Chilean Journal of Agricultural & Animal Sciences

MICROALGAS EN LA AGRICULTURA: UN IMPULSO AL CUMPLIMIENTO DE OBJETIVOS DEL DESARROLLO SOSTENIBLE

vie, 29 ago 2025 00:00:00 -0400

La agricultura se enfrenta actualmente a algunos de los desafíos más grandes de su historia: satisfacer la creciente demanda de alimentos y, al mismo tiempo, alcanzar la sostenibilidad, en concordancia con varios Objetivos de Desarrollo Sostenible (ODS) establecidos por la Organización de las Naciones Unidas, y que están estrechamente relacionados con el sector agrícola. Las investigaciones recientes se han centrado en buena medida hacia el uso de microorganismos como fuente de insumos para optimizar los sistemas productivos. Entre ellos, destacan las microalgas, por su notable potencial como herramientas innovadoras para abordar estos apremiantes retos. El objetivo de la presente revisión fue recopilar y sintetizar los conocimientos científicos relacionada con aplicaciones agrícolas de las microalgas que contribuyen positivamente en el logro de los ODS 02, 06 y 15. Este documento examina los beneficios documentados de la utilización de microalgas, según lo documentado en investigaciones recientes, haciendo hincapié en sus aplicaciones actuales y potenciales en cinco áreas clave de los sistemas de producción agrícola.

SILAGE CHARACTERISTICS OF MAIZE-FORAGE LEGUME MIXTURES ENSILED AT DIFFERENT HARVEST PERIODS

Poloko Mosebi, Casper Madakadze, Moeketsi Ntakatsane, Ratsele Ratsel — vie, 29 ago 2025 00:00:00 -0400

This study was conducted to evaluate the effects of different harvest periods on the ensiling characteristics of maize-forage legume mixtures. Sole maize (Zea mays L.), sole common vetch (Vicia sativa L.), sole lablab (Lablab purpureus), maize + common vetch, and maize + lablab intercrops were harvested on different days after planting (DAP). The experiment was conducted using a completely randomized design with a 5 (forage systems) x 3 (harvest periods) factorial treatment arrangement and three replicates. Forage samples were ensiled at early, medium, and late harvest maturity: 50, 75 and 100 DAP. After ensiling in a laboratory mini-silo, samples were collected to determine chemical composition, microbial populations, and fermentation quality. Early harvest demonstrated lower contents of dry matter (DM) and crude protein, with values of 16.99 and 15.84% DM, respectively, in sole forage silages. High water-soluble carbohydrate concentrations and low fibre values (p < 0.05) were recorded when ensiled forage mixtures were harvested at the medium maturity stage. In mixed silages, the medium harvest time resulted in significantly lower populations of enterobacteria, yeasts and moulds, and higher populations of lactic acid bacteria, with values of 3.61, 4.83 and 5.17 log10 cfug-1, respectively. Lower pH values, NH3-N content, and greater lactic acid production (p < 0.05) were observed when the ensiled mixture and sole forages were harvested at the medium maturity stage compared to early and late harvest periods. Mixed silages from the medium harvest produced lower butyric acid and higher acetic and propionic acid concentrations (0.19, 1.07 and 1.25% DM, respectively) in the medium harvest, followed by silages from the late and early harvests. A medium harvest for ensiling mixed forage has the potential to produce high-quality silage for ruminant feeding.

NUTRIENT COMPOSITION, FERMENTATION QUALITY, in vitro DEGRADABILITY, AND METHANE EMISSIONS OF WHOLE-CROP CORN SILAGES TREATED WITH ARBUSCULAR MYCORRHIZAL FUNGI BIOFERTILIZERS DURING PLANTING

Muhammad Ridla , Iwan Prihantoro, Emiralda Prastiwi Gamasari — vie, 29 ago 2025 00:00:00 -0400

