Weeds decrease yield in crops through competition for water, nutrients, and light. Due to the circumstances mentioned above and the challenge of the emergence of herbicide-resistant weeds, developing sustainable alternatives becomes imperative. Plant extracts formulated into nano- and micro-encapsulates (NPs) emerge as a viable option for weed management. The objectives of this study were to identify phytochemical compounds within the ethanolic extracts of Carya illinoinensis, Ruta graveolens, and Solanum rostratum; determine their pre-emergence herbicidal activity on the indicator plants Sorghum bicolor and Phaseolus vulgaris; produce and characterize NPs with plant extracts; and assess their phytotoxicity under greenhouse conditions. The extracts were provided by Greencorp Biorganiks de México. Phytochemicals were identified through colorimetric assays and HPLC-MS, while pre-emergence tests were conducted in vitro, assessing concentrations of 12.5, 25, and 50% for each extract. NPs were synthesized using the ionotropic pre-gelation method, with size, zeta potential, and encapsulation efficiency (EE) being characterized. Finally, post-emergence tests were carried out in a greenhouse with seedlings. Compounds belonging to the hydroxycinnamic acid, flavonol, methoxyflavonol, hydroxybenzoic acid, methoxyflavone, tyrosol, stilbene, and lignan families were identified in all extracts. The pre-emergence herbicidal activity was observed for all extracts, with germination percentages ranging from 0 to 41% in both indicator plants. NPs exhibited sizes between 290 and 345 nm, zeta potentials ranging from −30 to −35 mV, and EE up to 94%. Finally, enhanced herbicidal activity was observed with plant extract NPs, with the species S. bicolor being more susceptible. NPs containing plant extracts are a viable option for bioherbicide production; however, continued research is necessary to refine formulations and enhance efficacy.

Introduction: In several regions of the world, Fusarium oxysporum causes losses on tomato crops; for control it, chemical fungicides are used. Nevertheless, these fungicides causing environmental and resistance problems; therefore, ecological alternatives as plant extracts have been developed. Due to the aim of this work, identify phytochemicals present in ethanolic and aqueous extracts from Agave lechuguilla qualitatively, Carya illinoinensis, Jatropha dioica, Larrea tridentata, and Lippia graveolens and determine their antifungal activity against F. oxysporum.Method: The plants collected from the northeast of Mexico; crudes and concentrated plant extracts obtained; the inhibition percentage and inhibitory concentration to 50 % (IC50) of F. oxysporum for each plant extract were determinate trough microdilution in the plate methodResults: The essential phytochemicals were flavonoids, saponins, tannins, and quinones. The antifungal activity showed at 1000 mg/L inhibition around 40 to 60% by aqueous crude extracts from leaves of L. graveolens and concentrated aqueous extracts from the stem of L. graveolens, respectively. The ethanolic extracts presented 100 % of inhibition for crude extracts of husk from C. illinoinensis; in leaves and stem from L. graveolens the inhibition started from 250 mg/L; for resuspended extracts, the inhibition started from 125 mg/L with L. graveolens stem and leaves; and finally in roots of A. lechuguilla and leaves from L. graveolens the inhibition started from to 250 and 500 mg/L respectively. The best IC50 was of 8.02 mg/L from the ethanolic resuspended extract of L. graveolens stem.Conclusion: The ethanolic plant extracts from L. graveolens, A. lechuguilla, and C. illinoinensis, showed 100 % of inhibiting activity against the development of F. oxysporum, representing an alternative for control of F. oxysporum.

El cancro bacteriano es una de las enfermedades del tomate (Solanum lycopersicum), la cual es causada por la bacteria Clavibacter michiganensis subsp. michiganensis (Cmm). En el presente trabajo se realizó la identificación de Cmm mediante PCR de punto final utilizando los primers CMM5F y CMM6R. Se evaluó la efectividad de los extractos metanólicos de Agave striata y Fouquieria splendens sobre Cmm in vitro e invernadero, así también se obtuvo información acerca de la composición de fitoquímicos presentes en las plantas. El ensayo in vitro se realizó mediante la técnica de microdilución en placa desde los 3.9 mg/L a 1000 mg/L, se determinó la Ci50 y Ci90 de cada extracto . En el experimento en invernadero se evaluó el efecto de los extractos y un producto orgánico “Biobacter” contra Cmm, se calculó la incidencia, severidad y parámetros morfométricos. Los resultados in vitro indicaron que los extractos de F. splendens y A. striata presentan inhibición sobre el fitopatógeno, sin embargo, el extracto de F. splendens mostro control a menores concentraciones que con A striata. El ensayo en invernadero demostró que la incidencia, severidad y parámetros morfométricos fue menor con el extracto de F. splendens, así después con el producto Biobacter.

Plant extracts (PEs) and essential oils (EOs) contain phytochemical compounds (PCs). Nevertheless, PCs can be degraded when applied on field. The use of nano-encapsulates (NEs) and micro-encapsulates (MEs) arise as an alternative to the application of botanical products. However, NEs and MEs with PCs in plant disease control have not been explored enough. This review discusses the use of PCs for plant disease control and the benefits obtained from formulations with NEs and MEs; furthermore, it discusses methods to produce NEs and MEs.

This chapter will cover topics about the microbial antagonists Trichoderma spp. and Bacillus spp. from the perspective of use as potential biological control agents on plant diseases. Results obtained in the laboratory about from their isolation, microbial strain collections for both genera, taxonomic identification, antifungal activity in in vitro tests, obtained evaluation of the antifungal effect of secondary metabolites from microbial antagonists will be shown. Besides, results obtained from bioassays in the greenhouse and field are used as biopesticides in the control of diseases in fruit trees and vegetables and their effects on the promotion of plant growth and increased crop yield.

Los herbicidas químicos para control de malezas, representa un problema en la actualidad, ya que su uso indiscriminado causa la aparición de poblaciones resistente de malezas, además de afectar el medio ambiente y la salud humana. Por lo que los metabolitos secundarios de microrganismos (MSMs) y los extractos vegetales (EVs) en formulaciones micro-nano encapsulados (NPs) surgen como una posible alternativa al uso de herbicidas de síntesis química, razón por la cual dilucidar su mecanismo de acción es necesario para entender los cambios bioquímicos que estos inducen en las plantas, para poder desarrollar estrategias de control de malezas. El objetivo de la investigación fue determinar la actividad de las enzimas antioxidantes fenilalanina amonio liasa (PAL), peroxidasa (POD) y super oxido dismutasa (SOD) en plantas de Sorghum bicolor, tratadas con metabolitos secundarios de Alternaria sp. (MSAs) y un extracto vegetal de Solanum rostratum (EVSR) solos y formulados en NPs a base de los biopolímeros alginato y quitosan. El estudio se realizó durante el mes de junio del año 2024, para esto se utilizaron plantas de S. bicolor y se determinó la actividad de las enzimas durante 0, 3, 6, 12, 24 y 48 h. Se pudo observar que los NPs cargados con el EVSR y los MSAs fueron los que indujeron mayor actividad enzimática a distintos tiempos, alcanzando 0.36 y 0.34 U mol-1 respectivamente en el caso de PAL, 4.7 y 4.3 U mol-1 con la enzima POD, y 7.3 y 6.5 U mol-1 con SOD. Se concluye que los MSAs y el EVSR formulados en NPS tiene potencial como agentes que pueden modificar los procesos bioquímicos en plantas.