263 research outputs found
A targeted management of the nutrient solution in a soilless tomato crop according to plant needs
The adoption of closed soilless systems is useful in minimizing the environmental impact of the greenhouse crops. Instead, a significant problem in closed soilless systems is represented by the accumulation of ions in the recycled nutrient solution (NS), in particular the unabsorbed or poorly absorbed ones. To overcome such problem, we: (1) studied the effect of several values of the electrical conductivity (EC) of NS in a NFT (Nutrient Film Technique) system on a cherry type tomato crop, and (2) define a NS (called recovery solution), based on the concept of uptake concentration and transpiration-biomass ratio, that fits the real needs of the plant with respect to water and nutrients. Three levels of EC set point (SP), above which the NS was completely replaced (SP5, SP7.5, and SP10 for the EC limit of 5, 7.5, and 10 dS m(-1), respectively), were established. The SP10 treatment yield was not different from other treatments, and it allowed a better quality of the berries (for dry matter and total soluble solids) and higher environmental sustainability due to a lower discharge of total nutrients into the environment (37 and 59% with respect to SP7.5 and SP5, respectively). The recovery solution used in the second trial allowed a more punctual NS management, by adapting to the real needs of the crop. Moreover, it allowed a lesser amount of water and nutrients to be discharged into the environment and a better use of brackish water, due to a more accurate management of the EC of the NS. The targeted management, based on transpirationbiomass ratio, indicates that, in some stages of the plant cycle, the NS used can be diluted, in order to save water and nutrients. With such management a closed cycle can be realized without affecting the yield, but improving the quality of the tomato berries
Solar radiation distribution inside a monospan greenhouse with the roof entirely covered by photovoltaic panels
In the present work the variation over space and time of the amount of the photosynthetic photons flux density, inside a greenhouse entirely covered with photovoltaic panels was investigated experimentally and numerically. The greenhouse had 10.00 m spam width, 50.00 m length, 3.00 m height of the gutter, 6.60 m height of the edge. Data were acquired in the period 18th April-8th June 2014 by one sensor outside and one inside the experimental greenhouse built in Southern Italy. Numeric simulations were performed by means of commercial software Autodesk® Ecotect®. For the investigated greenhouse model, the exposed percentage the ratio of the calculated insolation at a particular point within an enclosure to the simultaneous unobstructed outdoor insolation under the same sky conditions-was calculated over a three dimensional grid formed by 50×10 ×15 cells each with 1.00×1.00×0.20 m size. The long-term analysis demonstrated a good capability of the numerical model to predict the shading effect inside a photovoltaic greenhouse combining the daily calculated exposed percentage with measurements of solar radiation. The model was able also to predict the qualitative behaviour of the variation of photons flux during the day even if the measured values showed a higher fluctuation of values
Growth Analysis and Nutrient Solution Management of a Soil-Less Tomato Crop in a Mediterranean Environment
The data contained in this article are strictly related to our previous article titled "A Targeted Management of the Nutrient Solution in a Soilless Tomato Crop According to Plant Needs" (Signore, A. et al. 2016). The detailed datasets regards the amount of dry matter (Table 1), the nutrient solution consumption (Table 2) and the mineral composition of plant tissues (Tables 3–7) in a soil-less tomato crop. The information contained in this article are necessary since, unlike the northern European countries, such data are generally missing for the crops in the Mediterranean environment. By correlating the parameters reported above, we were able to provide a more precise management of the nutrient solution, by providing the correct nutrient concentration into the nutrient solution in function of (i) the volume of water absorbed, (ii) the growth rate and (iii) the nutrient concentration in tomato plant. Finally, the more precise management of the nutrient solution allowed discharging a lesser amount of water and nutrients into the environment, improving the sustainability of the crop
Applications and Development of LEDs as Supplementary Lighting for Tomato at Different Latitudes
High-tech greenhouses and artificial light applications aim to improve food production, in line with one of the sustainable development goals of the UN Agenda 2030, namely, “zero hunger”. In the past, the incandescent lamps have been used for supplementary lighting (SL) at higher latitudes to increase greenhouse production during the dark season. Light-emitting diodes (LED) have been replacing gas discharge and incandescent lamps, and their development is expanding SL applications in different agricultural scenarios (e.g., urban farming, middle latitudes). In fact, recent research on LED applications in Mediterranean greenhouses have produced encouraging results. Since middle latitudes have a higher daily light integral (DLI) than higher latitudes in the dark season and climate conditions influence the installed power load of greenhouses, LED installation and management in Mediterranean greenhouses should be different and less expensive in terms of investment and energy consumption. Accordingly, the aim of this review is to outline the state of the art in LED applications and development, with a focus on latitude-related requirements. Tomato was used as a representative crop
Biodiversity of vegetable crops, a living heritage
Biodiversity is the natural heritage of the planet and is one of the key factors of sustainable development, due to its importance not only for the environmental aspects of sustainability but also for the social and economic ones. The purpose of this Special Issue is to publish high-quality research papers addressing recent progress and perspectives while focusing on different aspects related to the biodiversity of vegetable crops. Original, high-quality contributions that have not yet been published, or that are not currently under review by other journals, have been gathered. A broad range of aspects such as genetic, crop production, environments, customs and traditions were covered. All contributions are of significant relevance and could stimulate further research in this area