Silage fermentation quality and nutrient composition are significantly influenced by the raw material used before ensiling, including agronomic practices such as fertilizer application. This study evaluated the effects of different levels of Arbuscular Mycorrhizal Fungi (AMF) biofertilizer applied during corn cultivation on nutrient composition, silage fermentation characteristics, in vitro rumen fermentation dynamics, and methane emissions. Corn plants were harvested 82 days post-planting, cut 10 cm above ground level, and manually chopped into pieces of 3–5 cm in length. The chopped forage was packed into 10-liter silos, compacted to expel air, and sealed to ensure anaerobic conditions. All samples were ensiled for 30 days. A completely randomized design was employed with three AMF biofertilizer levels (0, 10, and 20 g per planting hole) and six replications. Data were analyzed using ANOVA followed by Tukey’s test for multiple comparisons. The results indicated that AMF application had a limited effect on nutrient composition but significantly increased (P < 0.05) water-soluble carbohydrate (WSC) content, which is crucial for efficient fermentation. All silages were well preserved, as evidenced by a pH below 4. Enhanced in vitro rumen fermentation, indicated by increased total short-chain fatty acid (TSCFA) production, higher gas output, and a slight improvement in degradability, was associated with higher WSC content. Elevated WSC levels also contributed to reduced methane emissions by promoting more efficient microbial fermentation.

DEMOGRAPHIC AND GENEALOGICAL STRUCTURE OF THE COSTEÑO CON CUERNOS COLOMBIAN CREOLE CATTLE

vie, 29 ago 2025 00:00:00 -0400

The aim of this study was to assess the demographic structure and genetic diversity of the Costeño con Cuernos (CCC) Colombian creole cattle population using pedigree data. A total of 8,164 genealogical records of the CCC breed, spanning 1958 to 2023, were analyzed to estimate population censuses, effective population size, generational intervals, pedigree completeness, inbreeding coefficient, and effective number of founders. A progressive increase in population size was observed, reaching a population of 1,524 animals by 2022, with an average generational interval of 5.6 and 6.5 years for paternal and maternal lines, respectively. Pedigree completeness has significantly improved since the 1990s, reaching current values close to 100% over six generations. Inbreeding coefficients increased over time and estimates of effective population size were 253 and 89 based on census and inbreeding, respectively. Among the animals analyzed, 852 were found to have both parents unknown. The effective number of founders and ancestors was 69.6 and 42, respectively. The breed conservation strategy has maintained its genetic variability, but there is a need to incorporate new individuals into the Germplasm Bank.

UTILIZACIÓN DE UN ÍNDICE DE DIMORFISMO SEXUAL MULTIVARIANTE: UN EJEMPLO EN Bos taurus L.

vie, 29 ago 2025 00:00:00 -0400

El dimorfismo sexual se refiere a las diferencias morfológicas entre machos y hembras de una misma especie, tradicionalmente evaluadas usando métodos univariantes (ej., tamaño), y con poca frecuencia, mediante métodos multivariantes que integran caracteres cuantitativos y cualitativos. Este estudio propone el uso del índice de Gower para la evaluación del dimorfismo sexual multivariante en Bos taurus L. La solidez de este enfoque se basa en los valores medios de descriptores etnológicos de 25 razas bovinas taurinas actuales (ibéricas, europea y criollas). Para cada raza, se obtuvieron nueve caracteres: dos cualitativos ordinales y siete cuantitativos continuos. Los caracteres cualitativos fueron la longitud del cuello y el tamaño de la papada, mientras que las variables cuantitativas incluyeron peso vivo, alzada a la cruz, diámetro longitudinal, diámetro dorso-esternal, perímetro torácico, perímetro de la caña anterior y diámetro bicostal. Se concluye que, al integrar variables de diferentes tipos, el índice de Gower es un buen indicador de dimorfismo sexual en Bos taurus L.

DEVELOPING A BREEDING OBJECTIVE FOR DUAL-PURPOSE MERINO PRECOZ BREED IN CENTRAL CHILE: DERIVATION OF ECONOMIC WEIGHTS

Felipe Lembeye , Giorgio Castellaro — vie, 29 ago 2025 00:00:00 -0400

Defining economically important traits is crucial in the design of a genetic program. These are referred to as the breeding objective, and determining their economic values ( ) is essential. Currently, no breeding objective has been established for Merino Precoz sheep in central Chile. This study proposes a breeding objective and calculates for five traits: greasy fleece weight (GFW), fiber diameter (FD) with three pricing scenarios: 3.5%, 7% and 14% of GFW price, number of lambs weaned (NLW), weaning weight (WW), and adult weight (AW). Economic values were: USD5.42 for GFW; USD-0.59, USD-1.18, USD-2.35 for FD scenarios (3.5, 7, 14%, respectively); USD151.1 for NLW; USD4.93 for WW, and USD-0.09 for AW. The greatest emphasis was placed on NLW and WW, which collectively represent over 80% of the breeding emphasis. A negative value for AW indicates that smaller ewes are preferable in production systems operating in drylands like central Chile. Furthermore, the inclusion of NLW in the breeding objective must be supported by reliable data-recording protocols and effective management practices to ensure accurate selection.

