Recent series of hot summers is motivating growers to use coatings for traditional cucumber crops
Young cucumber plants require protection against the sun’s bright radiation. This is why Kwekerij IJsselgrow has outfitted its greenhouse roof washer with spray booms so they can apply and remove coatings whenever this is desirable.
Cucumber grower Klaas Limburg emphasized several times : cucumbers like light. ‘The rule of thumb is: 1% light = 1% production. A mature crop can manage a great deal of solar radiation and convert it into production. This is why we never applied chalk in the past, because everything you apply to the greenhouse roof is at the expense of light. Young plants are an exception, however. They are always vulnerable when it gets too hot,” he says.
Kwekerij IJsselgrow in IJsselmuiden in the Netherlands has ten hectares of greenhouses and produces three crops per year. This means that there are also young plants in the greenhouse when it is very hot. “That is not an ideal situation; this can deform the young leaves and heads, cause burnt heads and the plants may be affected by Pythium. This is why we applied a coating for the first time last year, just before changing crops,” he says.
Klaas Limburg of Kwekerij Ijselgrow
Hot summers
They were so pleased with the results that they would like to continue using this system. “We have had a number of hot summers; one after the other. It would appear that something is changing. We would like to as much as possible respond to the current situation. This is why we outfitted the roof washer with three spraying booms. We are able to apply or remove a coating ourselves whenever we want to,” says the grower.
When the new greenhouse was being built they practiced applying and removing coatings. “As soon as the glass was installed on the roof, we applied ReduSol in order to improve working conditions. The result was that people preferred to stay in the greenhouse instead of going outside during their breaks. In other words, they considered inside conditions more pleasant.”
Better greenhouse climate control
The new greenhouse was built last year and is equipped with a continuous ridge venting system on the north side. This increases venting capacity by 100% in comparison to individual vents. “We chose this approach because we wanted to install an insect screen. When you do this for ordinary vent windows you lose too much capacity. With a continuous ridge venting system you lose approximately 20%, which still leaves you with an 80% increase in venting capacity,” says Limburg.
That enables you to effectively control the greenhouse climate on hot days.
ReduFuse IR
Many cucumber growers are reconsidering how to optimally control the greenhouse climate after the recent series of hot summers. ReduFuse IR is drawing noticeably more interest. This coating improves the diffusion of light inside the crop and reflects heat radiation.
Limburg is also giving this some thought. “For a traditional crop this is still less urgent than it is for a high-wire crop like cucumbers. However, ReduFuse IR causes only limited light loss and is effective in terms of heat control. We haven’t quite figured it all out yet, but because we are now able to apply our own coatings, we have maximum flexibility. We can experiment from time to time and respond to what is actually happening.”
