Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Vervolgonderzoek emissiearme Lisianthus
Raaphorst, Marcel ; Eveleens, Barbara ; Burg, Rick van der; Schuddebeurs, Lisanne - \ 2017
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1440) - 30
kasgewassen - kassen - glastuinbouw - snijbloemen - emissiereductie - voedingsstoffen - gewasbescherming - kooldioxide - substraten - cultuur zonder grond - fusarium - bodemschimmels - kunstmatige verlichting - kunstlicht - greenhouse crops - greenhouses - greenhouse horticulture - cut flowers - emission reduction - nutrients - plant protection - carbon dioxide - substrates - soilless culture - soil fungi - artificial lighting - artificial light
Lisianthus growers look for methods to minimise the emission of nutrients, crop protection chemicals and CO2. In 2014 and 2015, nine crops with Lisianthus have been tested at the Delphy Improvement Centre. This report describes the four trials that have been carried out in the extended research in 2016. With this extension, a distinction was made between different substrates and intensities of assimilation lighting. In addition to knowledge about light use efficiency, water use, heat use, substrate differences and growth development, these extra crop cycles have brought to light that growing Lisianthus on substrate gives a less resilient plant against soil fungi than was experienced during the first crop cycles.
Energiebesparing door lokale verwarming : test op teelttafels bij Elstgeest Potplanten
Raaphorst, Marcel ; Noort, Filip van - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1439) - 18
kasgewassen - glastuinbouw - kassen - dieffenbachia - potplanten - sierplanten - verwarming - verwarmingssystemen - energiebesparing - greenhouse crops - greenhouse horticulture - greenhouses - pot plants - ornamental plants - heating - heating systems - energy saving
On a pot plant nursery three cultivation tables are heated directly with mat heating and one cultivation table is heated indirectly with tube heating. At these four tables the effect is measured on the air temperature below the table, the pot temperature, the energy use and the crop growth of Dieffenbachia. The conclusion is, that with mat heating a lower air temperature can be held under cultivation table to achieve a certain pot temperature. It is estimated that with this lower air temperature 10-30% of heat is saved because less heat disappears to the soil. For Dieffenbachia, the greenhouse air temperature above the pot is more determining for crop development than the pot temperature is. It is expected, that the energy-saving effect of mat heating is larger for plants with a low growth point, for which the pot temperature has more effect on growth.
Vochtgedrag schermsystemen : een zoektocht naar de oorzaak van toenemende problemen met druipend condensvocht in kassen met dubbele schermen
Weel, P.A. van; Vanthoor, B.H.E. - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1436) - 34
kastechniek - kasgewassen - kassen - afschermingsmateriaal - condenseren - greenhouse technology - greenhouse crops - greenhouses - screens - condensation
Het Nieuwe Telen (The New Growing) results in applying more screen layers that stay completely closed. In practise this causes problems with drip. In this research the impact of 2 screen layers and using screen gaps on the amount of drip from the screens or the greenhouse cover is investigated. Solutions to reduce the problems related to drip were proposed and tested in the greenhouse. During spring and winter 2016, measurements were performed at a tomato greenhouse with artificial lighting, blackout screen, energy screen and a Ventilationjet system. The daily amount of the condensation water that drips from the greenhouse ridge, gutter and the Ventilationjet was determined. In contrast to the general expectations, the drip does not come from the screens but from the greenhouse cover and from the Ventilationjets. Condensation occurred at the screens but this did not result in drip from these screens. Only 0.2% of the condensation against the greenhouse cover drips into the greenhouse. If this drip would be re evaporated, the energy costs for heating would increase with 0.0008 m3 gas /m2/week. Investments to reduce drip can thus only be paid back by a better crop quality and not by energy savings. The use of the inlet ventilator of the Ventilationjet system or the use of a screen gap increases the amount of condensation on a cold greenhouse cover. Drip from the greenhouse gutter was solved by applying a condensation gutter and the drip from the duct of the Ventilationjet was solved by applying a collecting tray with drain hose.
