| 1. |
- Asp, Håkan, et al.
(författare)
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Development and Acclimatisation of Horticultural Plants Subjected to Narrow-Band Lighting
- 2014
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 79, s. 45-51
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Tidskriftsartikel (refereegranskat)abstract
- Light-emitting diodes (LED) allow narrow-band light to be easily obtained and can be used for narrow-band lighting in plant cultivation, with possible effects on plant growth and development. This study examined use of narrow-band lighting of different wavelengths in the cultivation of ornamental pot plant (Pelargonium and Petunia), tomato (Solanum lycopersicum) transplants and sunflower (Helianthus annuus), either as sole light source in growth chambers, or as end-of-day (EOD) treatment in a greenhouse environment. Biometric measurements on plant growth and measurements of photosynthesis and stomatal conductance showed that when Helianthus was grown exclusively in blue light, stem elongation was greater than when it was grown exclusively in yellow, red, green or white light. Similar results were obtained when blue light was supplied in EOD treatments for Petunia and Pelargonium and for tomato. However, stem elongation was also high when red light was given as EOD treatment to tomato, whereas green light gave the least elongated plants in these conditions. Biomass production was generally not affected by the different EOD treatments. For Helianthus plants grown solely in monochromatic light, plant biomass production was highest in red light. For Pelargonium, photosynthetic rate was highest in blue light. It was conduded that plant response to different wavelengths is species-dependent and that EOD treatment with narrow-band lighting might be useful for plant growth regulation.
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| 2. |
- Bergstrand, Karl-Johan, et al.
(författare)
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Growth, Development and Photosynthesis of some Horticultural Plants as Affected by Different Supplementary Lighting Technologies
- 2013
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 78, s. 119-125
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Tidskriftsartikel (refereegranskat)abstract
- New lighting technologies of interest for the greenhouse horticulture have been introduced in the market during the last couple of years. The LED-technology has attended special interest from researchers and business, with attractive features such as long lifetime, high efficiency and possibilities for tailoring the light spectrum. In this study, common horticultural crops were grown in greenhouse conditions using different LED-light sources as well as HPS-lamps for supplementary lighting. Experiments were conducted both during increasing (spring) and decreasing (fall) natural light conditions. Biometric as well as photosynthetic evaluation of plant performance was performed. Plant parameters such as internodal length, development of flowers and lateral shoots, biomass accumulation (fresh/dry weight) and developmental time were recorded, in addition to photosynthesis and stomata conductance. Results indicate that biomass production was the highest when HPS-light was used. For photosynthesis and stomata conductance there were no differences with respect to the different treatments. Plant morphology was affected, with a reduction in stem elongation when red/blue or white LEDs were used as light source in ornamental plants grown during autumn period, and development was also delayed when LEDs were applied. However, in experiments performed during springtime there were no differences in plant morphology related to the different light sources.
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| 3. |
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| 4. |
- Bergstrand, Karl-Johan, et al.
(författare)
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Plant developmental consequenses of lighting from above or below in the production of Poinsettia
- 2015
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 80, s. 51-55
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Tidskriftsartikel (refereegranskat)abstract
- Artificial light is used for many horticultural crops produced in greenhouses, not least ornamental pot plants. New technologies such as LEDs will possibly replace high intensity discharge lamps as the main technology for lighting in horticulture. However, LEDs are quite different from discharge lamps as regards the handling of waste heat. They have low output of radiant heat, but the waste heat is produced in the fixture and must be cooled away using fans or heat sinks. The low radiant heat will result in lower leaf temperature in the crop, possibly prolonging production time. LED fixtures are often voluminous due to the need for cooling systems, creating large shade effects when installed at the top of the greenhouse. To overcome these issues, this greenhouse study tested placing the light source, in the form of LED bars, under the crop, thus illuminating the abaxial side of the leaves. The results showed that the growth and elongation of the Euphorbia plants was similar irrespective of whether the light was supplied at the abaxial or adaxial side of the leaves. The air temperature within the canopy increased when the light source was placed within the canopy and fresh weight, dry weight and bract length of the bract also increased compared with when the same light was supplied from above, probably due to the higher temperature. Placing LED light sources below the canopy of potted ornamentals was found to be a feasible solution for supplying supplementary light.
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| 5. |
- Drottberger, Annie, et al.