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Red light is effective in reducing nitrate concentration in rocket by increasing nitrate reductase activity, and contributes to increased total glucosinolates content
Rocket cultivation is increasing to supply the expanding ready-to-eat market because of its unique taste, but crops are often over fertilized to avoid nitrogen deficiencies. This leads to nitrate accumulation in leaves, and the products of their degradation (nitrites and nitrosamines) have been related to several health problems. Nitrate concentrations in rocket and other leafy vegetables are subject to limits by the EU legislation, yet rocket holds a great nutritional value. Degradation products of glucosinolates (isothiocyanates) have been consistently linked with benefits to human health. We investigated the influence of nitrogen application (1 and 8 mM), species (Eruca sativa (L.) Cav. and Diplotaxis tenuifolia (L.) DC.) and light spectrum (full spectrum, red, blue and red+blue) on the nitrate concentration, nitrate reductase activity and glucosinolate content of rocket grown in a soil-less system. Red light decreased the nitrate concentration with respect to the blue spectrum (4,270 vs 7,100 mg·kg-1 of fresh weight, respectively), but such reduction was influenced by the species and the nitrogen level (significantly higher in D. tenuifolia and with the higher concentration of N). The nitrate reductase activity increased under red light in D. tenuifolia, with the lower N concentration. Rocket is known to contain several health-promoting compounds mainly antioxidants and glucosinolates, as secondary metabolites that act as part of plant defense mechanisms. The total content of glucosinolates was mainly affected by the species (D. tenuifolia showed the highest concentrations). Our results will help growers to tailor light spectra with the aim of reducing nitrate concentration and to remain within EU legislative limits, without any detrimental influence on other qualitative parameters in rocket
The SUMO ship detection software for satellite radar images - Short installation and user guide
This is a brief manual for the SUMO software.
SUMO is a software package for semi- or fully-automatic ship detection in satellite SAR (Synthetic Aperture Radar) images, for experimental use. It can work on images from most of the recent and contemporary satellite SARs, across a range of radar frequencies and resolutions. It has been developed at European Commission’s Joint Research Centre (JRC) over the last 15 years, and has been extensively tested, demonstrated and validated.
Ship detection from satellite images is used for maritime spatial planning, fisheries control, pollution control, maritime border control, counter-piracy, and other applications in the field of maritime safety, security and sustainability.
The SUMO algorithm, that is behind the software, has recently been described in detail in a journal publication.
This document describes the purpose of SUMO, how to compile the run-time code from the Java source code, how to start and run SUMO in interactive mode as well as in batch mode, and SUMO’s input and output data. It also mentions known problems and the necessary maintenance. A list of questions and answers is attached in annex for quick reference.
This manual is published together with the release of the SUMO software as open source under the FreeBSD two-clause license. The software was developed for use at JRC for R&D purposes and is released “as is”.JRC.E.7-Knowledge for Security and Migratio
Supplementary Far-Red Light Did Not Affect Tomato Plant Growth or Yield under Mediterranean Greenhouse Conditions
In the Mediterranean region, tomato plants are often cultivated in two short cycles per year to avoid the heat of summer and the low solar radiation of winter. Supplementary light (SL) makes it possible to cultivate during the dark season. In this experiment, a tomato F1 hybrid cultivar DRW7723 was cultivated in a greenhouse for a fall-winter cycle. After transplant, light emitting diode (LED) interlighting, with two light spectra (red + blue vs. red + blue + far-red) was applied as SL. Plant growth, yield, gas exchange, nutrient solution (NS) consumption, and fruit quality were analyzed. In general, the eects of adding far-red radiation were not visible on the parameters analyzed, although the yield was 27% higher in plants grown with SL than those grown without. Tomatoes had the same average fresh weight between SL treatments, but the plants grown with SL produced 16% more fruits than control. Fruit quality, gas exchange and NS uptake were not influenced by the addition of far-red light. Interlighting is, therefore, a valid technique to increase fruit production in winter but at our latitude the eects of adding far-red radiation are mitigated by available sunlight
Use and attitudes toward dietary supplements and drugs amongst Italian elite athletes and its correlation with banned doping substances
Athletes frequently use dietary supplements (DS) to find better results as soon as possible. Moreover, they also will be occurring in “polypharmacy” or in substances prohibited for doping. The aim of this retrospective sectional study was to explore use and attitudes toward drugs and dietary supplements (DS) in Italian Sports Federations and its correlation with banned doping substances token amongst elite athletes. The data shows the results from 2012 to 2017, among Italian Sports Federations elite athletes and the analysis of the anti-doping controls from the Ministry of Health annual reports. The results show that the largest number of supplements consumption declarations was recorded in 2014 in sport as cycling and athletics. Moreover, in the same year and in 2012 there were 48 and 42 declarations on 58 and 52 doped athletes. Among the Italian federations, three are particularly controlled: FCI - cycling, FIDAL - athletics and FIGC – football. Most of the consumers subjects are male athletes. So maybe there is a link between NS and positive results in anti-doping test. The consumption of health products is constantly expanding and educational interventions will be needed to improve drugs and DS use about elite athletes as well in amateur athletes
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