Tesis Agronomía
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Item Bacillus subtilis y calidad del huevo en gallinas en postura tardía: una revisión sistemática(Universidad Técnica de Ambato Carrera de Medicina Veterinaria, 2026-07) Silva Gaspata, Silvia Maribel; Núñez Torres, Oscar PatricioPhysiological aging in late-phase laying hens affects egg quality and represents a challenge for the sustainability of poultry production. To compile available scientific evidence on the use of Bacillus subtilis as a probiotic to improve egg quality in late-phase laying hens. A quantitative systematic review was conducted using information obtained from scientific articles published between 2018 and 2026 in high-impact databases, following PRISMA criteria and search strategies with Boolean operators. Variables related to egg quality, intestinal morphometry, cecal microbiota, and enzymatic activity were analyzed. The analyzed studies showed increased villus height (1343±1045), reduced crypt depth (206±114), and improved villus height/crypt depth ratio (VH/CD) (6.25±1.89); an increase in beneficial bacteria such as Lactobacillus (28%) and a reduction in pathogenic bacteria (40%) such as E. coli, Clostridium, and Salmonella; as well as improvements in eggshell thickness (0.39±0.0373), shell strength (38.6±0.546), egg weight (62.1±4.98), Haugh units (81.3±10.1), and yolk color (7.42±1.96). Supplementation with B. subtilis constitutes a promising strategy to improve the internal and externalItem Evaluación de tres bioestimulantes mediante endoterapia en Persea americana, en sector Las Viñas, parroquia Picaihua, provincia de Tungurahua(Universidad Técnica de Ambato Carrera de Agronomia, 2026-07) Morales Morales, Mauro David; Velástegui Espín, Giovanny PatricioAvocado (Persea americana) cultivation represents a key economic alternative in the inter-Andean region of Ecuador; however, its productivity in the Tungurahua province is limited by acidic andosol soils that fix essential micronutrients, reducing the efficacy of conventional fertilization. Faced with this problem, the present applied research with a quantitative approach aimed to evaluate the efficacy of three foliar biostimulants (Algeed Plus, Kelpak, and Turbo Mix) at different concentrations (5 and 10 ml/L) applied via plant endotherapy to optimize fruit sizing. The methodology employed a Randomized Complete Block Design with a factorial arrangement (3x2 + 1 control), with three replications, in the Las Viñas sector, Picaihua parish. The response variables evaluated at 25 and 50 days were fruit diameter and weight. The results demonstrated highly significant differences (p < 0.0001), highlighting the Algeed Plus treatment at 10 ml/L as the most effective, achieving an average weight of 502.0 g and a diameter of 8.04 cm, surpassing the control by 87.1% and 11.7%, respectively. As a scientific novelty, this study validates endotherapy as a superior nutritional administration pathway that avoids edaphic fixation, offering a technically and economically profitable proposal for small and medium-sized producers in the Ecuadorian sierra, ensuring sustainable agronomic management.Item Aplicación de extracto de ajo ozonizado para el control de paratrioza (Bactericera cockerelli) en el cultivo de papa (Solanum tuberosum) en el Cantón Mocha(Universidad Técnica de Ambato Carrera de Agronomia, 2026-07) Freire Bonilla, Edith Scarlet; Zurita Vásquez, José HernánPotato cultivation (Solanum tuberosum) is a fundamental socioeconomic pillar for food security in the Ecuadorian Andean region; however, its productivity faces critical challenges due to the psyllid Bactericera cockerelli, the vector of the phytoplasma responsible for "purple top" disease, which can cause yield losses of nearly 100%. Given the urgent need to reduce reliance on synthetic agrochemicals, this research— framed within the line of sustainable phytosanitary management—evaluated the efficacy of ozonated garlic extract in controlling this pest in the Mocha Canton. A Randomized Complete Block Design (RCBD) with a factorial arrangement (2x2+1) was used, comparing doses of 2.5 cc/L and 5 cc/L against application frequencies of 8 and 15 days. The incidence of eggs, nymphs, the presence of phytoplasma in tubers, and total yield were quantified. The scientific novelty lies in the application of ozonolysis to stabilize the secondary metabolites of garlic, forming highly reactive ozonides that enhance its insecticidal and repellent action against sedentary stages of B. cockerelli. Results indicated that the most effective treatment was D1F1 (2.5 cc/L every 8 days), followed by D2F2. Compared to the control group, these treatments showed a lower population incidence and greater crop stability, establishing that the application of 2.5 cc/L every 8 days constitutes the most efficient technical strategy under local conditions. This proposal confirms that the ozonation of plant extracts optimizes phytosanitary control, offering an innovative, economically viable, and environmentally responsible solution that guarantees tuber quality in the face of pesticide pressure.Item Evaluación de sustratos para el trasplante de mora de castilla (Rubus glaucus Benth.) en Pelileo(Universidad Técnica de Ambato Carrera Agronomia , 2026-07) Barrera Castro, Wilman Joel; Villacis Aldaz, Luis AlfredoThe objective of this study was to evaluate the effect of four substrate types on the initial transplanting of Castilla blackberry (Rubus glaucus Benth.) seedlings into nursery bags in order to improve plant growth prior to field establishment in Pelileo and to identify the substrate mixture with the best agronomic performance under local agroecological conditions. The experiment was conducted at an altitude of 2912 m above sea level using a Randomized Complete Block Design (RCBD) with