The Impact of Semi‐Transparent Solar Panels on Tomato and Broccoli Growth

The emergence of semi‐transparent solar panels offers opportunities for their application in greenhouses where the radiation is a critical issue. The light passing through these panels is often affected, leading to a decrease in certain wavelengths that could potentially impact plant growth and quality. To address this concern, this study is performed to investigate the growth and yield of tomato and broccoli plants cultivated under semi‐transparent photovoltaic solar panels compared to those grown under conventional greenhouse plastic. Their physiological and metabolic changes are also examined. A decrease in the yellow/green spectrum after installation of the solar panels is observed. In both plants, slight alterations are observed by solar panels, enhancing even the height of plants and fruit yield in case of tomato. However, both plants showed changes related to their photosynthetic activity and some metabolite concentration. Specifically, there are significant reductions in An (photosynthetic rate) and lower levels of trigonelline in plants grown under solar panels. These reductions may be attributed to the different radiation conditions experienced by the plants, which do not appear to directly impact plant growth. The obtained results highlight the promising potential of solar panel‐integrated greenhouses that optimize economic and energy benefits while maintaining product quality.


Introduction
Greenhouses provide a controlled environment for growing plants, increasing efficiency and productivity.However, maintaining a suitable environment for plants can be expensive, as a high energy demand is required to maintain the heating, facts, some studies have also demonstrated various benefits in crops, such as an increase in biomass production per unit of solar radiation, [12] along with favourable microclimatic conditions, [13] reduced temperature variation and evapotranspiration, and improved water flow. [14]Consequently, transparent solar panels are starting to be developed for reducing the negative effect of conventional ones. [15]However, it is essential to ensure that the photovoltaic cells do not alter the radiation and absorption characteristics that can be tuned to meet the specific spectral light requirements of the plants. [16]ased on this previous information, the aim of the present study is to assess the influence of semi-transparent, pinkcoloured solar panels installed in a greenhouse on the performance of tomato and broccoli plants.Specifically, we aimed to investigate the impact on plant physiology and fruit production by analysing growth and fruit yield, mineral composition, leaf gas exchange, photosynthetic efficiency, and fruit quality.In addition, for determining if the quality of the edible parts (tomato fruits and broccoli inflorescences) was altered by the use of the solar panels, a metabolomic characterization was performed.

Experimental Orchard Conditions and Solar Panels Characteristics
The experiments were conducted from September 19th to November 26th in greenhouses in CEBAS-CSIC Experimental Farm in Santomera (Region of Murcia, Spain), under Mediterranean climate conditions (Figure 1).The average temperature in this area during the 2 months was 23.5 °C, with an average maximum of 31 °C, during daylight in September and an average minimum of 12 °C during night in November.The average relative humidity was 54%.The seedlings of Solanum licopersicum L. cv.Muchamiel and Brassica oleracea L. var.italica from Deitana seedbed (S.L., Mazarrón, Spain) were transplanted on September 19th, 2022.
The substrates Golden Grow HP Balance EW EP 25 Â 20 Â 20 (Projar, Murcia, Spain) were prehydrated with water 2 days before transplants, making small holes in them to allow excess water to evacuate.All plants were irrigated with Hoagland's solution 5 times per day during the first month and 8 times per day the following month, through droppers of 3 L h À1 , during 5 min each irrigation.
The experimental design was a completely randomized design (CRD).Nine plants per line were placed.Under the solar panel conditions, two lines contained tomatoes plants and two other lines broccoli plants.Other two lines with the same irrigation system were used like control, placed in an annexed greenhouse without solar panels (Figure 1).During the experiment, light parameters were measured using Asensetek spectrometer (Pro Standard) coupled to the Spectrum Genius Agricultural Lighting (SGAL) application to determine the efficiency of grow light.The data of sunlight spectrum were represented as photosynthetic photon flux density (PPFD), which is the amount of sunlight that reaches the plants within the photosynthetically active radiation (PAR) region to contribute to photosynthesis.They were represented relative to 1 as maximum value.The representations of chlorophylls and carotene spectra have been made with McCree's action spectrum (Spectrum Genius Agricultural Lighting (SGAL).The spectral McCree curve was used as a reference to determine the ideal wavelength range as well as the spectral ratios related to the quantum efficiency of photosynthesis for different plant types.They were relative intensity as reported by Zielinska-Dabkowska et al. [17] About the solar panels set up, a final structure of 3 rows of 7 modules commercially obtained from Soliculture (CA, USA) arranged in a coplanar (or titled) structure from Schletter (Krichdorf, Germany) were installed.These transparent panels consist of a low-density arrangement of silicon photovoltaic (PV) strips periodically placed on a glass panel, allowing light to transmit between the strips.The core technology, LUMO, is a thin of a dye adhered to the back of the glass that converts green light into red light.Final installation was achieved in August and data from photovoltaic production was collected from August to December, encompassing the whole experiment.

