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Item An Assessment of the Feasibility of Phytoextraction for the Stripping of Bioavailable Metals from Contaminated Soils(2022-12-29) Santa‐Cruz, Javier; Robinson, Brett; Krutyakov, Yurii A.; Shapoval, Olga A.; Peñaloza, Patricia; Yáñez, Carolina; Neaman, AlexanderPhytoextraction has been proposed in many papers as a low-cost method for remediating contaminated soil. However, if national regulation is based on total metal(loid) concentrations in soil, phytoextraction is generally infeasible because of the long time required for remediation. Assessing phytoextraction requires determination of the dynamic rate of metal removal from soil. Phytoextraction may be feasible if the main goal is to reduce the soluble fraction of the metal(loid) with the goal of reducing bioavailability. However, it has been reported that there is a large mass balance mismatch between the reduction of the soluble metal fraction in contaminated soil and metal uptake by plants. Several studies report that the decrease of soluble fraction of metals in soil is higher than can be accounted for by plant uptake. In other words, studies generally overestimate the feasibility of bioavailable contaminant stripping. Therefore, a more rigorous approach is advisable to ensure that papers on bioavailable contaminant stripping include relevant information on mass balances. Furthermore, to implement the concept of bioavailable contaminant stripping, regulations must distinguish between the bioavailable fraction and the total metal concentration in soil.Item Impact of monochromatic lights on the in vitro development of Cattleya walkeriana and effects on acclimatization(2023-06-03) Nadal, Michele Carla; Bernardes Machado, Natalia; dos Santos, Cyntia Stephânia; Nunes Flores, José Henrique; Dória, Joyce; Pasqual, MoacirLight quality is an important factor for the adequacy of plant production through plant tissue culture, as it directly interferes with morphogenesis and photosynthetic capacity of explants. The objective of this study was to analyze the impact of monochromatic lights such as light emitting diode (LED) on the in vitro development of Cattleya walkeriana G. and their effects on acclimatization. The plants were developed in vitro under the colors of green, blue, yellow, red, 2 red:1 blue, and white LED lights. For in vitro cultivation, Knudson medium was used, supplemented with 20 mg L-1 sucrose, 5.5 mg L-1 agar, 2% activated charcoal, 100 mL coconut water, and pH 6.0. For ex vitro cultivation, the plants were acclimatized in styrofoam trays containing sphagnum as a substrate. In general, the supplied light lengths impactedin vitro growth and acclimatization analyses. There was influence on the cuticle thickness of plants in vitro. Chlorophyll and carotenoid contents were not significant. We can conclude that light lengths formed by 2 red:1 blue, red and yellow LEDs can be indicated for better performance in the production of C. walkeriana. The 2 red:1 blue and red LEDs provide superior in vitro development than the others, with gains for the species in acclimatization. The yellow LED provided a possible in vitro hardening, which ensured the greatest success of the seedlings during acclimatization.Item Servicios ecosistémicos asociados al salar de Llamara, Pozo Almonte, Tarapacá, Chile(2023-03) Vicencio-Campos, Omar; Chirino-Gálvez, Luis; Silva-Bobadilla, HéctorEl salar de Llamara es un sistema salino ubicado en la región de Tarapacá, desierto de Atacama, en el cual existe una biodiversidad dominada por diatomeas, cianobacterias, bacteroides y proteobacterias, además de una gran gama de especies vertebradas como zorros, aves y roedores. Considerando los efectos asociados al cambio climático y la alta susceptibilidad de este ecosistema, se evaluó cuáles son los servicios ecosistémicos prestados a la comunidad en las categorías de Provisión, Regulación, Soporte y Cultural, y cómo estos mejoran el ámbito social, económico y ambiental en la comuna de Pozo Almonte.Item Diagnóstico organizacional en empresas de Popayán: antes y después de la pandemia(2023-08-05) Saldarriaga Salazar, María Eugenia; Benítez Chará, Willington; Concha Cerón, Eduardo AndrésLa investigación propuso realizar el diagnóstico organizacional en mipymes del sector gastronómico de la Popayán, con el fin de identificar como se adaptan a las a condiciones del entorno en pandemia. Se estudiaron autores como Herrera, Bernal, Pupo, Tamayo, Gamboa, entre otros, y sus postulados, analizado diagnóstico