IMPACTO DE DOS MÉTODOS DE FERMENTACIÓN DE CAMA AVÍCOLA SOBRE EL RENDIMIENTO PRODUCTIVO-ECONÓMICO EN POLLOS DE ENGORDE

vie, 29 ago 2025 00:00:00 -0400

La fermentación de la cama avícola es una práctica sanitaria que contribuye a eliminar patógenos residuales y a mejorar las condiciones higiénicas del ambiente de crianza, favoreciendo así la reducción de los costos de producción y el impacto ambiental. El objetivo del estudio fue evaluar el efecto de dos métodos de fermentación de la cama avícola en el rendimiento productivo y económico de pollos de engorde. Se compararon dos tratamientos: fermentación aeróbica (34.272 aves) y fermentación anaeróbica (36.288 aves). Se evaluaron peso vivo final, consumo de alimento, conversión alimenticia y mortalidad, y las variables económicas: factor de eficiencia europeo (FEE) y el costo de producción. Los resultados muestran que la fermentación aeróbica fue mejor que la anaeróbica, con mayor peso corporal final (2,49 kg vs. 2,46 kg; p<0,05), similar consumo de alimento (3,57 kg vs. 3,53 kg; p>0,05), mejor eficiencia de conversión alimenticia (1,43 vs. 1,45; p<0,05), menor mortalidad (3,32% vs. 3,78%; p<0,05), menor FEE (482 vs. 466; p<0,05), y menor costo de producción por kg (S/ 0,011 vs S/ 0,014; p<0,05). La fermentación aeróbica de la cama avícola resultó técnica y económicamente más eficiente que la fermentación anaeróbica al mejorar el desempeño productivo y la rentabilidad en la crianza de pollos de engorde.

IMPORTANCE OF THE MILPA SYSTEM IN ANIMAL FEED IN MIXTEC COMMUNITIES: USE OF PRODUCTS AND BY-PRODUCTS

vie, 29 ago 2025 00:00:00 -0400

The milpa system is the foundation of traditional agriculture in Mesoamerica. It is characterized by the polyculture of maize (Zea mays L.), beans (Phaseolus spp.), and squash (Cucurbita spp.), and is associated with a wide diversity of crops and wild species. In Oaxaca, this crop-growing system is closely linked to backyard livestock farming, as its products and by-products serve as an essential source of animal feed. The objective of this study was to evaluate the diversity and quantity of milpa-derived products and by-products used for domestic animal feed in the municipalities of Santo Domingo Yanhuitlán and San Martin Huamelúlpam, Mixtec region, Oaxaca, Mexico. The study used a qualitative approach, supported by site visits, interviews, field trips, and semi-structured surveys conducted with 194 household heads in the two municipalities. The results showed that, among products derived from the milpa system for animal feed, 68.5% of the surveyed households used maize seed and 4.2% used squash. Among by-products, 46.9% used maize stover, while 34.02% combined maize stover with grasses and weeds. Most milpa-derived feed lasted four to six months, after which animals were supplemented with forage species, primarily alfalfa (17%), along with grazing and/or purchased feed. The main animal species reared in the surveyed households included sheep, goats, poultry, pigs, rabbits, and large livestock. This study highlights the central role of the milpa system in supporting both household livestock production and family subsistence in the Mixtec region, Mexico.