Weight, Height, Germination, and Abortion
After 2 months of growth, 27 plants (9 control plants and 18 plants grown under solar panels) from each species (tomato and broccoli), were weighed to obtain the fresh weight, sampling the roots from the aerial part.During last month, each week total number of flowers, fruits, and flowering abortion was counted in tomato plants to determine their productivity.Total amount of tomatoes from each plant was weighted in order to know the production per plant.In broccoli plants, each one generated an inflorescence with commercial size (>12 cm ø).At the end of the harvest, the fresh weight of broccoli and tomato plant was determined for each treatment.

Mineral Concentration
After 2 months of the plant transplant, in order to analyse the mineral content, three independent tomato plants were sampled in leaves, fruits, and roots for further analysis.Samples were placed in an oven at 70 °C for 6 days until they were completely dried.Same was proceeded with the broccoli plants, analysing the leaves, inflorescences, and roots separately from three different plants.All the samples were finely ground in a mill grinder (model A10, IKA, Staufen, Germany).Macro and micro minerals contents were determined according the ISO 11.885 (1996)  by inductively coupled plasma-optical emission spectrometry (ICP-OES) using a Thermo ICAP 6500 Duo equipment (Thermo Fisher Scientific, Waltham, MA, USA).For each sample, 200 mg were added in a microwave furnace equipment to a 25 mL tube with a mixture of 4 mL of HNO 3 (68% purity) and 1 mL H 2 O 2 (33% purity) for their subsequent digestion.300 mL high-purity de-ionized water, 30 mL H 2 O 2 (33% purity) and 2 mL H 2 SO 4 (98% purity) were also added in the Teflon reactor.The microwave heating digestion program consisted of 3 steps: starting at 20 °C and 40 bar; increasing 10 bar min À1 for 30 min up to 220 °C; and keeping 220 °C for 20 min.After cooling, the mineralized sample were transferred to double gauge tubes of 10 mL (micro minerals) and 25 mL (macro minerals) and the volume made up with high-purity de-ionized water.A multimineral standard solution containing 31 minerals supplied by SCP Science (Quebec, Canada) was used to prepare calibration standards in high-purity de-ionized water.For ICP-OES analyses, two control samples containing high-purity de-ionized water and a multimineral standard were used.Each mineral determination was performed at specific wavelengths ranging from 167.1 to 670.8 nm.The concentration of macro and micro minerals were calculated according the formula "mg Kg À1 or μg Kg À1 = (C Â D)/W"; where C was mineral concentration, D was the dilution factor and W was sample weight.These analyses were carried out at the Laboratorio de Ionómica (CEBAS-CSIC).

Transpiration Rate, Stomatal Conductance, Net Photosynthetic Rate, and Internal Concentration of CO 2
After the first 20 days of growth, transpiration rate (E, mmol m À2 s À1 ), stomatal conductance (Gs, mmol m À2 s À1 ), internal concentration of CO 2 (mmol m À2 s À1 ), and net photosynthetic rate (A n , μmol m À2 s À1 ), were measured 5 times, 1 time per week.Measurements were performed on five to seven leaves on the fourth and fifth ramification of each tomato plant and on the third and fourth fully-expanded leaves in broccoli plants.
The experiment was performed 1 h after sunrise, using the TPS-2 Portable Photosynthesis System (PP Systems, Inc., Amesbury, MA, USA).

PSII Efficiency and Chlorophylls Content
Chlorophyll content was measured in two leaves of five different plants, using the SPAD 502 Plus Chlorophyll Meter (Minolta, Japan).The potential quantum efficiency of PSII (ratio between variable and maximum fluorescence, F V /F M ), being the most used parameter for plant stress detection, was measured on five leaves on the fourth and fifth ramification on tomato plants and on the third, and fourth fully-expanded leaves in five broccoli plants, 2 h after sunrise, with the OS30pþ (Opti-sciences, MA, USA).