organizacional, entorno externo e interno. Se utilizó metodología cualitativa de tipo descriptivo, aplicando entrevistas semiestructuradas en 5 micro y 5 pequeñas empresas de gastronomía de Popayán. Los resultados indican cambios en los factores externos que revelan crisis económica por cierre de empresas, disminución de ventas al inicio, labores a puerta cerrada y políticas que limitaban operaciones. Se evidenció temor al adquirir productos, cambios de comportamientos y nuevas preferencias de clientes. Los factores internos ocasionaron reducción de recursos físicos, personal, recursos financieros, y escasez de materia prima. Implementaron herramientas digitales de publicidad. Se concluye que el diagnóstico organizacional permite conocer la situación de las empresas. Hoy se debe considerar el uso de aplicaciones para solicitudes de productos y continuar domicilios. Superar los límites de aforo en instalaciones y premura de espacios abiertos después de la pandemia.Item Emprendimiento social: Situación y factores de éxito en Colombia(2023-08-05) Vásquez Bernal, Jairo AlbertoEl emprendimiento social permite el desarrollo de comunidades con productos o servicios que generan impacto social positivo cuando se presentan problemas generados principalmente por la pobreza. El objetivo del presente estudio es determinar los factores de éxito del emprendimiento social en Colombia, su conceptualización, situación y aspectos relevantes desde empresas sociales como asociaciones, corporaciones, fundaciones, cooperativas y organizaciones sociales. El trabajo es de corte mixto, cualitativo, cuantitativo, realizado a empresas sociales, la información primaria se obtuvo de una muestra de 270 unidades, con un proceso de muestreo estratificado proporcional por ciudades, mediante un instrumento de 20 preguntas cerradas, cuya validación se realizó por el método Delphi. Los resultados indican que personas, crean y/o consolidan organizaciones que generan un beneficio social de acuerdo con factores como la orientación al servicio, la propuesta de valor, impactos positivos en problemáticas sociales. Se concluye que el emprendimiento social es relativamente nuevo desde lo conceptual y legal; asimismo que los factores de éxito son la calidad, experiencia, el tipo de producto o servicio social, la planeación, estrategia, el trabajo social y los recursos.Item Veronica Cymbalaria (Plantaginaceae): A New Species For The Exotic Flora Of Chile(2023-06) Cisternas, Mauricio A.; Cádiz Véliz, Arón; Novoa, Patricio; Macaya Berti, JorgeBackground and aims: Botanic gardens play a fundamental role in conservation due to the maintenance of seed and live plant collections. However, the exchange of ornamental plant seeds between botanic gardens can facilitate the entry of seeds of alien species with invasive potential. In 2018, during a visit to the collections of the National Botanical Garden (Chile), we discovered populations of an herb of the genus Verónica (Plantaginaceae). The aim of this paper is to report for the first time the presence of Verónica cymbalaria as a new exotic feral species for the flora of Chile. M&M: Live material was studied and compared with the original description of the species. The collected material was deposited in the herbarium of the National Botanical Garden (JBN). Results: Verónica cymbalaria, which grows abundantly in and around the biological collections of the National Botanical Garden, is described. Images of the species, a map of the site of occurrence and a key to distinguish Verónica species growing in Chile are included. Conclusions: Verónica cymbalaria is reported for the first time for the flora of Chile. The distribution range of this alien species is extended to southern America. The genus Verónica is represented by ten allochthonous species in Chile.Item Seaweed restocking along the Chilean coast: History, present, and inspiring recommendations for sustainability(2023-01-09) Oyarzo-Miranda, Carolina; Otaíza, Ricardo; Bellorín, Alexis; Alonso Vega, J.M.; Tala, Fadia; Lagos, Nelson A.; Oyarzún, Fernanda X.; Estévez, Rodrigo A.; Latorre-Padilla, Nicolás; Mora Tapia, Ana María; Figueroa-Fábrega, Luis; Jara-Yáñez, Roddy; Bulboa, Cristian; Contreras-Porcia, LorettoSeveral seaweed species are commercialized worldwide both due to high demand for food and feed and as a raw material for the extraction of phycocolloids such as agar, carrageenan, and alginates that are used broadly in the food, cosmetic, and pharmaceutical industries. Chile is the world’s leading marine seaweed