Resumen Los sistemas térmicos solares emplean radiación solar para calentar un fluido, generalmente, constan: de colectores solares que absorben la luz y cubierta de vidrio que protege la instalación y permite conservar el calor, produciendo un efecto invernadero. Según el propósito de uso y las condiciones del lugar pueden presentar modificaciones. Dichos sistemas pueden adaptarse en actividades como la agricultura, por ello, se implementó los sistemas térmicos solares activos forzados híbridos modificados, así como los sistemas pasivos autónomos en diferentes unidades productivas agrícolas y agroindustriales en la región Huetar Norte de Costa Rica. La instalación de estos sistemas se realizó a través de un programa local piloto, financiado por instituciones gubernamentales, desde el 2016 al 2019 para mejorar el proceso de secado de los productos agrícolas en comparación con los sistemas tradicionales. Se pretende que, con el uso de estos sistemas, se logre disminuir los gases de efecto invernadero, tanto a nivel local como global y que estos sistemas sean una alternativa de producción limpia que mejore la eficiencia energética de pequeños y medianos productores. Los sistemas híbridos forzados están equipados con registro de datos computarizados. Al más actual, se le diseñó y aplicó un suelo radiante, y al pasivo se le adicionó un sistema fotovoltaico de 1 K, el cual le da autonomía. Los resultados han permitido verificar que las unidades productivas beneficiadas mejoraron sus procesos productivos al reducir los tiempos de trabajo y al aumentar la eficiencia de los procesos, la calidad e inocuidad de sus productos.

Abstract Thermal solar systems use solar radiation to heat a fluid, generally consist of solar collectors that absorb the light and a glass cover that protect installation and maintains the heat producing a greenhouse effect. Depends of the use and place conditions can present modifications. These systems can adapt in agricultural activities thus was implemented the modified hybrid forced active solar systems as well as autonomous passive systems in different agricultural and agro-industrial productive units in the Huetar Norte region of Costa Rica. Through a local pilot program, were financed by governmental institutions from 2016 to 19, with a view to improving the drying process of agricultural products compared to traditional systems. It is intended that, with the use of these systems, greenhouse gases will be reduced, locally and globally, and these systems are a clean production alternative that improves the energy efficiency of small and medium producers. The hybrid forced systems are equipped with computerized devices for data recording. The most current, it was designed and applied a radiant floor, and the passive was added a photovoltaic system of 1 K, which gives it autonomy. The results have made it clear, the production units that were benefited improved their production process by reducing working times and increasing the efficiency of the process the quality and safety of their products.

Resumen [18] La transición generacional que experimenta la población costarricense ha impulsado el planteamiento de diversas estrategias para mejorar la alimentación y la calidad de vida de las personas adultas mayores. Debido a esto, en el sector agroalimentario se fomenta el desarrollo de alimentos especializados para cumplir esta demanda, por lo que el objetivo de este trabajo consistió en desarrollar un producto alimenticio nutracéutico con base en camote (Ipomoea batatas)y yuca (Manihot esculenta) biofortificados y, pejibaye (Bactris gasipaes). En la primera etapa del desarrollo de este producto, se elaboró una torta pre-cocida congelada de 60 g, la cual fue seleccionada por razones nutritivas, tendencias de mercado e innovación de una lista de catorce posibles productos por desarrollar. En la siguiente etapa se definió el proceso y la formulación. Finalmente, se realizó un análisis químico para comparar las materias primas y el producto terminado, lo que permitió determinar que este producto cubre entre 30 y 38% de los requerimientos diarios de vitamina A en personas adultas mayores costarricenses.

Abstract [22] The generational transition experienced by the Costa Rican population has driven the approach of various strategies to improve nutrition and life quality of elder people. On this concern, the development of special food products is encouraged in the food industry to accomplish this demand, so the objective of this work was to develop a nutraceutical food product based on biofortified sweet potato (Ipomoea batatas) and cassava (Manihot esculenta) and, pejivaye (Bactris gasipaes). On the first stage of the development of this product, a 60g pre-cooked frozen cake was elaborated. This cake was selected due to nutritional purposes, market trends and innovation from a list of fourteen possible products to develop. In the next stage, the process and formulation were defined. Finally, a chemical analysis was performed to compare the raw materials and the finished product. This comparison allowed determine that this cake covers between 30 and 38% of the daily requirements of vitamin A in the Costa Rican senior citizens.