CHARACTERIZATION AND COMPARISON OF THE BIOCHEMICAL PROFILE AND ANTIOXIDANT CAPACITY OF TWO LETTUCE VARIETIES (COSTINA AND ESCAROLE)

Javier Leiva-Vega, Lucía De La Fuente-Jiménez, Luis Ríos-Soto — vie, 29 ago 2025 00:00:00 -0400

Leaves are a potential source of biologically active lipids; however, effective extraction requires cell disruption. The objective of this study was to characterize and compare the lipid content, total phenolic compounds, vitamin C, nitrogen, and total chlorophyll levels in two lettuce varieties (costina and escarole), in order to evaluate their biochemical profiles and antioxidant capacities. Nitrogen and total chlorophyll levels in leaves were measured. Lipid extraction was carried out using vortex-agitation with hexane and distilled water as solvents. Phenolic content was determined using the Folin-Ciocalteau method, and vitamin C was measured using spectrophotometry in the extracted lipid fractions. Escarole lettuce exhibited lower nitrogen (3.15 ± 1.74 mg kg^-1) and total chlorophyll levels (10 ± 5.38 SPAD). Conversely, it showed a higher concentration of polar lipids (5.28 ± 1.28 g g^-1 dry weight), while non-polar lipids were not detected in either variety. The phenolic content was higher in costina lettuce (60.34 ± 17.08 mg tannic acid g^-1 dry polar lipid) compared to escarole lettuce (21.24 ± 12.76 mg tannic acid g^-1 dry polar lipid). Similarly, vitamin C content was greater in costina with respect to escarole lettuce, with values of 0.2167 ± 0.0347 and 0.1038 ± 0.0166 mg ascorbic acid g^-1 dry polar lipid, respectively. The results suggest that lettuce leaves are a valuable source of lipids, phenolic compounds, and vitamin C. The concentration of these bioactive compounds appeared to be influenced by nitrogen and total chlorophyll levels in the leaves, as well as by lettuce variety.

RESPUESTA AGRONÓMICA A NANOPARTÍCULAS DE QUITOSANO E INDICADORES DE CALIDAD EN FRUTOS DE PEPINO (Cucumis sativus L.)

vie, 29 ago 2025 00:00:00 -0400

El cultivo de pepino (Cucumis sativus L.) ha adquirido importancia en la agricultura a nivel mundial, tanto por su contribución económica como por su valor nutricional, lo cual genera una fuente de ingreso sostenible y fomenta la diversidad de los sistemas agrícolas. El uso de quitosano en la agricultura representa una estrategia innovadora y sostenible, al promover el crecimiento vegetal, mejorar la salud del suelo y reducir la dependencia de agroquímicos, contribuyendo así a una producción de alimentos más segura y ambientalmente responsable. El objetivo de la presente investigación consistió en determinar las respuestas de las plantas de pepino a la aplicación de nanopartículas de quitosano. Las concentraciones aplicadas fueron 1.000 mg L^-1 (T-1), 1.500 mg L^-1 (T-2), 2.500 mg L-¹ (T-3) y control (T-4), las cuales se distribuyeron un diseño de bloques al azar con cuatro tratamientos y tres repeticiones. Se evaluaron diferentes variables del crecimiento de las plantas: altura y diámetro del tallo, largo de la raíz, número de hojas y zarcillos, y número de flores, así como la producción de masa fresca y seca de diferentes órganos de las plantas. Al final del ciclo, se evaluó el rendimiento y la calidad nutracéutica de los frutos, al determinar en la pulpa los contenidos de polifenoles, flavonoides, capacidad antioxidante y sólidos solubles totales. Las aplicaciones en sus distintas concentraciones de quitosano favorecieron el crecimiento, en general, de las plantas, aunque no todas las variables respondieron de la misma forma. La concentración 2.500 mg L^-1 incrementó el rendimiento, así como la calidad nutracéutica de los frutos.

DIVERSITY OF ARBUSCULAR MYCORRHIZAL FUNGI ACROSS TWO PRODUCTION SYSTEMS OF SOURSOP (Annona muricata L., 1753) IN MEXICO

vie, 29 ago 2025 00:00:00 -0400

Soursop (Annona muricata L., 1753) is a valuable tree native to Mexico and other regions of Central and South America, known for its edible fruit and medicinal properties. Few studies have examined the interactions between Annona muricata and arbuscular mycorrhizal fungi (AMF). However, understanding the biology, ecology, diversity, and limiting factors of AMF is essential for their agricultural application. This study aimed to compare the diversity parameters of AMF associated with Annona muricata under conventional and agroecological production systems in Nayarit, Mexico. The high-input (HT) field received periodic fertilization and irrigation, whereas the low-input (HNT) field did not receive either. AMF spores were extracted for morphological identification and the abundance and diversity index were estimated. Soil characterization included measurements of pH, potassium, phosphorus, magnesium, calcium, and nitrogen. The diversity index and percentage of root colonization by AMF were higher in the HNT field compared to the HT field. These findings suggest that AMF communities associated with Annona muricata under organic or agroecological management (low-input) exhibit greater diversity of species than those in conventional cultivation systems (high-input).

