In México, avocado production is an important economic source. In the last season it generated $ 3. 27 billion USD of foreign currency in the country. Irpex spp. are wood decay fungi. In the period 2019-2022, in the state of Michoacán (19°13' N; 101°55' W), México, basidiomes of Irpex sp. were observed on the base of trunks and crowns of 5-years-old and older avocado (Persea americana) trees. The trees exhibited disease symptoms that included white root rot, leaf yellowing, small leaves, branch diebacks, generalized defoliation, apical flaccidity, abundant but small sun burnt fruits due to the lack of foliage, and after 2-4 years of first disease appearance, the infected trees died. In the place where fungus was established, abundant white and cottony mycelium was formed, which caused trees decay. The incidence of the disease in the sampled orchards was estimated to be 30% per ha with 350 - 400 trees, which was determined through a simple sampling design focused on trees with signs and symptoms of the disease due to the phytopathogen. Samples of infected tissue (roots and stems) and fungal basidiomes were collected from 90 trees (5-6 per orchard). The symptomatic avocado trees studied were randomly selected from 17 orchards. For the fungal macroscopic characterization, the synoptic keys described by Gilbertson and Ryvarden (1986) and by Largent (1973) were used. The samples showed typical structures corresponding to Irpex sp., including rosettes, annual basidiomes, a system of monomitic hyphae, and subglobose basidiospores. In vitro fungal isolation from basidiomes and infected tree tissues was done according to the protocol of Agrios (2004). The fungal strains were maintained on PDA at 28 °C. At 16 days of incubation the colonies were opaque, whitish with fluffy and corky mycelium. Microscopic analysis of the fungus showed typical yellowish spores, with an ellipsoid shape of 3-4 x 4-5.5 µm (50 accounted structures per isolate [N=19]) and basidia of 20-25 x 4.5-5.5 µm (n=20 basidiomes). For molecular characterization, two molecular markers were used, the internal transcribed spacer rDNA-ITS1 5.8 rDNA-ITS2 (ITS; White et al. 1990) and the large ribosomal subunit (LSU; Vilgalys and Hester 1990). The PCR reaction was performed as described by Martínez-González et al. (2017). The consensus sequences were compared with those deposited in the NCBI-GenBank, using the BLASTN 2.2.19 tool (Zhang et al. 2000), the samples showed 99% match with the species, Irpex rosettiformis. GenBank accession numbers of the submitted isolates are summarized in supplementary Table 4. To test Koch's postulates, 3-months old avocado plants grown in greenhouse conditions were inoculated (n = 10 per each isolate [N= 19]) on the roots with 3 g of I. rosettiformis mycelium. The experiment was done twice with 20 non-inoculated plants as control. After 67 days, basidiomes (50 x 70 x 1.5 mm in average) were observed where the disease incidence was >77%, with subsequent tree decline. The pathogen was re-isolated in vitro in PDA and its identity was confirmed by morphological characteristics of mycelium. This work shows that I. rosettiformis is not only a wood decay fungus, but also a phytopathogen, the causative agent of white root rot disease in P. americana var. drymifolia, cultivar 'Hass', which establishes a precedent for monitoring and preventing its proliferation to other regions in the American continent and the world where nursery avocado seedlings are exported.

México is the world’s leading producer of avocado, with 2,540,715 tons in the last year. Trametes spp. are macromycete fungi that rot wood. In 2022, in the state of Michoacán, México, sporomas of Trametes sp. were found in the trunks of avocado trees (Persea americana var. Hass) of 10 years old and older. The trees showed disease symptoms including yellowing of leaves, widespread defoliation, and wilting. It was observed that 10% of the infected trees were felled after heavy rains. In the place where the fungus settled, abundant cream-colored and cottony mycelium developed, causing “white rot”. The incidence of the disease in the sampled orchards was 60% in the tree population per hectare with 350 trees. The symptomatic trees studied were randomly selected from seven orchards. The collected fungal samples show typical structures corresponding to Trametes sp., including large sporomas, a pileus with a surface of concentric zones of various ocher tones, and a porous hymenium. The samples showed a 99% match with the species Trametes hirsuta. Laboratory bioassays of inoculation in fresh wood segments of avocado formed typical sporomas of the pathogen. Finally, the fungus was recovered and reisolated in vitro in PDA, and its identity was confirmed through the morphological characteristics and molecular tests. To the best of our knowledge, this article reports for the first time that P. americana cv. Hass and Mendez are new hosts for T. hirsuta. Therefore, the environmental and horticultural management conditions that favor the proliferation of T. hirsuta must be investigated.