Systeemstap naar minimaal energieverbruik Alstroemeria : metingen op praktijkbedrijven en een energiezuinige teeltconcept
Garcia Victoria, N. ; Zwart, Feije de; Weel, Peter van; Steenhuizen, Johan ; Groot, Marco de - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1372) - 66
kasgewassen - glastuinbouw - kastechniek - kassen - alstroemeria - energiebehoeften - energiebesparing - verwarming - aanvullend licht - kunstlicht - simulatiemodellen - isolatie (insulation) - evaporatie - greenhouse crops - greenhouse horticulture - greenhouse technology - greenhouses - energy requirements - energy saving - heating - supplementary light - artificial light - simulation models - insulation - evaporation
Alstroemeria cultivation in The Netherlands requires energy for heating, supplementary light and root cooling. For the program “Greenhouse as Source of Energy” we calculated to which extent the energy demand for growing this crop can be reduced with existing energy saving innovations. Some innovations were tested in practice, others were calculated by means of the greenhouse climate simulation model Kaspro. Results showed that it is possible to save up to 34% energy for heating compared to the reference situation. 40% energy can be saved on electricity for supplementary light and root cooling. However, this strategy leads to a reduced amount of PAR-light in the winter, and 4% less flowers in comparison with the reference. The greatest impact can be achieved by increasing the insulation of the greenhouse by using double screens, reducing the evaporation from the soil, improving the crop hygiene to avoid extra evaporation from crop debris and reduce pest pressure, and implementing controlled dehumidification of the greenhouse air.
Ontwikkeling teeltstrategie voor weerbare planten tegen bovengrondse ziekten
Hofland-Zijlstra, J.D. ; Breeuwsma, S. ; Noordam, M. - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1442) - 58
kasgewassen - glastuinbouw - geïntegreerde plagenbestrijding - gewasbescherming - schimmels - schimmelziekten - botrytis - schimmelelicitoren - elicitoren - greenhouse crops - greenhouse horticulture - integrated pest management - plant protection - fungi - fungal diseases - fungal elicitors - elicitors
Within a project Sustainable control strategies Wageningen University & Research Greenhouse Horticulture literature screening to develop an integrated pest management strategy to control airborne fungi. This project was funded by the former Dutch Horticultural Production Board and accompanied by the Dutch growers association, LTO Glaskracht Nederland. In 2016 two greenhouse trials were performed with pot tomato, Petunia and pot gerbera. Additionally, a greenhouse test was performed at a commercial greenhouse with pot gerbera. Goal was to test the side effects of synthetic elicitors which stimulate systemic acquired resistance against biotrophic fungi on disease resistance against nectrotrophic fungi like Botrytis. A commercially available synthetic elicitor, Fado (Nufarm) was able to reduce the Botrytis infection in pot tomato and in flowers of pot gerbera. Effectivity was supported by a combined treatment with Jiffy mineral (soil addition) and Serenade. Two experimental products of BASF and Nufarm were effective in reducing Botrytis in pot gerbera. Botrytis infection was not only related to light and relative humidity, but was also correlated with nutrients and chlorophyll content. Based on this knowledge, prediction models for Botrytis can be improved.
Crop growth and development in closed and semi-closed greenhouses
Qian, Tian - \ 2017
University. Promotor(en): Leo Marcelis, co-promotor(en): Anja Dieleman; Anne Elings. - Wageningen : Wageningen University - ISBN 9789463430708 - 112
crops - crop production - growth - greenhouse crops - greenhouse horticulture - climate - semi-closed greenhouses - photosynthesis - temperature - gewassen - gewasproductie - groei - kasgewassen - glastuinbouw - klimaat - semi-gesloten kassen - fotosynthese - temperatuur

(Semi-)closed greenhouses have been developed over the last decades to conserve energy. In a closed greenhouse, window ventilation is fully replaced by mechanical cooling while solar heat is temporarily stored in an aquifer. A semi-closed greenhouse has a smaller cooling capacity than a closed greenhouse and, in which mechanical cooling is combined with window ventilation. (Semi-)closed greenhouses create new climate conditions: high CO2 concentrations irrespective of the outdoor climate, and vertical gradients in temperature and vapour pressure deficit throughout the canopy. This thesis focuses on the crop physiology in (semi-)closed greenhouses, and investigates the effects of the new climate conditions on crop growth, development and underlying processes.

