Carbon fluxes and partitioning in Eucalyptus and Pinus plantations across a climatic gradient in Brazil

Brazilian Eucalyptus and Pinus forests are the most productive forests worldwide. The growth rates of these intensively managed plantations depend strongly on environmental conditions and matching genotypes to local environments. Changing climates underscore the value of understanding the intricacies of how these plantations can fix high amounts of carbon (C) and grow so much wood. We measured the full C budgets of Eucalyptus and Pinus forests across climate gradients in Brazil, focusing on the rates of C uptake, the allocation of C to belowground roots and mycorrhizae, and stem growth. We found that gross primary production (GPP) varied more than sixfold across the climate conditions in Brazil. Maximum temperature was the main climatic driver of productivity, where extreme temperatures reduced fluxes to stem production while increasing fluxes to root production. Net ecosystem production varied with management and age across the sites. The ecophysiological investigation presented in this work is fundamental for understanding C partitioning behavior under extreme temperature conditions. In this way, our results provide tools for forest managers to support their decision-making processes as well as starting points for strategies to be implemented in projects aimed at mitigating the effects of climate change

Surface albedo and thermal radiation dynamics under conservation and conventional agriculture in subhumid Zimbabwe

While conservation agriculture (CA) has been widely evaluated for its biogeochemical effects (e.g soil organic carbon sequestration and greenhouse gas emissions) for climate mitigation, its biogeophysical impacts related to changes in surface albedo remain understudied. This study assessed the biogeophysical effects of CA cropping systems with maize (Zea mays L.) in Zimbabwe. Measurements were conducted continuously over two cropping years at two long-term experiments with contrasting soil characteristics, on an abruptic Lixisol and on a xanthic Ferralsol. The dynamics of surface albedo, longwave radiation, leaf area index, soil moisture and temperature were monitored under three different treatments: conventional tillage (CT, tilled to ~15 cm), no-tillage (NT) and no-tillage with mulch (NTM, 2.5 t DM ha⁻¹). Our results revealed that, on the Ferralsol, NT and NTM significantly (p < 0.05) increased mean annual albedo (0.17) relative to CT (0.16), resulting in a negative instantaneous radiative forcing (iRF) and indicating a net cooling effect. iRF was stronger in 2021/22 (NT: -0.83 ± 0.17 W m-2; NTM: -1.43 ± 0.7 W m-2) than in 2022/23 (NT: -0.43 ± 0.09 W m-2; NTM: -1.03 ± 0.21 W m-2). Conversely, on the Lixisol, while NT increased surface albedo (0.27 vs. CT: 0.24), NTM significantly reduced albedo (0.23), causing positive iRF (warming). iRF was -3.34 ± 0.69 W m-2 and -2.78 ± 0.77 W m-2 for NT in the first and second cropping year, respectively, and increased from 1.14 ± 0.21 W -2 (2021/22) to 2.77 ± 0.41 W m-2 (2022/ 23) under NTM. Overall, our results suggest that the soil background albedo is an important site characteristic that needs to be considered and demonstrates the importance of considering biogeophysical effects when promoting practices of CA for climate change mitigation

Quantifying impacts of biomass feedstock attributes in optimizing tropical biorefineries: Case of Peninsular Malaysia

Amid growing global energy demands and climate concerns, sustainable biofuels offer a key alternative to fossil fuels. This study quantifies the impacts of spatial fragmentation, moisture content, resource yield density, and sourcing strategies on biofuel production costs and scalability in Peninsular Malaysia. Oil palm fronds with high moisture and fragmentation and reduced capacity by 36 % compared to rice straw. Single-feedstock systems like palm press fiber proved more cost-effective unless moisture in multi-feedstock combinations was reduced. For example, a PPF-EFB combination with 48.1 % moisture is 31 % cheaper than EFB alone at 60 % moisture. These results emphasize early-stage moisture management through mobile drying units or pre-treatment hubs are essential for economic viability. By benchmarking against crude oil prices, this study challenges assumptions about multi-feedstock cost savings and offers actionable insights for building scalable, cost-effective tropical biofuel supply chains

Cassava cooking properties characterization using NIRS on fresh ground cassava – Updated dataset 2020-2023

This report, written under the RTB Breeding project, explores the characterization of cassava cooking properties using Near-Infrared Spectroscopy (NIRS). The study, conducted over five years, is based on the analyses of 3049 cassava genotypes (5815 samples) originated from various breeding populations at the CIAT research centre and from experimental fields. The samples were evaluated for their water absorption capacity after 30 minutes of boiling (WA30, a key indicator of cooking quality) and their near infrared fingerprints. Genotypes were classified into 2 classes according to their WA30 values with C1 corresponding to WA30 < 12% and C2 corresponding to WA30 ≥ 12%. The repartition by classes was 3111 samples in C1 and 2704 samples in C2. To classify the genotypes, the study used Principal Components Analysis (PCA) to reduce the dimensionality of the spectral data, followed by Locally Weighted Partial Least Squares Regression Discriminant Analysis (LWPLSRDA) for predicting the genotype classes. The robustness and accuracy of these models were key focuses. The final LWPLSRDA model achieved a classification accuracy of 80% in distinguishing between "low cooking time" and "long cooking time" genotypes. The model was balanced in terms of sensitivity and specificity, which means a high capacity to detect true positives and true negatives genotypes. This study confirms that there is a relationship between the NIR fingerprint of fresh cassava tubers, largely due to chemical composition, and their cooking capacity. By integrating NIRS technology into cassava breeding, researchers can more efficiently identify varieties with optimal cooking properties, thereby supporting the development of superior cassava cultivars