four treatments and three replications, resulting in a total of twelve experimental units. The evaluated substrates were: T1 = 100% commercial peat, T2 = 100% leaf litter, T3 = 40% black soil + 30% rice husk + 30% organic matter, and T4 = 100% local soil (control). The variables assessed at 45 and 60 days after transplanting were plant height, stem diameter, number of leaflets, and chlorophyll content. Data were subjected to analysis of variance (ANOVA), and mean comparisons were performed using Tukey's test at the 5% significance level. The results showed significant and highly significant differences among treatments for plant height, number of leaflets, and stem diameter. Treatment T1 (100% commercial peat) exhibited the best performance, reaching 21.27 cm in plant height, 26.33 leaflets, and 3.00 mm stem diameter at 60 days after transplanting. Treatments T2 and T3 showed statistically similar values, whereas T4 presented the lowest agronomic performance.Item Evaluación de productos alternativos en la poscosecha de frutos de mora de Castilla (Rubus glaucus)(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Villalva Villalva, Ivonne Noemi; Zurita Vásquez, José HernánAndean blackberry (Rubus glaucus) is highly perishable, leading to significant postharvest losses due to its rapid deterioration. This study aimed to evaluate the effectiveness of alternative products for postharvest management in order to identify the most suitable treatment to extend shelf life and maintain fruit quality. The research followed a quantitative experimental approach using a completely randomized design (CRD) with a 2×3 + 1 factorial arrangement and three replications, where treatments included albumin + glycerin at doses of 3, 5, and 7 g/L, ozonized oil at doses of 3, 5, and 7 cc/L, and a control. The evaluated variables were weight loss, fruit firmness, total soluble solids (°Brix), and shelf life over a five-day storage period. The results showed significant differences among treatments, with ozonized oil presenting the lowest weight loss (16.31%–17.95%), the highest firmness values (0.43–0.44 kg/cm²), and reduced fruit deterioration, while albumin + glycerin treatments resulted in higher total soluble solids (10.98–11.91 °Brix). Additionally, the 7 cc/L dose of ozonized oil achieved the best numerical values in terms of firmness and preservation. It is concluded that ozonized oil was the most effective alternative for postharvest conservation of Andean blackberry, as it reduced weight loss, maintained firmness, and minimized fruit deterioration during storage.Item Efecto de recubrimientos comestibles en la calidad del fruto de la fresa(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Torosina Bastidas, Marjorie Yadira; Dobronski Arcos, Jorge EnriqueStrawberries are a fruit highly susceptible to deterioration during post-harvest storage, which reduces their shelf life and negatively impacts their marketability. Therefore, this study aims to evaluate the use of different biodegradable coatings to combat post- harvest losses in this fruit. The research was conducted using a quantitative approach with a completely randomized experimental design. Six formulations of linseed mucilage and cassava starch, combined with water and glycerin, were tested, along with an uncoated control. Data were collected on days 1, 5, and 8 to the variables weight, pH, total soluble solids (°Brix), firmness, and percentage of pathogen contamination. Analysis of variance and Tukey's test at the 5% significance level were used to compare treatments. The results showed that coatings made with linseed mucilage influence the preservation process, resulting in more stable weight, firmness, and °Brix, while treatments with cassava starch showed greater increases in °Brix and greater weight loss, suggesting a reduced capacity to control moisture loss during postharvest storage. Although all treatments showed some contaminated fruit, the linseed mucilage treatment with glycerin showed the lowest percentage of pathogen contamination compared to the other treatments and the control. Therefore, it is concluded that formulations with linseed mucilage and glycerin have the potential to improve the postharvest storage conditions of strawberries.Item Efecto del hidropriming y del tiempo de almacenamiento post-priming sobre la germinación y vigor de semillas de maíz criollo variedad Chazo en la Sierra ecuatoriana(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Saltos Cañizares Enrique Augusto; Velástegui Espín Giovanny PatricioMaize (Zea mays L.) Creole variety "Chazo" constitutes a strategic resource for food security in the Ecuadorian Andean region; however, its field establishment is often hindered by irregular germination due to low temperatures in high-altitude zones. To mitigate this limitation, this research evaluated the effect of hydro-priming using five immersion times (0, 12, 24, 36, and 48 hours) combined with three post-treatment storage periods (10, 20, and 30 days) on the physiological quality of the seed. The experiment was conducted under a completely randomized design with a 4x3+1 factorial arrangement at the Technical University of Ambato laboratories. Analysis of variance determined that hydro-priming as an isolated factor does not significantly increase the final germination percentage, but critically optimizes emergency uniformity (p = 0.0488) by concentrating cellular metabolic activity. Furthermore, post-conditioning storage time exerted the greatest individual impact (p < 0.05), revealing that a prolonged 30-day rest period acts as a complementary ripening process, raising mean viability to 62.83% and doubling the global vigor index compared to short storage periods. The factorial interaction determined that the H3A3 treatment (36 hours of immersion and 30 days