comparative assessment of energy-cum-carbon flow of diverse tillage production systems for cleaner and sustainable crop production in the middle Indo-Gangetic Plains of South Asia
No full textThe most common cropping production system in South Asia, transplanted puddled rice followed by conventional-tillage wheat, is highly unsustainable, extremely energy-intensive, and emits a large amount of greenhouse gases. The practices used in conservation agriculture, including diversified cropping rotations, residue retention, zero-tillage direct-seeded rice, and zero-tillage wheat, can increase crop productivity while reducing energy use requirements and carbon footprints. Therefore, to promote a sustainable and energy-efficient conservation agriculture-based system with a less energy-intensive rice–wheat system, contrasting tillage and residue management scenarios were evaluated in this study. The treatments include triple cropping systems of zero-tillage direct-seeded rice (ZTDSR) during the rainy season, followed by zero-tillage rice–wheat–mungbean (ZTRWM) in winter, as well as zero-tillage rice–lentil–mungbean (ZTRLM), zero-tillage rice–chickpea–mungbean (ZTRCM), and zero-tillage rice–mungbean–mustard (ZTRMM) along with the conventional-tillage rice–wheat (CTRW) system. Zero-tillage systems exhibited significantly lower operational energy for irrigation (~40%), sowing (~26%), and land preparation (100%) compared to a conventional-tillage (CT) system. Compared to the conventional-tillage rice–wheat system, zero-tillage cropping systems achieved significantly higher system biomass yields. The zero-tillage system also increased wheat yields, resulting in a significant reduction in resources (fuel, fertilizer, and machinery) under zero-tillage (ZT) interventions. More than 60% of energy utilization came from crop residue, irrespective of the diverse cropping production systems. The maximum net energy returns, energy ratios, energy productivity, and energy intensity were recorded with the zero-tillage rice–wheat system. Zero-tillage production systems had significantly lower carbon footprints, higher carbon efficiency, and better carbon sustainability index than the conventional-tillage (CT) management system. Thus, it can be concluded that triple-zero-tillage production systems, along with residue management, yield lower net energy output, greenhouse gas emissions, and carbon footprints as compared to conventional-tillage-based systems
Transfer of cytoplasmic male sterility to the female parents of heat- and drought-resilient maize (Zea mays L.) hybrids
No full textMaize is the second most important staple food crop in the world after wheat. For maize hybrid seed production, a prominent step is detasseling in the female parent, which is laborious, time consuming, and increases the hybrid seed cost by 15 to 20 percent. Hence, to overcome this problem, exploitation of male sterility in maize crops gains special significance. In this direction, the research was conducted to transfer cytoplasmic male sterility (CMS-C) from a CMS donor (VL192114) into the female parents (CAL1514 and ZL153493) of heat- and drought-resilient maize hybrids (RCRMH-2 and RCRMH-3) by a marker-assisted backcross scheme. The present research used Diversity Array Technology (DArTag) and Kompetitive Allele Specific PCR (KASP)-based single-nucleotide polymorphic markers for background selection in backcross populations. Genome recovery percentage ranged from 64.25 to 72.70, 78.94 to 87.69 and 82.28 to 90.77 percent in the BC1F1, BC2F1 and BC3F1 population, respectively, in the CAL1514 population, while it was 63.47 to 73.55, 78.16 to 88.76 and 83.96 to 91.81 percent in the BC1F1, BC2F1 and BC3F1 population, respectively, in the ZL153493 population. When the near-isogenic CMS lines of both populations are compared for agro-morphological traits with their recurrent parents, the agronomic qualities of recurrent parents, as well as the attributes of distinctness, uniformity and stability, are shown. Therefore, male sterility-transferred, female lines of RCRMH-2 and RCRMH-3 maize hybrids can be used directly to produce maize hybrid seed without the need of the detasseling process
Early sowing enhances genotypic performance in mitigating the risk of wheat blast-induced yield loss: evidence from a 23-year simulation study in Bangladesh
No full textWheat is a crucial staple crop in South Asia and faces increasing risks due to interconnected agronomic and climate-related pressures. Wheat blast, caused by Magnaporthe oryzae pathotype Triticum (MoT), presents a persistent threat to wheat production in the region. This study evaluates its impact by analyzing the effects of sowing dates and wheat varieties on irrigated wheat grain yield in Bangladesh, where MoT was first identified in South Asia. A generic disease model (GDM), parameterized to reflect the disease's characteristics, was used to simulate wheat blast inoculum build-up. The GDM incorporates temperature, relative humidity, and precipitation data to model the fungal life cycle and disease progression. The wheat crop simulation model, DSSAT-Nwheat, was integrated with the GDM to simulate MoT's life cycle. This coupled model has been embedded into the Geospatial Crop Modeling and Decision Support Tool (GSSAT) to enhance agricultural decision-making. Using a primary dataset for validation and NASA Power reanalysis weather data, the simulated effects of wheat blast on wheat grain yield were analyzed across five sowing dates and four varieties in Bangladesh over a 23-year period from 2001 to 2023. The results indicate that late sowing leads to lower yields and higher disease incidence due to increased atmospheric moisture and temperature. Both model simulations and primary data demonstrated that varietal resistance to wheat blast can significantly mitigate yield losses of wheat. However, in southern Bangladesh, where weather conditions favor the disease, even the most resistant variety, BARI Gom 33, showed yield reductions resulting from wheat blast. These findings highlight the need for long-term breeding programs to develop cultivars suited to hot, humid conditions with high disease pressure, alongside short-term agronomic practices that minimize disease risk through sowing in optimum dates and less susceptible cultivars in Bangladesh
