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Background: Consecutive droughts and quantitative and qualitative reduction of surface and underground water resources have caused an increase in greenhouse and hydroponic cultivation for most garden crops, including strawberries, in Iran. On the other hand, most of the inputs of greenhouse crops in Iran are imported. To possibility of replacing vermicompost with peat moss under hydroponic cultivation, an experiment was done in a split plot based on randomized complete blocks design in three replications in Isfahan (Iran) Agricultural and Natural Resources Research Center in 2019. The main treatment was substrate at four levels included different levels of vermicompost (30 and 50%) and peat moss (30 and 50%) in combination with perlite and sub-treatment were Selva and Camarosa cultivars. Results: The results showed that Camarosa cultivar and Selva cultivar in (perlite/ peat moss 50:50) and Selva cultivar in (perlite / vermicompost 70:30) had maximum yield. Leaf number and chlorophyll index were maximum in Camarosa cultivar in peat moss substrates. Strawberry cultivars had the highest root fresh weight, the content of vitamin C and total soluble solids (TSS) in substrates containing vermicompost. Camarosa cultivar in (perlite / peat moss50:50) and Selva cultivar in (perlite /vermicompost 50:50) had maximum root dry weight. Also, the highest number of inflorescences was related to substrates containing peat moss and (perlite /vermicompost 70:30). Maximum amount of fresh and dry weight of shoots were observed in (perlite/ peat moss70:30). Selva cultivar had more inflorescences (16.5%) than Camarosa cultivar and Camarosa cultivar produced more fresh and dry weight of shoots (16.5%, 23.01%) than Selva cultivar. Conclusion: Expriment results highlighted the importance of considering both main and sub-treatments in agricultural research, as they interacted to influence various growth and yield parameters. 50% vermicompost treatment combined with perlite had a positive impact on plant growth and in quality index such as vitamin C content and TSS was highest. while the choice of cultivar affected different aspects of plant development. Selva cultivar was known to be more tolerant to salinity caused by vermicompost. Vermicompost is local and more economical, also salt resistant cultivars are recommended in a controlled (30%) amount of vermicompost. [ABSTRACT FROM AUTHOR]

Background: Consecutive droughts and quantitative and qualitative reduction of surface and underground water resources have caused an increase in greenhouse and hydroponic cultivation for most garden crops, including strawberries, in Iran. On the other hand, most of the inputs of greenhouse crops in Iran are imported. To possibility of replacing vermicompost with peat moss under hydroponic cultivation, an experiment was done in a split plot based on randomized complete blocks design in three replications in Isfahan (Iran) Agricultural and Natural Resources Research Center in 2019. The main treatment was substrate at four levels included different levels of vermicompost (30 and 50%) and peat moss (30 and 50%) in combination with perlite and sub-treatment were Selva and Camarosa cultivars. Results: The results showed that Camarosa cultivar and Selva cultivar in (perlite/ peat moss 50:50) and Selva cultivar in (perlite / vermicompost 70:30) had maximum yield. Leaf number and chlorophyll index were maximum in Camarosa cultivar in peat moss substrates. Strawberry cultivars had the highest root fresh weight, the content of vitamin C and total soluble solids (TSS) in substrates containing vermicompost. Camarosa cultivar in (perlite / peat moss50:50) and Selva cultivar in (perlite /vermicompost 50:50) had maximum root dry weight. Also, the highest number of inflorescences was related to substrates containing peat moss and (perlite /vermicompost 70:30). Maximum amount of fresh and dry weight of shoots were observed in (perlite/ peat moss70:30). Selva cultivar had more inflorescences (16.5%) than Camarosa cultivar and Camarosa cultivar produced more fresh and dry weight of shoots (16.5%, 23.01%) than Selva cultivar. Conclusion: Expriment results highlighted the importance of considering both main and sub-treatments in agricultural research, as they interacted to influence various growth and yield parameters. 50% vermicompost treatment combined with perlite had a positive impact on plant growth and in quality index such as vitamin C content and TSS was highest. while the choice of cultivar affected different aspects of plant development. Selva cultivar was known to be more tolerant to salinity caused by vermicompost. Vermicompost is local and more economical, also salt resistant cultivars are recommended in a controlled (30%) amount of vermicompost. [ABSTRACT FROM AUTHOR]