PRODUCTIVIDAD Y CALIDAD DEL PIMIENTO (Capsicum annumm L.) EN RESPUESTA A CONCENTRACIONES DE SILICIO

vie, 29 ago 2025 00:00:00 -0400

El efecto de la fertilización con silicio en el crecimiento vegetal está bien documentado en plantas monocotiledóneas; sin embargo, este efecto no ha sido ampliamente estudiado en plantas dicotiledóneas. El objetivo del presente estudio fue determinar el efecto de diferentes dosis de silicio sobre las características morfofisiológicas, productivas y de calidad de la planta del pimiento (Capsicum annuum L.) de la variedad Quetzal. Se utilizaron cuatro dosis de silicio (0, 20, 25 y 30 g planta^-1) bajo un diseño de bloques al azar con cuatro repeticiones por tratamiento. A los 60 días post trasplante, se evaluaron tres variables morfofisiológicas (altura de la planta, diámetro del tallo y número de hojas), nueve variables productivas (longitud, diámetro, peso y número de frutos; biomasa del fruto, biomasa del fruto sin pedúnculo central; grosor de la pulpa; biomasa del pedúnculo central con semillas; y rendimiento) y tres variables de calidad de los frutos (flavonoides totales, contenido fenólico y capacidad antioxidante). La respuesta en todas las variables fue determinada mediante un análisis de varianza y la tendencia de respuesta a la dosis de silicio mediante un análisis de regresión. En todas las variables hubo diferencias significativas (P<0,05) entre las concentraciones de silicio, presentándose una tendencia lineal positiva. Por tanto, se concluye que la aplicación de 30 g planta^-1 de silicato de potasio mejora las características morfofisiológicas, productivas y de calidad del pimiento.

PRODUCCIÓN DE HIJUELOS Y CARACTERÍSTICAS MORFOLÓGICAS EN Agave americana var. Oaxacensis EN RESPUESTA A ESTIMULANTES Y SOLUCIÓN NUTRITIVA

vie, 29 ago 2025 00:00:00 -0400

Agave americana var. Oaxacensis, es una especie silvestre usada en la obtención de mezcal. Presenta baja reproducción asexual y una producción de semillas hasta los 15-20 años. El objetivo de este estudio fue evaluar el efecto de estimulantes y solución nutritiva en la producción de hijuelos. El experimento se realizó en San Agustín Amatengo, Ejutla de Crespo, Oaxaca, México, con un diseño de bloques completos al azar, con factorial 3x2. El factor estimulante incluyó: un tratamiento sin estimulante 0, 2,5 L ha^-1 de SeaMel Booster y 2.0 L ha^-1 Algaroot^MR; el factor nutrición incluyó: solución Steiner al 0 y 100%. Cada tratamiento se integró con cuatro repeticiones, y la unidad experimental se conformó por seis plantas. En las plantas madre se midieron: diámetro de base de la roseta, diámetro de roseta, altura de la planta y número de hijuelos. En los hijuelos, se cuantificaron las variables anteriores más el número de hojas. Se obtuvieron muestras de suelo para determinar propiedades físicas y químicas. Las variables diámetro de base de la roseta, diámetro de roseta y altura en plantas madre no mostraron efectos significativos debido al uso del estimulante y la nutrición. El estimulante Algaroot^MR produjo significativamente el mayor número de hijuelos en plantas madre, mientras que las variables morfológicas fueron mayores en los hijuelos. El pH del suelo fue medianamente alcalino con efectos despreciables de la salinidad. El contenido de materia orgánica y nitrógeno alcanzó un nivel medio, mientras que el de fósforo estuvo en un rango medio a alto. La densidad aparente del área muestreada se sitúa en suelos francos y arenosos, con texturas franco limoso, franco arenoso y arenoso franco.

