Records 1 - 20 / 922
Mobiele waterzuivering glastuinbouw
Ruijven, Jim van; Os, Erik van; Vermeulen, Peter - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1424) - 54
kassen - glastuinbouw - afvalwaterbehandeling - afvalwater - waterverontreiniging - afvoer - zuiveren - waterzuivering - oppervlaktewater - oppervlaktewaterkwaliteit - gewasbescherming - pesticiden - substraten - cultuur zonder grond - mobiele uitrusting - greenhouses - greenhouse horticulture - waste water treatment - waste water - water pollution - discharge - purification - water treatment - surface water - surface water quality - plant protection - pesticides - substrates - soilless culture - mobile equipment
Application of a mobile unit for discharge water purification is one of four options to apply to the purification obligation per 1-1-2018. Depending on the amount of discharge, future water strategy and investment options, mobile purification can be an interesting option. The amount of discharge water varies with crop, irrigation strategy and quality of the irrigation water and is between 122 and 3.340 m3/ha/year for surveyed companies. About 65% of greenhouse companies discharges
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 - fusarium - 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 - dieffenbachia - 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 - alstroemeria - 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.
Meetprotocol voor lichttransmissie van materialen met condens
Swinkels, Gert-Jan ; Breugel, Bram van; Tsafaras, Ilias - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1438) - 42
kassen - meettechnieken - lichtdoorlating - glas - diffuus glas - condenseren - greenhouses - measurement techniques - light transmission - glass - diffused glass - condensation
Measuring the light transmittance of greenhouse covering materials has become a standard procedure for the
horticultural industry. This measurement is based on dry materials. However, transmittance changes (strongly)
when water condenses on the inside of the material. For example, transmittance of traditional clear non-diffusing
greenhouse glass usually decreases because the condensed droplets tend to reflect the light instead of transmit
it, while some varieties of diffuse glass could increase light transmittance. Because a greenhouse is wet on the
inside during a large period of the year it is important to be able to measure transmission with a standardized
protocol. In this research a measurement protocol and associated equipment are developed for determining the
effect of condensation on the hemispherical light transmission in a standardized way.
The protocol is based on natural condensation on a material under a slope according to common greenhouse roof
slopes, which is forced by a combination of temperature and humidity. In this way the natural process of draining
of condensate is taken into account. The results show that the transmission of traditional clear uncoated (new)
horticultural glass drops with about 3%-points while the effects on the behaviour of the tested types of diffuse
glass vary between -1%- point up to + 1.5%-point.
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 - capsicum annuum - 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 - gerbera - 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 - chrysanthemum - 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 - pythium ultimum - meloidogyne - rhizobium rhizogenes - fusarium oxysporum - fusarium - microorganisms - proteinase inhibitors - beta-glucanase - chitinase
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.
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.
Potential for greenhouses to make sustainable leap in the tropics : businesses learn from low-tech greenhouses in Rwanda
Elings, Anne - \ 2016
greenhouse horticulture - projects - agricultural education - rwanda - greenhouses - development projects
Winter light greenhouses at research centre ready for cucumber trial : will new greenhouse lead to 10% more light?
Kempkes, Frank - \ 2016
greenhouses - greenhouse technology - artificial lighting - experimental stations - light transmission - innovations
Simply hanging the fans will not deliver best results : checks and maintenance increase effectiveness
Weel, Peter van - \ 2016
greenhouse horticulture - greenhouses - greenhouse technology - air conditioning - fans - usage
Vochtbeheersing in kassen en terugwinning van latente energie : Een verkenning naar vochtbeheersing in kassen en de mogelijkheden van het terugwinnen van de energie die opgesloten zit in de gewasverdamping
Weel, P.A. van; Zwart, H.F. de; Voogt, J.O. - \ 2016
Wageningen UR Gastuinbouw (Rapport GTB 1421) - 76
kassen - kastechniek - tomaten - glastuinbouw - ontvochtiging - energiegebruik - energiebesparing - ventilatie - greenhouses - greenhouse technology - tomatoes - greenhouse horticulture - dehumidification - energy consumption - energy saving - ventilation
Dehumidification of a greenhouse by ventilation increases the energy input with 8-10 m3/m2.year of natural gas to compensate the heat losses. This study shows different methods to reduce those energy losses. A 25% reduction in ventilation is obtained by using heat exchangers connected to plastic distribution ducts or by using the Ventilationjet system. The sensible heat from the exhaust air can be used to heat the incoming outside air to greenhouse temperature. Heat exchangers with 100% efficiency to do that are available. The latent heat included in the water vapour leaving the greenhouse can be recovered by means of a condensating wall. A good working priciple is the Dewpoint Heat Exchanger in which outside air is wettened to reach the lowest possible temperature and then used to cool down the greenhouse air far below the temperature where condensation begins. The recovered latent heat must be stored in a water tank to use it in the heating pipes. Another approach is to skip ventilation and use a set of a cold and warm heat exchanger connected to a heat pump or to use a salt water absorber. The absorber opens the possibility to use solar or wind energy to dehumidify the greenhouse and collect 100% of the sensible and latent heat.
