A new tandem repeat-based genotyping scheme for the global surveillance of Xanthomonas citri pv. mangiferaeindicae, an understudied bacterial pathogen of major importance to mango and cashew production

Bacterial canker, caused by Xanthomonas citri pv. mangiferaeindicae (Xcm), is a disease that has a devastating impact on mango and cashew industries in many regions. Yet, despite its agricultural importance for these Anacardiaceae species, Xcm has been neglected. Little is known about its epidemiology, evolution and molecular interactions with host plants. The most relevant studies reporting its genetic structure were primarily based on amplified fragment length polymorphism (AFLP) data. This technique provides reliable assessments of the genetic relatedness among bacteria, but is limited in terms of interlaboratory comparisons. Alternative genotyping techniques are required to decipher the global epidemiology and geographic expansion of Xcm. Herein, we screened the genome of the Xcm strain CFBP1716 for tandem repeats. We developed and evaluated the performance of an optimized Multi Locus Variable number of tandem repeat Analysis (MLVA), targeting 16 tandem repeat loci primarily with large repeat units, i.e., minisatellites (MLVA-16). To achieve this, we genotyped a comprehensive collection of 152 Xcm strains, representative of the pathogen's worldwide genetic diversity, together with some reference strains of X. citri pv. anacardii, another genetically-related pathogen of Anacardiaceae. MLVA-16 allowed us to distinguish the two pathovars. Although MLVA-16 was slightly less discriminative than AFLP, the two derived datasets were strongly correlated, suggesting that MLVA-16 provides a good phylogenetic signal. Five clusters with some geographic coherence were delineated, based on discriminant analysis of principal components. The two major clusters grouped strains from multiple geographic origins. In contrast, all strains that have emerged on mango or cashew in West Africa grouped in one cluster, which did not contain any strains of different origin. MLVA-16 represents an opportunity to improve our understanding of the structure of Xcm populations, by sharing genotyping data. The MLVA-16 data generated in this study was deposited in a dedicated online database

Evaluation of opportunity costs in cocoa production in three ecological zones in Côte d'Ivoire

This article examines the production costs of cocoa farming in Côte d'Ivoire, West Africa, taking into account the opportunity cost approach. To this end, surveys were conducted among 228 farmers in three regions, Bonon, Soubré and Biankouma, following an east–west gradient. The estimated costs of using family labor and land were based on the opportunity cost approach. The financial costs associated with production were also taken into account. Comparative analyses between different localities and cropping systems highlighted specific workload characteristics. Finally, a principal component analysis (PCA) was used to profile producers according to their income levels and profits. The findings showed that family labor was the main component of cocoa production costs. Prices paid to farmers did not always cover all production costs, with 38% of farmers producing at a loss, and this was contingent on the agro-ecological zone. Furthermore, the agroforestry system proved to be more economical in terms of labor than the full-sun system. These results underline the relevance of the opportunity cost approach in assessing production costs and setting cocoa selling prices. This should lead to a review of public price-setting mechanisms to ensure fair remuneration for family labor

First report of Diaphorina citri and 'Candidatus Liberibacter asiaticus' associated with the Huanglongbing disease on Citrus spp. in French Guiana

Huanglongbing (HLB) is a disease on citrus associated with three unculturable phloem-limited gram-negative bacterial species transmitted through grafting or by two psyllids: Diaphorina citri (ACP) and Trioza erytreae (Bové 2006). HLB is considered the worst constraint on citrus worldwide, where major active epidemics involve 'Candidatus Liberibacter asiaticus' (CLas) and ACP. In the French West Indies, ACP was detected in Guadeloupe (1998) and Martinique (2012), followed by CLas detection in 2012 and 2013, respectively. In French Guiana, under the direction of the French Ministry of Agriculture regional services (DEAAF), FREDON Guyane has been monitoring HLB and its psyllid vectors since 2016. The first detection of D. citri occurred on 22 July 2021 in the Madeleine district of Cayenne within the Murraya paniculata sentinel network and on various Citrus spp. Species identification was confirmed morphologically on 2 August 2021 by the French National Reference Laboratory for Insects (ANSES, Plant Health Laboratory, Entomology and Botany Unit), but no Liberibacter sp. test was done. At this stage, citrus trees did not show clear HLB symptoms (blotchy mottle patterns and yellow islands on leaves). Suspicious plant samples of M. paniculata and Citrus spp. were regularly transmitted to the National Reference Laboratory for bacteria on citrus and tropical plants (ANSES, Plant Health Laboratory, Tropical Pests and Diseases Unit, Reunion Island) for analysis, using the official French method ANSES/LSV/MA 068 based on the Li et al. (2006) real-time PCR. DNA extractions (DNeasy Plant Mini Kit, Qiagen) were performed on leaf midribs, along with a negative control (Citrus paradisi 'Star Rubis'). Amplifications were performed on two wells, giving an average Cq value. In September 2021, typical amplification curves were obtained on one sample of M. paniculata (Cq = 34.36; SD = 0.314). The same scenario occurred in March 2022 on a sample from an old citrus tree (Cq = 31.27; SD = 0.241) collected in a private courtyard in Sinnamary and in July 2023 on a citrus tree (Cq = 31.83; SD = 0.074) from an orchard in Kourou. This last sample's positive status was further confirmed through the real-time PCR protocols from Morgan et al. (2012) (Cq = 33.25; SD = 0.027), Zheng et al. (2016) (Cq = 33.05; SD = 0.237), and de Chaves et al. (2023) (Cq = 34.19; SD = 0.850). Following the impossibility to characterize the species of 'Ca. Liberibacter spp.' detected (40 out of 352 samples since 2022), hampered by its in planta low titer, a field survey was organized in November 2024. CLas was detected on one sample of citrus tree from a private courtyard in Kourou (Cq = 26.31; SD = 0.288), confirmed by the method of de Chaves et al. (2023) (Cq = 27.507; SD = 0.07). Higher in planta titer allowed for the CLas species characterization through conventional PCR (CLas observed band of 703 bp) (Hocquellet et al. 1999; Teixeira et al. 2005). Sanger sequencing (Genewiz U.K., 678 bp) of this amplicon (Genbank no. PV018783) showed 100% identity (BLASTn) with the CLas strain CP131152. To our knowledge, this is the first report of the presence of HLB in French Guiana, involving the CLas species and the vector D. citri. All year long, high heat could explain in planta HLB low titer. The introduction events remain unclear. This report highlights the importance of plant certification, psyllid population control, and surveillance of territories close to French Guiana

