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Impact of feeding level and multi-nutrient blocks with polyherbals on weight changes and greenhouse gas emissions in lambs
No full textIn small-scale livestock production systems, low-quality diets constrain animal performance and increase enteric emissions, but both these impacts can be remediated using optimized feeding strategies. An experiment was conducted with lambs fed at two levels-maintenance (MN) and growth (GR)-using multi-nutrient blocks formulated with different concentrations of polyherbal nutraceuticals to compare the lambs' reactions in terms of their productive performance and estimated enteric methane emissions. Thirty-two lambs were fed at two feeding levels-(a) maintenance (MN) at 9% CP and 1.85 Mcal ME/kg DM and (b) growth (GR) at 13.24% CP and 2.15 Mcal ME/kg DM)-and did or did not have access to MBs with different polyherbal percentages (BioCholine (R), OptiLysine (R), and OptiMethione (R) (0:0:0, 3:0:0, 3:0.75:0.25)). No interactions between the feeding level and supplementation were detected. Lambs fed at the MN level showed lower productive indicators (p < 0.001) than those fed at the GR level, with a lower dry matter intake (DMI, 512 vs. 1009 g/d), MB consumption (61 vs. 84 g/d), and daily weight gain (26 vs. 187 g/d), resulting in lower enteric methane emissions (8.74 vs. 18.18 g CH4 /d) and a lower emission intensity (15.25 vs. 16.55 CH4 g/kg DM). Supplementation with MBs improved the average daily weight gain (ADG) (p < 0.001) at the GR level, but no differences were detected at the MN level. However, lambs in the control group lost weight (-20 g/d) and those supplemented gained weight (g/d), with increases of 49 (0:0:0), 25 (3:0:0), and 52 (3:0.75:0.25). The highest ADG for lambs in the GR group was observed with MBs containing all three polyherbals (215a, 3:0.75:0.25), an intermediate ADG was seen with MBs without herbals or with Biocholine (200.75ab, 0:0:0; 198ab, 3:0:0), and the lowest ADG was observed with no MBs (134c g/d). The use of MBs reduces the time to reach market weight by 265 days, resulting in a 50% reduction in the enteric methane emissions per product (animal by animal), making multi-nutrient blocks a viable option to improve production indicators and reduce enteric methane emissions
Essential oils as sustainable alternatives for managing plant-parasitic nematodes: a comprehensive review
No full textPlant-parasitic nematodes (PPNs) pose a serious threat to global agriculture by reducing both yield and quality in high-value crops. Although chemical nematicides provide rapid control, their application is increasingly restricted due to environmental pollution and toxicity to non-target organisms. These limitations have increased the search for sustainable and environmentally friendly alternatives. Plant-derived essential oils (EOs) have emerged as promising nematicides due to their sustainable nature and bioactivity. EOs of plant families such as Lamiaceae, Amaryllidaceae, Lauraceae, Apiaceae, and Zingiberaceae have been reported to exhibit nematicidal activity. Their major constituents include linalool, thymol, carvacrol, diallyl disulfide, cinnamaldehyde, γ-terpinene, cumin aldehydes, eucalyptol, and spathulenol. EOs suppress nematode populations through mechanisms including inhibition of egg development, increased larval mortality, and reduction in root gall formation. However, field efficacy can be limited by chemical composition variability, volatility, and phytotoxicity. Advanced formulation techniques, such as micro and nano-encapsulation, can improve EO stability, controlled release, and consistent efficacy. Future research should focus on clarifying synergistic and antagonistic interactions among EO constituents, optimizing field applications, and integrating EO-based products with other sustainable strategies. In addition, studies should prioritize standardizing extraction methods, conducting chemical profiling, and verifying their efficacy and safety through repeated field trials in various agricultural systems. In conclusion, plant-derived EOs represent promise as a sustainable method of managing nematodes and contribute to sustainable agriculture
Unraveling the genetic basis of general combining ability in CIMMYT elite bread wheat germplasm: implications for breeding strategies optimization
