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Light-emitting diode (LED) lamps signify one of the most important advances in artificial lighting for horticulture over the last few decades. The objective of this study was to compare the cultivation of four horticultural plants using a conventional white LED tube (T0) light against one with a good spectral fit to the maximum photosynthetic response (T1) at two intensities. The experiment was carried out with two types of young lettuce, tomato, and bell pepper plants. In a controlled environment chamber, six and four lamps per square meter were used to achieve high (H) and low (L) intensity, respectively. We measured the lighting parameters illuminance (lux) and photosynthetic photon flux (PPF) intensity (µmol·m−2·s−1). The dry and fresh weight, leaf area (LA), and specific index were measured to gauge plant growth. The photosynthetic activity and energy efficiency (EE) were recorded for each species over 60 days of cultivation. The results clearly demonstrate that, compared with conventional LED lamps, the specific horticultural LED lamps with an improved light spectrum increased the EE of the evaluated vegetables by 26%. At both the studied light intensities, plant growth was clearly more closely linked to the spectral fit of the light to the maximum photosynthetic response recorded by McCree (1972) than to PPF or illuminance (lux). We therefore suggest that a specific, detailed spectral distribution study be conducted to predict the effect of the specific quantity and quality of light used in this study on a single parameter of plant growth.

At present, trends exist in the production of food for the benefit of human health. The negative effect of an excessive intake of nitrates accumulated in vegetables is well known, causing worldwide concern. Light plays an important role in the accumulation of this ion. The objective of this work was to evaluate the effect of light-emitting diode (LED) spectra used in artificial lighting for horticulture on the accumulation of nitrates in leafy and root vegetables compared with the effects with white LED lights. Two independent experiments were carried out in the culture chamber. In Expt. 1, six species of nitrate accumulators were used: arugula, spinach, lettuce, endive, radish, and beetroot. In Expt. 2, four lettuce cultivars were used. In both experiments, the treatments were two spectra—T1 = AP67 Valoya® and the control (T0) = white Roblan®—at two illumination intensities [high (H) and low (L)] with a 16/8-hour (day/night) photoperiod. The fresh biomass and the concentration of nitrates were measured at 35 days of treatment posttransplantation. An important and significant increase of 50% of the mean fresh weight was obtained in all the species when the light intensity increased. Except for spinach in the low-intensity treatment, all nitrate content values were less than the maximum limits of European regulation. The nitrate content generally decreased with increasing intensity, and this benefit was greater in the T1 treatment. T0 showed a reduction in the nitrate content compared with T1 in only one case, which was the H in beetroot. A large and significant reduction was observed in the nitrate content in T1. For L in Expt. 1, the nitrate decrease was 18%, whereas for H, it was 35%. In Expt. 2, the decrease in the nitrate content was 10% for L and 21% for H. A greater benefit was derived when using the photosynthetic spectrum in the growing chambers under low light intensity.

Plant quality and survival prediction tools are useful when applied in the field in different agricultural sectors. The objectives of this study were to conduct a review and bibliometric analysis of the Dickson Quality Index (DQI) as a key plant quality indicator and with respect to its scientific applications. A third objective was to identify the main morphological and physiological parameters used in plant production research. The methodology and findings of 289 scientific articles were analysed based on the morphological, physiological, and mathematical parameters used as plant quality indicators in research on forest, medicinal, horticultural, aromatic, and ornamental species. During the last 10 years, the number of publications that have used the DQI as a plant quality parameter has increased by 150%, and Brazilian researchers stand out as the most frequent users. Forestry is the discipline where quality parameters and their biometric relationships are most often used to facilitate intensive plant production. Use of the DQI increases the certainty of prediction, selection, and productivity in the plant production chain. The DQI is a robust tool with scientific application and great potential for use in the preselection of plants with high quality standards among a wide range of plant species.

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The growing demands for food with high quality standards and high nutritional value have caused agriculture to evolve towards agricultural innovation go hand in hand with technological development, as is the case of vertical farming (VF) development. VF is a competitive system for sustainable food production, reducing space, and natural and human resources for agricultural production, and it is a system that can be developed anywhere in the world and at any time, without seasonality being a factor that influences production. Light is the most important factor to consider when it comes to vertical farming, replacing sunlight with artificial light has had great advances in improving productivity, especially when using LED lighting. Despite the exponential growth of the system, there is a paucity of analysis on the research that has been carried out to date using a VF system, and on information on the most relevant parameters to be considered for optimum production. This review is a bibliometric analysis of 318 scientific articles taken from the SCOPUS database, where information from 109 papers published in relevant journals was used. During the last 10 years, the number of publications that have been carried out in a VF system has increased by 195%, with China standing out as the geographical location where field experiments are carried out. Lettuce crop predominates in the investigations, with a light intensity of 200 μmol∙m−2∙s−1 and with a photoperiod of 16 h·day−1, using spectra between 450 and 495 nm, and a combination of blue and red (450–495 and 620–750 nm). The use of the research in the VF system for fresh, quality, local produce has increased in recent years, and has proven to be highly effective in productivity and quality. Conditions and management have been generalized, with more than 50% of researchers deciding to perform this cultivation method with similar photoperiod, spectrum, and intensity. Among the conclusions obtained by each researcher, it is also agreed that it is a potentially sustainable and controllable system that can be developed in urban locations, benefiting the social economy, food security, and the environment, while the conclusions on the cent per cent utilization of natural resources (such as energy from sunlight) in the system remain open and improving.

The use of colored shade nets is a method to protect plants from direct solar radiation and optimize the light spectra they transmit. The purpose of this work was to evaluate the photosynthetically active radiation (PAR), the photosynthetically active integrated radiation (IPAR), temperature, relative humidity, growth, production, and fruit quality of Physalis ixocarpa variety Tecozautla, cultivated under nets generating 60% shade in the colors beige, blue, green, red, and black and under a treatment without netting (control group). Different variables were observed: climatic variables, such as radiation, temperature, and relative humidity; growth variables, such as plant height and stem diameter; production variables, such as number, weight, and caliber of the fruit; and quality variables of the fruit, such as pH and total soluble solids. The highest PAR, IPAR, and temperature and lowest relative humidity were obtained in the absence of netting. The white net resulted in the highest PAR and IPAR but no difference in temperature or relative humidity. In addition, an increase in the height, stem diameter, number of branches, and weight, number, and size of the fruit was observed. The white net resulted in the highest yield: 88% higher than in the control group. The pH of the fruit was significantly higher under the white netting, and no differences among the treatments in terms of the content of total soluble solids were found.

En la actualidad, el estudio de la diversidad de género en el ámbito empresarial está alcanzando una relevancia considerable, debido a la incorporación de la mujer a la vida laboral. Las Empresas Familiares han sido claves para la incorporación de las mujeres al mercado de trabajo, debido, entre otros motivos a la existencia de roles compartidos y al solapamiento de valores familiares y empresariales. La mayor parte de los estudios existentes sobre temas de género se centran en el efecto de la presencia femenina sobre distintas medidas de rendimiento, pero los resultados no son concluyentes en absoluto. Para ahondar en estas cuestiones, el presente trabajo analiza cómo influye la participación femenina en tres órganos de gobierno corporativo: Consejo de Administración, Junta General de Accionistas y Equipo Directivo, sobre la eficiencia económica de las Empresas Familiares Agroalimentarias. Los resultados obtenidos de una muestra de 147 Empresas Familiares Agroalimentarias Españolas, ponen de manifiesto que, la presencia femenina en los Consejos de Administración y en la Junta General de Accionistas, ejerce un impacto positivo y significativo en la eficiencia económica.