biomass producer when it comes to the exploitation of natural kelp beds. This extraction pressure has persisted for decades and has resulted in a reduction in natural stocks along the benthic ecosystems of the Chilean coast. Over the last three decades, several strategies aimed at restoring seaweed stocks have been implemented (i.e., sexual and asexual reproduction, the use of spore-type propagules or fragments of thalli, and entire thallus transplants). Success rates have varied, but the biological feasibility of such strategies has been demonstrated for several species. However, technological improvements must be achieved to move from small-scale, pilot experiments to cost-effective restocking strategies that are easy to transfer to fisher communities and another end-user, scalable to marine field conditions, and socio-ecologically sustainable. Researchers in other geographic areas have explored similar pathways for developing kelp restocking strategies and have tackled the research gaps regarding its massification. This work summarizes the research activities carried out in recent decades in the search for sustainable strategies to restore algal stocks in Chile.Item Hydrolyzed protein from Lupinus albus (INIA-Boroa variety) for the functional food industry: An example of partnership between farmers and academia(2023-01-04) Oliveira, Patricia E.; Benavides, Sergio F.; Huenufil, Daniel; Zarate, Pablina; Petit-Breuilh, XimenaThis work presents investigations carried out to obtain by-products of bitter lupine (Lupinus albus), using a variety created specially in the Chilean Agricultural Research Institute (INIA). We present new information on obtaining protein isolates and hydrolysates as a way of adding value to bitter lupine, which promises to help return this crop to profitability in Chile. Lupine in this country is produced almost exclusively in the Araucanía Region, for the most part by small-scale farmers of the Mapuche ethnic group. An experimental design was drawn up based on one-factor experiments, for obtaining both protein isolate and protein hydrolysate. The best process conditions were achieved with stirring times of between 60 and 90 min; the concentrations (consistency of the mixture) were between 5 and 10%, with pH of the solution 12. The maximum yield achieved was 33% pure protein isolate (dry weight). After the protein isolates had been formulated, they were characterised by their functional properties: solubility, water retention capacity, lipid adsorption index, swelling capacity and foam stability. These properties are important for determining the quality of the protein hydrolysate, as they will affect its digestibility and thus its bioavailability in the organism. The protein hydrolysate was characterised by its complete proximal parameter, vitamins, total sugars, and amino acids. These results show that Lupinus albus (var. INIA-Boroa) is an excellent raw material for the existing functional foods industry.Item Protocol for in vitro rooting of Pyrus comunnis rootstocks(2023-04-15) Nadal, Michele Carla; Bernardes Machado, Otávio; Araújo, Ronilson Carlos; Rodrigues, Filipe Almendagna; Rufato, Leo; Dória, Joyce; Pasqual, MoacirEffective protocols for in vitro rooting for woody fruit trees are still a challenge for in vitro seedling production, especially when there is a need to insert new cultivars or rootstocks. These protocols are essential to accelerate studies in plant breeding programs and for seedling distribution. This study evaluated the use of 6-Benzylaminopurine (IBA) in in vitro rooting of Pyruscomunnis rootstocks, clones ‘OHxF87’ and Pyrodwarf. Explant exposure times (0, 24, 48, 72, and 96 hours) to 20 mg L-1 IBA were tested for in vitro rooting. The exposure to IBA resulted in rooting rates above 80%, surpassing some results reported in the literature. The 24-hour treatment provided 81,81% survival, leading to an average growth of five roots with 19 mm length, for ‘OHxF87’ rootstock. The same exposure time resulted in the highest survival rate (75%) and the highest mean root number, seven roots per plant with 10 mm length, for ‘PDW’ rootstock. Root formation did not occur in the absence of synthetic auxin. Therefore, it can be concluded that a 24-hour exposure at 20 mg L-1 IBA was sufficient to promote in vitro rooting in ‘OHxF87’ and Pyrodwarf rootstocks’.Item Dendrobium nobile in vitro flowering induction(2023-05-22) Nadal, Michele Carla; Silva Andrade, Gracielle Vidal; Nunes Flores, José Henrique; dos Reis, Michele Valquíria; Rodrigues, Vantuil