Currently, the selection of tomatoes with a high content of biologically active substances and antioxidant properties at the large green and breaker stage is relevant since mature tomatoes cannot tolerate storage and transportation. For this purpose, 11 tomato genotypes, chosen in a preliminary study in 2018-2020 from the Genetic Collection of Plant Resources of Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center (FSBSI FSVC), Moscow, Russia, and Tomato Genetics Resource Center (TGRC), the University of California, Davis, USA, for further studies during 2020-2022 for antioxidant pool changes: measuring the contents of chlorophyll, lycopene, β-carotene, ascorbic acid, and lutein. The experiment arranged in a randomized complete block design proceeded in the film unheated greenhouses. The results showed five promising tomato genotypes, i.e., VFN Hi Sugar, VS-420, Paul Robeson, Black Cherry, and VS-410. The genotype Black Cherry fruits with breaker ripeness contained 42% lycopene and 93% β-carotene, while the genotype Paul Robeson at the same stage contained 80% β-carotene. The three other tomato genotypes, viz., VFN Hi Sugar, VS-420, and Paul Robeson, also gave a higher content of ascorbic acid in the fruits at the breaker ripening stage. [ABSTRACT FROM AUTHOR]

A greenhouse experiment was conducted at GKVK Bengaluru, Karnataka during 2013 to decide the best dilution of distillery spentwash to be utilized as a foliar spray for tomato crop. Results revealed that a foliar application of 1:5 dilution of distillery spentwash resulted in higher growth parameters compared to other dilutions. Based on greenhouse experiment results, a two year field experiment was conducted in a farmer's field at Mandya district, Karnataka during 2013 and 2014. Pooled analysis of two years of data (2013 and 2014) revealed that at 60 DAT, the treatment which received 100% RDF + 5 sprays of distillery spentwash at 1:5 dilution recorded significantly higher plant height (110.2 cm), SPAD meter reading (22.9) and higher fruit yield (7.14 kg plant−1 and 78.9 t ha−1) compared to other treatments. Lower plant height, SPAD reading and yield were recorded in the 100% RDF + water sprays (5 times). Also, significantly higher ascorbic acid content (54.2 mg 100–1) and lycopene content (14.0 mg 100–1) of tomato fruits were determined in the treatment receiving 100% RDF + 5 sprays of distillery spentwash at 1:5 dilution. After harvest of tomato crop, soil properties were higher in treatment which received 100% RDF + 5 sprays of undiluted distillery spentwash; but soil pH was higher in the treatment that received water spray. [ABSTRACT FROM AUTHOR]

The objective of this paper is to experimentally study the optimal spectrum and duration of illumination in regulating yield and quality of sweet pepper (Capsium annuum L.) grown in greenhouse. The cultivar of 'Aodaili' was used as the model plant and LED was used as the light source. We compared nine combinations of three light durations (2h, 18:00-20:00; 4h, 18:00- 22:00 and 8h, 18:00-02:00) and three light spectra measured with red (R) : blue (B) ratio at 2:1 (2R1B); 4:1, (4R1B), and 8:1 (8R1B); without supplemental light served as the control (CK). In each treatment, we measured the growth, yield and fruit quality of the sweet pepper. Results showed that the diameter of the canopy, soluble proteins, soluble sugar, and Vitamin C under 2R1B for 2h were the highest, increasing by 24.6%, 33.8%, 15.2% and 29.9%, respectively, compared to those in the CK. Nitrate content and acid-sugar ratio under 2R1B for 8h were the lowest, reduced by 19.4% and 27.0% respectively, compared to that in the CK. The dry biomass of the shoot and whole plant in 4R1B for 2h were the highest, increasing by 58.4% and 62.4% respectively, compared to that in the CK. In contrast, the fresh weight of the shoot and whole plant under 8R1B for 8h were the highest, increasing 55.1% and 48.9%, respectively, compared to that under the CK. Compared to those under the CK, the leaf area, fruit number and single plant yield under 4R1B for 8h increased by 32.4%, 37.9% and 47.2%, respectively. The SPAD, acid-sugar ratio and output-input ratio of the pepper under 8R1B for 2h increased significantly compared with that in CK, while no significant differences were found in the soluble proteins, soluble sugar, Vitamin C and nitrate content between them. These results revealed that the duration and spectrum of the supplemental light had a combined impact on growth, yield and fruit quality of sweet pepper at significant level. Supplemental lighting increased fruit number, single plant yield, soluble proteins, soluble sugar, titratable acid, Vitamin C, nitrate content, acid-sugar ratio. We used electricity consumption to analyze the effect of spectrum and duration of light on plant growth, based on the fuzzy membership function. The best three treatments calculated by the method are in the order of 8R1B for 2h > 4R1B for 8h > 8R1B for 8h. In summary, the optimal supplemental lighting for the greenhouse sweet pepper is 8R1B for 2h. The results presented in this paper has implications for using supplemental lighting to improve green peppers production in greenhouse. [ABSTRACT FROM AUTHOR]

