Maize is the most important crop for the Mexican society. Phytopathogenic fungi pose a major challenge to this cereal. These fungi are harmful to people and animals, mainly as a result of their mycotoxins. The objective of this research was to identify the fungi found in 18 maize genotypes collected in fields from the states of Morelos, Coahuila, Chiapas, and Puebla, Mexico. Pathogens were isolated in potato dextrose agar (PDA) culture medium and identified using morphological criteria. The pathogens were purified using monoconidial cultures and sheltered at 4 °C ± 2 °C. An analysis of variance was carried out using the SAS® 9.1 statistical software. Fungi from the following genus and species were identified: Aspergillus, Penicillium, Alternaria, Bipolaris, Trichothecium roseum, and Fusarium verticillioides. It is worth mentioning that F. verticillioides and Penicillium sp. are the most common pathogens in maize genotypes, with an incidence of 63.68 and 6.57%, respectively. Moreover, along with genus Aspergillus, they are considered to be the most important toxicological fungi, given the harm that they cause to humans and animals. Therefore, management strategies are needed to guarantee that grains can be safely consumed by society

Background. The chili is a cornerstone of Mexican culture and cuisine, deeply embedded in the country's history and identity. Objective. To identify genetically and phylogenetically the virus that affects the native Apaxtleco chili pepper in Guerrero, Mexico, and to recognize symptoms of virosis in plants. Methodology. Young leaves of native Apaxtleco chili pepper plants with typical virosis symptoms were collected. The alignment of 13 sequences of DNA nucleotides was carried out, 11 of which belong to the fragment of region that codifies for the gene of “capsid protein / nuclear exportation factor BR1” of PepGMV two of these were obtained in this study, Aymedi-02 (KX641201.1) and Aymedi-01 (KX641200.1), and the nine remaining sequences were obtained from the GenBank database. Two more sequences were included for the purpose of tree rooting; one corresponds to the chlorotic leaf curl virus (AF325497.1) and another to the mosaic virus of African cassava (J02057.1), obtained from GenBank. The alignment of 13 sequences consisted of a total extension of 541 bases. To obtain descriptive information about the PepGMV sequences, only the sequences corresponding to it (11 sequences) were used, with a total of 326 conserved sites and 211 variable sites; of these, 89 are parsimony informative sites and 120 Singleton. Results. The sequence analysis showed 99% of identity with sequences of the PepGMV and the phylogenetic analysis confirmed the identification. Implications. Our results highlight a significant opportunity to enhance the control of this pathogen in this crop. Conclusion. Pepper Golden Mosaic Virus (PepGMV) was identified in Guerrero, Mexico, the symptoms presented in plants infected by this pathogen were: chlorosis, deformation, and mosaics.

Thirty accessions of cotton (Gossypium) in the INIFAP genebank in the Iguala Experimental Field were analyzed for resistance to eriophyid mites. Vegetative structures such as leaves and petioles and reproductive structures such as the bract calyx with galls were collected from cotton plants. Galls were cut into cross section to locate mites; taxonomic keys were used to identify the mites. Damage to accessions of cotton was evaluated on a scale of six classes. Damage by eriophyid mites was analyzed with PROC RANK, subjecting it to analysis of variance with PROC GLM, and mean comparison by Tukey (P = 0.05) using statistical software SAS® 9.2. Eriophyidae was reported associated with formation of galls in cotton. Severity of damage was 0 to 85%, but cotton accessions TOA-06, FZ-06, GOS-16, GOS-34, TOA-09, TOA-02, GOS-17, TOA-04, and TOA-05 were resistant. More studies of biology and ecology and molecular analysis are needed to better understand and develop management strategies against mites in cotton.