Antonio; Pasqual, MoacirIn vitro flowering is a technique used in genetic improvement that accelerates generations and favors the faster fixation of new traits of agronomic and market interest. The study aimed to establish a protocol for the in vitro flowering of Dendrobium nobile, through the combined temperature and of the growth regulator thidiazuron (TDZ) effects. Experiments was performed in a flask that was kept in a BOD incubator at 18, 21, or 24 °C or in a growth room at 26 °C. The TDZ concentrations were 0.0, 0.5, 1.0, and 2.0 mg L-1. The highest percentage of flowering shoots of 13.7% occurred at a concentration of 2 mg L-1 of TDZ grown at a temperature of 18 °C. Dendrobium nobile in vitro flowering was promoted in plants cultivated in ½ MS supplemented with 30 g L-1 sucrose, 5.5 g L-1 agar, 100 mL L-1 coconut water, pH 6.0, and 2.0 mg L-1 TDZ at a controlled temperature of 18 °C and a photoperiod of 16 h. The in vitro flowering induction protocol of the D. nobile species could be used or improved for future studies.Keywords: flowering, temperature, thidiazuron, Orchidaceae.Item Conocimiento, prevalencia y valoración de prácticas deshonestas en estudiantes universitarios de Artes y Humanidades y de Ciencias de la Salud(2022-10) Vásquez-Rocca, Liliana; Cuba Raime, Claret; Vásquez Velasco, CarolinaEl avance tecnológico trajo consigo ventajas y desventajas en el ámbito académico, dando la posibilidad a las y los estudiantes y profesoras y profesores de acceder a una amplia información especializada. Entre las desventajas, se ubica el plagio, la copia y otras acciones similares. De hecho, la práctica deshonesta más frecuente entre las y los estudiantes del mundo es el plagio académico. Al respecto, las indagaciones en esta área son múltiples y desde diferentes aproximaciones teóricas. A nivel iberoamericano, Sureda, Comas y Urbina, (2005) y Comas-Forgas y Sureda-Negre (2010) realizaron estudios pioneros en el campo. En este marco, esta investigación tiene como objetivo comparar el conocimiento, prevalencia y valoración de prácticas deshonestas por parte de las y los estudiantes ingresantes a la universidad de las disciplinas de Artes y Humanidades (Perú) y de las Ciencias de la Salud (Chile). El método utilizado es el cuantitativo descriptivo con un diseño no experimental y transversal, la muestra consideró 217 participantes a los cuales se les aplicó un cuestionario validado previamente. Tras el análisis, los resultados muestran que el conocimiento del plagio y de las referencias no difiere entre ambos campos del saber. En cuanto a la prevalencia y valoración, en su mayoría presentan datos similares, salvo acciones y prácticas específicas que su sanción podría estar más normada por cuerpos legales.Item Scratch and Arduino for Effectively Developing Programming and Computing-Electronic Competences in Primary School Children(2019-11) Vidal-Silva, Cristian; Serrano-Malebran, Jorge; Pereira, FelipeProgramming and designing computing-electronic solutions imply complex competences, which usually demand to restructure previous thinking and problem-solving knowledge. Both programming and computing-electronic design solutions ask for step-by-step thinking, and also being cautious regarding involved hardware items for the second one. Designing computing-electronic solutions is a non-trivial task since it unifies both worlds, even though platforms such as Arduino notably simplify that development. This article describes experiences of programming and computing-electronic teaching to a group of primary school children in Valparaiso-Chile by the use of Scratch and Tinkercad for the goal of developing programming and Arduino-based computing-electronic competences in school children. The obtained results demonstrate that children can effectively develop programming and computing-electronic theoretical and practical skills. These results also show that students can get abilities and enthusiasm to know more advanced skills and applications concerning sensing systems. Thus, programming and electronics can motivate the learning process in children.Item Cambios en la densidad y distribución espacial de las poblaciones del género Fissurella Spp. (Fissurellidae) y de Concholepas Concholepas (Muricidae), en áreas de manejo y explotación de recursos bentónicos con extracción de Lessonia Trabeculata (Phaeophyceae) de las regiones de Atacama y Coquimbo.