Cumulative production in (semi) closed greenhouses increased by 6-14% compared to the open greenhouse, depending on the cooling capacity. The production increase in the (semi-)closed greenhouses was explained by the higher CO2 concentrations. In many species, feedback inhibition of photosynthesis occurs when plants are grown at high CO2. The results, however, suggest that high CO2 concentrations do not cause feedback inhibition in high producing crops, because the plants have sufficient sink organs (fruits) to utilise all assimilates. Pruning experiments showed that photosynthetic acclimation to elevated CO2 concentration only occurred when the number of fruits was considerably reduced.

Cooling below the canopy induced vertical temperature and vapour pressure deficit gradients. These gradients correlated with outside radiation and outside temperature. Despite the occurrence of vertical temperature gradients, plant growth and fruit yield were mostly unaffected. Leaf and truss initiation rates did not differ in the presence or absence of a vertical temperature gradients, since air temperatures at the top of the canopy were kept comparable. The only observed response of plants to the vertical temperature gradient was the reduced rate of fruit development in the lower part of the canopy. This resulted in a longer period between anthesis and fruit harvest and an increase in the average fruit weight in summer. However, total fruit production over the whole season was not affected.

The effects of the climate factors light, CO2 concentration, temperature, and humidity on leaf photosynthesis were investigated. The photosynthesis model of Farquhar, von Caemmerer and Berry (FvCB) was modified by adding a sub-model for Ribulose-1,5-bisphosphate carboxylase (Rubisco) activation. The photosynthetic parameters: the maximum carboxylation capacity (Vcmax) and the maximum electron transport rate (Jmax), α (the efficiency of light energy conversion), θ (the curvature of light response of electron transport), and Rd (the non-photorespiratory CO2 release) were estimated based on measurements under a wide range of environmental conditions in the semi-closed greenhouse. The simultaneous estimation method and the nonlinear mixed effects model were applied to ensure the accuracy of the parameter estimation. Observations and predictions matched well (R2=0.94).

The yield increase in a closed greenhouse, compared to that in an open greenhouse was analyzed based on physiological and developmental processes. The yield increase in the (semi-)closed greenhouses was the result of an increase of net leaf photosynthesis. The (semi-)closed greenhouses have been applied commercially first in the Netherlands, and later in other countries. The knowledge obtained from (semi-)closed greenhouses is applied in conventional open greenhouse as well, which is called the next generation greenhouse cultivation. A number of innovations are being developed for greenhouse industry to reduce energy consumption while improving production and quality.

Paprikateelt in de hooggeïsoleerde VenLow Energy kas
Zwart, H.F. de; Gelder, A. de; Hofland-Zijlstra, J. ; Noordam, M. - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1435) - 34
paprika's - capsicum annuum - kassen - kasgewassen - glasgroenten - glastuinbouw - energiebesparing - energiegebruik - isolatie (insulation) - broeikasgassen - kooldioxide - sweet peppers - greenhouses - greenhouse crops - greenhouse vegetables - greenhouse horticulture - energy saving - energy consumption - insulation - greenhouse gases - carbon dioxide
In order to realise a horticultural sector that operates without the combustion of fossil fuel, the first step is to reduce the demand for heating by improving the insultation of greenhouses. This holds especially for crops that are grown at high temperatures, like sweet pepper. The Venlow Energy greenhouse with its double glass cladding and energy screen is a good example of such a highly insulated greenhouse. This report presents the results of a one year cultivation and serves as a bench mark for the state of the art in energy conserving production of Sweet Pepper in the Netherlands. It shows the greenhouse climate conditions required, and the possibilities to meet these requirements with a low energy consumption and options to realise this from sustainable sources. The application of sustainable energy sources was not tested in practice, but since the exact resources (heat and CO2) required from hour to hour were measured, it is easy to do the math on the amounts and capacities needed. The application of pure CO2 or CO2 from another sustainable source is essential when aiming at a fossil energy free horticulture. Without external CO2 the production will drop substantially, especially because an energy conserving greenhouse has typically a strongly reduced air exchange. But, for the same reason, the amount of CO2 needed to increase the CO2 concentration is quite limited, 25 kg/m² per year in this experiment. With a production of 32.5 kg class I of red Sweet Pepper per m², the experiment has shown that halving the energy consumption compared to the general practice did’nt reduced the production.