• N dose should be optimized when shadecloths are used to mitigate high temperatures. • Shading decreased yield when combined with a dose of 14 mM. • Shading did not affect sugars but decreased most of the studied bioactives. • Shading lessened the negative effect of N dose on β -carotene concentration. • Contrary to the effect observed for other metabolites, shade increased lycopene. Although the use of shade cloths is an economic and common practice to mitigate the effect of high temperatures in greenhouse crops in warm areas, the decrease of solar radiation may alter some physiological processes of the plant, modifying their nutritional needs and ultimately affecting production and quality. In this paper we study the effect of nitrogen dose and its interaction with the use of shade cloths on the quality of tomatoes, with particular attention paid to their bioactive compound content. The treatments consisted of three levels of N (14, 7 and 3 mM), combined with two levels of light intensity, control (100% light), and shading (60% light) provided by shade cloth. Shading adversely affected the production of tomatoes cultivated with 14 mM N, although a lower dose of N offset the negative effect of shade on performance. Shading did not affect the concentration of sugars in the fruit, but decreased the phenolic compound and vitamin C contents. By contrast, a decrease in the dose of N increased the concentration of phenolic compounds at 100% light and that of vitamin C with and without shading. Shading decreased the concentration of β -carotene only in the case of plants grown with the highest concentration of N. The concentration of lycopene, contrary to that observed for all other metabolites of interest, increased with shading. Under these shading conditions, the decrease in the dose of N did not affect the β -carotene and lycopene concentrations. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: This research focused on the effect of organic production systems on initial quality and postharvest performance of lamb's lettuce leaves stored in air or under modified atmosphere at refrigerated temperature. Different strategies of organic soil fertility management were compared under the same environmental conditions: (i) a simplified organic production system based on organic commercial fertilizers to recover crop uptake (SB); (ii) an organic production system based on organic matter amendment mainly supplied by animal manure (AM); and (iii) an organic production system based on organic matter amendment supplied by green waste compost (AC). Fully developed lamb's lettuce leaves were harvested and then packed into perforated bags (control in AIR) or in modified atmosphere packaging (MAP) and stored at 4 °C. RESULTS: At harvest, the yield of lamb's lettuce in the AM and AC systems was higher than that in SB. Phenol and dehydroascorbic acid accumulation was observed in the system with the lowest initial supply of organic amendment (SB). Regarding the effect of packaging, AIR conditions maintained the initial quality attributes for a longer period than MAP, which developed off‐odours above the threshold of acceptability at 11 days, irrespective of the production system used. CONCLUSION: In general, the initial differences among the production systems were minimal during the postharvest storage. As for the tested packaging systems, AIR successfully maintained the initial quality attributes for a longer period than the MAP. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, the effects of supplementary UV radiation during the vegetative period on antioxidant compounds, antioxidant activity and postharvest quality of broccoli heads during long term storage was studied. The broccolis were grown under three different doses of supplementary UV radiation (2.2, 8.8 and 16.4 kJ/m 2 /day) in a soilless system in a glasshouse. Harvested broccoli heads were stored at 0 °C in modified atmosphere packaging for 60 days. The supplementary UV radiation (280–315 nm) during the vegetative period significantly decreased total carotenoid, the chlorophyll a and chlorophyll b content but increased the ascorbic acid, total phenolic and flavonoid contents of broccolis. All supplementary UV treatments slightly reduced the antioxidant activity of the broccolis, however, no remarkable change was observed between 2.2 and 8.8 kJ/m 2 radiation levels. The sinigrin and glucotropaeolin contents of the broccolis were substantially increased by UV treatments. The prolonged storage period resulted in decreased ascorbic acid, total phenolic and flavonoid contents, as well as antioxidant activity. Discoloration of the heads, due to decreased chlorophyll and carotenoid contents, was also observed with prolonged storage duration. Glucosinolates levels showed an increasing tendency till the 45th day of storage, and then their levels started to decline. The weight loss of broccoli heads during storage progressively increased with storage time in all treatments. Total soluble solids, solids content and titratable acidity decreased continuously during storage. Titratable acidity was not affected by UV radiation doses during the storage time whereas soluble solids and solids content (dry matter) were significantly affected by UV doses. Supplementary UV radiation increased the lightness ( L* ) and chroma ( C* ) values of the broccoli heads. Pre-harvest UV radiation during vegetative period seems to be a promising tool for increasing the beneficial health components of broccolis. [ABSTRACT FROM AUTHOR]