of storage) is optimal for general crop establishment, maximizing real germination (68.00%), radicle morphometric development (46.58 mm), and sprout synchrony (1.29). Nonetheless, when field precocity is required, the H2A2 combination (24 hours of immersion and 20 days of storage) provides a highly efficient kinetic alternative, registering the lowest mean germination time at only 3.01 days. It is concluded that the coupled management of hydro-priming and rest periods represents a low-cost, viable, and reproducible biotechnological tool to enhance the initial vigor of this ecotype in the high Andean ecosystemItem Evaluación de productos alternativos en la poscosecha de frutos de fresa Monterrey (Fragaria x ananassa)(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Nuñez Aldas, Luz María; Zurita Vásquez, José HernánThe objective of this research was to evaluate alternative products for the postharvest conservation of Monterey strawberry (Fragaria × ananassa) fruits in order to identify the most efficient treatment to extend shelf life and maintain fruit quality during storage. The study was conducted at the Plant Health Laboratory of the Technical University of Ambato using a completely randomized design (CRD) with a 2×3+1 factorial arrangement and three replications.Two alternative products were evaluated: albumin + glycerin (F1) and ozonized oil (F2), applied at concentrations of 3, 5, and 7 g/L for F1, and 3, 5, and 7 cc/L for F2, in addition to an untreated control. The variables analyzed were weight loss, firmness, total soluble solids (°Brix), and shelf life.The results showed significant differences among treatments. The F2D2 treatment (ozonized oil at 5 cc/L) recorded the lowest weight loss (22.49%), while the control treatment showed the highest value (31.20%). The F1D3 treatment (albumin + glycerin at 7 g/L) achieved the highest firmness (1.56 kg/cm²) and the greatest total soluble solids content (15.77 °Brix). Regarding shelf life, F1D3 and F2D2 exhibited lower incidence of severe damage and better preservation of the fruit’s commercial quality during storage. It is concluded that the application of alternative products improves the postharvest conservation of Monterey strawberries, with albumin + glycerin at 7 g/L and ozonized oil at 5 cc/L being the most effective treatments.Item Producción y viabilidad de semillas sintéticas ¿n vitro de Cannabis sativa (100% critica al CBD) en conservación criogénica y refrigeración(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Mosquera Gonza, Jonathan Martin; Zurita Vásquez, José HernánCannabis sativa is a species of great agricultural importance due to the production of cannabinoids, terpenes, and other compounds of medicinal and industrial interest. Because of its high genetic variability, in vitro cultivation techniques have been developed to obtain uniform plant material and preserve selected genotypes. This research evaluated the preservation of meristematic buds using two methods: refrigeration of synthetic seeds and cryopreservation. MS and DKW culture media were used for storage periods of 15, 30, 45, and 60 days. The study was conducted in the in vitro propagation laboratory of Andean Food. The synthetic seeds were prepared from meristematic buds encapsulated in an agar matrix, while cryopreservation was carried out by vitrification and immersion in liquid nitrogen at - 196 °C. The evaluation considered the percentage of viability and the development of the explants after sowing. The results showed that refrigeration was the most efficient method for preserving the viability of the plant material, with the following standing out: MS medium showed viability values of 80.0% at 15 days and 53.3% at 60 days. Cryopreservation, on the other hand, exhibited low recovery percentages ranging from 6.7% to 20.0%. Regarding explant development, DKW medium showed better initial results, reaching 10.48 mm at 15 days. This indicates that storage time affects the viability and development of the C. sativa explants evaluated during this study.Item Evaluación del efecto caldo sulfocálcico + ceniza vegetal para el control de Oidio (Erysiphe polygoni) en el cultivo de Delphinium sp.(Universidad Técnica de Ambato Carrera de Agronomía, 2026-07) Manotoa Paredes, Matilde Rosario; Curay Quispe, Segundo EuclidesThis research was conducted to evaluate the effect of lime-sulfur solution + plant ash for the control of powdery mildew (Erysiphe polygoni) in Delphinium sp. cultivation. This disease is one of the main phytosanitary limitations in cut flower production due to economic losses and reduced flower quality. The importance of this study lies in the need to implement sustainable alternatives that reduce dependence on synthetic fungicides, minimizing chemical residues and meeting the demands of international markets, which are oriented towards environmentally friendly production systems. A Randomized Complete Block Design with a 3 × 2 + 1 factorial arrangement was used, evaluating three doses of lime-sulfur solution + plant ash (15, 20, and 25 cc/L), two application frequencies (every 8 and 18 days), and a control treatment corresponding to conventional cut flower production management. The variables analyzed were incidence, severity, number of live plants, and cost-benefit ratio. Significant differences were observed between treatments, with the 20 cc/L dose applied every 8 days showing the lowest levels of powdery mildew incidence and severity. Furthermore, the economic analysis showed that all treatments were cost- effective, with the highest cost-benefit ratio recorded for treatment T3. This research aimed to validate the use of lime-sulfur solution + plant ash as a technical, economic, and agroecological alternative for the sustainable management of powdery mildew in Delphinium sp. cultivation.