Abstract: Water stress is a major cause of mortality in plants. It occurs when transpiration exceeds the amount of water absorbed by roots. The morphological and physiological effects of plant water stress have been well documented in adult trees but little is known about effects on seedlings. The aim of this study was to evaluate, under semi-controlled conditions, the effect of water stress on growth and water use efficiency of productivity (EUAp) in seedlings of deciduous Leucaena leucocephala, Cordia dodecandra and Piscidia piscipula. The study was undertaken in a greenhouse at the Campus de Ciencias Biológicas y Agropecuarias of the Universidad Autónoma de Yucatán between January and March, 2011. Four seedlings of each species were subjected to two treatments, induced water stress (CEI) and without induced water stress (SEI). Sampling was done when all CEI seedlings of each species exhibited the first signs of wilting. We determined the water status (water potential Ψ, relative water content in soil, leaves and stem and evapotranspiration), plant growth (height, root length, leaf area, leaf, stem and root biomass) and EUAp for each species under both CEI and SEI treatments. CEI seedlings had a 20% more negative Ψ, lower evapotranspiration and relative water content than SEI seedlings. EUAp showed no significant differences between treatments for any species, except for leaf area which was lower in CEI seedlings of P. piscipula and L. leucocephala. In this study, water stress mainly affectedΨ and leaf area. Under conditions similar to those of this study, we recommend watering the seedlings of the three studied species before they reach a Ψ of -3 MPa. | Resumen: El estrés hídrico es una de las principales causas de muerte en plantas, ocurre cuando la transpiración excede el agua absorbida por las raíces. Los efectos morfológicos y fisiológicos del estrés hídrico sobre los árboles están ampliamente documentados pero se carece de información suficiente para el estado de plántula. El objetivo del presente estudio fue determinar el efecto del estrés hídrico, bajo condiciones semicontroladas, sobre el crecimiento y eficiencia de uso del agua en la productividad (EUAp) en plántulas caducifolias de Leucaena leucocephala, Cordia dodecandra y Piscidia piscipula. El estudio se llevó a cabo en un invernadero del Campus de Ciencias Biológicas y Agropecuarias de la Universidad Autónoma de Yucatán de enero a marzo de 2011. Se compararon cuatro plántulas de cada especie sometidas a dos tratamientos: con estrés inducido (CEI) y sin estrés inducido (SEI). El muestreo se realizó cuando todas las plántulas CEI de cada especie presentaron el primer síntoma de marchitez. Se midió el estado hídrico (potencial hídrico (Ψ), contenido relativo de agua en el suelo, hojas y tallo y evapotranspiración), crecimiento (altura de la planta, longitud de la raíz, área foliar, biomasa de hojas y tallo, y biomasa de la raíz) y la EUAp. Las plántulas del tratamiento CEI presentaron Ψ 20% más negativos, menor evapotranspiración y contenido relativo de agua que las plántulas SEI, con diferencias significativas entre tratamientos por especie (P ≤ 0.05). Las variables de crecimiento y la EUAp no presentaron diferencias significativas entre tratamientos para ninguna especie, excepto el área foliar que fue menor en P. piscipula y L. leucocephala CEI. En este estudio, el estrés hídrico afectó principalmente las variables de estado hídrico y el área foliar. Bajo condiciones similares a las de este estudio, se recomienda regar las plántulas de las especies estudiadas antes de alcanzar un Ψ de -3 MPa.

The southern region Espirito Santo state is characterized by topographic strong wavy, with highly weathered soils and low fertility. Most of the land of family farms requires intensive soil use and, consequently, promotes soil loss, water and nutrients by erosion. Coffee conilon and grazing are the main systems of food production in the region. The aim of this study was to estimate, during the rainy season, soil loss and nutrient of areas under coffee cultivation systems under conservation (and agroforestry with management of soil cover) and conventional tillage (non-coverage soil). Collectors of soil and water were installed in 6 observation units, being 2 in conventional systems, 3 in conservationists systems and 1 in native forest that was used as a reference. Meteorological data were collected at the rainy season of 2009/2010. The soil and water losses estimated for the period, were higher (98 and 68%) in the conventional systems compared to conservation systems. Potassium was the nutrient that had higher losses in the systems (from 0.17 to 33 g/ha, respectively).