Teelt Gerbera in Balans : de invloed van lichtsom, etmaaltemperatuur en daglengte op productie, energiegebruik en plantbalans
Garcia Victoria, Nieves ; Gelder, Arie de; Kempkes, Frank ; Dings, Eugenie - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1417) - 102
glastuinbouw - kasgewassen - kassen - gerbera - energiegebruik - kooldioxide - kunstlicht - gewaskwaliteit - productie - greenhouse horticulture - greenhouse crops - greenhouses - energy consumption - carbon dioxide - artificial light - crop quality - production
“Gerbera: Growing in Balance” was a research project to support the reduction of energy and CO2 consumption in the cultivation of Gerbera. The varieties Pre-Semmy, Rich, Whisper and Suri were grown in three glasshouses with different treatments: “Cool Cultivation” (15°C temperature; 90 μmol light, day length 13 hour in winter); “Practice” (temperature depending on day light integral, 100 μmol/m2s light, day length 11.5 hours) and “Light Dependent” (temperature depending sharply on day light integral, 90 μmol/m2s light, day length 13 hours in winter). The day light integral was kept equal in all treatments, regardless the difference in light intensity and day length in the winter. For flower quality and energy use “Cool Cultivation” was the best treatment, but required the most kg / m² of CO2. Whisper and Suri produced more flowers / m2 in the treatment “Light Dependent” but flower weights were low. Pre-Semmy and Rich gave more flowers in the treatment “Practice”, but spalkes were weak in May and June. The 13 hour day length in winter was not detrimental to production or quality. Light sum, day length and daily temperature are the three buttons to control the plant balance for optimum production and quality. The project was Funded by the Program “Greenhouse as Energy Source” (Ministry of Economic Affairs and LTO Glaskracht) and the Knowledge Cooperative Gerbera.
Overzichtsdocument: 7 jaar Chrysant op water
Vermeulen, Tycho ; Blok, Chris ; Eveleens, Barbara - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1430) - 22
greenhouse crops - greenhouse horticulture - greenhouses - chrysanthemum - hydroponics - water systems - microbial contamination - inoculation - kasgewassen - glastuinbouw - kassen - hydrocultuur - watersystemen - microbiële besmetting - inoculatie
Over a period of seven years (2009-2016) hydroponic chyrsanthemum cultivation has been developed and
tested in practice. Where the system delivered up to 25% higher yields at smaller scale, the larger systems of
250-300 m2 turned out very sensitive to root infection. Research then focussed to understanding the key factors
that caused the plants to become sensitive. However, where the larger system showed much disease incidence
every summer for three years in a row, at smaller scale the symptoms could not be induced despite application
of extreme cultivation measures.
The studies were the first to apply next generation sequencing to microbial populations in cultivation systems.
The results gave evidence for shifting population dynamics due to inoculation and water temperature. Also the
inoculation with beneficial microbes was found to have a positive effect on recovery of the roots upon infection.
This effect, however, was only found in the research-facility. At larger scale potential beneficial effect could not
prevent significant yield loss.
Nieuwe methoden in plantversterking tegen ondergrondse ziekten en plagen : gebruik van lokaal aanwezige antagonisten uit groeisubstraat en plant
Wurff, Andre van der; Streminska, M.A. ; Boer, F.A. de; Bruyant, Ewen ; Cuesta Arenas, Y. - \ 2016
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1427) - 42
kasgewassen - kassen - glastuinbouw - gewasbescherming - plantenziekteverwekkers - antagonisten - bacteriën - verdediging - verdedigingsmechanismen - endofyten - pythium ultimum - meloidogyne - rhizobium rhizogenes - fusarium oxysporum - fusarium - micro-organismen - proteïnaseremmers - bèta-glucanase - chitinase - greenhouse crops - greenhouses - greenhouse horticulture - plant protection - plant pathogens - antagonists - bacteria - defence - defence mechanisms - endophytes - microorganisms - proteinase inhibitors - beta-glucanase
Within this project, two new methods of the control of pathogens were investigated. New methods are: a. use of local bacteria that are isolated from soils or growing substrates; and b. bacteria that are present within the plant. By using local antagonists, already present in growing substrates or within plants in the greenhouse, the chance is higher that antagonist can be successfully used against local pathogens. Bacteria that were isolated from soil of growers were assessed on their antagonistic potential in lab trials against Pythium ultimum, Meloidogyne spp. and Rhizobium rhizogenes and Fusarium solani and F. oxysporum. Finally, the effect of antagonists against Pythium and Meloidogyne was evaluated in pot trials in the greenhouse. All antagonists diminished brown colourization symptoms in stems caused by Pythium. Alcaligenues sp., Bacillus sp. en two unidentified species diminished root damage and Alcaligenues sp. as well as Bacillus also reduced also the number of offspring of Meloidogyne spp. within the roots. The use of local microorganisms offers a sustainable-, new solution to control pathogens. In this study, it was shown that Proteinase inhibitor 2 (PINII), Glucanase (LeGluB) and Chitinase (LeChi3) can be used in tomato to investigate the influence of antagonists or endophytes on the plant defence.