AMARANTHUS (Amaranthus hybridus L.) RESPONSE TO COCOA POD HUSK POWDER AND NITROGEN FERTILISER APPLICATIONS

Tajudeen B. Akinrinola, Adedayo O. Salami, Samuel A. Adegoke — vie, 29 ago 2025 00:00:00 -0400

Amaranthus is a fast-growing vegetable affected by inadequate soil nutrient supply due to intensive cultivation. Inorganic fertiliser application reduces vegetable quality, thus, farm waste such as Cocoa pod husk (CPH) was encouraged as organic fertiliser. However, limited information is available on CPH powder or its combination with urea on amaranthus performance. Therefore, the response of amaranthus to CPH and urea fertiliser was investigated. In a replicated 3 × 3 factorial experiment, CPH powder at 0, 30, and 60 kg N ha^-1 and urea fertiliser at 0, 30, and 60 kg N ha^-1 were evaluated in a randomised complete block design with five replicates using 4 kg soil. Data collected were subjected to ANOVA and significantly different means were separated at p<0.05. The results indicated that the control (0 kg CPH) had better growth than the CPH-treated plants at both plantings. Applying 60 kg N ha^-1 urea significantly increased the number of leaves and shoot biomass compared to the other treatments in both plantings. The CPH × urea interactions resulted in significant variations in amaranthus height, number of leaves and shoot biomass among the treatments. The growth parameters observed at 0 kg CPH × 60 kg N ha^-1 urea were significantly higher than other treatments but not different from CPH at 60 kg N ha^-1 × 60 kg N ha^-1 urea and CPH at 30 kg N ha^-1 × 30 kg N ha^-1 urea applications in both plantings. Consequently, CPH powder at 30 kg N ha^-1 with urea at 30 kg N ha^-1 was considered appropriate for sustainable amaranthus production.

MORPHOLOGICAL AND BIOCHEMICAL RESPONSES OF Amaranthus viridis TO CHEMICAL FERTILIZER AND BLACK SOLDIER FLY FRASS

Shao-Zhen Teo, Raihana Ridzuan, Fazilah Abd Manan — vie, 29 ago 2025 00:00:00 -0400

The prolonged use of chemical fertilizer is associated with adverse environmental effects. To date, insect-derived fertilizer from Black Soldier Fly (BSF), has emerged as a promising organic alternative. However, the impact of BSF frass on the morphology and biochemical compositions of leafy vegetables necessitates further investigation. Therefore, the objective of this study was to evaluate the effects of chemical NPK fertilizer and BSF frass fertilizer, applied individually or in combination, on the morphology and biochemical composition of Amaranthus viridis (A. viridis). The experiment consisted of four treatments; untreated control (T1), BSF frass (T2), NPK fertilizer (T3), and BSF frass + NPK fertilizer (T4). The results indicated that A. viridis plants in T4 exhibited the highest stem length, root length, leaf area, as well as weight of the stems, leaves, and roots. However, no significant differences were observed in terms of plant morphology and total chlorophyll content among the fertilizer treatments. Additionally, T4 significantly increased the total phenolic content in A.viridis (0.481 ± 0.012 mg GAE/g DW) compared to plants treated solely with NPK fertilizer. These results indicate that the combined application of BSF frass and NPK fertilizer significantly enhances plant growth of leafy vegetables, particularly by influencing specific biochemical compositions.

HYDROLATES AND ESSENTIAL OILS AFFECT Varroa destructor MITES IN in vitro ASSAYS

vie, 29 ago 2025 00:00:00 -0400

The beekeeping industry is affected by infestation of hives by Varroa destructor mites, reducing both honey yield and quality. The objective of this study was to evaluate the effects of hydrolates or essential oils on the survival of V. destructor mites using in vitro assays. Six hydrolates obtained from Lavandula angustifolia, Tithonia diversifolia, Ruta graveolens, Dalbergia palo-escrito, Populus alba, and Retama sphaerocarpa, as well as two essential oils from Lavandula angustifolia and Origanum vulgare were used. Behavioral changes and survival rates were evaluated to determine the effects of hydrolates or plant-based essential oils on V. destructor mites. Results indicate that essential oils of L. angustifolia and O. vulgare at low concentration (1.25 µL), as well as the hydrolate obtained from the flowers of Retama sphaerocarpa are effective against V. destructor without compromising bee survival. In conclusion, essential oils and hydrolates may serve as alternative treatments to reduce V. destructor mite infestations, particularly R. sphaerocarpa flower and T. diversifolia hydrolates, and 4 µL of O. vulgare essential oil.