Tomato (Solanum lycopersicum, L.) is the most important vegetable in the world in terms of production volumes, which will have to continue to increase to meet future consumption needs. In this regard, the use of nanotechnology could make the supply of nutrients to plants more efficient and improve and increase agricultural production. The objective of the study was to determine the effect of foliar application of Zn, Cu, and Fe nanoparticles on tomato production and quality. In 2021, a Roma-type tomato crop was established under protected agriculture. The treatments consisted of the individual and combined foliar application of nanoparticles of Zn, Fe, Cu, Zn+Fe, Zn+Cu, Fe+Cu, Zn+Fe+Cu, plus a control without application. It was found that the individual application of the nanoparticles did not improve tomato production, however, the combined supply increased the yield. The highest production was recorded with Zu+Fe+Cu, which was 66% higher than the control plants, with this treatment the lycopene content also doubled (2.23 mg g-1 dry matter). The nanoparticles increased the nutrient content within the maximum limit allowed for consumption. Therefore, the application of micronutrient nanoparticles supplied in combination is a viable alternative to improve tomato yield and quality. El tomate (Solanum lycopersicum, L.) es la hortaliza de mayor importancia a nivel mundial por volúmenes de producción, que deberá seguir aumentando para satisfacer la necesidad de consumo futuro. Al respecto, el uso de la nanotecnología podría eficientar y mejorar el aporte de nutrientes a las plantas y aumentar la producción agrícola. El objetivo del estudio fue determinar el efecto de la aplicación foliar de nanopartículas de Zn, Cu y Fe, sobre la producción y calidad del tomate. En el año 2021 se estableció el cultivo de tomate tipo roma en agricultura protegida. Los tratamientos consistieron en la aplicación foliar individual y en combinación de nanopartículas de Zn, Fe, Cu, Zn+Fe, Zn+Cu, Fe+Cu, Zn+Fe+Cu, más un testigo sin aplicación. Se encontró que la aplicación individual de las nanopartículas no mejoró la producción de tomate; sin embargo, el suministro combinado aumentó el rendimiento. La mayor producción se registró con Zu+Fe+Cu, que fue 66% superior a las plantas del testigo, con este tratamiento también aumentó al doble el contenido de licopeno (2.23 mg g-1 de materia seca). Las nanopartículas aumentaron el contenido nutrimental dentro del límite máximo permitido para consumo. Por lo que la aplicación de nanopartículas de micronutrientes suministradas en combinación es una alternativa viable para mejorar el rendimiento y la calidad del tomate.

Woody tissue diseases of avocado (Persea americana Mill. var. Hass) pose a major phytosanitary threat due to their chronic progression, late symptom expression, and severe impact on tree stability and productivity. Although white rot has traditionally been attributed to saprobic basidiomycetes, increasing evidence suggests corticioid fungi may act as facultative pathogens in agricultural systems. This study examined corticioid basidiomycetes associated with white rot in stems and branches of avocado in Michoacán, Mexico. Field surveys revealed consistent symptoms of structural weakening, branch dieback, and wood decay. Fungal isolates obtained from symptomatic tissues and sporomes were characterized morphologically and identified through ITS-based phylogenetic analyses. Representative isolates of Grammothele spp. and Dentocorticium portoricense were evaluated in pathogenicity assays under controlled conditions. All isolates reproduced field symptoms, confirming pathogenicity, though aggressiveness varied. D. portoricense exhibited the highest incidence, severity, and AUDPC values, indicating greater virulence, while Grammothele isolates showed slower, moderate progression. Phylogenetic analyses provided robust support for D. portoricense, whereas Grammothele was resolved at genus level. Integration of field, pathogenicity, and molecular data demonstrates corticioid fungi are not merely secondary saprotrophs but relevant pathogens in avocado white rot. These findings highlight the need to include corticioid fungi in diagnostic, monitoring, and management strategies for trunk and branch diseases.