Praktijkimplementatie zuiveringstechnieken
Ruijven, J. van; Os, E. van; Beerling, E. ; Staaij, M. van der - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1419) - 42
kasgewassen - kassen - glastuinbouw - afvoer - zuiveren - gewasbescherming - ozon - greenhouse crops - greenhouses - greenhouse horticulture - discharge - purification - plant protection - ozone
To apply to the Dutch generic obligation to purify discharge water, each horticultural company needs to treat it’s discharge water with a technology that removes 95% of plant protection products. This report shows the process that growers need to go through to make a good choice for a purification technology: mapping of water flows, decrease the amount of discharge water, determine the strategy to apply to the generic obligation and make a choice for a purification technology. For a cucumber production company and a company that combines vegetable plant propagation and growth of potted plants this process is followed. A design for a purification system is developed and built for a semi-practice scale cucumber and sweet pepper production system. In the semi-practice scale and the cucumber production company, an ozone installation (Agrozone) is chosen, either to disinfect drain water and eventually purify discharge water. At the propagation company, an Opticlear Diamond (WaterIQ) is chosen to disinfect the drain water and eventually purify discharge water. For both installations the purification efficacy is measured. In the second part of the project the practical format for the generic obligation for discharge water purification is elaborated.
Geïntegreerde bestrijding van plagen in de sierteelt onder glas : een systeembenadering met preventieve biologische bestrijding als basis
Messelink, G.J. ; Leman, A. ; Ghasemzadeh Dizaji, Somaiyeh ; Bloemhard, C.M.J. ; Holstein, R. van; Vijverberg, Roland ; Muñoz-Cárdenos, Karen - \ 2016
Bleiswijk : WageningenUR Glastuinbouw (Rapport GTB 1420) - 98 p.
siergewassen - glastuinbouw - kasgewassen - rozen - chrysanten - alstroemeria - biologische bestrijding - organismen ingezet bij biologische bestrijding - geïntegreerde bestrijding - geïntegreerde plagenbestrijding - thrips - neoseiulus cucumeris - trialeurodes vaporariorum - aleyrodes - bemisia tabaci - amblyseius swirskii - euseius - iphiseius - roofmijten - orius - cryptolaemus montrouzieri - anagyrus pseudococci - planococcus citri - ornamental crops - greenhouse horticulture - greenhouse crops - roses - chrysanthemums - biological control - biological control agents - integrated control - integrated pest management - predatory mites
The control of greenhouse pests in ornamental crops is getting more difficult because of the decreasing number of available pesticides. Alternative methods of pest control, based on biopesticides and natural enemies is promising, but not yet robust and reliable enough. In this project we developed and evaluated several methods to enhance the biological control of western flower thrips, Echinothrips americanus, whiteflies and mealybugs. Most studies were focused on preventive control measures that promote the establishment and efficacy of natural enemies by using top layers, alternative food, artificial domatia and a banker plant system. Furthermore we studied the interaction between parasitoids and predatory beetles for curative control of mealybugs. Finally, a number of (bio)pesticides was evaluated for their potential use as a correction tool against western flower thrips.