POPULATION FLUCTUATION OF Bemisia tabaci IN Capsicum chinense THROUGH APPLICATIONS OF Cordyceps fumosorosea UNDER GREENHOUSE AND OPEN-FIELD CONDITIONS

Omar Pinto Gonzalez, Wilberth Chan Cupul, Andrea Mendoza Arceo — vie, 29 ago 2025 00:00:00 -0400

Bemisia tabaci is the main insect pest affecting Capsicum chinense production worldwide. Although Cordyceps fumosorosea has demonstrated efficacy against multiple insect pests under in vitro and in vivo conditions, further in situ evaluations are required to determine its effectiveness in real-world environments. The objective of this study was to evaluate the population fluctuation of B. tabaci in C. chinense cultivation under greenhouse and open-field conditions through the application of C. fumosorosea (Cf) as a biological control agent. A factorial experimental design A×B was used, where factor A corresponded to the site (greenhouse or open-field) and factor B to the application of Cf conidiospores (with or without application). Four treatments were established: T1) greenhouse + application of Cf; T2) greenhouse without application of Cf; T3) open-field + application of Cf; and T4) open-field without application of Cf. Response variables were population fluctuation (PF), efficacy, and the area under the population progress curve (AUPPC) in adults and nymphs. A multifactorial analysis of variance (ANOVA) followed by Tukey’s test was used to analyze the response variables. A greater fluctuation of adults and nymphs was found in the open-field; however, from 56 DAT, the greenhouse crop showed greater fluctuation. The efficacy of Cf in adults was greater in the greenhouse (52.4%) than in the open-field (27.2%). The same effectiveness was found in nymphs in both the open-field (64.6%) and greenhouse (62.7%). AUPPC showed that the use of Cf, under both greenhouse and open-field conditions, helped maintain low population levels of B. tabaci nymphs and adults. Overall, the application of Cf effectively suppressed B. tabaci population fluctuations in habanero pepper, highlighting its potential for its integration into sustainable management strategies against B. tabaci.

PRODUCCIÓN DE ASOCIACIONES DE GRAMÍNEAS Y LEGUMINOSAS FORRAJERAS TRATADAS CON INOCULANTES BACTERIANOS (Azotobacter spp. y Pseudomonas fluorecens)

vie, 29 ago 2025 00:00:00 -0400

La producción ganadera en Ecuador enfrenta el desafío de mejorar la productividad de los pastos de manera sostenible, procurando mantener la economía del sector frente a las fluctuaciones en los precios de la carne y de insumos como los fertilizantes. El objetivo de la presente investigación fue evaluar la producción de biomasa, concentración bromatológica y población microbiológica de las asociaciones de los pastos festuca (Festuca arundinacea) y ray grass (Lolium multiflorum), asociados con trébol rojo (Trifolium pratense) y alfalfa (Medicago sativa) e inoculados con rizobacterias promotoras del crecimiento vegetal. Se evaluaron los siguientes inoculantes bacterianos: Azotobacter chroococum, Azotobacter vinelandii, Azotobacter beijerinck, Pseudomonas fluorecens, y un testigo. Las asociaciones de gramíneas y leguminosas (relación 2:2) estuvieron distribuidas en un diseño de bloques con arreglo de parcelas subdivididas y tres repeticiones. Se destinaron edades de cosechas que fueron 30 y 60 días después de la siembra (DDS) y se evaluaron las siguientes variables: longitud de raíz, peso de raíz, concentración de proteínas, ceniza, extracto etéreo, fibra y materia seca. Se encontró que el pasto L. multiflorum asociado con M. sativa e inoculado con + A. beijerinck tuvo la mayor biomasa seca (2454,75 kg ha^-1) y la leguminosa M. sativa asociada con F. arundinacea e inoculada con A. vinelandii, presentó la mayor biomasa seca (1464,40 kg ha^-1) a los 60 DDS. Las mayores concentraciones de proteínas con el inoculante A. beijerinki en los forrajes de F. arundinacea + T. pratense y L. multiflorum + T. pratense fueron 28,12% y 26,87%, respectivamente. Se evidenció que los inoculantes bacterianos serían una estrategia amigable con el medio ambiente para mejorar la morfo-productividad y calidad nutricional de las especies forrajeras.