Resumen La dependencia por los combustibles fósiles insta a buscar alternativas de producción más limpias que contribuyan a mitigar los efectos del cambio climático. El objetivo del presente trabajo fue determinar el potencial del uso de la energía solar para el calentamiento de agua y generación de energía eléctrica. El estudio se desarrolló en la lechería de la Sede Regional San Carlos, Instituto Tecnológico de Costa Rica, entre mayo de 2015 y abril de 2016. Se determinó la cantidad de electricidad producida y las temperaturas alcanzadas, por medio de los sistemas fotovoltaicos y térmicos instalados mediante un registro computarizado. También se calculó la cantidad de dióxido de carbono equivalente que se dejó de emitir a la atmósfera y, el ahorro energético y económico de su consumo. El uso de los sistemas de energía solar permitió lograr un autoabastecimiento de energía eléctrica entre 30 y 40% del consumo total de la unidad productiva. En la producción de energía para calentar el agua para la limpieza y sanitización de los equipos de ordeño, el sistema térmico fue capaz de lograr un incremento entre 20 y 37 ºC, lo que representó más del 70% de la energía necesaria para alcanzar la temperatura requerida (70 ºC) y un ahorro económico de aproximadamente $90 mensuales. Estos sistemas contribuyeron a disminuir la dependencia de los combustibles fósiles, al mejorar la eficiencia económica y productiva en unidades de producción agropecuaria en la Región Huetar Norte de Costa Rica.

Abstract The dependence on fossil fuels urges society to seek for clean energy alternatives, in order to mitigate the effects of climate change. The objective of this study was to determine the potential of solar energy used for water heating and electricity generation. The study was conducted at the dairy of the Technology Institute of Costa Rica, San Carlos Headquarter, from May 15 to April 2016. The data related to the amount of the electricity produced and the temperature reached by water was obtained from the installed photovoltaic and thermal systems, the data was recorded by a computerized register. The obtained information about electricity production allowed researchers to calculate the amount of carbon dioxide equivalent that was not emitted into the atmosphere, and also the acquired economic saving on consumption. The use of these systems allowed the production unit have a self- sufficient source of electrical energy percentage, actually around 30 to 40% of the total electrical consumption. According to the energy production, the solar thermal system was capable to increase water temperature between 20 to 37 °C, temperature that represents more than 70% of the energy needed in order to reach the required water temperature (70 °C) for cleaning and sanitizing the milking equipment, and also an economical saving around $90 per month was achieved. The results showed that these systems allow to improve the economical and productive efficiency of agricultural production units in the Northern Huetar Region of Costa Rica.

Resumen La agricultura ha progresado ininterrumpidamente, pasando de la utilización de recursos naturales gratuitos al uso creciente de recursos fósiles como fuentes energéticas. Si bien la agricultura depende fundamentalmente de los recursos y servicios del ecosistema, su desarrollo se ha centrado sólo en la producción, sin tomar en cuenta el valor ecológico de las externalidades negativas ni la descapitalización de los recursos que inciden en la sustentabilidad, por lo que la información sobre la evaluación de la sustentabilidad de los diferentes estilos de agricultura es poca o casi nula. En la presente investigación se evaluó la sustentabilidad de los estilos de agricultura (horticultor intensivo, tradicional campesino y horticultor auto sostenible) establecidos en la comuna de Hualqui (Región del Biobío, Chile), mediante los flujos de energía presentes en cada estilo, para medir el impacto que generan sobre el paisaje. Los resultados muestran que el estilo de agricultura horticultor auto sostenible presenta una mayor sustentabilidad en comparación con los estilos tradicional campesino y horticultor intensivo y pueden contribuir a nivel de políticas públicas para reorientar la estrategia de acción y fomentar la sustentabilidad en los distintos estilos de agricultura.