Lettuce (Lactuca sativa) is a nutritious leafy vegetable, rich in minerals and vitamins. It is considered as one of the most important salad crops, grown around the world, which is used particularly as the base for salad. Salad has short vegetation period, so several production cycles can be achieved during the year. It has sedative, diuretic and expectorant features and is beneficial for functioning of the cardiovascular and digestive systems. Among the other valuable compounds, lettuce contains vitamin C, one of the essential nutrients for humans. It is very important to store lettuce after harvest in the environment in which its nutritional value does not deteriorate. Therefore, the aim of this study was to assess the effect of different cold storage conditions on concentration of vitamin C in lettuce. Four cultivars of lettuce (Murai, Kitare, Carmesi and Levistro) were included in the experiment. Plants were grown under controlled conditions ofa greenhouse to technological maturity, in growing cubes. After harvest, lettuce heads were stored in the refrigerator in two ways: 1) together with growing cube or 2) without growing cube. Every three days after the beginning of the storage period, at three time points in total, concentration of vitamin C was determined. These results were also compared to concentration of vitamin C in lettuce which was not harvested and continued growth in a greenhouse, in growing cubes, during the entire period. Storage conditions effected concentration of vitamin C to varying extent in different cultivars. In cultivar Murai concentration of vitamin C declined the least over time, regardless of storage conditions (the lowest recorded value was 60% since the beginning of storage period). In the other three cultivars concentrations of vitamin C were very similar in cold storage. However, the differences between cultivars were observed in lettuce stored with growing cubes in a greenhouse where Kitare and Murai had 98-80% of vitamin C in comparison with respective controls. In Carmesi and Levistro concentration of vitamin C declined much more (in Levistro to about 25%, and this cultivar had the highest initial concentration of vitamin C). Generally, the results showed that there was a decrease in the concentration of vitamin C in lettuce over time, but less when lettuce was stored in the refrigerator without a growing cube. [ABSTRACT FROM AUTHOR]