Size, pH and Firmness of Tomato Fruits
In tomato fruits, the most common quality parameters were measured after sample harvest.pH of the tomatoes was measured with a pH-meter (Hach pH3.1) and the firmness with Durofel 100 DFT durometer (Agro-technologie, France).

Primary Metabolites Analysis
Primary metabolites (amino acids, sugars, and reducing sugars) were determined by HPLC-QTOF-SPE-MNR on the Metabolomics Platform of CEBAS-CSIC (Murcia, Spain).For the measurements, 50 mg of freeze-dried powder from each sample was used.

Statistical Analysis
Statistical analysis was performed using R Studio software.Significant differences between the values from all parameters were determined at p < 0.05, according to a one-way ANOVA, Student's t-test.All the results are presented as the mean AE SE.R packages FactoMineR [18] and factoextra [19] were used to generate principal component analysis (PCA) results.

Light Quality and Photosynthetic Spectrum
As can be observed in both conditions, the full spectrum and the PPFD (Figure 2), which is the actual amount of the visible spectrum reaching plants in the PAR region and contributes to photosynthesis, there is a loss of wavelengths around 400-700 (blue-green-red spectrum).
This generates a decrease in the μmol m À2 s of irradiated blue light (400-499 nm) in the plants under solar panels of 20.13% (161.87 μmol m À2 under control vs 129.28 μmol m À2 under panels).Something similar was observed with green length (500-599 nm), where the loss is 50.16%(269.58 μmol m À2 under control vs 134.38 μmol m À2 under panels) or red light (600-700 nm), where the loss is 7.23% (323.52 μmol m À2 under control vs 300.14 μmol m À2 under panels).Also, total decrease in the lux received was also observed, being 42.931 lux in the control situation, while in under solar panels it was 9.910 lux.
The absorption spectrum of chlorophyll a and b was represented in the Figure 2B (control) and E (solar panels).It can be observed that under control all the absorption spectrum of the chlorophyll a is covered by the light spectrum, but only the first peak and maximum of the second peak of the chlorophyll b was not covered.Under panels, the maximum of the second peak of the chlorophyll a was not covered but first peak of the chlorophyll b was fully covered and the same maximum of the second peak as under control was not covered.
Also, the absorption spectrum of the β-carotene was represented (Figure 2C,F).It can be observed that in control, the first part of the absorption spectrum, from 350 to 400 nm was not covered, together with the higher intensity of the first peak.However, under solar panels, only the maximum intensities of the first and second peak were not covered.

Power Generation
In order to determine the energy yield from the solar panels, the ratio of the power production obtained (KWh/KWp), from the semi-transparent photovoltaic panels installed in the roof of the experimental greenhouse during the 5 months duration of the test (Table 1).It was observed that the highest electricity production occurred in August (160.350KWh KWp À1 ), followed by a gradual decrease in subsequent months, with December recording the lowest energy production (81.911KWh KWp À1 ).

Production and Quality Parameters
In Figure 3, different parameters related to fresh weight (FW) are represented for both tomato and broccoli plants.In addition, the plant height of tomato plants (Figure 3D) was also analyzed.Tomato plants did not show any statistically significant differences in either the aerial parts or the roots (Figure 3A,B).Nevertheless, a significant increase of approximately 38% in FW of tomato fruits was observed under the solar panels' conditions (Figure 3C).Furthermore, the plant height also was significantly higher by 12% in the tomato plants harvested in the solar panels greenhouse (Figure 3D).According to broccoli plants, no differences were found in the FW of both the aerial part and roots (Figure 3E,F).Similarly, no differences were observed in the edible part (inflorescences) of broccoli plants harvested under the solar panels compared to control greenhouse condition (Figure 3G).Table 1.Ratio of the power production obtained (KWh/KWp), from August to December from the semi-transparent photovoltaic panels installed in the roof of the experimental greenhouse.For further physiological understanding of the solar panel effect under the tomato plants growth, the parameters represented in Table 2 were studied.The number of flowers and tomato fruits did not show any statistically significant differences between conditions.Furthermore, there were no statistically distinctions observed in terms of the number of abortions per plant and rennet percentage between both conditions.
In addition, for determining quality parameters related to the tomato fruits, pH and firmness were determined (Table 3), but no statistically significant differences were found between treatments.