Physiological and biochemical responses to cold stress in sesame (Sesamum indicum L.) during the early growth stage
No full textCold stress significantly impacts sesame during its early growth stages, with varying responses observed among different genotypes. Ten genotypes were evaluated for phenotypic response to various temperatures during germination. Cold stress at 10, 12, 14, and 16 °C inhibited germination, with zero germination at 10 °C. At 14 °C, genotypes showed significant germination variation, and it was selected as the threshold temperature for assessing cold tolerance in sesame. Four genotypes were grouped into two, and each group with extreme germination responses (high and low) were selected for further biochemical and physiological studies. Genotypes V5 and V7 exhibited higher cold tolerance, better germination percentage, and seedling parameters under low temperatures, while V8 and V9 showed significant reductions, indicating cold sensitivity. Biochemical analyses revealed that cold-tolerant genotypes had enhanced activities of antioxidant enzymes, including catalase, superoxide dismutase, and peroxidase, as well as higher proline accumulation compared to sensitive genotypes. These antioxidants played a crucial role in mitigating the oxidative stress induced by cold, as evidenced by lower levels of hydrogen peroxide and malondialdehyde in the tolerant genotypes. Cold-tolerant genotypes also accumulated higher soluble sugars and protein levels, contributing to osmotic regulation and membrane stability. The findings highlight the importance of enzymatic and non-enzymatic antioxidants in cold stress tolerance, suggesting these biochemical markers could be used to identify and develop cold-resistant sesame cultivars. The results offer valuable insights into the mechanisms underlying cold tolerance and provide a foundation for breeding efforts to improve sesame cold resistance.293-30
Climate-resilient strategies for wheat farming: minimizing climate impact, optimizing productivity, and maximizing profitability in the subtropical agroecological landscape of India
No full textThis study builds upon existing knowledge to quantify the extent of on-farm yield gaps and identify the most effective climate-resilient strategies (CRSs) to bridge them. By addressing these objectives, the study seeks to enhance wheat yield and resilience in the adverse climatic conditions. Productivity and adoption of CRSs are key indicators to monitor the progress toward more resilient production systems. Total eight project hubs were identified across Bihar (Banka, Bhagalpur, Gaya, Khagaria, Madhubani, Munger, Nalanda, and Nawada) for farmers-field experiment-cum-demonstration during rabi season (2019-2020). Three climate-resilient technologies (i) zero tillage (ZT), (ii) raised bed (RB), and (iii) happy seeder (HS) were evaluated across varying planting times from November 13 to December 31. Field experiments-cum-demonstrations conducted across 566 hectares involving 980 farmers in eight districts of Bihar revealed that early wheat planting (13-30 November) significantly enhanced grain productivity (up to 4.96 t/ha) and profitability (net returns up to $863/ha, B:C ratio 1.92), while delayed sowing (post-mid-December) led to yield reductions of up to 57%. Among crop establishment methods, happy seeder (HS) and zero tillage (ZT) consistently outperformed conventional farmer-managed practices, achieving 12.6-14.5% higher net returns and benefit-cost ratios up to 2.02, underscoring the agronomic and economic advantages of timely planting and resource-conserving technologies. The study concludes that sowing wheat in the second week of November using the Happy Seeder (HS) significantly boosts productivity and profitability. These results offer robust evidence to refine regional planting advisories and promote climate-resilient practices for enhancing wheat adaptation across subtropical India
Institutional efforts and regional distribution of climate-smart agriculture (CSA) initiatives in Ghana
No full textMapping climate-smart agriculture (CSA) initiatives enable countries to account for emissions and develop adaptation measures. While discourse on CSA implementation exists, developing countries lack empirical evidence to support intervention design. This study analyzes actor networks and assesses social benefits through a comprehensive review of 153 CSA projects across Ghana's 16 regions from 1971 to 2023. The Northern region hosted the highest concentration (17 %) of CSA projects, followed by Upper West, Upper East, Bono, Eastern, and Ashanti regions, primarily focusing on drought adaptation. Crop production emerged as the dominant system (56 %), with governmental entities leading 80.4 % of initiatives. Regional variations show post-harvest loss reduction as the primary aim in southern regions, while forestry and aquaculture initiatives concentrate in Eastern and Western regions to address flood vulnerability in degraded landscapes. The study reveals spatial and temporal patterns in Ghana's CSA implementation, identifying gaps in coverage and stakeholder participation. These findings provide an evidence base for policymakers to optimize resource allocation, strengthen underserved regions' climate resilience, and align CSA initiatives with national sustainable development goals