(författare)
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Adoption of technological innovations in production of leafy vegetables in Sweden
- 2022
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 87, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Leafy vegetable production represents high commodity and trade values. Consumption has increased, and will continue doing so according to trading operators. This study examined production of leafy vegetables in different systems and adoption of technological innovations from the firms’ perspective. A qualitative approach was applied to investigate technological innovation adoption in three different production systems: open-field, greenhouse and plant factories with artificial lighting (PFAL). Fifteen owners/managers (five per production system) were interviewed, using semi-structured questions. The firms differed in individual business characteristics and in their decisions to adopt innovations and knowledge. Open-field growers focused on packaging and automation. Growers with closed production systems (greenhouses) were more interested in energy-saving technologies, recirculation of irrigation water and LED lighting. Growers with PFAL systems opted for vertical farming, hydroponic growing techniques and LED lighting. Sources of knowledge on innovations included networks, the internet, international contacts, trade shows, extension services and universities. Overall, adoption of innovations largely depended on what suited the production system. Open-field and greenhouse firms were more interested in new technologies, but certain characteristics in their current systems determined whether an innovation was appropriate. Firms interested in new technologies actively searched for best practice using knowledge inputs from multiple sources.
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| 6. |
- Fernqvist, Fredrik, et al.
(författare)
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Consumer Attitudes towards Origin and Organic - The Role of Credence Labels on Consumers' Liking of Tomatoes
- 2013
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 78, s. 184-190
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Tidskriftsartikel (refereegranskat)abstract
- The tomato is one of the most popular vegetables in Europe, but since the introduction of modern production systems much attention has been paid to the issue 'lack of taste'. Consumers' experienced taste and quality, however, are not only dependent on attributes of the tomato such as taste and texture, but also on product appearance and labels signalling credence (e.g. origin and production method) and personal factors such as attitudes affecting consumers' quality experience. In this paper we hypothesise that credence labels (i.e. 'Swedish', 'Dutch' and 'Organic') have an effect on consumers' experienced liking of taste and total impression of tomatoes, and that attitudes towards those labels are correlated with experienced quality. Through a taste assessment with a Swedish consumer panel, we found a significant difference in liking of taste between tomatoes labelled 'Dutch' (Mean (M) = 4.54, Standard deviation (SD) = 1.68) and tomatoes labelled 'Swedish' (M = 5.88, SD = 1.70) and 'Organic' (M = 6.05, SD = 1.70), respectively. As for overall impression, tomatoes labelled 'Dutch' (M = 4.24, SD = 1.74) received lower grades than 'Swedish' (M = 5.59, SD = 1.76) and 'Organic' (M = 6.00, SD = 1.63). We found that attitudes towards origin are significantly correlated with liking of taste of tomatoes labelled 'Swedish' in a positive direction and 'Dutch' in a negative direction. We also found that positive attitudes towards organic products are positively correlated with liking of tomatoes labelled 'Organic'. The hypotheses are accepted and theoretical and practical implications are discussed.
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| 7. |
- Fernqvist, Fredrik, et al.
(författare)
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Who's to Blame for Tasteless Tomatoes? The Effect of Tomato Chilling on Consumers' Taste Perceptions
- 2012
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 77, s. 193-198
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Tidskriftsartikel (refereegranskat)abstract
- The most common stated reason to consumer dissatisfaction with tomatoes is lack of flavour. It has been shown that a common storage practice among consumer households is to store tomatoes in the refrigerator, which have a negative impact on tomato taste. Thus, consumer postharvest treatment in home may be a reason to diminishing taste. In a Swedish consumer survey we find that 53 % are dissatisfied with tomato taste and that 74 % store their tomatoes after purchase in a temperature below recommendations. Research done on the effect of tomato storage has led to the suggestion that growers should educate consumers on handling practices in order to remove the negative effect chilling has on taste experience. However, past research has been conducted on samples that potentially do not represent the target consumer, as trained sensory panels do not perceive taste as untrained consumers do. Based on previous empirical studies using expert panels, we hypothesise that panels consisting of ordinary consumers will prefer tomatoes stored in room temperature to those chilled under ordinary refrigerated conditions (i.e. 7 degrees C) regardless of variety. Thus, we replicate and challenge past findings and normative recommendations through the use of two experiments involving consumer panels evaluating two varieties of tomatoes, 'Arvento' and 'Tiesto', stored two days in refrigerator (7 degrees C) and room temperature (21 degrees C) respectively. We found a significant difference in consumer liking for 'Arvento' that were unchilled (M=6.443, SD=+/- 1.765) and chilled (M=5.849, SD=+/- 1.894), t(351)=4.270, p<0.001 (two tailed), albeit with a small effect size (eta squared statistic (.049)). No significant difference in liking was found for the 'Tiesto' variety. We find, contrary to previous research, that storage temperature has no or only a marginal effect on perceived taste among respondents in untrained consumer panels for the two varieties in our trial. Theoretical and practical implications are discussed.