(2020-08) Morales Gallardo, Vanessa; Padilla Zambrano, Tiare; Figueroa-Fábrega, Luis; Ariz, LuisLessonia trabeculata es conocida por su rol como estructurador del ecosistema marino. Sin embargo, en la actualidad, las densidades naturales del alga han disminuido considerablemente, debido a la intensa actividad extractiva. Concholepas concholepas, Fissurella latimarginata y Fussurella cumingi son especies que cohabitan con huiro palo, por ende, dependen en gran medida unas de otras. Por este motivo el objetivo de este estudio es determinar si la extracción del recurso L. trabeculata genera cambios en la dinámica de las poblaciones submareales de C. concholepas, F. latimarginata y F. cumingi. Para ello se analizaron las densidades históricas registradas en AMERBs representativas de las Regiones de Atacama y Coquimbo. Los resultados muestran que tanto en las áreas de manejo de Atacama como en las de Coquimbo existen cuatro tendencias marcadas en la relación entre las densidades de L. trabeculata y C. concholepas, F. latimarginata y F. cumingi, observándose que áreas donde la densidad del huiro palo es alta, existen dos posibles situaciones; la primera en donde también lo es para los otros recursos asociados o que no lo sea. Y la segunda, en donde la baja densidad de huiro palo, genera mayor o menor densidad en el resto de los recursos.Item Utilización de los Índices de Hábitat Fluvial, Bosque de Ribera y Macrófitas para la Determinación de Calidad del Recurso Hídrico del Estero Catapilco, Región de Valparaíso(2015-03-02) Silva Haun, Rodrigo; Arancibia Fortes, JavierEl Estero Catapilco está ubicado en Chile central. Su alimentación corresponde a un régimen 100% pluvial, desarrollándose flora mediterránea en su cauce (bosque esclerófilo e hidrófilo). La intervención antrópica ha modificado la vegetación ribereña, el caudal disponible y la calidad del agua. Para caracterizar la calidad del recurso hídrico se estableció seis (6) estaciones a lo largo de la cuenca, aplicando en cada una de ellas el Índice de Hábitat Fluvial, Índice de Calidad Bosque de Ribera y el Índice de Macrófitas. Dichos resultados fueron correlacionados utilizando la metodología de Spearman (1904) con los análisis físicos y químicos realizados al agua. El análisis de la calidad del agua del Estero Catapilco mostró que estas no se encontraban en la mejor condición. La correlación con muestreos físicos y químicos de las aguas, mostró marcadas diferencias entre ambas metodologías. Estas situación puede deberse a la baja diversidad de especies nativas y un número importante de especies introducidas, lo que incide directamente con los valores entregados por los índices. Asimismo se observó que los cambios en el uso de suelo, aumento de plantaciones forestarles, está influyendo en la cantidad del recurso hídrico disponible en la cuenca.Item Quantifying effects of irrigation and soil water content on electricalpotentials in grapevines (Vitis vinifera) using multivariate statisticalmethods(2014-05-20) Gil, Pilar M.; Saavedra, Jorge; Schaffer, Bruce; Navarro, Rosa; Fuentealba, ClaudiaSeveral studies have shown that physiological responses in plants, including fruit crops, are associated with changes in electrical potentials (EP), but it is often difficult to statistically quantify these responses. This study tested the effects of irrigation on EP in grapevines (Vitis vinifera), taking into account vapor pressure deficit (VPD) and position of electrodes along the stem by using multivariate analytical methods and a suite of statistical pretreatments. In two separate experiments, plants were exposed to one of two irrigation treatments in a greenhouse: (T1) irrigation once per day (Experiment 1), or no irrigation (Experiment 2); or (T2) irrigation three times or twice per day (Experiments 1 and 2, respectively). In each experiment, EP at three positions along the stem, soil (potting medium) water content, and VPD were continuously measured. In Experiment 2, stomatal conductance (gs) and stem water potential (SWP) were also measured for plants in each irrigation treatment as indicators of plant water status. Data were analyzed by Principal Component Analysis (PCA) to determine the effects of irrigation treatment on EP and difference in EP between pairs of electrodes (ΔEP) at various locations along the stem. Data were also analyzed by partial least squares (PLS) analysis to determine if EP or ΔEP could be used as predictors of changes in soil water content due to different irrigation treatments. Significant differences in soil water content due to irrigation treatments could be readily detected by difference in EP or ΔEP using PCA with Orthogonal Signal Correction