In Mexico, there are 29 native species of the genus Hymenocallis, including H. glauca, which is characterized by a bulb that stores carbohydrates, giving energy for the emergence of foliage and floral scapes; it is the most cultivated species and holds economic value as a potted plant and cut flower (Leszczyñska-Borys and Borys, 2001). In September 2024, a survey was conducted at the Center for Research in Horticulture and Native Plants (18°55'55.6"N 98°24'01.4"W) at UPAEP University, where there was an average temperature of 25 °C and 75% relative humidity (RH) for 10 consecutive days. Approximately 30-day old H. glauca seedlings exhibited symptoms of root and bulb rot in a 0.4 ha area, with a 45% disease incidence. Symptoms included root and bulb rot with constriction at the base of the bulb and the presence of brown mycelia. Symptomatic tissues from 50 seedlings were collected, cut into 5 mm pieces, sterilized with 3% NaClO for a minute, rinsed with sterile distilled water, and placed in Petri dishes with potato dextrose agar (PDA) medium. Samples were incubated in the dark for six days at 28 °C. An isolate was obtained from each diseased seedling using the hyphal tip method. After six days, the colonies consisted of white mycelium that turned brown with age. Right-angle branching hyphae were observed, with slight constriction at the base of the branches. The hyphae were multinucleate, containing four to nine nuclei per cell. After 15 days, some isolates produced dark brown sclerotia. Based on these morphological characteristics, isolates were tentatively identified as Rhizoctonia solani Kühn (Parmeter, 1970). To confirm the anastomosis group (AG), two isolates (RsHg4 and RsHg8) were selected for molecular identification. Genomic DNA was extracted using the CTAB protocol. The ITS region was amplified and sequenced (White et al. 1990) in both isolates, and the sequences were identical. Thus, only the sequence of isolate RsHg8 was deposited in GenBank (PQ524600). BLAST analysis of the partial ITS sequence (639 bp) showed 99.84% similarity with R. solani AG 2-1 isolate (GenBank: JF792354) (Mercado et al. 2012). Phylogenetic analysis of AGs sequences allowed assignment of the isolate RsHg8 to the AG 2-1 clade. Pathogenicity was confirmed by inoculating 50 30-day old H. glauca seedlings, grown in pots with sterile substrate. A 5 mm diameter PDA plug colonized with mycelium from the RsHg8 isolate was placed on each bulb, 10 mm below the soil surface. For control treatment, a PDA plug without fungal growth was placed on the bulb of 25 seedlings. The inoculated seedlings were incubated in a greenhouse at 28 °C and 90% RH. After six days, inoculated seedlings showed root and bulb rot with constriction at the base of the bulb. No symptoms were observed in controls. Fungus was re-isolated from the inoculated seedlings and characterized both morphologically and molecularly, yielding identical results as described above and identified as R. solani AG 2-1, thereby fulfilling Koch's postulates. Pathogenicity tests were repeated thrice. R. solani AG 2-1 has been reported infecting Allium tuberosum in Hokkaido, Japan (Misawa and Kuninaga, 2013), and Allium cepa in Morrow, Oregon (Patzek et al. 2013). To the best of our knowledge, this is the first report of R. solani AG 2-1 causing root and bulb rot in H. glauca in Mexico. Data on diseases affecting this plant is scarce, highlighting the importance of this research in developing integrated management strategies and preventing pathogen spread.

Rhipicephalus microplus ticks harm cattle health and productivity. Frequent use of ixodicides can result in resistant tick populations and environmental contamination, as residues enter soil. Nematophagous (NF) and entomopathogenic fungi (EF) are natural enemies of nematodes and insect pests. This study tested the in vitro lethal effects of liquid culture filtrates (LCFs) from selected NF on R. microplus. Fungi were grown in Czapek-Dox broth for 30 days at room temperature to obtain LCFs, which were tested using the immersion method. Experimental groups included: (1) Arthrobotrys musiformis, (2) Purpureocillium lilacinum, (3) Flavocillium subprimulinum, (4) Lecanicillium psalliotae, (5) ixodicide mixture (permethrin and chlorpyrifos), (6) negative control (water), and (7) negative control (Czapek-Dox broth). Differences in tick mortality among filtrate treatments starting on day 10 were observed. Filtrates from L. psalliotae and A. musiformis caused the highest mortality, with A. musiformis reaching 40% and L. psalliotae 33.3% on days 14, 16, and 18 (p < 0.01). We anticipated that combining ixodicides would lead to substantial tick mortality; however, the ixodicidal compounds (chlorpyrifos and permethrin) resulted in 33.3% mortality by day 18, which was similar to that observed for L. psalliotae during the same period. Filtrates from P. lilacinum and F. subprimulinum had no effect. The ixodicide treatment led to a significant reduction in oviposition, averaging 69.8% (p < 0.05). LCFs of selected NF could be used against either nematodes or R. microplus ticks.

The objective of this research was to evaluate the effect of polydimethylsiloxane (PDMS) CH3[Si(CH3)2O]nSi(CH3)3 as an adjuvant in bioherbicides and synthetic herbicides (chemicals) for weed (Johnson grass S. halepense and star grass Cynodon sp.) management in the lime plot. A total of 20 treatments were conducted, which included bioherbicides and synthetic herbicides, each with three replications, the dose was 50% more polydimethylsiloxane and 100% according to the product label. The experimental design was a randomized block design, with a factorial arrangement with three factors: A (products) with 10 levels, B (adjuvants) with 2 levels and C (evaluation dates) with 5 levels, each block consisted of an area of 5 m by 4 m. The assessment was carried out periodically, every week (5 evaluations), the scale proposed by EWRS was used. The results were in percentages and a 3-factor factor analysis was performed, where A (products) = 10 levels, B (adjuvants) = 2 levels and C (evaluation dates) = 5 levels, and the mean comparison test with Tukey (α ≤ 0.05), using SAS software. According to the results obtained, a significant difference is only presented between factors A (products) and B (adjuvants) (P < .0001). In factor A, the highest levels in weed control were glyphosate, diuron + carfentrazone and ammonium glufosinate with an average of 80.8, 74.0 and 70.8%, respectively. Regarding the interaction between the factors, only the A*B factors were present (P < .0001), only in the glyphosate, BH2 and diuron were the treatments with the highest interaction when using the 50% dose + polydimethylsiloxane as an adjuvant at a dose of 2 ml per 1 L of water with 76.2, 72.93 and 71.33%, respectively. The date when the treatments had the highest weed control effect was at the second and third week. These results underline the effect of polydimethylsiloxane to optimize the use of herbicides, not only in combination with chemical herbicides, but also with bioherbicides, offering an efficient and economic alternative for weed management (Johnson grass S. halepense and star grass Cynodon sp.).