LIQUID FERTILIZATION AND BIOCHAR TO BOOST THE YIELD AND PROFITABILITY OF Arachis hypogaea L. IN DRYLAND AGROECOSYSTEMS

vie, 29 ago 2025 00:00:00 -0400

Temporary water deficits during the rainy season adversely affect surface soil, limiting the solubilization of granular fertilizers applied in surface bands. The objective of this study was to evaluate the effectiveness of liquid and granular fertilization in combination with biochar on the yield and profitability of peanut (Arachis hypogaea L.) in rainfed agroecosystems. The study was carried out during the January-June period of both the 2023 and 2024 seasons. Four treatments were evaluated: liquid fertilization + biochar (LFB); conventional fertilization + biochar (CFB); conventional fertilization (CF); and a control treatment (no fertilization). The main variables recorded were seed yield, the partial factor productivity of NPK (PFP_NPK), and net economic benefit (NEB) of fertilization. The results showed that fertilization treatments significantly influenced (p < 0.05) seed yield and partial factor productivity of NPK (PFP_NPK). LFB produced the highest yield values with 2007 kg ha^-1, exceeding CFB, CF, and the control by 182, 396, and 637 kg, respectively. LFB also achieved the highest increases in PFP_NPK compared with CFB and CF, indicating greater nutrient use efficiency. The highest NEB of fertilization was obtained with LFB, with USD 518 ha^-1, compared with USD 377 and 186 ha^-1 for CFB and CF, respectively. It is concluded that the combined application of liquid fertilizer and biochar is an economically viable and sustainable strategy for rainfed peanut production, particularly under surface soil water deficit.

FIRST REPORT OF IMIDAZOLINONE-RESISTANT Bassia scoparia IN ARGENTINA: EVIDENCE FROM DOSE-RESPONSE BIOASSAYS AND ALS GENE SEQUENCING

Jorgelina C. Montoya, Esteban E. Fabressi, Marcos E. Yanniccari — vie, 29 ago 2025 00:00:00 -0400

Kochia (Bassia scoparia (L.) A. J. Scott.) is a problematic weed. In Argentina, farmers have recently experienced poor control over imidazolinone-resistant sunflowers, specifically the sensitivity of putative kochia resistant plants to imidazolinone herbicides. Seeds from putative resistant populations from Pellegrini (P), De Bary (DB), and 30 de Agosto (A) and a known susceptible (S) population from Col. Martín Fierro were sown in pots. A mixture of imazapyr (Clearsol® WG 80%) and imazamox (Trigosol WG 70%) was sprayed when plants reached approximately 6 cm in height and 10-leaf stage using a boom sprayer. A trial was conducted to determine the response of kochia to the recommended doses (1x) of imazapyr 80.00 g ai ha^-1 + imazamox 20.30 g ai ha^-1. Plants were harvested 30 days after treatment to determine fresh shoot weight. A dose–response experiment was performed using imazapyr + imazamox at concentrations of 0x, 1/4x, 1/2x, 1x, 2x, 4x, and 8x. Partial ALS gene amplification was performed using leaves of plants that survived an 8x dose. The 1x fresh weight of the putative populations did not differ from 0x. LD₅₀ of imazapyr+imazamox (g ai ha^-1) for each biotype was: S, 18.86 + 4.79; DB, 82.48 + 20.93; A, 179.36 + 45.51; and P, 550.88 + 139.79. The three resistant populations exhibited a single-point mutation from guanine to thymine, detected in codon 574 of the ALS gene. This mutation confers resistance to ALS inhibitors. This is the first reported case of kochia resistance in Argentina, providing valuable insights that extend beyond sunflower weed management.