The effect of radial distance from water sources (RDW) on plant volume, hiding cover (HC) and the presence of white-tailed deer was assessed. The study was conducted in the state of Puebla, Mexico. Stratified random sampling was used to select five areas with a RDW of less than 800 m, four between 800-1,600 m and four greater than 1,600 m. Plant volume was estimated in these areas and they were the starting point of transects in which HC and the number of white-tailed deer and coyote fecal pellet groups (PGs) were estimated. The number of white-tailed deer PGs increased as the RDW increased (Tukey; P < 0.05), while coyote PGs remained within the 800-m radius (X2 = 0.004). The RDW did not affect HC (Tukey, P > 0.05). The relationship between RDW, HC and PGs was established using Poisson and polynomial regression. Poisson regression showed that RDW and HC significantly changed (X2; P < 0.0004 and P < 0.0001) the PG number. The polynomial equation showed that HC has a good correlation (R2 = 0.72) with PGs. | El efecto de la distancia radial al agua (DRA) sobre el volumen vegetal, la cobertura de escape (CE) y la presencia del venado cola blanca, se evaluó. El trabajo se realizó en el estado de Puebla, México. Cinco áreas con una DRA menor a 800 m, cuatro entre 800-1,600 y cuatro mayores a 1,600 m, fueron seleccionadas utilizando un modelo completamente al azar. El volumen vegetal se estimó en estas áreas y fueron el punto de inicio de transectos en los cuales se estimó la CE y el número de grupos fecales (GFs) de venado cola blanca y coyote. Los GFs de venado cola blanca aumentaron conforme aumentaba la DRA (Tukey; P < 0.05) mientras que los de coyote se mantuvieron dentro de los 800 m de radio (X2 = 0.004). La DRA no afectó la CE (Tukey; P > 0.05). La relación entre la DRA, CE y GFs, se estableció con un análisis de regresión de Poisson y un polinomial. La regresión de Poisson mostró que la DRA y la CE modifican significativamente (X2; P < 0.0004 y P < 0.0001) el número de GFs. La ecuación polinomial mostró que la CE tiene buena correlación (R2 = 0.72) con los GFs.

A pulverização de agrotóxicos tornou-se uma das operações mais repetidas nas propriedades rurais, isto ocorreu, principalmente, em função da adoção do sistema de semeadura direta. A facilidade para a aquisição de agrotóxicos é notória em todo o Brasil. Entretanto, a tecnologia para sua aplicação tem encontrado dificuldades para alcançar os produtores, inclusive, nas regiões de maior potencial agrícola. Objetivou-se, portanto, com este trabalho, desenvolver um sistema de controle do espectro de gotas, a fim de alterar os parâmetros da pulverização de agrotóxicos em função do déficit de pressão de vapor d água no ar. Na automatização do pulverizador utilizou-se um servomotor e um microcontrolador alimentados pela bateria do trator. Após a seleção da ponta, da ponta de jato cônico vazio JA-2, fez-se um estudo do espectro de gotas em toda a faixa de pressão recomendada para seu uso, em pulverizadores hidropneumáticos. Neste estudo utilizou-se um analisador de partículas laser. As pulverizações foram realizadas em três déficits de pressão de vapor d água no ar e em treze pressões de trabalho. O coeficiente de variação das pontas na bancada padrão apresentou valores entre 13 e 22% para as pressões de 633 e 1.477 kPa, respectivamente. O diâmetro da mediana volumétrica reduziu de 151 para 109 μm com o aumento da pressão. A menor percentagem de gotas com tamanho menor que 100 μm, maior que 300 μm e entre 100 e 200 μm foi obtida na pressão de trabalho de 774 kPa. O aumento do déficit de pressão de vapor d água no ar afetou os parâmetros da pulverização, e reduziu o tamanho de gotas. A automatização permitiu a manutenção do volume de calda, alterando o espectro de gotas em função do déficit de pressão de vapor d água no ar. O fluxo turbulento de ar e a configuração de projeto do ventilador foram um dos responsáveis pela distribuição irregular do liquido. A altura do dossel, a posição no plano horizontal da planta e a profundidade na copa afetam a pulverização de agrotóxicos na cultura da laranja. O aumento do déficit de pressão de vapor d água no ar, elevou o risco de evaporação e diminuiu o tamanho das gotas, reduzindo a deposição da calda. | Pesticide spraying is one of the most repeated operations in farms, this has occurred mainly due to adoption of no tillage. Facility for purchasing pesticides is notorious throughout Brazil. However, technology for its application has been difficult to reach the producers, even in regions with high agricultural potential. This work aimed to develop a system for controlling the droplet spectrum in order to change parameters for spraying pesticides according to the deficit of water vapor pressure in the air. For automating the spray we used a servomotor and a microcontroller fed by tractor battery. After selection of the tip, hollow cone JA-2, we made a droplet spectrum study throughout the pressure range recommended for use in hydro-pneumatic