Transpiration Rate, Stomatal Conductance, Photosynthetic Rate and Internal Concentration of CO 2
According to the measurement of gas exchange parameters, the data related to tomato plants are presented in Figure 4. Regarding the transpiration rate (E) (Figure 4A) and stomatal conductance to water vapour (Gs) (Figure 4B), no statistically significant differences were observed.However, a statistically significant decrease was observed in the net photosynthetic rate (An) (Figure 4C).
No differences were found for the internal CO 2 concentration of the sub-stomatal cavity (Figure 4D), maximum quantum yield of primary photochemistry of photosystem II (Fv/Fm) (Figure 4E), and the chlorophyll content of the chlorophyll content (Figure 4F).Similarly, in Figure 5, the gas exchange parameters obtained for broccoli plants are displayed.Like tomato plants, only a significant decrease in the An was observed in the plants grown under solar panels (Figure 5C).

Mineral Concentration
In our study, principal component analysis (PCA) was employed to examine the similarities and differences in the mineral composition of tomato and broccoli plants harvested from greenhouses under control conditions or with solar panels (Figure 6).The results of this multivariate analysis revealed no significant differences in the mineral composition of any analyzed part (aerial part, root, and edible part) for both tomato (Figure 6A-C) and broccoli (Figure 6D-F) plants, since both groups (control and solar panels) were not significantly separated along the X and Y axes.differences were detected between the conditions for all four types of pigments.

Primary Metabolites Analysis
In order to deepen our knowledge about the influence of solar panels on plant metabolism, primary metabolites were analysed by H þ -MNR.The complete list of analysed metabolites for tomato leaves and fruits, as well as for broccoli leaves and inflorescences, is presented in Table 5 and 6, respectively.For tomato leaves, the main differences were found in GABA and succinate concentrations, which decreased in the samples obtained from the greenhouse with solar panels.Regarding tomato fruits, a statistically significant increase was observed for glutamine  and sucrose (Table 5).According to broccoli plants, the leaves analysed from solar panels greenhouse showed an increase in leucine, while a decrease in proline was observed.When analysing the inflorescences, a decrease in samples from the greenhouse with solar panels was found in asparagine, isoleucine, and trigonelline (Table 6).In addition, for a better understanding, metabolites related to carbohydrate metabolism in broccoli leaves are represented in Figure 7.In this case, a decrease in citrate (Figure 7A), malate (Figure 7B), fructose (Figure 7C), glucose (Figure 7D), and sucrose (Figure 7E) was analysed for leaves from broccoli plants grown in the solar panel greenhouse.

Analysis of Glucosinolates
Since glucosinolates are secondary metabolites mainly present in the vegetables from the family Brassicaceae, its content was also measured in broccoli leaves from both greenhouses (Figure 8).However, no statistically significant differences were detected in the five different glucosinolates analysed: glucoraphanin, 4-hydroxyglucobrassicin, glucobrassicin, methoxyglucobrassicin, and neoglucobrassicin.