Less at the top, more gain at the bottom : better light penetration leads to higher production
Heuvelink, E. ; Kierkels, T. - \ 2016
In Greenhouses : the international magazine for greenhouse growers 5 (2016)4. - ISSN 2215-0633 - p. 18 - 19.
greenhouse horticulture - greenhouses - light penetration - crop production - farm management - diffused glass - glastuinbouw - kassen - lichtpenetratie - gewasproductie - agrarische bedrijfsvoering - diffuus glas
If light penetrates the crop better, it results in higher production. This is because the leaves that are deeper in the crop are a long way from their light saturation point. Diffuse glass or coatings and the distribution of the crop are the most applicable ways to achieve better light penetration. Other methods are usually beyond the reach of the grower
Prima opbrengst winterlichtgewas komkommer in innovatieve kas : zowel energiebesparing als productieverhoging haalbaar
Janse, Jan - \ 2016
greenhouses - greenhouse horticulture - cucumis - innovations - winter - light - light transmission - cultivation - energy consumption
Winterlichtkas in Bleiswijk is klaar voor komkommerproef : gaat nieuwe kas meer dan 10% lichtwinst opleveren?
Kempkes, Frank - \ 2016
greenhouse horticulture - greenhouses - greenhouse technology - greenhouse experiments - experimental design - light transmission - building construction
Grote productiestijging door verrood licht bij onderzoek tomaat
Dieleman, Anja - \ 2016
crop production - tomatoes - illumination - greenhouses - greenhouse horticulture - far red light - experimental plots - agricultural research
Evaluatie zuiveringstechniek voor verwijdering gewasbeschermingsmiddelen III
Ruijven, J.P.M. van; Beerling, E.A.M. ; Staaij, M. van der; Os, E.A. van - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1414) - 30
afvalwaterbehandeling - waterzuivering - afvalwater - waterverontreiniging - glastuinbouw - kassen - cultuur zonder grond - gewasbescherming - pesticiden - ozon - verwijdering - filtratie - technieken - waste water treatment - water treatment - waste water - water pollution - greenhouse horticulture - greenhouses - soilless culture - plant protection - pesticides - ozone - removal - filtration - techniques
Dutch greenhouse horticulture has to treat all discharged water from soilless cultivations for the removal of plant protection products, to meet the new Dutch Directive Hoofdlijnenakkoord (2015). Building on previous research, (1) the life span of activated carbon filters, (2) the effect of increasing concentrations of plant protection products on the removal efficacy of ozone and the removal efficacy of (3) multimedia filtration and (4) ultrasonic water treatment have been investigated. It turned out to be difficult to design an active carbon based water treatment system capable of durable treatment of greenhouse discharge water: organic and mineral material in the water blocked the pores, thereby clogging the filter system and causing leakage by pressure build-up. Activated carbon filtration (granular activated carbon, 48 min contact time, 50 μm prefiltration with sand filter) achieved a removal efficacy of >95% for up to 430 bed volumes treated. Combination with advanced oxidation improved the removal efficacy, but the removal time of the filter could not be determined due to leakage. The removal efficacy of ozone oxidation remained >98%, even at increased concentrations (factor 10 and 100) of plant protection products in the untreated water. The multimedia filter removed 75% of the plant protection products by adsorption, biological breakdown within the filter was not determined. Treatment of the water with ultrasonic waves hardly had any effect (maximum 30% efficacy) on the breakdown.