sprayers. For this study, a laser particle analyzer was used. Sprayings were carried out in three deficits of water vapor pressure in the air, for thirteen working pressures. The coefficient of tip variation on the pattern bench presented values between 13 and 22% for pressures of 633 and 1.477 kPa, respectively. The diameter of volume median reduced from 151 to 109 μm with the increase of pressure. The lowest percentage of droplets with size lower than 100 micron, greater than 300 μm and between 100 and 200 microns was obtained from the working pressure of 774 kPa. Increasing the deficit of water vapor pressure in the air effected spray parameters and reduced droplet size. Automation allowed the maintenance of spray volume by changing the droplet spectrum according to deficit of water vapor pressure in the air. The turbulent air flow and configuration design of fan were responsible for the liquid irregular distribution. The height of canopy, in horizontal position of the plant and canopy depth affects spraying of pesticides in orange crop. Increasing the deficit of water vapor pressure in the air, also increased risk of evaporation and reduced droplet size also reducing the deposition of the syrup. | Conselho Nacional de Desenvolvimento Científico e Tecnológico

[EN] Device for remotely tracking bodies of water by means of a GPS positioning device provided with a telecommunication modem and an electronic control board, which is henceforth called a "GPS locator", and enclosed inside a floating watertight container, which is henceforth called a float, as well as the method for simultaneously managing and operating a set of one or more of said devices | [ES] Dispositivo de segmmlento remoto de masas de agua mediante un dispositivo de posicionamiento GPS dotado de un módem de telecomunicaciones y una placa de control electrónico, lo que de aquí en adelante ser denominado "localizador GPS", encerrado en el interior de un recipiente flotante y estanco, lo que de aquí en adelante se denominar flotador, as como al procedimiento de gestión y operación simultanea de un conjunto de uno o varios de dichos dispositivos. | Peer reviewed | Consejo Superior de Investigaciones Científicas (España) | A1 Solicitud de patente con informe sobre el estado de la técnica

The cultivation of oysters (Crassostrea rhizophorae) in the city of Graçiosa-BA is to influence the waters of the mouth of the Una river, water body that suffers with the release of domestic sewage by a lack of sanitation in the city. On this basis, this study aimed to analyze the microbiological water quality and oyster cultivation in an area of bivalve molluscs, using the group as bioindicators of fecal coliforms and Salmonella sp. Were performed to 11 samples of water and 12 of oysters in the period December 2010 to November 2011 with monthly sampling at three points of water and one oyster. The Most Probable Number of thermotolerant coliform in water samples at the point P1 (upstream of cultivation) ranged from <1.8 to 2.4 x 104 NMP/100 mL, the point P2 (cultivation area) ranged from <1, 8 to 1.6 x 105 NMP/100 mL Point and P3 (downstream of cultivation) values were <1.8 to 5.4 x 105 NMP/ 100mL. In the oyster samples NMP/100 g was <1.8 to 3.5 x 104. The presence of Salmonella sp. was observed both in the samples water (12%) as the oyster samples (25%). The high microbial load in the samples shows that the area of the estuary of the river Una, not favors the cultivation of bivalve molluscs, except that the bodies pass through a purification process or heat treatment before being forwarded to the consumer. | O cultivo de ostras (Crassostrea rhizophorae) no município de Graçiosa-BA tem como influência as águas da desembocadura do rio Una, corpo d’água que sofre com o lançamento de esgotos domésticos pela falta de saneamento básico no município. Com base nisto, este trabalho teve como objetivo analisar a qualidade microbiológica da água e das ostras em uma área de cultivo de moluscos bivalves, usando como bioindicadores o grupo dos coliformes e Salmonella sp. Para isso foram realizadas 11 coletas de água e 12 de ostras no período de dezembro de 2010 a novembro de 2011, com amostragens mensais em três pontos de água e uma de ostra. O Número Mais Provável de coliformes termotolerantes nas amostras de água no Ponto P1 (a montante do cultivo) variou de <1,8 a 2,4 x 104 NMP/100 mL, no Ponto P2 (área do cultivo) variou de < 1,8 a 1,6 x 105 NMP/100 mL e o no Ponto P3 (a jusante do cultivo) os valores foram de <1,8 a 5,4 x 105 NMP/100 mL. Nas amostras de ostras o NMP/100 g foi de <1,8 a 3,5 x 104. A presença de Salmonella sp., foi observada tanto nas amostras de água (12%) quanto nas amostras de ostras (25%). A elevada carga microbiana nas amostras analisadas demonstra que a área do estuário do rio Una, não é propicia ao cultivo de moluscos bivalves, a não ser que os organismos passem por um processo de depuração ou tratamento térmico antes de serem encaminhados para o consumidor.