BACKGROUND The effect of light quality on phytochemicals in romaine baby leaf lettuce 'Thumper' was investigated in (I) a closed environment and ( II, III) a greenhouse (16 h, 21/17 °C): (I) basal (638, 455, 660, 735 nm) LEDs supplemented with UV (380 nm), green (510 nm), yellow (595 nm) or orange (622 nm) LEDs ( PPFD of ∼175 µmol m−2 s−1); ( II) high-pressure sodium ( HPS) lamps (90 µmol m−2 s−1) supplemented with blue (455, 470nm) or green (505, 530nm) LEDs (30 µmol m−2 s−1); ( III) at 3 days before harvesting, HPS lamps (90 µmol m−2 s−1) supplemented with red (638 nm) LEDs (210 µmol m−2 s−1). RESULTS (I) Supplemental UV or orange light enhanced phenolic compounds, supplemental UV or green light enhanced α-carotene, and supplemental green light enhanced anthocyanins. All supplemental LED colours had a negative effect on tocopherol and ascorbic acid levels. ( II) HPS lighting supplemented with different LEDs was not efficient, since the increase in some compounds did not compensate the decrease in major tested phytochemicals. ( III) Short-term irradiation with supplemental 638 nm LEDs before harvesting in the greenhouse did not have a significant effect on phytochemical contents, apart from enhancing tocopherols. CONCLUSION Wavelength control using LED technology affects the production of secondary metabolites, as the metabolism of many nutrients is light-dependent. The narrow-bandwidth supplemental light effects were diminished by broader-spectrum HPS light or natural daylight in the greenhouse. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Simple Summary: LED lighting is increasingly applied to increase yield and quality of greenhouse produced crops, especially tomatoes. Tomatoes cannot be stored at cold temperatures due to chilling injury that manifests as quick quality deterioration during shelf life. The aim of this study is to investigate whether additional blue LED lighting can mitigate the negative effects of cold storage for 'Foundation' tomatoes. We applied three treatments, 0, 12 or 24% additional blue light during cultivation, and investigated quality attributes at harvest, after cold storage and subsequent shelf-life. We observed that red harvested tomatoes cultivated with 12% additional blue light acquired cold tolerance. Interestingly, these tomatoes were slightly less red colored at harvest and showed a faster loss of red color during cold storage. The measured red color is closely related to the lycopene concentration. We hypothesize that lycopene, a known antioxidant, present in 12% additional blue cultivated tomatoes mitigates chilling injury. Other antioxidants present in tomatoes were only affected by the ripeness at harvest and were therefore not involved in the acquired cold tolerance. The cultivation of tomatoes using additional blue LED is an attractive way to produce tomatoes that can withstand long transport at cold temperatures at the expense of a slightly less red tomato at the consumer. Tomato is a chilling-sensitive fruit. The aim of this study is to examine the role of preharvest blue LED lighting (BL) to induce cold tolerance in 'Foundation' tomatoes. Blue and red supplemental LED light was applied to achieve either 0, 12 or 24% additional BL (0B, 12B and 24B). Mature green (MG) or red (R) tomatoes were harvested and cold stored at 4 °C for 0, 5, 10, 15 and 20 d, and then stored for 20 d at 20 °C (shelf life). Chilling injury (CI) indices, color and firmness, hydrogen peroxide, malondialdehyde, ascorbic acid and catalase activity were characterized. At harvest, R tomatoes cultivated at 12B were firmer and showed less coloration compared to fruit of other treatments. These fruits also showed higher loss of red color during cold storage and lower CI symptoms during shelf-life. MG tomatoes cultivated at 12B showed delayed coloring (non-chilled) and decreased weight loss (long cold stored) during shelf life compared to fruit in the other treatments. No effects of light treatments, both for MG and R tomatoes, were observed for the selected antioxidant capacity indicators. Improved cold tolerance for R tomatoes cultivated at 12B points to lycopene having higher scavenging activity at lower concentrations to mitigate chilling injury. [ABSTRACT FROM AUTHOR]

Abstract: We report on the application of supplementary light-emitting diode (LED) lighting within a greenhouse for cultivation of red, green and light green leaf baby lettuces (Lactuca sativa L.) grown under natural illumination and high-pressure sodium (HPS) lamps (16-h; PPFD-170μmolm−2 s−1) during different growing season. Supplementary lighting from blue 455/470nm and green 505/530nm LEDs was applied (16-h; PPFD-30μmolm−2 s−1). Our results showed that to achieve solely a positive effect is complicated, because metabolism of antioxidant properties in lettuce depended on multicomponent exposure of variety, light quality or seasonality. The general trend of a greater positive effect of supplemental LED components on the vitamin C and tocopherol contents was in order: 535>505>455>470nm; on the total phenol content: 505>535=470>455nm; on the DPPH free-radical scavenging capacity: 535=470>505>455nm; on the total anthocyanins: 505>455>470>535nm. Further investigations are needed for understanding the mechanism and interaction between antioxidants and light signal transduction pathways. [Copyright &y& Elsevier]

Nowadays, off-season leafy vegetables are generally characterized by low vitamin C (Vc) content and high nitrate accumulation due to low light intensity inner protected systems and high-level nitrogen supply. A glasshouse experiment was conducted to investigate the effects of three kinds of nitrogen-free solution treatments before harvest on Vc and nitrate contents in expanded leaf blades, expanded leaf petioles and old leaves of hydroponic lettuce. The results showed that using nitrogen-free solutions could decrease nitrate contents of expanded leaf blades, expanded leaf petioles and old leaves, also nitrate contents in above parts reduced increasingly with treatment time extending. In addition, three nitrogen-free solution treatments increased the Vc content of expanded leaf blades instead of expanded leaf petioles and old leaves. There were instead of significant positive correlations between nitrate contents but Vc contents of expanded leaf blades, expanded leaf petioles and old leaves. To conclude, nitrogen disruption treatment before harvest could effectively reduce nitrate contents in edible parts of lettuce, and also improve Vc content in expanded leaf blade. [ABSTRACT FROM AUTHOR]