El jitomate (Solanum lycopersicum L.) es una de las hortalizas de mayor importancia para el consumo humano por su aporte de vitaminas, minerales y antioxidantes; por ello es necesario buscar alternativas de manejo amigables con el ambiente. Las algas marinas y el ácido acetilsalicílico han demostrado mejorar la nutrición de las plantas, promover el crecimiento y conferir resistencia contra factores bióticos y abióticos. El objetivo del estudio fue determinar el efecto de la aplicación de algas marinas y ácido acetilsalicílico en la producción y calidad de jitomate bajo malla sombra, en el año 2022. En plantas de jitomate se realizó la aplicación foliar de extractos de Ascophyllum nodosum, Ecklonia maxima, Sargassum vulgare, ácido acetilsalicílico, solos y en combinación Ascophyllum nodosum +ácido acetilsalicílico, Ecklonia maxima+ ácido acetilsalicílico, Sargassum vulgare+ácido acetilsalicílico y el testigo. Se encontró que los tratamientos no modificaron el rendimiento del fruto, ni componentes de rendimiento. El contenido de licopeno aumentó en los frutos con las algas marinas y con Sargassum vulgare+ácido acetilsalicílico y los frutos más firmes se registraron con Ascophyllum nodosum, por lo que la aplicación de algas marinas y ácido acetilsalicílico, bajo las condiciones en que se cultivaron las plantas, a pesar de no mejorar las variables de producción, aumentaron el contenido de licopeno y firmeza con algunos tratamientos, parámetros que mejoran en el fruto su calidad como alimento funcionales en la salud humana y soportar mejor el transporte y comercialización.

El nopal (Opuntia spp.) es una planta originaria de América, adaptada a zonas áridas mediante un metabolismo tipo MAC, que reduce significativamente la pérdida de agua. México es el principal centro de diversidad de esta especie, con múltiples variedades tanto silvestres como cultivadas. Además de su importancia ecológica, el nopal tiene usos alimenticios, forrajeros, medicinales y nutracéuticos, gracias a sus compuestos bioactivos. El mucílago del nopal es un hidrocoloide vegetal formado principalmente por amilosa y amilopectina. Su estructura polimérica le confiere propiedades hidrofílicas y una alta viscosidad. Entre sus componentes se encuentran compuestos fenólicos con propiedades antioxidantes y antiinflamatoria, como los flavonoides, especialmente los flavonoles como la quercetina, cuya capacidad para neutralizar especies reactivas de oxígeno (ROS) ayuda a prevenir el estrés oxidativo y enfermedades crónicas. La presente investigación se realizó en el laboratorio de Bromatología de la Facultad de Agrobiología “Presidente Juárez” de la UMSNH con el objetivo de determinar el contenido de mucílago, de compuestos fenólicos totales, de flavonoides y la capacidad antioxidante de distintos genotipos de Opuntia. Las recolectas de nopal se realizaron en agosto del 2023 a abril del 2024. Se encontró que el mayor rendimiento de mucilago se obtuvo en el cultivar de nopal tunero rojo con 0.04 gps/gpf, equivalente al 0.4 % del peso del cladodio. Este genotipo presentó también los niveles más altos de fenoles totales (1.768 mg EAG/gps) y flavonoides (0.105 mg EQ/gps). Además, mostró la mayor actividad antioxidante frente a los radicales DPPH (96.53 %) y ABTS+ (91.4 %), así como una capacidad antioxidante general de 0.9 mg EAG/gps, lo que destaca su potencial funcional y nutracéutico.