| 1. |
- Abouhatab, Assem, et al.
(författare)
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Determinants of import demand for Egyptian potatoes in Germany and the United Kingdom
- 2016
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1132, s. 39-48
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The European Union (EU) is the major import market for Egyptian fresh potatoes. Germany and the United Kingdom (UK) jointly imported about 44% of Egyptian potato exports to the EU during the period 1994-2012. This study sought to identify the determinants of import demand for Egyptian potatoes in these two countries. A general differentiated demand system approach was used to estimate conditional potato import demand per country. For each country, it was assumed that the system of conditional import demand equations for potatoes is specified according to the sources of origin and also depends on all imported potato prices and total import potato expenditure. When estimated econometrically, this import demand model allows conditional price and expenditure elasticities to be derived. The econometric results indicated that with an estimated elasticity of 1.95, Egyptian potato exports responded significantly to total expenditure on imported potatoes by Germany. On the other hand, Egyptian potato exports to Germany did not exhibit significant price responses. In all cases but one, estimated conditional uncompensated price elasticities were not statistically different from zero. However, more interesting results were obtained concerning the price responses of Egyptian potato exports to the UK, whereby the conditional (uncompensated) direct elasticity of potato imports from Egypt to the UK (-0.71) showed an inelastic response to its own price. Furthermore, Egyptian potato exports seemed to compete on the UK market with potatoes originating from Israel and France, while they displayed complementarity with Dutch imports.
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| 2. |
- Abouhatab, Assem, et al.
(författare)
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Exchange rate uncertainty and Egyptian exports of horticultural commodities into the EU
- 2019
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1258, s. 11-18
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the impact of exchange rate volatility on Egyptian exports of fresh fruit and vegetables (FFVs) to their major importing markets in the EU. Using quarterly data covering the period 1994-2016, we examine the determinants of Egypt’s exports of FFVs to the EU, and then derive the long-term effects of exchange rate volatility on the FFV exports. The empirical results show that exchange rate volatility has a long-run significant effect on Egypt’s FFV exports to the EU. Overall, the findings highlight the importance of exchange rate volatility in understanding the behavior of Egyptian exports of FFVs to the EU. Thus, the design and implementation of exchange rate policies and export promotion programs in Egypt should take into consideration the stability and level of the real exchange rate.
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| 3. |
- Ahmadi Afzadi, Masoud, et al.
(författare)
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Genetics of resistance to blue mould in apple: inoculation-based screening, transcriptomics and biochemistry
- 2016
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1127, s. 55-60
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Konferensbidrag (refereegranskat)abstract
- Blue mould caused by Penicillium expansum is a major contributor to loss of marketable fruit during storage. Damage is also aggravated by the prohibition of postharvest fungicides in many countries, and in organic production everywhere. Robust data on levels of resistance to this disease are crucial for further research and for breeding of improved cultivars. Inoculation of fruit with fungal spores and estimation of the diameter of resulting lesions after cold storage demonstrated significant variation among cultivars. In addition, cultivars with high firmness at harvest and little softening, i.e., loss of firmness during storage, had less susceptibility, as also did late-ripening cultivars. In another part of the study, a possible association between lesion diameter and chemical contents in fruit flesh and fruit peel of 23 cultivars was investigated. Content of different quercetins and procyanidin B2 was positively associated with the level of tolerance. Samples taken after inoculation showed stronger association with the chemical contents than did samples of control fruit, suggesting that disease development had triggered a defence reaction. In a third part of the study, gene regulation in apple fruit after inoculation was evaluated in two relatively resistant and two relatively susceptible cultivars using an AryANE chip covering 60K apple transcripts. Validation of the most highly up-and down-regulated genes was undertaken using qPCR. Some genes related to disease resistance, biosynthesis of flavonoids and to cell-wall structure were identified as most likely to be responsible for differences in susceptibility to blue mould. These results will be used to search for candidate genes that can be used in marker-assisted selection in apple breeding.
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| 4. |
- Alsanius, Beatrix
(författare)
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An updated glossary of terms and basic characteristics of growing media
- 2023
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1377, s. 925-934
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Konferensbidrag (refereegranskat)abstract
- In the research community of growing media, there is an increasing confusion related to inappropriate use of terms, and to a lack of description of minimal chemical, physical, biological characteristics of growing media and their components for adequate data interpretation in scientific publications. A survey was conducted between the summer of 2019 and the autumn of 2020 among growing media scientists worldwide to help addressing these two issues and published later as a basic framework (Caron and Zheng, 2021). In 2022, a workshop was organized to update terms and definitions and report further progress with respect to terms and basic characteristics. This paper summarizes the improvement of the glossary suggested by Caron and Zheng (2021).
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| 5. |
- Alsanius, Beatrix, et al.
(författare)
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Concept based mapping as a tool to disentangle biological properties and interactivities in research on growing media and hydroponics
- 2024
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; , s. 163-174
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Konferensbidrag (refereegranskat)abstract
- The cascading use of valorized constituents from societal side-streams in growing media (GM), but also the reuse of growing media, has brought increased attention to their biological properties and processes. These processes are complex, dynamic and interconnected. They are a result of the origin and treatment in previous steps of the cascading use as well as in the re-use. Furthermore, they are affected by physical and chemical characteristics in the GM and in the environment that they are exposed to. Thus, the complexity of factors and events shapes the outcome of research studies as well as product development and the manner how such outcome may be interpreted and how manufacturing processes and product quality can be standardized. In addition, the recent development of high-throughput methods for culture independent description of microbial community composition, gathering a copious volume of data, increases the level of complexity even more. To draw clear-cut conclusions on biological characteristics, processes and dynamics in GM, this complex picture needs to be disentangled, a process that already has to be in place at the early step of the study, process or product design. Based on three examples, we describe the power of conceptbased mapping to disentangle biological properties and interactivities in research and product development of GM and hydroponics and show its potential for big data analysis and modeling.