A field experiment was carried out in the years 2007-2009 at the Research Development Station of the Department of Horticulture at the Wrocław University of Environmental and Life Sciences. The experiment involved two botanical varieties of endive: var. latifolium (nine cultivars) and var. crispum (five cultivars). Endive was cultivated from transplants produced in a greenhouse in two terms, for spring and autumn harvesting. The harvest took place 90-100 days after the seeds were sown. In the course of harvesting, the total and marketable yields were determined, while biological value was assessed on the basis of analyses regarding the content of dry matter, vitamin C, chlorophyll and carotenoids, as well as the amounts of such elements as Mg, P, K, Ca and nitrates. [ABSTRACT FROM AUTHOR]

The determination of °Brix, pH, titratable acidity and antioxidant composition such as β-carotene, lycopene, and vitamin C was done in greenhouse “Savoura” tomatoes during maturation. The chromatic values L*, a*, b* were determined at the top surface of the tomato, and its strength-deformation curve was tested with a texturometer. Results pointed out that °Brix and titratable acidity did not change during postharvest, while β-carotene, lycopene, and vitamin C contents increased continuously toward the red stage of tomato. The colour values L*, a*, b*, and ratio a*/b* had a good correlation with the maturity stages. Also, a high correlation between lycopene content and (a*/b*) ratio was found, which was well represented with a second order polynomial function (r2 = 0.95). This equation permits to appropriately estimate lycopene content of tomato as a function of its color, without any chemical analysis. During ripening, tomato texture changed from firm turgid to soft and the puncture deformation degree increased. Tomato firmness and chromatic values had a good correlation, and the lycopene content was a logarithm function of firmness (r2 = 0.81). The strength in puncture test increased linearly with deformation until the bioyield point. The measured force was analyzed as the sum of the compression and the shear forces. The two force coefficients can be considered as tomato properties, independent of the puncture probe. These coefficients were found to decrease during tomato maturation. [ABSTRACT FROM AUTHOR]

The colour and the antioxidant content of five different cultivars of tomatoes (Lycopersicon esculentum L.), grown in glasshouses using commercial hydroponic techniques, were measured in freshly harvested tomatoes and after 2 and 5 days of storage in the dark at 15°C. The two cocktail cultivars of tomatoes, Aranca and Flavourine, were the smallest tomatoes but they contained higher dry matter contents compared with the three standard salad cultivars, Excell, Celero and Dutch Chaser. There were significant differences (P<0.001) in lycopene (the major carotenoid), ascorbic acid and total antioxidant activity in the whole fruit of the five different cultivars evaluated at harvest, while the total phenolic contents were very similar. The lycopene levels of all the cultivars increased significantly (P<0.001) after storage for 2 and 5 days at 15°C. Overall, the total phenolic content of all the cultivars did not change appreciably after storage at 15°C while the levels of ascorbic acid fell by 12.6% when stored for 5 days in the dark. There was a significant difference (P<0.001) in the total antioxidant activity between the five different cultivars when freshly harvested; the highest levels of total antioxidant activity were observed in the two cocktail cultivars, Aranca and Flavourine. Antioxidant activity showed different patterns of change depending on cultivar. An increase in the total antioxidant values could be seen in cultivars Dutch chaser and Excell, after storage for 5 days at 15°C. The total antioxidant activity values of Flavourine and Celero fell on storage while the values for stored Aranca were very similar to the values when freshly harvested. The skin colour, as shown by Commission Internationale l'Eclairage (CIE) L*a*b* values of each cultivar were markedly different at harvest even though each cultivar was harvested at the same maturity. The a* value of each cultivar increased significantly (P<0.001) when they were stored in the dark, for either 2 or 5 days, at 15°C. Regression analysis showed that overall there was no significant relationship (R 2 =0.14) between the lycopene content and the a* value of all the tomatoes; however, when examined individually, the two cocktail tomatoes Aranca and Flavourine showed strong correlation—R 2 =0.96 and R 2 =0.97, respectively. Overall, the (a*/b*) 2 was the most reliable indicator of lycopene concentration (R 2 =0.96) in the tomatoes examined in this study. [ABSTRACT FROM AUTHOR]