No full textIn wheat breeding programs, several hundred crosses are performed annually, but only individuals from a few families advance to the final stages of the breeding pipelines. Therefore, a deeper understanding of the general combining ability (GCA) of wheat genotypes might enhance the breeding efficiency in selecting parents. For this reason, we tested the performance of the offspring of similar to 1200 parental elite lines. Using a genome-wide association study (GWAS), gene ontology (GO) analysis, and genomic prediction (GP), our objectives were to i) identify marker-trait associates (MTAs) and candidate genes, ii) assess temporal allele frequency dynamics of identified MTAs, and iii) estimate prediction accuracy (PA) for key traits: Progeny Number per-Cross (PNC), grain yield (GY), and a combined index incorporating these traits ("index"). Our findings revealed a total of 13 MTAs: eight for GY, four for the "index", and one for PNC. The GO analysis highlighted several genes involved in hydrogen peroxide metabolism and catabolism processes (H2O2), reactive oxygen species, response to oxidative stress, cell wall biogenesis, the metabolic process of modified amino acids at the cellular level, and glutathione metabolic process for the studied traits. Notably, allele frequency analysis over time indicated that most MTAs are under positive selection, likely reflecting indirect breeder-driven selection. The highest PA was reached by using the reproducing kernel Hilbert space (RKHS) model for the trait GY (0.34). The identification of MTAs for PNC and GY provided insight into the biological pathways underpinning combining ability and demonstrated the potential for predicting the ability of the genotypes to be crossed. These findings might contribute to the optimization crossing strategy saving costs and increasing the breeding program efficiency
Sparse testcrossing for early-stage genomic prediction of GCA to increase genetic gain in maize hybrid breeding programs
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Breeding and deployment of high Zn wheat in South Asia
No full textWheat is one of the most important staple food crops which contribute about 20% of daily calories and protein intake for the human population globally. Beyond wheat production challenges, South Asia and Sub-Saharan Africa have a high burden of micronutrient malnutrition with 33.3% of the children under the age of five being Zn deficient. Moreover, Zn deficiency affects a large proportion of the population, particularly women (pregnant and lactating >48%) and children in rural areas. Therefore, enhancing wheat cultivation through the introduction of early maturing, climate-resilient, high-yield, and Zn enriched biofortified varieties is imperative to address food and nutrition security challenges in these regions. After years of targeted biofortification breeding and extensive multi-location testing, partner countries in South Asia and Africa released about two dozen biofortified zinc-enriched wheat varieties. The zinc content of these varieties exceeds 36 mg kg−1. For instance, Akbar-19, high-yielding and high zinc variety is becoming a mega variety and grown over 42% area in Pakistan. Additionally, several pipeline varieties are poised for commercial release in the near future. These varieties exhibit climate resilience and have demonstrated a higher yield potential (5–10%) compared to their local counterparts, along with broader adaptability. To expedite the seed multiplication and dissemination, efforts are underway, CIMMYT together with NARES partners (both public and private), is emphasizing source seed production (pre-basic and basic seeds) and employing fast-track seed production approaches, including community-based seed production (CBSP). Capacity development and awareness-building events among relevant stakeholders are integral components of efforts to promote the adoption of these varieties. These strategies aim to enhance the accessibility of nutritious wheat sustainably, particularly in remote areas where household level food insecurity and malnutrition persist.17-3923 page
Alternating tillage with conservation agricultural practices in intensive rice (Oryza sativa L.)-based cropping systems can improve soil health and increase crop and systems productivity in the Eastern Indo-Gangetic Plains
No full textAvailable ariable land for agriculture in South Asia's Eastern Indo-Gangetic Plains (EIGP) is decreasing while the population and the demand for food is increasing. Despite this pressure to intensify land use, large tracts of land still remain fallow during the dry season. Making productive use of these lands is essential to increasing farm output while safeguarding food security. One potential part of the solution to this challenge lies in improved land management practices. Conservation agriculture with no or reduced tillage (CA), or alternating tillage where monsoon rice is established with full tillage and dry season crops with reduced or zero tillage (AT), can potentially facilitate improved crop establishment, increase yield, and improve soil health and the resilience of cropping systems. This study was undertaken to evaluate CA, AT and conventional tillage (CT) under double- or triple cropping sequences on loamy soil in a (sub) tropical environment in the EIGP northern Bangladesh. The experiment included six cropping systems (CS) over three consecutive years: CS1, Aman rice (Oryza sativa L.) – Boro or winter rice (Oryza sativa L.) (R-R); CS2, Aman rice – Wheat (Triticum aestivum L.) (R-W); CS3, Aman rice – Maize (Zea mays L.)