Onderzoek Waterkringloopsluiting Tulpenbroeierij : overzicht huidige en toekomstige technieken om waterkringloopsluiting mogelijk te maken
Os, E.A. van; Feenstra, L. ; Ruijven, J. van; Stijger, C.C.M.M. ; Koeman-Stein, N. ; Appelman, W. - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1394) - 38
tulpen - forceren van planten - glastuinbouw - kasgewassen - afvalwaterbehandeling - afvalwater - recirculatiesystemen - drainagewater - pathogenen - pathogeen eliminatie - gewasbescherming - voedingsstoffen - fenolen - tulips - forcing - greenhouse horticulture - greenhouse crops - waste water treatment - waste water - recirculating systems - drainage water - pathogens - pathogen elimination - plant protection - nutrients - phenols
Closing of the water cycle is required in the forcing of tulips. For growers it is important to know if and how they can eliminate pathogens at an adequate way and which equipment is most suitable to break down plant protection products from waste water. Now participating growers have various equipment for full or partly disinfection. It is recommended to start with good pre-filtration methods to eliminate pathogens which can be fully achieved with UV and ozone, while products such as hydrogen peroxide with additives or chlorite products can be used for an after-effect in the pipe work. Phenolic compounds, released by the roots, can be eliminated with oxidising methods. However efficacy has not been investigated. Purification of discharge water, before entering the waste ditch, will be obliged. New, certified, equipment will come on the market soon. Reuse of discharge water, after pre-fi ltration and disinfection, is also an option.
Alternatieven voor neonicotinoïden in de sierteelt onder glas : bestrijding van tabakswittevlieg en bladluis in kuipplanten en perkgoed
Messelink, Gerben ; Vijverberg, Roland ; Bloemhard, Chantal ; Leman, Ada - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1418) - 42
tuinplanten - containerplanten - insectenplagen - bemisia tabaci - aphididae - kasgewassen - glastuinbouw - biologische bestrijding - insecticiden - lecanicillium muscarium - entomopathogene schimmels - roofinsecten - bedding plants - container grown plants - insect pests - greenhouse crops - greenhouse horticulture - biological control - insecticides - entomogenous fungi - predatory insects
The control of phloem feeding insects such as aphids, whiteflies, cicadas, mealybugs, scales and plant feeding bugs in greenhouse crops still largely depends on the use of neonicotinoids. However, the increased found negative effects on the environment will soon results in a total ban on the use of these pesticides. In this project we summarized the possible alternative control measures with pesticides and biological control agents. Furthermore, a number of preventive and curative control measures was evaluated for the control of aphids in bedding plants and the tobacco whitefly in container plants, with Calibrachoa and Mandevilla as model plants. An endophytic application of an isolate of the entomopathogenic fungus Lecanicillium gave a clear trend of 25% reduced population growth of aphids on Calibrachoa. Curative control of aphids with lacewings was not effective. Mullein plants enhanced tobacco whitefly control by the predatory bug Macrolophus pygmaeus in Mandevilla and increased predator survival and reproduction. Among the tested alternative control measures, we found 5 products that controlled tobacco whiteflies effectively in Mandevilla.
Het Nieuwe Gewas : sturen van de plantvorm voor verhoogde lichtbenutting
Gelder, Arie de; Janse, Jan ; Warmenhoven, Mary - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1407) - 62
tomaten - solanum lycopersicum - kasgewassen - glasgroenten - glastuinbouw - energiebesparing - plantenontwikkeling - gewasteelt - licht - tomatoes - greenhouse crops - greenhouse vegetables - greenhouse horticulture - energy saving - plant development - crop management - light
Wageningen UR Greenhouse horticulture searched in the “The New Crop” project for the crop structure that best contributes to the goal of energy-efficient production and therefore energy saving, by removing 33, 44 or 55% of the leaves at a young stage. On October 10th 2014 the experiment started with topped plants of the tomato variety Brioso grafted on Maxifort. Dry matter production was lowest in the very open crop, however partitioning to the fruits was highest in that treatment. Therefore, this crop produced in the winter under assimilation lighting most. In summer, the standard treatment was the best and the production in this treatment was highest. The plants in the very open treatment were shorter and had smaller leaves than the plants of the standard treatment. This is might be due to a different red: far red ratio of light in the crop. Leaf picking at a young stage contributes to better distribution of assimilates to the fruits. This can be used as a crop management measure as the plant in winter develops too much leaves. The project was funded by the Dutch energy transition program “Kas als Energiebron”.