Tomato is one of the most widely used vegetables in the world. In Canada, it is predominantly a greenhouse grown crop during the colder seasons. Hence it is necessary to study the environmental impacts of its production to improve the sustainability of greenhouse grown tomato. In this study, the organic tomato production in Quebec, Canada was conducted using life cycle assessment (LCA) method considering the cradle-to-packing system boundaries to assess environmental impacts. The system was modeled based on the value of fresh tomato at the rate of one tonne fresh product from the greenhouse and its vitamin C content represented as mg/100 g of tomato pulp. The parameters considered in the study were varying irrigation levels, and the amounts of Azolla based organic fertilizers considered, since Azolla is valued for its plant growth promoting capabilities. The results show that the production of one tonne of tomato packed had a negative-impact to human health (1.21 × 10−3 to 3.79 × 10−3 DALY), ecosystem (1.50 × 10−4 to 8.96 × 10−4 species.yr), and resources (1.89 × 10 to 3.35 × 10 $). Based on results, reduced irrigation led to increased adverse environmental impacts of production per tonne of packed tomato. However, the changes in the fertilization rate had less effect on environmental damage. The highest level of environmental damage was related to the lowest level of irrigation and the lowest level of fertilization, which mainly resulted from electricity consumption. Also, the highest level of irrigation and the lowest level of fertilization led to best environmental performance production per tonne of packed tomato. The results of this study emphasize that, although irrigation and fertilization have an important role in the performance of tomatoes and their environmental impacts, they did not significantly alter the amount of vitamin C. Image 108175 • The environmental sustainability in organic tomato production was analyzed. • The role of irrigation and biofertilization on environmental impacts was studied. • The lowest damage to human health was 1.21 × 10−3 DALY/tonne. • The lowest damage to ecosystem was estimated 1.50 × 10−4 species. yr/tonne. • The environmental impacts based on vitamin C were not very dependent on cultivation conditions. [ABSTRACT FROM AUTHOR]

• Rice plants with high ABA content always attain low net photosynthetic rate (PN) of leaf under natural conditions. • Stomatal aperture and ribulose-1,5-bisphosphate carboxylase/oxygenase activity mainly responsible for photosynthesis of leaf in rice. • Strong antioxidant capacity improves PN by regulating Cond and rubisco activity of leaves to reduce photorespiration. ABA is important for plant growth and development; however, it also inhibits photosynthesis by regulating the stomatal aperture and ribulose-1,5-bisphosphate carboxylase/oxygenase activity. Noteworthy, this negative effect can be alleviated by antioxidants including ascorbic acid (AsA) and catalase (CAT), but the underlying mechanism remains unclear. Two rice cultivars, Zhefu802 (recurrent parent) and its near-isogenic line, fgl were selected and planted in a greenhouse with 30/24 °C (day/night) under natural sunlight conditions. Compared to fgl , Zhefu802 had significantly lower net photosynthetic rate (PN) and stomatal conductance (Cond) as well as significantly higher ABA and H 2 O 2 contents. However, AsA and CAT increased PN, Cond, and stomatal aperture, which decreased H 2 O 2 and malondialdehyde (MDA) levels. In this process, AsA and CAT significantly increased the ribulose-1,5-bisphosphate carboxylase activity, while they strongly decreased the ribulose-1,5-bisphosphate oxygenase activity, and finally caused an obvious decrease in the ratio of photorespiration (Pr) to PN. Additionally, AsA and CAT significantly increased the expression levels of RbcS and RbcL genes of leaves, while H 2 O 2 significantly decreased them, especially the RbcS gene. In summary, the removal of H 2 O 2 by AsA and CAT can improve the leaf photosynthesis by alleviating the inhibition on the stomatal conductance and ribulose-1,5-bisphosphate carboxylase capacity caused by ABA. [ABSTRACT FROM AUTHOR]

This study was commissioned to study the effect of the growing season on the antioxidant components of greenhouse sweet pepper crops, which is of scientific interest because of their possible beneficial health effects. The total antioxidant activity (estimated by ferric reducing antioxidant power-FRAP assay) major antioxidants (ascorbic acid, phenolics and carotenoids) and taste fruit quality characteristics (soluble solids, titratable acidity, dry matter and sugars) were recorded in soilless-grown sweet pepper cultivars of red, orange, yellow and green color at four harvesting season months, i.e., February (winter), May (spring), July (summer) and October (autumn). The results showed seasonal variations in antioxidant components and activity of pepper fruits. In most cases measured parameters showed higher values in spring (May) and summer (July) compared with winter (February) and autumn (October) growing seasons. This study indicates that during late autumn and winter, lower levels of solar irradiance, ultraviolet radiation and temperature in Mediterranean greenhouses can be insufficient to stimulate phytochemicals production in peppers; thus, plant–light interception must be more actively managed. [ABSTRACT FROM AUTHOR]