Histone ZmH2B regulates resistance to the Southern corn leaf blight pathogen Bipolaris maydis in maize
No full textBackground: H2B histones play crucial roles in plant responses to biotic stress. However, to date, most research on H2B histones has focused on their roles in post-translational modification, and studies specifically investigating the intrinsic properties of these histones remain relatively limited. Here we identified the ZmH2B in maize (Zea mays) and investigated its role in the response of maize to infection by the Southern corn leaf blight pathogen Bipolaris maydis. Result: In this study, a nucleus-localized ZmH2B was identified from maize. To characterize the role of this histone in disease resistance, we employed virus-induced gene silencing (VIGS) and transient overexpression (VOX) to generate ZmH2B-silenced (FoMV:ZmH2B) and ZmH2B-overexpressing (FoMV:ZmH2B-VOX) lines. FoMV:ZmH2B lines showed enhanced B. maydis infection and an inhibited chitin-induced reactive oxygen species burst, whereas FoMV:ZmH2B-VOX lines exhibited the opposite effects. Furthermore, ZmH2B overexpression induced the expression of various pathogenesis-related genes, suggesting that these genes enhance resistance against B. maydis. Transcriptome analysis of ZmH2B-silenced plants revealed that the differentially expressed genes were predominantly enriched in photosynthesis-related pathways, pointing to a role for photosynthesis in B. maydis resistance. Conclusions: These results suggest that ZmH2B positively regulates maize resistance to B. maydis
Potential impacts of carbon pricing on vegetable cold chains
No full textThe urgent need to address climate change has prompted growing interest in carbon pricing mechanisms as tools for reducing emissions in food systems. This review explores how carbon pricing may affect vegetable cold chains, which rely on energy-intensive, temperature-controlled networks essential for preserving produce quality and limiting food loss. While carbon pricing can serve as an incentive for adopting energy-efficient technologies, renewable energy, and sustainable logistics practices, its implementation can also trigger adverse consequences. These include increased operational costs, potential disruptions to supply chains, food affordability challenges, and public health concerns, particularly for vulnerable populations. Drawing on global evidence, this paper discusses both the enabling conditions for carbon pricing (when applied to vegetable cold chains or relevant stages within them) to deliver environmental benefits and the risks of socio-economic trade-offs, including potential impacts on labour, equity, and food security. Mitigation strategies, such as revenue recycling, targeted subsidies, and hybrid policy designs, are also discussed. Overall, the paper emphasizes the need for carefully designed carbon pricing mechanisms tailored to the structure of vegetable cold chains to ensure a just and effective transition to low-carbon food systems
Public-private partnerships for seed industry development in developing countries: Lessons from MasAgro maize in Mexico
No full textPublic-private partnerships (PPPs) are globally recognized for their potential to accelerate genetic improvement and delivery of new high-yielding seed varieties in developing countries. However, despite the strong advocacy for PPPs in crop improvement, there is little empirical evidence about their performance, capacities, and contribution to the development of seed industries and the promotion of competitive seed markets. This paper uses the experience of the MasAgro maize consortium, a PPP in Mexico, to examine crop variety innovation and delivery through PPPs, assess PPPs' capacities to commercialize public germplasm-based varieties, and derive lessons for the design and implementation of future PPPs. Drawing on a combination of multiple data sources, we examined the PPP's performance in the generation, dissemination, and commercialization of new maize hybrids. Our examination over the period 2011-2019 shows that the consortium was successful in maintaining a substantial flow of agronomically competitive maize hybrids, which compared favourably with the number of new varieties generated by national and international seed companies and the public sector. The partnership also contributed to refreshing and rejuvenating the variety portfolios of the consortium companies, which appear to have succeeded in bringing MasAgro varieties quickly into the market. However, seed sales achieved by MasAgro hybrids over this period remained small and multinational companies consistently maintained their leadership in the maize seed market. Our analysis shows that PPPs have strong capacities for the development of competitive seed varieties, but they face significant challenges in scaling up the uptake and adoption of these innovations in highly concentrated markets. To succeed in their objective of delivering affordable, high-quality seed on a large scale to smallholder farmers in developing countries, PPPs need to urgently incorporate a commercial and market-oriented perspective along all steps of the plant breeding and dissemination process