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| 8. |
- Khalil, Sammar
(författare)
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Growth performance, nutrients and microbial dynamic in aquaponics systems as affected by water temperature
- 2018
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 83, s. 388-394
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Tidskriftsartikel (refereegranskat)abstract
- Aquaponics is an integrated production of fish and hydroponic crops with recirculation of the nutrient solution in which fish wastes are used as plant fertilizers. Development towards bioeconomical based cultivation system using industrial symbioses makes application of aquaponics systems in areas with surpluses or excess heat of great interest. Within the frame of these surpluses a significant amount of energy leaves the processes as low-grade heat through flue gas stacks and cooling water. However, little knowledge is available about the effect of low water temperature on the growth and microbial parameters in an aquaponics system. Investigations in the current study were thus carried out to study the effect of water temperature of 11 degrees C compared with 21 degrees C on plant growth, nutrient and microbial dynamic in aquaponic systems. Two cultivation systems (treatments) were used, an aqua ponic system consisted of a fish tank, a biofilter and a plant unit, and a hydroponic system (control) consisted of a water tank and a plant unit. Basil and trout were used as model organisms. The experiment was run for a period of eight weeks and repeated over time. The results indicated good fish growth and better plant growth in aquaponics systems compared with hydroponic systems at both water temperatures. The growth, as indicated by plant biomass, leaf length and width as well as nitrate content in the leaves, was better at water temperature of 21 degrees C compared with 11 degrees C. Low water temperature of 11 degrees C indicated a negative effect on biofiltration, microbial dynamics and disease incidence in the system. Negative correlation between the total nitrogen removal rate and low water temperature was also indicated.
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| 9. |
- Kosiba Held, Andrea, et al.
(författare)
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Effect of Fertilisation on the Development of Freezing Tolerance in Silver Birch (Betula pendula Roth.) and Blue Holly (Ilex x meserveae S.Y. Hu 'Blue Princess')
- 2010
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 75, s. 165-171
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Tidskriftsartikel (refereegranskat)abstract
- Swedish ornamental nurseries are supplying fertiliser to field crops only during the first half of the growing season, due to the concern of growers that late fertilisation will delay development of freezing tolerance. Effects of fertilisation on freezing tolerance were investigated in two climate chamber experiments. Three different fertilising strategies were used on plants of silver birch and blue holly; one treatment according to ordinary practice with all fertiliser applied within the first half of the growing season, secondly a treatment with all fertiliser almost evenly spread out over the growing season, and the third treatment as the second one but with additional potassium and phosphorus added at the end of the growing season. The total applied amount of nitrogen was the same for all treatments. The plants had a growing season of 12 weeks, followed by 6 weeks of autumn climate, simulated in the climate chamber. During the autumn period plants were tested for freezing tolerance in freezing tests. The study showed that a fertiliser strategy with an almost even distribution of a balanced fertiliser during the growing season had no negative effect on the development of frost tolerance in silver birch and blue holly. Growth and freezing tolerance showed small differences between treatments, although the rate of development of freezing tolerance seemed to be slightly faster in the third treatment. However, the results showed differences in growth and development of freezing tolerance between the experiments, indicating that other growth factors than nutrient distribution had an impact on developing freezing tolerance. Nevertheless, the results indicate that growers can even out the application of fertilisers over the entire growing season without jeopardising the development of freezing tolerance and, thus, decrease the risk for nutrient leakage to underlying soil and water table.
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| 10. |
- Spoor, Tim, et al.
(författare)
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Chemical contents and blue mould susceptibility in Swedish-grown cider apple cultivars
- 2019
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Ingår i: European Journal of Horticultural Science. - 1611-4426 .- 1611-4434. ; 84, s. 131-141
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Tidskriftsartikel (refereegranskat)abstract
- Craft apple cider is obtained by fermentation of juice from tannin-rich cider apple cultivars. Polyphenols in cider apples are very important; while procyanidins are the only true tannins, other phenolic compounds can act as precursors for cider aroma. Several recent studies have also reported that a high content of polyphenols in apple decreases susceptibility to the common storage rot blue mould caused by Penicillium expansum. Chemical content was determined in fruit of 19 Swedish-grown cider apple cultivars and 5 dessert apple cultivars in 2016. Inoculation with blue mould spores was undertaken in 2016 on 5 cider apple cultivars and 5 dessert apple cultivars, and repeated again in 2017 on 8 of these cultivars. Contrary to expectations, the cider apple cultivars were significantly more susceptible to blue mould in spite of their higher phenolics content. Although apparently unrelated to amount of phenols in the fruit of our study cultivars, heritability of blue mould susceptibility should be further investigated since all of the cider apples had one parent in common; 'James Grieve'.
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