Background/Objective. The aim of this study was to determine the combined effect of an environmental strain of Purpureocillium lilacinum (MTL01) together with Bacillus velezensis 83, upon infection by the root-knot nematode Meloidogyne enterolobii. Experimental development. Three greenhouse experiments were conducted at different times (July–October 2022, February–June 2023, and September 2024–January 2025). In each experiment, treatments included uninoculated controls, plants inoculated only with P. lilacinum MTL01, with B. velezensis 83 only, or with both microorganisms, with and without nematode infection. Certified tomato seeds were inoculated with MTL01 spores or solution as a control and transplanted after germination. B. velezensis 83 was inoculated one week later, followed by two additional applications. Nematodes were introduced three weeks after transplanting, and plants were subsequently maintained in a greenhouse for an additional eight weeks. At harvest, growth parameters and infection levels were quantified (biomass, length, number of flowers, root weight, number of galls, and galling index). Results. Data of vegetative growth varied among experiments, with no clear evidence of effects associated with microbial inoculation. However, the combination of P. lilacinum MTL01 and B. velezensis 83 showed reproducible results, reducing gall formation caused by M. enterolobii by more than 60% and promoting a consistent tendency toward increased flowering relative to nematode-infested control plants. These results demonstrate the potential of using combined microorganisms to improve tomato performance under greenhouse conditions. Conclusion. Our findings highlight the importance of mitigating M. enterolobii infection in tomato using a combination of microorganisms, not only to control nematode populations but also to increase flower yield by up to 4.3-fold (Experiment 3) in plants without nematodes, and 1.6-fold in the presence of M. enterolobii. This represents a promising strategy; however, further research is needed to confirm its safety and optimize its application under real agricultural conditions.
Background/Objective. Bell pepper (Capsicum annuum) is one of the most important agricultural crops of Mexico. Globally, over 60 virus species have been reported infecting Capsicum spp., some of them are associated with significant losses in yield and quality. The objective of this report is to determine the presence of bell pepper endornavirus (BPEV, Alphaendornavirus capsici) in bell pepper crops in Guanajuato, Mexico. Experimental development. Samples of bell pepper plants were collected from a commercial greenhouse in Guanajuato, Mexico, in May 2024. A symptomatic plant (mosaic, leaf yellowing, and dwarfing symptoms) was analyzed by high throughput sequencing (HTS). Detection and identification were performed on individual samples using reverse transcription PCR (RT-PCR) and corroborated by Sanger sequencing. A phylogenetic analysis was conducted to investigate genetic diversity of the virus. Results. A partial sequence of BPEV was generated by HTS and de novo assembly (GenBank: PZ103604), this virus was part of a mixed infection in the symptomatic plant, including Begomovirus capsicumhuastecoense (pepper huasteco yellow vein virus) and Cucumber mosaic virus. In addition, five bell pepper plants, including symptomatic and asymptomatic, tested positive for BPEV using RT-PCR, the identity of the virus was confirmed through Sanger sequencing and phylogenetic analysis. Conclusion. The detection of BPEV in commercial bell pepper crops in Guanajuato highlights the importance of continuous monitoring of emerging viruses, including possible mixed infections with other viruses, and further studying their impact on crop health and productivity. Although BPEV was detected in symptomatic plants, the observed symptoms cannot be attributed to it as it was detected as part of a co-infection. To our knowledge, this is the first report of BPEV infecting bell pepper in Mexico.
Background/Objective. Coffee leaf rust is the primary disease affecting this crop. The objective was to evaluate the incidence and severity of coffee leaf rust under the influence of a systemic fungicide and two biofungicides on varieties cultivated in the Northern and Northeastern Sierra regions of Puebla. Experimental development. The effects of Azoxystrobin, Melaleuca alternifolia, and Bacillus subtilis were evaluated across six shade-grown plots featuring the Typica, Costa Rica 95, Garnica, Marsellesa, and Oro Azteca varieties, located in Huehuetla, Ixtepec, and Zongozotla. Sixteen sampling events were conducted, for each, of evaluation rust incidence and severity, shade percentage, the weight of 100 ripe cherries, and altitude were assessed. Additionally, temperature and relative humidity were recorded in Huehuetla. Incidence and severity were compared using the Kruskal-Wallis test and the Dwass-Steel-Critchlow-Fligner (DSCF) method. Furthermore, the correlation of these variables with altitude and shade percentage was analyzed. Cherry weight data underwent analysis of variance and mean comparison, while a risk analysis was performed using the climatic variables. Results. Rust reached maximum severity and incidence (19.9 and 100%, respectively) in the Typica variety (March 2025). Azoxystrobin significantly reduced the disease, followed by M. alternifolia and B. subtilis. No influence of shade on incidence (r=0.33360) or severity (r=0.30735) was identified. In contrast, altitude showed a moderate negative correlation with incidence (r=-0.4632, p<0.0001) and with severity (r=-0.57433, p<0.0001). The Typica and Garnica varieties were the most susceptible. Conclusion. The fungicides demonstrated control of the disease compared to the control treatment; therefore, they could be considered for the management of H. vastatrix.