Prevalence of mealybug wilt-associated viruses in pineapple 'Queen Victoria' cultivars in Reunion Island and the potential of virus-free vitroplants for disease management

Mealybug wilt disease of pineapple (MWP) poses a significant threat to global pineapple production, yet its etiology remains poorly understood. The disease is believed to involve mealybugs, multiple pineapple mealybug wilt-associated viruses (PMWaVs, genus Ampelovirus), and possibly other viruses from the Badnavirus, Secovirus, and Vitivirus genera. This study examines the distribution and prevalence of three ampeloviruses (PMWaV1, PMWaV2, PMWaV3) and two badnaviruses (PBERV, PBCOV), previously associated to MWP symptoms, across 15 pineapple plots of the 'Queen Victoria' cultivar in Reunion Island. A total of 450 symptomatic and asymptomatic leaf samples were analyzed using PCR and RT-PCR-based diagnostics. Globally, 93 % of samples were infected with at least one virus, and 76 % were co-infected with two to four viruses. PMWaV1 (78 %) and PBCOV (87 %) were the most prevalent, while PBERV was not detected. Virus presence was associated with leaf dieback, wilting, and curling. Leaf reddening and yellowing, commonly associated with MWP, were not associated with viral infection, suggesting that other biotic or abiotic factors may be responsible for these symptoms. Viral infections and MWP symptoms were significantly lower in plots planted with vitroplants (VPs) compared to those using suckers, highlighting the potential of VPs in reducing viral infections. These findings highlight the complexity of MWP and underscore the potential benefits of using virus-free VPs to manage the disease

Overall performances of Leucaena leucocephala and Morus alba in high-density protein banks at maturity in western Burkina Faso

The objective of this work was to carry out long-term monitoring of protein banks (PB) established under the real-low-input-farm conditions of Burkina Faso, characterized by a Sudano-Sahelian climate type with wide variations in rainfall. The PBs, planted in 2016–2017 with Leucaena leucocephala (LL) and Morus alba (MA) at a high density (20,000 plants/ha), were monitored from 2016/2017 to 2021 for their biomass (fodder) production, chemical composition and nutritional value of the edible fodder, and their impacts on soil carbon content. The average annual fodder production of LL for the 6 PBs (1, 2, 3, 4, 5, and 6) was 11.4 ± 2.12 t DM/ha/year, while that of MA was 3.8 ± 1.2 t DM/ha/year for the 3 PB (1, 2, and 3). Such differences are related to higher adaptive capacity for LL in such climatic conditions. Crude protein was higher in LL (19% versus 17%), but dry matter digestibility (65% versus 77%) was superior in MA. Soil carbon increased during the five monitored years, an exciting result for these poor, low-fertility soil conditions. Our results demonstrate the technical and environmental feasibility of establishing this low-input agroforestry technology in these conditions and inspire the potential of sustainable agriculture as an agroecological alternative to overcoming feed shortages for local livestock farming. However, the successful management of a PB relies on selecting the right suitable species, protecting them, and managing them during the establishment and fodder production periods with suitable cutting frequency and appropriate post-harvest management

Morphological variation and genetic diversity of breadfruit [Artocarpus altilis (Parkinson) Fosberg] in Vanuatu

Breadfruit, Artocarpus altilis (Parkinson) Fosberg, is a versatile tree crop widely distributed in Oceania and tropical regions. It produces starchy fruits that contribute to food security in Pacific Island countries. In Vanuatu, where it is considered as a secondary food crop, a better understanding of the diversity of this species is a prerequisite for setting up a genetic improvement strategy. A diversity study of 123 accessions collected in 27 villages on eleven islands across Vanuatu and conserved in an ex-situ field gene bank was conducted in 2023–24. Eighteen morphological descriptors of fruits and leaves were utilized and genotyping was performed using 15 single sequence repeat (SSR) markers. The results showed that Vanuatu cultivars exhibit important morphological variation. Most of them (except two) are diploid and seeded. Analysis of SSR profiles revealed four genetic groups and 99 unique multilocus genotypes. Cultivars collected in the northern and north-central regions of Vanuatu appeared to be more genetically diverse than those collected further south. A total of 152 alleles were detected across the 15 loci, with an average number of 10.13 alleles per locus. For comparison, SSR analysis of triploid seedless cultivars from Eastern Polynesia and the Indian Ocean showed that these cultivars, although morphologically different, share a very narrow genetic base and are hardly distinguishable with the set of markers used in this study. These results confirm that Vanuatu is an important centre of breadfruit diversity and that this diversity is dynamic due to the diploid nature of cultivars with a high percentage of seed propagated trees