Evaluation of geographical distortions in language models

Geographic bias in language models (LMs) is an underexplored dimension of model fairness, despite growing attention being given to other social biases. We investigate whether LMs provide equally accurate representations across all global regions and propose a benchmark of four indicators to detect undertrained and underperforming areas: (i) indirect assessment of geographic training data coverage via tokenizer analysis, (ii) evaluation of basic geographic knowledge, (iii) detection of geographic distortions, and (iv) visualization of performance disparities through maps. Applying this framework to ten widely used encoder- and decoder-based models, we find systematic overrepresentation of Western countries and consistent underrepresentation of several African, Eastern European, and Middle Eastern regions, leading to measurable performance gaps. We further analyse the impact of these biases on downstream tasks, particularly in crisis response, and show that regions most vulnerable to natural disasters are often those with poorer LM coverage. Our findings underscore the need for geographically balanced LMs to ensure equitable and effective global applications

Impact of soil chemical attributes on the behavior and spread of Fusarium oxysporum in date palm

Fusarium wilt of date palm (Phoenix dactylifera L.), caused by Fusarium oxysporum f. sp. albedinis, continues to threaten oases across the Maghreb. However, the disease has failed to establish in Southeastern Algeria, despite the ongoing movement of potentially contaminated plant material. This study investigated whether soil chemical properties contribute to this apparent epidemiological boundary. A total of 48 soil samples were collected from healthy and diseased date palm groves across infected (Adrar, Ghardaïa) and uninfected (Biskra) regions. Soils were analyzed for pH, electrical conductivity (EC), organic matter, calcium carbonate (CaCO3), soluble cations (Ca2+, Mg2+, Na+, K+), and available phosphorus (PO43−). While no consistent differences were observed between healthy and diseased trees within infected areas, five parameters—EC, Ca2+, PO43−, Mg2+, and CaCO3—differentiated uninfected from infected regions. Higher levels of EC, Ca2+, and CaCO3 in uninfected soils suggest a suppressive effect on the pathogen or enhanced host resistance. These findings align with previous studies showing that elevated salinity and calcium can limit Fusarium development by altering cell wall integrity, enzyme activity, and spore production. Phosphorus and magnesium may further modulate disease expression through effects on plant immunity and pathogen metabolism. Our results support the hypothesis that F. oxysporum f. sp. albedinis is constrained by edaphic factors in Southeastern Algeria. This study highlights the importance of soil chemistry in shaping pathogen distributions and suggests that nutrient-based management may help suppress Fusarium wilt in date palm agroecosystems

Environmental edutainment games and pro-environmental behavior of primary school students: Evidence from a field experiment

This study explores the effectiveness of behavioral interventions, specifically edutainment rooted in environmental education, in fostering pro-environmental behavior (PEB) among primary school students. Through a lab-in-the-field experiment, the research focuses on the impact of an environmental edutainment game on children's monetary donations to environmental non-governmental organizations (ENGOs) as PEB. Findings suggest that having played an environmental edutainment game does not significantly affect the amount donated, though it appears to influence the likelihood of making a donation, particularly among male and students from lower socio-economic backgrounds. Besides, female participants and students with a higher socio-economic and cultural profile exhibit higher likelihood to donate and higher effective donations, regardless of the edutainment intervention