Memoria para optar al Título Profesional de Ingeniero en Recursos Naturales Renovables | La calidad y el tiempo invertido en el proceso de toma de decisiones depende de la recopilación de antecedentes, información existente y la accesibilidad y entendimiento por parte de los tomadores de decisiones de ésta. Se plantea que estos procesos se ven facilitados con la utilización de sistemas de apoyo a la toma de decisiones. En este contexto se evaluó la aplicabilidad de un soporte de información y conocimiento, las bases de datos semánticas (BDS), como herramienta de transferencia de conocimiento científico y/o experto para la toma de decisiones en el sector público. En este estudio se construyó una base de datos semántica de la clasificación de cuerpos de agua de Chile. El proceso de construcción consideró la conceptualización del área de estudio o dominio de conocimiento, la explicitación de conceptos y la construcción de la ontología. Posteriormente, se realizó una evaluación de esta base de datos como herramienta de transferencia de conocimiento, para lo cual se realizaron dos evaluaciones. La primera evaluó el desempeño de profesionales en la solución de problemas relacionados con el conocimiento almacenado en la BDS, en comparación con el desempeño con soportes tradicionales para este mismo tipo de conocimiento. La segunda evaluó la percepción de la aplicabilidad de la herramienta en el sector público con profesionales del Ministerio del Medio Ambiente (MMA). La evaluación evidenció que las BDS presentan similares tiempos de acceso a la información que los soportes tradicionales, en dominios de conocimiento afines a los profesionales evaluados. El número de errores en el grupo evaluado con la BDS (10% de errores) es menor que el grupo evaluado con soportes tradicionales (35% de errores), lo cual sugiere que el uso de esta herramienta tiene potencialidad en procesos de comprensión de la información y toma de decisiones. Por otro lado, la herramienta fue evaluada positivamente por los profesionales del MMA considerando que la herramienta es útil y adecuada para el soporte de información y conocimiento en su quehacer en la toma de decisiones. Finalmente, se concluye que la herramienta mejora la gestión de las temáticas abordadas en la institucionalidad ambiental, disminuyendo las brechas entre el sector público y el científico y/o experto mediante la explicitación de conceptos y la interconexión de éstos, facilitando el entendimiento entre profesionales semánticamente distantes. | Quality and time invested in the process of decision making depends on the gathering of background information as well as the access and understanding that decision makers have on this. It's been argued that this processes are facilitated by the use of decision-making support systems. In this context, the applicability of an information and knowledge support, the semantic databases (SDB), as a tool for scientific and/or expert knowledge transfer has been evaluated, for the decision making processes in the public sector. In this study, a semantic database of the Chilean water bodies classification was built. The process of building considers the conceptualization regarding the study area or knowledge domain, the explicit statement of concepts and the construction of the ontology. Later, this database was evaluated as a tool for knowledge transfer, for which two assessments were carried out. The first one evaluated the performance of the professionals in the solution of problems related with the knowledge stored in the SDB, in comparison with the performance of traditional support for this same kind of knowledge. The second one evaluated the perception of the applicability of the tool in the public sector with professionals from the Environment Ministry. The assessment made evident that the SDB present similar times of information access than traditional supports, in similar knowledge domains as the evaluated professionals. The number of errors in the evaluated group with the SDB is lower than the group evaluated with traditional supports, which suggests that the use of this tool has a potentiality for information understanding and decision making processes. On the other side, the tool was positively evaluated by the professionals of the ministry, considering it as a useful and adequate tool for the information and knowledge support for their decision making work. Finally, it's concluded that the tool improves the management of the addressed themes in the environmental institutions, diminishing the gaps between the public sector and the scientist and/or expert, through the explicit statement of concepts and the interconnection between them, facilitating the understanding among semantically distant professionals.