pre-processing. Also, PLS showed that differences in soil moisture can be predicted by EP and/or ΔEP measurements at specific locations along the stem. Thus, the use of multivariate statistical methods was effective for relating EP and ΔEP measurements in grapevines to soil moisture due to differences in irrigation.Item Simazine transport in undisturbed soils from a vineyard at the Casablanca valley, Chile(2013-01-20) Suárez, Francisco; Guzmán, Edwin; Muñoz, José F.; Bachmann, Jaime; Ortiz, Cristian; Alister, Claudio; Kogan, MarceloSimazine is a soil-active herbicide that has been applied worldwide in agricultural soils, being the second most commonly detected herbicide in groundwater and surface waters. Although its use has been restricted in many countries of Europe, it is still applied in many locations around the world in orchards, vineyards and forestry. Therefore, it is important to study its fate and transport in the environment. This paper investigates simazine transport in undisturbed bare soils from a vineyard at the Casablanca valley, Chile. In the study site, shallow groundwater tables (<1.0 m depth) and high simazine levels (>15 μg L−1) in the groundwater were observed and thus, there is potential for simazine to be transported further away through the saturated zone. The soils from the study site were characterized and the hydrodynamic transport parameters were determined. Column leaching experiments showed that the two-site chemical non-equilibrium model correctly represented simazine transport. It was found that 36.3% of the adsorption sites achieve instantaneous equilibrium and that the first-order kinetic rate of the non-equilibrium sites was 6.2 × 10−3 h−1. Hydrus 2D was used to predict the transport of simazine in the study site under natural field conditions. Simulation results showed that simazine concentrations at depths shallower than 2.1 m are above the maximum contaminant level of 4 μg L−1 (defined by the U.S. Environmental Protection Agency). The timing of herbicide application was found to be important on simazine leaching and the main processes involved in simazine transport were degradation and adsorption, which accounted for 95.78 and 4.19% of the simulated mass of pesticide, respectively. A qualitative agreement in the timing and magnitude of simazine concentration was obtained between the simulations and the field data. Therefore, the model utilized in this investigation can be used to predict simazine transport and is a valuable tool to assess agricultural practices to minimize environmental impacts of simazine.Item Competitive Strategies and Growth of Neighbouring Bromus valdivianus Phil. and Lolium perenne L. Plants Under Water Restriction(2013-05) López, F.; Kemp, P. D.; Dörner, J.; Descalzi, C. A.; Balocchi, O. A.; García, S.Often perennial pastures have to tolerate soil water restriction during summer, which can affect the relative abundance of the most desired species. In the south of Chile, Bromus valdivianus and Lolium perenne are preferred species. The competitiveness of B. valdivianus and L. perenne was evaluated when sown in pots in a glasshouse as monocultures or a mix (50/50 %) with restricted water availability. The water restriction treatments were as follows: 80–85 % field capacity (FC), 45–50 % FC and 20–25 % FC, maintained for 1196 growing degree days. For both species, dry matter (DM) accumulated per plant and per pot decreased similarly with increasing water restriction, but at tiller level, resource allocation differed, for B. valdivianus root growth was accentuated over aerial development, but this was less so for L. perenne. The foliage mass per tiller for B. valdivianus decreased relatively more than that for L. perenne with increasing water restriction. As monocultures, B. valdivianus produced larger tillers than L. perenne, such that B. valdivianus tillers had 2.2 times greater lamina mass, 3.6 times more leaf area and 2.5 times greater root mass than those of L. perenne. However, L. perenne produced a larger number of smaller tillers that enabled foliage, root and total mass at plant level, to be similar to that of B. valdivianus. Within the mixed pasture, L. perenne tiller density increased compared with when grown as a monoculture, but not for B. valdivianus. The results of the study suggested that L. perenne and B. valdivianus have differences in growth strategies that allow them to survive under environmental stress and competition. Competitiveness increased for L. perenne aboveground without water