A global database on land use and management change effects on soil KMnO4-oxidisable organic carbon (POXC)

Soil carbon transformation is vital for ecosystem functions like food production and climate regulation. While soil organic carbon is a key soil health indicator, its sensitivity to management changes is debated. Alternative indicators, such as permanganate-oxidisable carbon (POXC), are being explored. This database compiles 10,068 comparisons of soil POXC content from 284 peer-reviewed studies published up to 2023, covering 45 countries and 63 land use types, including arable land, grassland, agroforestry, and forests. Most studies focused on arable land (n = 7,809), examining input changes (n > 500) and tillage intensity (n > 200). The most studied land-use changes were grassland conversion to arable land (n = 324) and vice versa (n = 261). The dataset includes rich metadata on geographical context, soil types, key properties (pH, clay content), POXC protocols, and data quality scores. This resource supports scientific and policy discussions on POXC's potential as a practical indicator for improving land use and soil health management

What sort of digitalization do family farmers need?

Digitalizing the agricultural sector in West Africa is a promising opportunity for stakeholders in the agricultural and technology sectors, an opportunity that relies on agricultural producers' voluntary mass appropriation of connected phone tools. Mobile phones and app use could foster independent producer networks, improve value chain structuring and boost the sector's economic value. Agricultural producers are now being targeted by a growing number of providers of “digital services”, in the form of apps developed by tech and agritech start-ups. However, apps developed specifically for agricultural producers have met with mixed success. What lessons can be drawn from this mixed bag of results, and what will it take for digitalization to truly serve producers and facilitate the transition to socially, economically and environmentally sustainable practices

Molecular and genetic determinism of sorghum grain quality

Sorghum grains are rich in proteins and starch but exhibit low protein digestibility, limiting their use in food and feed. However, the genetic and molecular mechanisms underlying these traits remain poorly understood, particularly the genomic regions involved, as well as the structural genes and transcription factors (TFs) that regulate them, hindering efforts to improve sorghum grain quality. To address this, we adopted an integrated genomic and genetic approach. At the genomic level, we constructed a gene co-expression network using transcriptomic data collected during grain development (10 stages) over two years. In parallel, we quantified starch and protein content and measured protein digestibility. Two major gene co-expression modules were identified. The first was linked to the loss of protein digestibility, involving genes related to disulfide bond formation and modulation. The second contained most kafirin and starch metabolism genes, as well as orthologs of TFs known to regulate protein and starch accumulation in other cereal species. Functional assays performed in protoplasts for six TFs revealed a central role for SbPBF1a, SbPBF1b, and SbNF-YC13 in modulating the expression of genes involved in protein and starch biosynthesis. In the genetic approach, we used a diversity panel of 300 sorghum genotypes representing global genetic diversity. This panel was cultivated at two sites in France over two growing seasons. Protein, starch contents and protein digestibility were measured. Whole-genome sequencing (WGS) was performed for all genotypes. These biochemical and genotypic data were analysed through genome-wide association studies (GWAS) using both single and multilocus models. Several significant SNPs were identified near genes previously associated with grain quality traits. Together, our work provides novel insights into the genetic basis and transcriptional regulation of protein and starch accumulation, as well as protein digestibility in sorghum grains. It also identifies regulatory and structural genes that could be targeted to enhance grain quality, thereby supporting the development of improved sorghum varieties with higher nutritional value

Leverage points for scaling nature-based adaptation to climate change

Despite ambitious goals and policies, climate change adaptation efforts remain slow and insufficient compared to the pace and magnitude of climate change. Nature-based Solutions (NbS) offer a holistic approach, with assumed co-benefits that jointly address climate change adaptation and mitigation, biodiversity conservation and other societal challenges. NbS are increasingly implemented to enhance local adaptation to climate change; however, they remain mostly marginal and isolated considering the magnitude of the challenge. Therefore, pathways to rapidly scale NbS are urgently needed. We hypothesise that NbS implementors are limited in their scaling strategies by their decision context. We propose an empirical framework for systemic analysis of decision contexts for scaling NbS, showcased for the Grenoble Region in the French Alps. We use mixed qualitative methods—policy and strategy document analysis, interviews and workshops with NbS experts, to explore a pathway to a conducive decision context. To characterize this context and the pathway to scaling, we identified the main leverage points, their underpinning levers and their interactions. According to workshops participants, NbS scaling should be supported by a combination of several deep and some shallow leverage points working simultaneously, including knowledge production and sharing, values and perception, local governance, supportive policies, financial support and landscape planning culture. Our results stress the need for more emphasis on how to support the integration of NbS principles into cultural roots and values; and on how to integrate deep leverage points into adaptation policies and strategies. However, this entails many challenges because of the diversity of actors with different objectives, values and power, and the multiple institutional scales and timeframes. We propose our integrative approach as a way to further support decision-makers in navigating complex decision contexts for scaling NbS and building on simultaneous progress within each leverage point