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| 6. |
- Alsanius, Beatrix, et al.
(författare)
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Decontamination of Irrigation Water under Field Conditions: Preliminary Results
- 2011
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 922, s. 61-66
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Konferensbidrag (refereegranskat)abstract
- Outbreaks of foodborne diseases (Norovirus, Salmonella spp., verotoxin producing E. coli, Campylobacter spp., Shigella spp.) related to fruit and vegetable have increased worldwide. Microbial hazards cause considerable and in some cases life-long suffering. Contamination may occur during the entire farm-to-fork continuum with irrigation water as one of the major vehicles for contamination. Therefore, the potential of photocatalytic oxidation water treatment (POWT) to improve inferior irrigation water quality was studied. A prototype of a photocatalytic unit was installed on an irrigation ramp at a commercial field site growing leafy vegetables. Water samples were collected at five distinct sites within the water pipe namely from (i) the irrigation pond, (ii) after coarse filtration, (iii) at the beginning of the field water pipe as well as (iv) before and (v) after treatment using photocatalysis at three occasions with three independent replicates at each event. The water samples were analyzed with respect to indicator organisms for water quality (heterotrophic microorganisms at 22 degrees C, total coliform bacteria, thermotolerant coliform bacteria, E. coli, intestinal enterococci, Salmonella spp.). After the photocatalytic treatment, the number of indicator organisms in the irrigation water decreased with respect to all monitored organisms. This was also observed for Salmonella spp. which was detected at a couple of incidents at the sampling sites prior to the photocatalytic unit. Indicator organisms in the treated water at the irrigation ramp were beyond the thresholds stipulated by guidelines for irrigation water quality in examples such as British Columbia in Canada and Germany.
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| 7. |
- Alsanius, Beatrix, et al.
(författare)
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Degradation of Pesticides in Nutrient Solution from Closed Hydroponic Systems
- 2014
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1034, s. 33-39
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Konferensbidrag (refereegranskat)abstract
- To protect aquatic systems in the Baltic Sea area, zero eutrophication has been proclaimed as one of the Swedish environmental goals. Closed hydroponic systems are generally used today to meet standards on reduced release of excess nutrient-rich drainage water from horticulture. In recent years, concerns have been expressed about emissions of plant protection products (PPP) from indoor cultivation systems to aquatic environments in the vicinity of commercial greenhouses. Some of the active ingredient in pesticides applied to the crop can end up in the nutrient solution (i) after canopy application, through plant run-off and infiltration through the growing medium or into collecting gutters, or (ii) after direct administration to the nutrient solution. This study monitored the concentrations of three PPP (fenhexamid, FEX; pyrimethanil, PYR; imidacloprid, IMI) on six occasions over 21 days in colonised nutrient solution obtained from a closed cropping system for greenhouse tomatoes and incubated at 20°C in darkness. The experiment with FEX (added at 0.01 times the recommended spray concentration) was conducted as a full-scale experiment with six replicates and examined the dynamics of microbiota associated with the nutrient solu¬tion. Monitoring of PYR and IMI (added at 0.01 and 1 times the recommended spray concentration, respectively) comprised chemical analysis of the compound in single samples on six sampling occasions. The results indicate that all three PPP persisted for 21 days in the microbe-colonised nutrient solution under the experimental conditions used.
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| 8. |
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| 9. |
- Alsanius, Beatrix
(författare)
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GREENRESILIENT – Applying agroecology to organic greenhouse production
- 2020
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1296, s. 1099-1105
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Some organic greenhouse production systems are very intensive with potentially negative effects on the public trust on organic products as a whole. In this context, the year-round production of high quality and tasty vegetables in unheated and low-energy greenhouses or polytunnels, using resilient, sustainable and local systems, is a challenge, especially in areas with long winters and low light, low temperature conditions. The CORE Organic Cofund transnational project titled “Organic and biodynamic vegetable production in low-energy GREENhouses – sustainable, RESILIENT and innovative food production systems” (GREENRESILIENT) has taken up the challenge and aims to demonstrate that an agroecological approach to greenhouse production is feasible and allows the establishment of robust agroecosystems in different European areas. The use of agroecological practices in organic greenhouse production systems is an innovative approach and a team of scientists with multidisciplinary competences (agronomy, agroecology, soil chemistry, entomology, plant pathology, weed science, life cycle analysis) from 12 research centres in eight European countries are involved. Research activities are carried out in five experimental sites (two in Mediterranean countries and three in central and northern countries), comparing innovative systems in unheated or frost protected conditions to a standard organic system specific for each experimental site. Results obtained will be used for actors’ involvement (farmers, consumers and policy makers) and sustainability assessment.
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| 10. |
- Alsanius, Beatrix, et al.
(författare)
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Integrated greenhouse production in new light: prospects on improved LED-assisted biocontrol of foliar diseases
- 2020
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; , s. 293-296
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Horticultural greenhouse production in circumpolar regions (>60°N latitude) is dependent of artificial assimilation lighting, which is a common tool to improve plant performance and consequently profitability of ornamental crops and to secure production of greenhouse vegetables and berries all year round. The anticipated light technology shift in the greenhouse industry not only affects crop growth and development but also quality of the produce. It also influences the interactions with the associated microbiota, i.e., community structure and function as well as establishment, dispersal, survival and propagation of microbial pathogens and biocontrol agents. We present a novel ecological theory and principle based approach for integrated production of greenhouse crops, using improved LED-assisted biocontrol of foliar diseases.
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