Ciencias Agropecuarias

URI permanente para esta comunidadhttp://repositorio.uta.edu.ec/handle/123456789/870

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  • Miniatura
    Item type:Ítem,
    Determinación de la actividad antifúngica in vitro de aceites esenciales de Eucaliptus sp microencapsulados sobre Cladosporium fulvum
    (2026-01)
    Zambrano Jordán, Jairo Dionicio
    ;
    Leiva Mora, Michel
    The present study aimed to evaluate the in vitro antifungal activity of microencapsulated essential oils from Eucalyptus sp. against Cladosporium fulvum, the causal agent of leaf mold in greenhouse-grown tomato. The essential oil was extracted from Eucalyptus globulus leaves using steam distillation. Subsequently, the oil was microencapsulated by the spray-drying method, employing maltodextrin and gum arabic as encapsulating polymers in order to improve its physicochemical stability and handling properties. Antifungal activity was assessed through mycelial growth inhibition assays and by determining the minimum inhibitory concentration (MIC) using the microdilution method. The results demonstrated that a concentration of 6% microencapsulated essential oil achieved 100% inhibition of C. fulvum mycelial growth, while the MIC was 5%. These values indicate high antifungal efficacy of the essential oil even at low concentrations. Furthermore, the results confirm that the microencapsulation process helps preserve the biological activity of the essential oil by reducing its volatility and promoting the controlled release of active compounds. Overall, the findings highlight the potential of microencapsulated Eucalyptus sp. essential oils as a natural, effective, and sustainable alternative to conventional synthetic fungicides for the management of C. fulvum in greenhouse tomato production systems, providing a solid basis for future field-scale evaluations and economic feasibility studies.
  • Miniatura
    Item type:Ítem,
    Evaluación de la actividad antifúngica in vitro de aceites esenciales microencapsulados de Cupressus sempervirens L. y Schinus molle L. frente a Cladosporium fulvum Cooke
    (2026-01)
    Tutillo Quilumbaquin, Silvia Dayana
    ;
    Bustillos Ortiz, Alcides Alberto
    This research was conducted to evaluate the in vitro antifungal activity of microencapsulated essential oils (MEO) from Cupressus sempervirens L. and Schinus molle L. against Cladosporium fulvum, a pathogen that causes significant economic losses in kidney tomato cultivation. To evaluate the percentage of mycelial growth inhibition (PMGI), a completely randomized experimental design was implemented with seven treatments and four replicates, using the agar dilution method. The treatments were concentrations of 15%, 10%, 9%, 8%, 7%, 6%, and 5% for Cypress MEO; and 15%, 14%, 13%, 12%, 11%, 10%, and 5% for Molle MEO. Likewise, to determine the MIC, eight treatments and eight replicates were used, using microdilution in multiwell plates with PDB medium. The concentrations used were 20%, 15%, 10%, 5%, 2.5%, 1.25%, 0.3125%, and 0.625% for both MEOs, applied to the pathogen C. fulvum. The results obtained by separating the means with the Tukey test (p<0.05) showed that the PMGI is equal to or greater than 8% for cypress MEO and equal to or greater than 13% for molleMEO. As for the MCI, both cypress and molle AEMs recorded an MCI of 5%. In conclusion, the microencapsulated essential oils of cypress and molle showed significant antifungal activity against C. fulvum, supporting their potential as a sustainable control alternative, as they act as natural fungicides without causing environmental damage
  • Miniatura
    Item type:Ítem,
    Evaluación in vitro del efecto antifúngico de los aceites esenciales de romero (Rosmarinus officinalis L.) y cúrcuma (Curcuma longa L.) contra Cladosporium fulvum Cooke.
