After several winter of growing under LED , contend with moisture and energy remains a challenge for growers . During theEnergiekEvent , various workshops discussed this matter once again . The growers and advisers present got ( new ) insights , but not always the answers they might have on the QT trust for .
seem back at ( old ) research is nice , but we have to grow a good illume light-emitting diode crop again this winter . This was mentioned by a young Lycopersicon esculentum raiser when a shop was a morsel too much about the past for his taste sensation . He level out that LED was n’t useable back then . Should n’t we try on to understand the big picture before we get lost in details ? He posed this question during a shop on dehumidification . This enquiry reflect that agriculturalist want to promptly become better at expose direct cultivation with the assistance of research results .
A public lecture by Silke Hemming during the EnergiekEvent . Click here for a full photo impression ( in Dutch ) .
fix well screen choicesIn her workshop on screens in the greenhouse , Silke Hemming of the WUR focused on energy , and the use of ( new ) filmdom cloths , also when it comes to exposed crop . The WUR research worker did so using sixth sense from an ongoing Energlik project .
Silke demonstrate which blind holding are important , and she emphasise the grandness of the behaviour of screen cloths under slopped weather condition . After all , screen textile in greenhouses tend to be wet rather than dry , for example because of condensation . In their research , the researchers look at different screen properties , which they measure and quantify for light transmittance , heat radiation place , air permeableness and wet transport .
During the workshop , the WUR researcher insist on the possibility of increase the RH set compass point . By doing so , important energy savings can be achieved . If you go from 80 % RH to 90 % ( much higher is not necessarily rede because of outgrowth suppression for crops , and other factors ) , you’re able to salvage 35 - 40 % energy at night . With twenty-four hour period CRT screen that percentage is lower , but still significant at 15 - 30 % .
Many growers have bulge to replace screen cloths during the energy crisis or have had an extra cloth take out in . research worker are happy to get the onetime screens , Silke said . " But one meter is enough , " she express mirth when there was a bit too much ebullience from the audience .
In some cases , Silke showed , for Nox screens it ’s deserving trying to pull in two regular textile rather of one " very near " newer cloth . During the day , the difference are small , even between the various canvases studied .
pic rollsResearch has shown that growing at 90 % RH is ' a gentle wind ' , though with dynamic dehumidification , Silke shared about the first studies in the Energlik undertaking that remain until former 2026 . Then again , a ' disadvantage ' of growing with higher RH is that the active dehumidification organization does not have to go as often , Silke express mirth . " That ’s good for in operation costs , but perhaps less so from an investment point of view . "
A new exploitation in the screen field is a transparent lowly - E screen . Another point of tending is research into screen cloth that take into account growers to invalidate CO2 loss , while the filmdom material continue to make for a role in dehumidification .
The low - due east screen is a projection screen that ’s not yet commercial , and that the researchers are test with . This twelvemonth and next year , Silke does n’t ask the screen to be on the market . She herself mention to it as ' a transparent Gore - Tex fabric ' , without in reality being Gore - Tex . The fabric used comes from outside the industriousness , from motion-picture show roller . Disadvantage for now : the mechanical properties of the cloth are still a challenge for screen installations .
get across here to watch Silke Hemming ’s intact demonstration on CRT screen ( in Dutch ) .
Silvester de Nooijer ( Delphy ) , Stefan van den Boogaart ( Plant Lighting ) , and Jos Paul ( WUR ) during the shop on evaporation . fall into place here for a full photo impression of the day .
How much evaporation is needed , and how can you control evaporation?In the session on dehumidification , shop player could advert three presentation that discussed studies on evaporation . Stefan van den Boogaart of Plant Lighting asked two questions , to which both answers were ' no ' .
The first doubtfulness : Do we know how much a crop needs to vaporise to develop within safe limits ? And the 2d question : Do we know at what time of the day a harvest should vaporise ? He had preliminary conclusions from a chrysanthemum study . leafage quality in chrysanthemum seems to be more of a climate consequence than an evaporation issue . Further inquiry will look for the lower demarcation line for vapor while maintaining quality .
When it comes to tomatoes , the guess in Delphy research is that too humbled drying up in commercial crop make problems in recent wintertime . The researcher are specifically expect at watering and nutrition as solutions . A abide by - up visitation in 2024 - 2025 will also focus on air motion .
After the third demonstration in this workshop on cucumber inquiry in an indoor growing electric cell there was a vivid discussion . One of the idea : Let ’s stop setting lacrimation strictly based on joules to avoid too much direction on radiation vapor .
Click here to see the integral presentation of the evaporation workshop ( in Dutch ) .
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