restriction and that for B. valdivianus increased belowground as water restriction was increased.Item Water and sediment dynamics of penoxsulam and molinate in paddy fields: field and lysimeter studies(2011-07-15) Kogan, Marcelo; Araya, Manuel; Alister, ClaudioBACKGROUND: In Chile, rice is cultivated under water-seeded and continuously flooded conditions. Because herbicide dynamics in paddy fields and non-flooded fields is different, 3 year experiments were performed to study the dissipation of molinate and penoxsulam in water and sediment. RESULTS: In field experiments, both herbicides dissipated by 45–55% from the initial applied amounts during the first 6 h after application in all crop seasons; in lysimeter experiments, dissipation amounts were approximately 10% for penoxsulam and 16% for molinate. Penoxsulam field water DT50 values varied from 1.28 to 1.96 days during the three study seasons, and DT90 values from 4.07 to 6.22 days. Molinate field water DT50 values varied from 0.89 to 1.73 days, and DT90 values from 2.82 to 5.48 days. Sediment residues were determined 2 days after herbicide application into the paddy water, and maximum concentrations were found 4–8 days after application. In sediment, DT50 values varied from 20.20 to 27.66 days for penoxsulam and from 15.02 to 29.83 days for molinate. CONCLUSIONS: Results showed that penoxsulam and molinate losses under paddy conditions are dissipated rapidly from the water and then dissipate slowly from the sediment. Penoxsulam and molinate field water dissipation was facilitated by paddy water motion created by the wind. SedimentItem Glyphosate Use in Forest Plantations(2010) Kogan, Marcelo; Alister, ClaudioUnder Chilean conditions the lack of weed control at forest tree establishment results in an average of at least 60% less biomass accumulation during the first year of growth of radiate pine or eucaliptus, and glyphosate offers a series of advantages in forestry weed management because its activity in both herbaceous weed groups, monocots and dicots, as well as annuals, biennials and perennials. Also, its efficacy in woody undesirable vegetation makes glyphosate a very important herbicide that can be applied to control herbaceous and woody weeds as pre-planting and during the second or third years of trees growth as strip applications. The aim of this review is to discuss the main uses of glyphosate in reforestation worldwide, during the first 2 yr after tree establishment, as broadcast application over the top of the forest trees and the most important factors that could affect glyphosate efficacy as a forest herbicide, like weed growth stage, application technique, volume and water quality, rainfastness, dew effect and the use of extra adjuvant with formulated glyphosate.Item Adsorption and desorption variability of four herbicides used in paddy rice production(2011-01) Alister, Claudio A.; Araya, Manuel A.; Kogan, MarceloThis investigation was performed to determine the effect of physicochemical soil properties on penoxsulam, molinate, bentazon, and MCPA adsorption-desorption processes. Four soils from Melozal (35° 43' S; 71° 41' W), Parral (36° 08' S; 71° 52' W), San Carlos (36° 24' S; 71° 57' W), and Panimavida (35° 44' S; 71° 24' W) were utilized. Herbicide adsorption reached equilibrium after 4 h in all soils. The Freundlich L-type isotherm described the adsorption process, which showed a high affinity between herbicides and sorption sites mainly because of hydrophobic and H-bonds interaction. Penoxsulam showed the highest adsorption coefficients (4.23 ± 0.72 to 10.69 ± 1.58 mL g⁻¹) and were related to soil pH. Molinate showed K(d) values between 1.72 ± 0.01 and 2.3 ± 0.01 mL g⁻¹ and were related to soil pH and organic matter, specifically to the amount of humic substances. Bentazon had a high relationship with pH and humic substances and its K(d) values were the lowest, ranging from 0.11 ± 0.01 to 0.42 ± 0.01 mL g⁻¹. MCPA K(d) ranged from 0.14 ± 0.02 to 2.72 ± 0.01 mL g⁻¹, however its adsorption was related to humic acids and clay content. According to these results, the soil factors that could explain the sorption process of the studied herbicides under paddy rice soil conditions, were principally humic substances and soil pH. Considering the sorption variability observed in this study and the potential risk for groundwater contamination, it is necessary to develop weed rice management strategies that limit use of herbicides that exhibit low soil adsorption in areas with predisposing conditions to soil leaching.