    (2026-01)
    Toapanta Quisaguano, Pablo Gilmar
    ;
    Mora, Michel Leiva
    This study evaluated in vitro the antifungal effect of microencapsulated essential oils (M.E.O) of rosemary (Rosmarinus officinalis L.) and turmeric (Curcuma longa L.) against the phytopathogen Cladosporium fulvum, one of the main causal agents of diseases in tomato crops. For this purpose, assays were carried out using agar dilution (PDA) and broth microdilution (PDB) methods, applying different concentrations of both essential oils to determine their minimum inhibitory concentration (MIC) and compare their antifungal efficacy. The results demonstrated that the rosemary microencapsulated essential oil (M.E.O) presented superior antifungal activity in all treatments, achieving total inhibition of mycelial growth at concentrations of 15% and 10% during the 21 days of evaluation. This effect is attributed to the joint action of monoterpenes such as 1,8-cineole and camphor, which present high volatility and rapid interaction with the fungal membrane. In contrast, the turmeric microencapsulated essential oil (M.E.O) showed moderate inhibition of mycelial growth, reaching its maximum inhibition values at concentrations of 15% and 10%, with a response dependent on the applied concentration, but less stable over time due to the progressive degradation of its bioactive compounds. In the PDB assay, the rosemary microencapsulated essential oil (M.E.O) evidenced a more marked decrease than that of turmeric on the metabolic activity of C. fulvum. In conclusion, microencapsulated rosemary oil represents a more effective and stable alternative for the biological control of C. fulvum under in vitro conditions, establishing a scientific basis for future, more sustainable plant-health management strategies
  • Miniatura
    Item type:Ítem,
    Evaluación de la actividad antifúngica in vitro de aceites esenciales microencapsulados frente a Cladosporium fulvum Cooke
    (Universidad Técnica de Ambato. Facultad de Ciencias Agropecuarias. Carrera de Agronomía, 2026-01)
    Apo Cunalata, César Alfredo
    ;
    Mora, Michel Leiva
    Tomato leaf disease caused by the phytopathogenic fungus Cladosporium fulvum Cooke is a high-impact phytopathological problem, especially in greenhouse production systems, where humidity favors its development. Both globally and in Ecuador, its control has traditionally been based on the application of chemical fungicides, contributing to the recurrent use of these products, generating resistance in the pathogen, increasing production costs, environmental risks, and affecting human and animal health. This situation highlights the need to implement sustainable alternatives for the management of leaf diseases. Among these alternatives, essential oils (EO) stand out, widely reported for their antifungal activity. However, their volatility and limited stability in aqueous media restrict their direct application. In response to this, this study evaluated the efficacy of microencapsulated essential oils (MEO) of basil and geranium, obtained by spray drying using a polymer mixture composed of 20% pure EO and 80% maltodextrin and gum arabic. Antifungal activity was determined by mycelial growth inhibition (MGI) in PDA medium and mínimum inhibitory concentration (MIC) using the microdilution method in PDB with Alamar Blue as a viability indicator. The results showed that both A.E.Ms were highly effective: basil A.E.M completely inhibited the growth of C. fulvum at 2.5%, while geranium A.E.M achieved 100% inhibition at 1.25%. The Alamar Blue microdilution method presented limitations due to interference from turbidity and phase separation of the microencapsulation. Overall, the results show that microencapsulated essential oils represent an ecological, efficient, and promising alternative for the sustainable management of gray mold in tomato cultivation.
  • Miniatura
    Item type:Ítem,
    Evaluación de la actividad antifúngica de extractos vegetales para el control de roya (Uromyces appendiculatus P.) en el cultivo de fréjol (Phaseolus vulgaris L.)
    (2021-03)
    Portilla Centeno, Fredy Alexander
    ;
    Curay Quispe, Segundo Euclides
    In Ecuador, one of the crops of greatest interest in the Andean zone is bean (Phaseolus vulgaris L.) and one of the most common diseases is rust (Uromyces appendiculatus P.), which causes considerable production losses, it generate orange colored pustules that mainly affect the foliar area and with it the photosynthesis process of the plant. The investigation was carried out in an established plot located at an altitude of 2393 meters above sea level, latitude 1º 23 ’54’ ’and longitude 78º 28’23’ ’in Patate. The purpose of the investigation was to evaluate the antifungal activity of plant extracts cola de caballo (E. arvense) and chamomile (M. chamomilla) for the control of rust (U. phaseoli) applied in three different doses (10, 15 and 20%). A randomized complete block design (DBCA) with factorial arrangement (2 x 3 + 2) with three repetitions was used. Using the statistical analysis, it was possible to determine that the treatments E1C3 (20% chamomile extract) and E2C2 (15% cola de caballo extract) are those that show the lowest values in incidence with percentages of 56.11 and 55.55 % reciprocally 35 days after application, something similar occurs in severity, achieving percentages of 19.47 and 19.66% respectively. In addition, it was identified that the yield was influenced by the application doses reaching 1.33 kg in E1C3 and 1.15 kg for E2C2.
  • Miniatura
    Item type:Ítem,
    Evaluación de la actividad antifúngica in vitro de cinco extractos vegetales (EV) contra Colletotrichum spp. Aislado de tomate de árbol (Solanum betaceum)
    (2017)
    Carranza Arévalo, Galo Eduardo
    ;
    Valle Velástegui, Luciano
    The present research was carried out with the objective of evaluating the antifungal activity of manzanilla (Matricharia recutita), chamico (Datura ferox), marco (Ambrosia arborescens Mill.), lavander (Lavandula officinalis) and nettle (Urtica dioica) against the fungus Colletotrichum acutatum. The experiment was carried out at the Plant Health Laboratory of the Faculty of Agricultural Sciences of the Technical University of Ambato. Two extraction methods were used in the test: maceration and steam trapping with Clevenger equipment. The fungal material was seeded in Agar-Potato-Dextrose culture medium and incubated at 23 ± 2 ° C and 75% moisture. A factorial experiment (A x B + 1) was performed in a completely randomized design (DCA) with three replicates, where the variables of percentage of mycelial inhibition, radial growth rate, number of conidia, conidia viability and biomass. The best results in the measured parameters were obtained with extract of L. officinalis obtained by drag of steam; The best percentage of mycelial inhibition (74,98%), biomass (1066, 67 μg), radial growth rate (2,0 mm / day), conidia number (2,92 x 106), viability Conidia (44,17%), however it is necessary to mention that all plant species used had antifungal activity against C. acutatum. The extract of L. officinalis was found to contain essential oils, alkaloids, ketones, phenols, flavonoids, quinones, saponins, tannins and terpenes, metabolites that are attributed to antibacterial, antifungal and insecticidal properties.