Backgrounds/Objective. Coffee cultivation is at risk due to the effects of climate change, which has created favorable conditions for the proliferation of diseases such as coffee leaf rust (Hemileia vastatrix). One of the most cost-effective and efficient control measures has been the use of materials that are tolerant or resistant to this fungus. The objective of this study was to analyze the response of 32 promising Coffea arabica accessions to coffee leaf rust and to describe their morphological characteristics, relating them to disease severity, under conditions prevailing in the municipality of Amatlán de los Reyes, Veracruz. Experimental development. A total of 32 C. arabica accessions were evaluated in a completely randomized block design with three replications, compiling a descriptive profile of the visible, identifiable, and measurable morphological traits of each evaluated accession. The incidence of coffee leaf rust (Hemileia vastatrix) was assessed on a five-level severity scale on a monthly basis over a two-year period. An ordinal mixed-effects model and post hoc tests were computed to identify significant differences in rust incidence. Hierarchical cluster analysis was carried out to group the materials according to susceptibility or severity level, and the relationship between morphological traits and infestation level was analyzed using multiple correspondence analysis. Results. The materials showed significant differences in tolerance to coffee leaf rust. Tukey's test (α = 0.05) identified three groups based on the severity of rust damage; the Pacamara variety was the most affected, while the H1 Centroamericano, Parainema, Catigua MG2, Col 1, EC 15, IPR 103, Kartila 1, Lempira, Paraíso, S795, and the Arabusta SLN 5B varieties were the least affected. The remaining varieties showed an intermediate severity of infestation. Conclusion. Under the conditions prevailing at the experimental site of the Colegio de Postgraduados Campus Córdoba, 11 C. arabica materials showed a favorable response to the severity of Hemileia vastatrix (H1 Centroamericano, Parainema, Catigua MG2, Col 1, EC 15, IPR 103, Kartila 1, Lempira, Paraíso, S795, and the Arabusta SLN 5B). This contributes to the options available to coffee growers in terms of production and plant health management against coffee leaf rust.
Background/Objective. Cucurbits are an economic pillar of global and national agriculture. However, their productivity is threatened by the increasing incidence of viral plant diseases. Consequently, coinfections with members of the Begomovirus and Crinivirus genera have been associated with exacerbated symptoms and high incidence rates in crops, leading to emerging disease patterns. The aim of this study was to identify and molecularly characterize the begomoviruses and criniviruses associated with an emerging disease in melon crops in a municipality of the Comarca Lagunera region, Mexico. Materials and Methods. A targeted sampling of nine melon plants exhibiting symptoms such as severe interveinal chlorosis, mottling, yellow mosaic patterns, and fruit deformation was carried out. For viral detection, DNA extraction was performed using 3% CTAB and RNA extraction using the TRIzol reagent. Begomoviruses and criniviruses were detected using PCR and RT-PCR with specific primers. Complete begomovirus genomes were enriched by rolling circle amplification (RCA). Amplicons derived from Open Reading Frame (ORF) of the capsid protein (CP) of criniviruses were generated using RT-PCR. Subsequently, the genomes and CP amplicons were cloned and sequenced for phylogenetic and evolutionary analysis. Results. Molecular identification revealed the prevalence of mixed infections in seven of nine samples, comprised of two begomovirus species, cucurbit leaf crumple virus (CuLCrV, Begomovirus cucurbitae) and watermelon chlorotic stunt virus (WmCSV, Begomovirus citrulli), and the crinivirus cucurbit yellow stunting disorder virus (CYSDV, Crinivirus cucurbitae). Genomic analyses confirmed that CuLCrV and WmCSV possess genomic structure typical of begomoviruses. Significant divergence was observed at specific loci (CuLCrV C4 gene, WmCSV NSP gene, and DNA-B intergenic regions of both species), suggesting their potential involvement in evolutionary adaptation processes. Phylogenetically, although the CuLCrV isolate showed close relationship to isolates from Arizona and Sonora, it was placed in a clade distinct from those previously reported in the region, indicating an independent evolutionary course. Furthermore, phylogenetic analysis based on the nucleotide sequence of the CYSDV capsid protein (CP) gene revealed a close relationship with isolates previously reported in Jordan and Mexico. Conclusions. This study represents the first report in Mexico of a disease associated with WmCSV, CuLCrV, and CYSDV coinfection in cucurbits. The findings amphasize the complexity of emerging diseases and highlight the importance of strengthening molecular epidemiological surveillance to mitigate the impact of these mixed infections on Mexican agriculture.