Energiebesparing met LED belichting in gerbera : resultaten van 1ste jaar LED onderzoek
García, Nieves ; Weerheim, Kees ; Helm, Frank van der; Kempkes, Frank ; Visser, Pieter de; Groot, Marco - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Report GTB 1389) - 66
gerbera - glastuinbouw - kasgewassen - kassen - kastechniek - teelt onder bescherming - energiebesparing - led lampen - kunstlicht - kunstmatige verlichting - licht - verlichting - greenhouse horticulture - greenhouse crops - greenhouses - greenhouse technology - protected cultivation - energy saving - led lamps - artificial light - artificial lighting - light - lighting
In the winter 2013-2014 Wageningen UR Greenhouse Horticulture conducted studies on energy saving opportunities in the cultivation of gerbera, CV Kimsey. The research was funded by the program Greenhouse as Energy Source from the Ministry of Economic Affairs and LTO Glaskracht. The contribution of LED lighting, LED interlighting, a lower intensity of the light installation, and light integration was investigated. An electricity savings of 45% was the target. By using LED lighting a 20% electricity savings are possible in exchange for a small production loss (2.3%) and some additional heat demand (9%). By installing 80 instead of 100 μmol light gerbera growers can save another 20% energy costing only 3.9% production without sacrificing quality. The targeted PAR sum for light integration was too high to contribute to electricity savings. The use of 20 μmol LED interlighting in combination with 60 μmol top light (LED or SON-T) resulted in significantly less production (9%) and lower flower quality: shorter and lighter, smaller diameter and a lower % of dry matter) than 80 μmol top light.
Snijbloemen telen bij hoge RV met behoud van kwaliteit : literatuuronderzoek in opdracht van Kas als Energiebron
Garcia Victoria, Nieves ; Slootweg, Casper ; Marissen, Nollie - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1410) - 58
snijbloemen - glastuinbouw - kasgewassen - kassen - relatieve vochtigheid - evaporatie - vaasleven - huidmondjes - literatuuroverzichten - cut flowers - greenhouse horticulture - greenhouse crops - greenhouses - relative humidity - evaporation - vase life - stomata - literature reviews
Om CO2 voor de fotosynthese naar het blad te leiden, hebben planten huidmondjes. Via de open huidmondjes verdampt water. De plant reguleert de opening en sluiting van huidmondjes, en dus haar waterhuishouding, aan de hand van prikkels uit de omgeving (water, CO2, licht). Snijbloemen verliezen na de oogst water door verdamping wat weer aangevuld moet worden via de steel met het vaaswater. Bij goed functionerende huidmondjes is die verdamping beperkt, maar de huidmondjes van snijbloemen die geteeld zijn bij aanhoudend hoge RV zijn anatomisch en fysiologisch anders: ze zijn ongevoelig voor sluitingsprikkels, waardoor ze in de vaas sterk door blijven verdampen. Dit leidt tot een korter vaasleven omdat de wateropname door de afgesneden steel beperkend wordt. Het ontbreken van een donkerperiode tijdens de teelt leidt ook tot niet-functionele huidmondjes. Als er gedurende de ontwikkeling regelmatig een sluitings-prikkel wordt gegeven, blijven huidmondjes functioneel. Dit zou gerealiseerd kunnen worden door het hanteren van een donker-periode in combinatie met een voldoende lage RV, periodieke verlagingen van de RV tijdens de teelt, de teelttemperatuur ’s nachts verhogen (waarmee de RV daalt), of een sterke luchtbeweging (kortstondig ingezet). Groen (LED) licht aan het begin van de nachtperiode en het gebruik van schermen tegen uitstraling kunnen wellicht ook de huidmondjes functionaliteit positief beïnvloeden, maar daar is nog onvoldoende over bekend. Het Nieuwe Telen is er sterk op gericht om de huidmondjes open te houden voor maximale fotosynthese en productie door, onder andere, het handhaven van een hoge RV. Bij producten die geen last hebben van waterverlies na de oogst, zoals vruchtgroenten leidt het tot zeer goede productie en kwaliteit met weinig inzet van energie. Het Nieuwe Telen is sterk in ontwikkeling. Bij het vertalen van Het Nieuwe Telen naar bladhoudende snijbloemen dient er ruimte te worden gemaakt voor een regelmatig terugkomende trigger om de huidmondjes te laten sluiten wil het succesvol toegepast kunnen worden.
