Cultivation-wise, it was another challenging year for bell pepper growers. Kwekerij De Westhoek is also familiar with the problems that many growers faced. Grower Robert Spruijt looks for improvements in the water system. Adjustments and investments have been made. In mid-December, when the greenhouses are replanted for a new season, he goes back to last spring one more time.
The Maasland greenhouses have been planted again for a new season. The bell pepper grower also has a trial of organic substrate mats.
At that time, the experienced bell pepper grower noticed that in one of the four greenhouses at the Maasland nursery, the plants were not looking equally vigorous throughout. This was especially noticeable in the newest greenhouse. The plants were not standing strong enough. "I missed spontaneity in the crop," he says. It was decided to measure the oxygen level in the water. "After all, poorer water quality might well exacerbate the problem with the weak plants," Robert explained over a cup of coffee.
On one side of the greenhouse, a noticeably low oxygen level is measured in the water. Erwin Gräfe from Sendot comes along to have a look at this issue. The company's oxygen sensor measures only 55 percent oxygen in the irrigation water on one side of the greenhouse. Now this is at the end of the drip hoses, but these days they are made in such a way that clogged drippers no longer occur, Robert knows. "The dispensing of this new type of drippers is reliable."
Kwekerij De Westhoek's newest greenhouse is equipped with a watering system with larger tap sections. The diameter of the pipes is also larger. "In our other greenhouses with thinner pipes, we have more speed through the pipes. So in the newest greenhouse, the water is in the pipes longer and we have less speed of water through the pipes. I never had any concerns about that. Until now." The concerns were confirmed with the oxygen measurement.
More oxygen
The bell pepper grower also consults with fellow growers. They too are aware that the outside of tap boxes and the ends of drip hoses are vulnerable points. Much of the talk is about oxygen. "Maybe too little oxygen in the water gives the plants just that push that makes them go weak, or just not able to perform optimally," Robert now thinks. Erwin nods. "Water is like gold to the plant. Investing in good water quality works like an insurance policy."
In Maasland, they decide that something has to be done anyway. The investment in three Vital-Oxidizer from JVR Tecmar is one of the steps being taken. This summer, the devices, which draw oxygen from the air and introduce it into the water, were installed. "It's basically a small water purifier that rids the water of organic contaminants," explains John van Ruyven of JVR Tecmar. "The system gives the oxygen a special swirl that makes the oxygen better bound to the water."
John at one of the Vital Oxidizers, where air is drawn in at the top left of the little 'u', mixed with water at the bottom of the little u and then reintroduced into the silo.
Variety choice
The Maasland bell pepper grower also decides to increase the circulation of the water system. "With our drippers, which only open at a certain pressure, we can flush the entire system without any water release. We now know how long we have to circulate before there is fresh oxygenated water everywhere."
In mid-December, all the greenhouses at Kwekerij De Westhoek were planted again. Last growing season, Robert noticed that one variety clearly proved more susceptible to root problems than the other. "That's why we have variety trials from the different seed houses again this season. Like our colleagues, we are always looking for the ideal variety. Reliable quality is paramount for us. Varieties with a strong root system that may be more resistant to root diseases are also becoming a point of focus into the future. We need to grow a resilient crop, especially toward the future."
A special room was built for the sand filters next to the silos and the CHP room.
Data
Despite all the investments, including in sand filters, a new tarp in the silo at the newest greenhouse and installation of a silodome, on top of the silos, Robert is still waiting to see what crop year 2024 will be like. "Maybe we're all growing at the edge of what the plant can handle as well," he thinks aloud. "Then let's at least make sure the starting points are optimal." This starts with good starting water. "This is what we have bet on for next season. Let's hope this contributes to a healthy crop."
A challenge for growers often still appears to be the availability of data to make decisions. For example, Robert acknowledges never taking oxygen measurements until problems arose. "We did take plant and water samples and also regularly tested the water to see if our sanitizer was working properly, but have no data on oxygen levels in our water over the past few years."
After installation of the Vital Oxidizers, oxygen measurements were taken again. John: "After installation, we measured 100% oxygen in the water in the silos." With Sendot's measurements from this spring and after installation, data building on oxygen in water quality has now begun. Erwin: "It's never too late for data building."
For more information:
Robert Spruijt
Kwekerij De Westhoek
[email protected]
www.kwekerijdewesthoek.nl
John van Ruyven
JVR Tecmar
[email protected]
www.jvrtecmar.nl
Erwin Gräfe
Sendot
[email protected]
www.sendot.nl