External Greenhouse Mobile Shading: Effect on Microclimate, Water Use Efficiency and Yield of a Tomato Crop Grown Under Different Salinity Levels of the Nutrient Solution

Lorenzo, P.; Sánchez-Guerrero, M.C.; Medrano, E.; García, María Concepción; Caparrós, I.; Giménez, María J.

doi:10.17660/actahortic.2003.609.24

Cited by 41 publications

(29 citation statements)

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“…Conversely, low nutritive solution concentrations, combined with environmental conditions of reduced evaporative demand by the atmosphere, diminish the dry mass content as well as the quality (Lorenzo et al, 2003). Another important characteristic, that should be considered in cultivation in vases for vegetables cropping, is the reuse of substrates, since it is extremely advantageous for the producers to have the option to utilize it for many times.…”

Section: Introductionmentioning

confidence: 99%

Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

Marín¹,

Melo²,

Gomes³

et al. 2017

Aust J Crop Sci

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Among the most modern techniques of vegetables production cultivation in substrate is highlighted. In this method the substrate and the nutritive solution are main components that deliver nutrients to the crop and directly influence the performance of the plants. The objective of this study was to evaluate the reuse of substrate with several concentration of the nutritive solution in cultivation of tomato plants of the salad group 'Paronset'. The experimental design was a randomized blocks in a factorial scheme 3x5, with four replicates. The plants were grown in coconut husk fiber, in three substrate reuse levels (new substrate, reused once and reused twice) and five concentrations of the nutritive solution recommended for the culture [25%; 50%; 100% (original solution); 150% and 200%]. The chemical and physical characterization of the substrate after cultivation was done such as fruit productivity and quality and nutritional status of the plants. Physical characteristics were only influenced when substrate was reutilized. Chemical characteristics of the substrate were influenced by both the reuse of the substrate and the concentration of the nutritive solution. It was observed that the nutritional status of the plants was influenced only by the concentration of the nutritive solution. It was also noted that the productivity and fruit mass decreased after the second reuse of the substrate. The use of the original solution (100%) allowed the highest productivity; however, the largest fruit mass was obtained with the most dilute solution (25%).

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Section: Introductionmentioning

confidence: 99%

Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

Marín¹,

Melo²,

Gomes³

et al. 2017

Aust J Crop Sci

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“…Dynamic shadowing systems that only reduce radiation at certain times of the day, when conditions are most stressful, result in smaller reductions in yield than in the intercepted radiation (De Koning, 1988, as reported by Stanghellini, 1994). Lorenzo et al (2003Lorenzo et al ( , 2004 pointed out the benefits of using external greenhouse mobile shading to control climate conditions in Mediterranean greenhouses during hot periods and highlighted its positive effect on fruit quality, as physiological disorders Shading screens for the improvement of the night-time climate of unheated greenhouses such as BER (blossom end root) were reduced. In addition, shading diminishes canopy transpiration as well as water uptake by crops, thus improving the efficiency of water use.…”

Section: Introductionmentioning

confidence: 99%

Shading screens for the improvement of the night time climate of unheated greenhouses

Montero¹,

Muñoz²,

Sánchez-Guerrero

et al. 2013

Span. j. agric. res.

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The objective of this work was to study the effect of shading screens, normally used during the day for cooling purposes, on the night-time climate of unheated greenhouses. For this purpose, first a number of experimental measurements were taken during cold nights to characterise the greenhouse climate both with and without an aluminised external screen. Secondly a Computational Fluid Dynamic (CFD) model of greenhouse was developed. After validation of the model by comparison with experimental data, the model was used to simulate the greenhouse climate for different sky conditions ranging from cloudless to overcast nights. Simulations were performed for a greenhouse with internal and external shading screens and for the same greenhouse without screens. Experimental results showed the positive effect of an external shading screen, whose use increased night-time temperature and reduced the risk of thermal inversion. Its effect was much stronger under clear sky conditions. The CFD model supported this conclusion and provided a detailed explanation of the temperature behaviour of all the greenhouse types considered. CFD simulations proved that an aluminised screen placed inside the greenhouse at gutter height gave the greatest thermal increase. Therefore, external or internal screens can help to increase the sustainability of greenhouse production in areas with mild winter climates by enhancing the use of solar energy stored in the greenhouse soil during the previous day and released at night-time.

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“…In addition to shading the greenhouse (Lorenzo et al, 2003), which can intercept or reflect a significant portion of the incident solar radiation, other methods of controlling the internal air temperature of the greenhouse are used: evaporative pad cooling systems, fog systems, or a combination of both, ventilation systems (mechanical or natural) and sky systems (coverage fully open).…”

Section: Introductionmentioning

confidence: 99%

Analysis of the internal shading in a photovoltaic greenhouse tunnel

Marucci

Monarca

Colantoni

et al. 2017

J Agricult Engineer

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In recent years, the increasing interest in energy production from renewable energy sources has led to photovoltaic elements being placed on greenhouse coverings. The shading of crops by these elements can, however, cause problems regarding the normal course of agricultural activity. All studies thus far on the application of photovoltaic (PV) panels as a greenhouse covering material have focused on flat roof structures. Tunnel greenhouses, due to their curved shape, do not lend themselves easily to accommodating PV panels on even part of the cover. In this study, we analysed the shading variation inside a tunnel greenhouse that was produced by applying flexible and transparent PV panels in a checkerboard arrangement. The transparent flexible PV panels are manufactured using monocrystalline silicon cells, with an efficiency of 18%, incorporated into polymers with high resistance. The PV panel dimensions are 1.116×0.165 m. The simulation software Autodesk® Autocad2010® was used for this study. The variation and distribution of the shading percentage of PV panels were analysed in relation to the surface area affected by the photovoltaic roof, the total area of the greenhouse and the section of the greenhouse. In particular, we studied the variations in the percentage of shading and the size of the shaded area on the twenty-first day of each month of the year. The results show some regularity in the shading percentage, mainly due to the curvilinear shape of the section of the greenhouse. From mid-March to midSeptember, the shading in the middle of the day is almost always inside the greenhouse. In the other months of the year, it is partly inside and partly outside the tunnel greenhouse. With the photovoltaic arrangement adopted, the percentage of shading during the year never exceeds 40%.

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External Greenhouse Mobile Shading: Effect on Microclimate, Water Use Efficiency and Yield of a Tomato Crop Grown Under Different Salinity Levels of the Nutrient Solution

Cited by 41 publications

References 0 publications

Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

Shading screens for the improvement of the night time climate of unheated greenhouses

Analysis of the internal shading in a photovoltaic greenhouse tunnel

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