Vergelijking tussen gangbaar en emissieloos teeltsysteem : waterefficiënte Emissieloze Kas
Os, Erik van; Ruijven, Jim van; Janse, Jan ; Beerling, Ellen ; Staaij, Marieke van der; Kaarsemaker, Ruud - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1406) - 62
paprika's - capsicum annuum - teelt onder bescherming - kasgewassen - glasgroenten - glastuinbouw - emissiereductie - emissie - stikstof - fosfaat - voedingsstoffen - pesticiden - sweet peppers - protected cultivation - greenhouse crops - greenhouse vegetables - greenhouse horticulture - emission reduction - emission - nitrogen - phosphate - nutrients - pesticides
Stricter legislation forces growers to decrease discharge of water with nitrogen, phosphate and plant protection products. A demonstration was set-up to compare emission free cultivation with a traditional growing method. Goal was to achieve a comparable yield and quality. Essential differences were disinfection of rainwater, ring pipes for drip irrigation, no discharge of first drain in cultivation, a filter without rinsing and weekly analysis of the nutrient solution. It appeared that production and quality were similar as were other climate parameters. Water use was higher in emission free crop, discharge was 4% in traditional crop realizing 152 kg N discharge per ha per year, which was more than the allowed 133 kg. Specific end cultivation strategy is useful to decrease nitrogen and phosphate stored in slabs and stock containers.
Consultancy genereren basiskennis fotosynthese aardbei
Kaiser, E. ; Janse, J. - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1411) - 22
aardbeien - fragaria ananassa - teelt onder bescherming - kasgewassen - glastuinbouw - fotosynthese - energiebesparing - licht - kooldioxide - strawberries - protected cultivation - greenhouse crops - greenhouse horticulture - photosynthesis - energy saving - light - carbon dioxide
To save electricity and CO2 during strawberry production, more knowledge about the photosynthesis of greenhouse-grown strawberry plants is necessary. This was tackled by measuring light- and CO2-dependent photosynthesis responses and by conducting a literature study in which several parameters of leaf-level photosynthesis were compared. From measurements conducted between middle of March and middle of May 2016 it was concluded that the rate of photosynthesis and electron transport was comparable between young and old leaves, while stomatal conductance in young leaves was always higher. Light- and CO2- saturated photosynthesis rates were higher in older leaves. Furthermore, a decrease of photosynthesis rates was visible in April, which may have been caused by acclimation of leaf biochemistry to elevated CO2 concentrations in the greenhouse. Conclusions from the literature study were that light saturation was reached at ~1000 μmol m-2 s-1 and that CO2 saturation was reached at ~1100 μmol mol-1. Average photosynthesis rates at these conditions were 18 and 35 μmol m-2 s-1, respectively. The average quantum yield of photosynthesis was ~0.06 μmol CO2 μmol-1 PAR, which is comparable to other, fast growing greenhouse crops (e.g. cucumber, tomato, sweet pepper). Large knowledge gaps about the course of photosynthesis during complete growing seasons remain.
Duurzaamheid als leidraad voor roos : vervolg onderzoek Perfecte Roos: energiezuinig geteeld
Gelder, Arie de; Warmenhoven, Mary ; Knaap, Edwin van der; Burg, Rick van der - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1412) - 50
rozen - teelt onder bescherming - kasgewassen - glastuinbouw - duurzame landbouw - energiebesparing - elektriciteit - assimilatie - kunstlicht - kunstmatige verlichting - verlichting - koelen - meeldauw - geïntegreerde bestrijding - geïntegreerde plagenbestrijding - roses - protected cultivation - greenhouse crops - greenhouse horticulture - sustainable agriculture - energy saving - electricity - assimilation - artificial light - artificial lighting - lighting - cooling - mildews - integrated control - integrated pest management
The project Sustainable rose cultivation aimed to achieve a sustainable and energy efficient rose cultivation by a controlled use of assimilation lighting, an optimum use of the cooling and an integrated control strategy for mildew. The production came to 320 stems.m-2 average weight 54 grams. The branch length and bud size varied through the season. There was no saving on electricity. There was a significant saving on heat. The improvement of the energy efficiency was totally determined by the reduction of the heat consumption. The light utilization efficiency was 2:44 g.mol-¹ and increased compared to the previous year. Cooling and forced ventilation had a positive effect on the stem elongation in the autumn. The installation with forced ventilation from above combined with the screen had a favourable effect on the climate, especially in the humidity control under a largely (95-98%) closed screen. The payback period of the investment in airconditioning is within 3 years.
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