(R-M); CS4, Aman rice - Mung bean (Vigna radiata L.) (R-M); CS5, Aman rice – Wheat – Mung bean (R-W-MB); and CS6, Aman rice – Maize – Mung bean (R-M-MB). In CS5 and CS6, mung bean replaced land fallowing after the predominant dry season crop. Maize, but not rice, yields were higher in AT or CA than CT. The R-W-MB and R-M systems had the highest system-level rice equivalent yield. Soil chemical properties, except SOM, total N, and Mn, in the 0–15 cm portion of the soil profile also differed significantly among the systems. Cropping systems had a significant effect on soil penetration resistance up to 30 cm soil depth. The buffering capacity of the soil under these treatments against diurnal temperature variation was also higher under CA followed by AT. These results suggest that AT with CA-based management practices can improve cropping systems level yields and soil properties. These practices can also be be adapted to rice-based farming systems where they can support improved land management and increase systems productivity and soil health. Long-term studies are required across soil types, climates, and socio-economic conditions to extrapolate findings to larger areas of the EGP
Effect of intercropping and mulching on weed composition in agroclimatic zones of Zimbabwe
No full textWeed species composition is significantly affected by crop management practices. Intensive cropping is often associated with a reduction in weed species diversity. This study was conducted to assess the effect of intercropping and mulching on weed flora in three agroecological regions in eastern Zimbabwe. Two replicated on-farm trials were laid out in three agroecological regions. Treatments included sole maize, sole maize with 4 or 8 Mg ha−1 mulch, sole cowpea, maize + cowpea intercrop and maize + cowpea intercrop with 4 or 8 Mg ha−1 mulch. Maize stover was used as mulch. Different weeds were identified and sampled at five positions within plots using 0.5 m × 0.5 m quadrats. Among the 34 weed species identified across sites, Richardia scabra and Cynodon dactylon were the most dominant weed species and were mostly associated with sole maize cropping. Maize stover as mulch contributed to a reduction in weed species density. Maize + cowpea intercropping systems proved effective particularly in suppressing the prevalence of R. scabra and C. dactylon. Cowpea grown as a sole crop was found to be effective in reducing the infestation of weeds. Maize intercropped with cowpea along with mulching resulted in a significant reduction of weed species, especially in arid agroecological zones
Enhancing wheat genomic prediction by a hybrid kernel approach
No full textThis study integrates genomic and pedigree data by leveraging advanced modeling techniques, aiming to enhance the predictive performance of genomic selection models by capturing complex genetic relationships through the interaction of both matrices and exploring the utility of non-linear methods, such as kernel matrices. Our goal was to improve genomic prediction accuracy by combining the pedigree-based or genetic similarity matrix ( A ) with the genomic similarity matrix ( G ). Using various wheat datasets, we performed five single-environment models and five multi-environment models that incorporated genotype-by-environment (G x E) interactions. The proposed models S5 and M5 significantly enhanced prediction accuracy by incorporating two novel symmetric kernels, C and P , derived from the interaction of genomic and pedigree matrices. These hybrid kernels captured additional, independent genetic variation not explained by conventional matrices. The proposed prediction model outperformed the standard conventional models in most single-environment and multi-environment models. The genomic models with non-linear kernels were better predictors than the linear prediction models
Programme des Cultures des Zones Sèches: Relever le défi 50:20
No full textEn 2024, le Programme des Cultures des Zones Sèches (DCP) du CIMMYT a posé les bases pour faire progresser sa vision et relever le défi 50:20. Cela est rendu possible grâce aux efforts de plus de 200 chercheurs issus d’institutions partenaires, travaillant en collaboration pour générer un impact concret.2 page