Discussion
Implementing and improving energy production systems toward renewable and efficient models is a necessity nowadays.Solar greenhouses have been deeply investigated during the last years examining specific solar technologies used in greenhouse constructions (for review see Gorjian et al. [20] ).The extensively explored solar energy technologies that are most commonly  Data are meansAE SE (n = 3-5).Asterisks indicate significant differences (p < 0.05) according to Student's t-test.ND: non-detected.
utilized and can be effectively incorporated into agricultural greenhouses.Nevertheless, the installation of modules on the roofs or walls of greenhouses creates shade that can have a negative impact on the growth of crops cultivated. [21]In contrast, the change in use from opaque solar panels to transparent or semitransparent photovoltaic panels could made possible to optimize land use and improve some negative points of opaque solar panels, such as the shade on vegetation. [2,15]Light is a fundamental environmental factor for plant growth [22] and one of the main problems we found with semi-transparent solar panels was that the spectrum of photosynthetic light reaching the plants changed, mainly in the blue-green (400-599) and red (600-699) wavelengths (Figure 2).This loss has been reported to affect plant growth, flowering, pollination, or the immune response of plants and modifies their gene expression patters. [8,10]This loss has been seen previously, where certain wavelengths were retained by the material from which the solar panels are made. [12]wever, in our experiments neither the fruiting of tomato nor the formation of broccoli inflorescences was affected (Table 2), although a decreasing trend in rennet can be seen in tomato plants grown under solar panels, possibly due to a decrease in pollinating agents (Miller et al. [8] ).There were also no changes at the level of biomass generation (root or aerial part), although an increase in the weight of tomatoes and the height of the tomato plants was observed (Figure 3).The increase in the weight of the tomatoes under solar panels could be explained due to an early flowering of these plants and with it an earlier development of the fruit, since these plants had fewer red wavelengths and this wavelength has been seen to it can slow down floral induction, mainly by the phyB receptor. [10]The increase in the height of the tomato plants could be a response due to the decrease in the lux received from the plants under the solar panels with respect to the control but also to the changes in the photosynthetic spectrum, since green wavelength can affect the growth. [6]egarding the rest of the physiological parameters (Figure 4 and 5), it is known that light changes can affect numerous processes such as stomatal opening, [23] which directly affects transpiration, or stomatal conductance.However, these two parameters did not show significant changes, although they did tend to decrease in plants under solar panels.This suggests that low reduction in blue light due to our semi-transparent panels did not have a significant negative impact on transpiration values or stomatal conductance.In contrast, a significant decrease was observed in the net photosynthetic rate in both tomato and broccoli plants under solar panels.This could be attributed to the decrease in blue and red light, as these wavelengths play a crucial role in driving photosynthetic metabolism, since red and blue light are the best drive photosynthetic metabolism. [6]Therefore, the light spectrum have been complemented in previous experiments with both blue and red lights. [22]pecifically, in tomato have been reported to observe that different wavelengths can alter both the development, the moment of flowering and the antioxidant content of the fruits, manipulating the blue light photoreceptor Cryp2.However, regarding the pigments, the authors did not observed changes in chlorophylls or carotenoids in the leaves, although the total anthocyanins did increase and the lycopene present in the fruit also increased suggesting that plans were suffering from stress. [24]In our study, we could find no changes in any pigment, neither lycopene, pointing higher changes in wavelengths are needed to produce these changes (Table 4).Also, the fact that there were no changes in mineral content (Figure 6) recall in the no alteration of the nutrient uptake processes.Since changes in mineral nutrition are typically connected to changes in water relations, [25] the fact that both processes remain unaltered is a favorable aspect.

Control
In terms of primary metabolites, both tomato and broccoli did not exhibit significant changes.In tomato plants (Table 5), leaves grown under solar panels showed a decrease in GABA and succinate.This finding is interesting because GABA is not just a metabolite but also acts as a signalling molecule in stressful conditions. [26]In our study, it could be possible plants grown under solar panels degraded GABA in order to limit the accumulation of reactive oxygen species. [27]If this was the case, it could indicate that tomato plants under solar panels were able to regulate stress response.Regarding the fruit, we observed significant increases in glutamine and sucrose levels.This increase is consistent with the notion that tomatoes under solar panels undergo slightly earlier ripening, as sucrose levels are known to rise during the ripening process through abscisic acid (ABA) signals. [28]owever, the quality parameters of tomato fruits (Table 3), including pH and firmness, did not exhibit significant changes.Hence, the alterations in chemical content did not impact the firmness or pH of the juice.
Differentially, broccoli leaves showed a significant increase in leucine levels and a decrease in proline, citrate, fructose, glucose, and sucrose (Table 6).The overall reduction in sugars and citrate could be correlated with the observed decrease in the photosynthetic rate of the plants and, consequently, the carbon fixation process.However, none of these changes were sustained in the inflorescences.Instead, a decrease was observed in the levels of asparagine, isoleucine and trigonelline.Asparagine has been described as a key transport compound in the xylem (from roots to leaves) and in the phloem (from leaves to the developing seeds). [29]Since it has been reported that asparagine synthetase is light-dependent, there might be a slight repression of this family of enzymes.In addition, red light and blue light has been suggested to strongly repress the expression of the asparagine synthetase encoding gene ASN1. [30,31]nterestingly, we observed an increase in trigonelline for tomato leaves and a decrease in broccoli inflorescences under solar panels conditions.Trigonelline is a naturally occurring alkaloid that could acts as a chemical defense compound against herbivores, pathogens, and certain microorganisms. [32]t has also been reported to play a role in the response of the plant to environmental stresses such as drought, high salinity, and temperature fluctuations. [33]Additionally, trigonelline is involved in the regulation of nitrogen metabolism in plants, serving as a storage and transport form of nitrogen and helping to regulate the availability and distribution within the plant. [34]t can also be converted into other nitrogenous compounds when needed. [35]Nevertheless, the most interesting role of trigonelline could be as growth regulator, since it was suggested to regulate auxins, cytokinins, and gibberellins, thereby affecting processes like stem elongation, root development, and overall plant architecture. [36,37]However, the direct association between the concentration of trigonelline and plant growth has not been directly associated and it can vary depending on the specific plant species and growth conditions.In this way, while trigonelline could act as growth regulator, promoting certain growth processes in plants, its decrease in concentration may not determine plant growth since the overall growth and development of a plant are regulated by multiple factors as it has been pointed in our results.Therefore, the lower levels of trigonelline found in broccoli plants grown under solar panels could be a result of the response to different radiation but their role need to be investigated.