Abstract Agriculture has been progressing continuously, from the use of free natural resources to the fossil fuels as energy sources. Even though agriculture depends mainly on ecosystem resources and services, its development has been apparently centered only on yield, not considering neither the ecological value of the negative externalities nor the decapitalization of the resources that influence sustainability. Thus, the information on the evaluation of the sustainability on different agriculture styles is scarce or almost null. This investigation evaluates the sustainability in different agriculture styles (intensive horticulture, traditional farm and self-sustaining horticulture) established in Hualqui (Region of Biobío, Chile), through the energy flows present on each style to measure the impact generated on the land. The results revealed that the self-sustaining horticulture style showed a higher sustainability compared to the traditional farm and intensive horticulture style. These results can contribute to the public, policies to reorient the action strategy to encourage the sustainability in the different agriculture styles.

Analisaram-se frutos de melão (Cucumis melo L.) provenientes de uma coleção de linhas quase-isogénicas (NIL), SC3-5 e outras sete climatéricas e duas não-climatéricas, para avaliar a ocorrência de acidentes fisiológicos e a suscetibilidade a podridões. Como termo de comparação utilizou-se duas cultivares não-climatéricas (Nicolás, grupo Inodorus, e Shongwan Charmi ou acesso PI161375, grupo Conomon) e duas cultivares climatéricas (Fado, grupo Reticulatus, e Védrantais, grupo Cantaloupensis). O experimento foi dividido em oito blocos contendo três plantas por repetição para NIL, dois para a cultivar parental Piel de Sapo (PS), e um ou dois para a cultivar testemunha. As repetições avaliadas foram mais de seis para as cultivares em estudo. Durante a produção, as folhas foram afetadas por pulgão, oídio e acidentes meteorológicos. Os acidentes fisiológicos que ocorreram nos frutos durante a produção incluíram fendilhamento na cultivar Védrantais e na NIL 5M2 e fendilhamento da zona pistilar na cultivar Fado. As NIL climactéricas com casca amarela revelaram-se muito suscetíveis à sobre-maturação, fendilhamento pistilar e queimaduras solares durante a produção. Duas NIL exibiram uma ligeira necrose do tecido placentar, carater herdado da linha PI161375. Outros acidentes fisiológicos atípicos observados na colheita ou após 30 dias a 8ºC incluíram casca verrugosa, descolorações castanho-claras na polpa, translucência da polpa, cavidades na polpa e ornamentação profundamente sulcada na casca, herdada do PI161375. Observou-se a ocorrência de podridões pouco usuais em melão, nomeadamente podridão cinzenta, podridão bacteriana, Penicillium sp., Phytium sp. e cladosporiose interna. Uma dureza da região pistilar inferior a 20 N mm-1 estava associada ao fendilhamento e ao amolecimento excessivo. A ocorrência destes acidentes fisiológicos ou podridões foi baixa para assegurar o envolvimento de fatores genéticos no seu desenvolvimento.

Postharvest disorders and rots can produce important economic losses in fruits stored for long time for exportation. The genetic and physiological basis of some disorders in melon (Cucumis melo L.) are unknown and particularly the possible relation with climacteric behavior. A collection of melon near-isogenic lines (NILs) (SC3-5 and seven more showing climacteric and two non-climacteric ripening pattern) were analyzed to study genetic and physiological aspects of fruit disorders and rots. Two non-climacteric (Nicolás; Inodorus Group; and Shongwan Charmi PI161375, Conomon Group) and two climacteric cultivars (Fado, Reticulatus Group; Védrantais, Cantaloupensis Group) were used as reference. The field was divided in eight blocks containing one three-plant replication for each NIL, two for the parental cultivar Piel de Sapo and one or two for the reference cultivars. Replications evaluated were more than six in the cultivars studied. Plant problems included aphids, powdery mildew, and leaf wind injury. Preharvest fruit disorders included whole fruit cracking in cultivar Védrantais and NIL 5M2, and stylar-end cracking in cultivar Fado. Climacteric NILs with yellow skin were particularly affected by over-ripening, stylar-end cracking, and sunburn during cultivation. At harvest, two NILs showed slight placental tissue necrosis which was inherited from SC and were also detected after storage. Other uncommon disorders seen at harvest or 30 days after storage at 8ºC included warted skin (scarring), flesh discoloration (light brown or translucent areas), hollow flesh disorder, and deep furrow netting inherited from SC. Less common rots included grey mould, bacterial soft rot, Penicillium rot, cottony leak and internal Cladosporium rot. Stylar-end hardness below 20 N·mm-1 was associated with cracking and softening. The incidence of the disorders and rots was too low to confirm that the genetic component played a role in their development.