Conclusions
In conclusion, the integration of solar panels in greenhouses offers an excellent means to reduce energy costs and contribute to environmental sustainability by providing free and renewable energy.Nevertheless, it is essential to acknowledge that certain plants may experience growth and/or yield alterations in their metabolism due to the reduction of specific wavelengths caused by the panels.Based on our results, we can state that both control and solar panel-affected plants demonstrated satisfactory growth and maintained standard production levels.The observed physiological changes, such as a decrease in photosynthetic rate and metabolite alterations, did not significantly impact the yield of broccoli and tomato crops.The metabolic changes suggest that tomato plants under solar panels could showed a greater ability to regulate stress responses compared to broccoli plants.The only shared response between both plant types was the reduction in trigonelline levels observed under solar panels.This response may be linked to the direct influence of different radiation conditions, and its impact on plant physiology requires further investigation.The results indicate a very promising technology, but additional research is necessary to fully harness the potential of greenhouses and semi-transparent solar panels combination and optimize its application for different crops.This will enable to achieve maximum economic and energy benefits while enhancing growth, yield, and product quality.

Figure 1 .
Figure 1.Site map depicting the orientation and coordinate location of the experimental setup was located, including an image of the disposition of the solar panels on the roof of the greenhouse.

Figure 2 .
Figure 2. Differences between the original spectrum in control conditions A-C) and solar plaque conditions D-F) with different references: McCREEs action spectrum, chlorophyll a and b, and β-carotene.

Figure 3 .
Figure 3. A) Fresh weights of the aerial part, B) root, and C) tomato fruit, and D) height of tomato plants growth under control and solar panels greenhouses.E) Fresh weights of the aerial part, F) root, and G) inflorescences of broccoli plants growth under control and solar panels greenhouses.Data are means AE SE (n = 4À8).Asterisks indicate significant differences (p < 0.05) according to Student's t-test.

FFigure 4 .FFigure 5 .
Figure 4. A) Measurement of gas exchange parameters: transpiration rate -E, B) stomatal conductance to water vapor -Gs, C) net photosynthesis rate -An, D) CO 2 concentration of sub-stomatal cavity, E) maximum quantum yield of primary photochemistry of photosystem II -Fv/Fm, and F) chlorophyll content of tomato plants in control and solar panels conditions.Data are means AE SE (n = 4À8).Asterisks indicate significant differences (p < 0.05) according to Student's t-test.

Figure 6 .
Figure 6.A) Principal component analysis (PCA) of the mineral elements in tomato aerial part, B) tomato fruit, C) tomato roots, D) broccoli aerial part, E) broccoli inflorescence and F) broccoli roots.The X and Y axes represent the first two principal components and the variation of the data included in them.The arrows indicate the strength of the variable influence on these principal components.

Figure 7 .
Figure 7.Primary metabolites analysis: A) citrate, B) malate, C) fructose, D) glucose, and E) sucrose of broccoli leaves from plants growth in control and solar panels greenhouse.Data are means AE SE (n = 5).Asterisks indicate significant differences (p < 0.05) according to Student's t-test.

Table 3 .
Quality parameters of tomato fruits from plants in control and solar panels greenhouses.

Table 4
presents the pigment analysis of chlorophyll a (Ca), chlorophyll b (Cb), total chlorophyll (Ctotal), carotenoids, and lycopene.A comparison between conditions (conventional greenhouse and solar panel greenhouse) was performed for tomato leaves and fruits, as well as for broccoli leaves and inflorescences.Nevertheless, no statistically significant

Table 4 .
Pigment analysis: chlorophyll a (Ca), chlorophyll b (Cb), total chlorophyll (Ctotal), carotenoids, and lycopene in tomato leaves and fruits, and broccoli leaves and inflorescences from plants growth in control and solar panels greenhouse.

Table 5 .
Primary metabolites in tomato leaves and fruits from plants growth in control and solar panels greenhouse.

Table 6 .
Primary metabolites in broccoli leaves and broccoli inflorescences from plants growth in control and solar panels greenhouse.