Interview with Dion Ten Have of Ten Have Brothers C.V.  The Ten Have family has been active in the glasshouse sector for many years. Their site is located in Honselersdijk, and the company was founded by Dion’s grandfather. His father and his father’s twin brother then took over the site. He has been running the site together with his two nephews for several years. Over the years, their glasshouse horticulture operation has expanded to some four hectares. Ten Have grows two different types of pot plants at the moment, campanulas in spring and cyclamen in the winter. Crops follow on from each other, with one crop being introduced while the other one is taken out.

What do you use Sensiplant for?
Our site used to be 2 hectares in size, and you could still establish the humidity content relatively quickly. We have expanded our site to 4 hectares this year. As the crop sections are now very long rows, it is no longer possible to do a quick round around the crop. To only check at the start of the row is no longer representative. If I had to go through the whole crop every time, you can imagine how much time this would consume every day!

At the moment, I go through the greenhouse in the mornings to have a look at the plants. I then put the Sensiplant sensors back in a good position. As the sensors move along with the moving crop sections, they have to be put back neatly into the centre of the greenhouse. If sensors are positioned correctly, I can rely on the signal from the sensors at noon. Of course, to be safe, I just check quickly at the beginning of a crop section whether the information on my screen agrees with the crop section itself.

Sensiplant is also a means of control. We have 24 rows. If I then forget one of the 24 rows, or if something happens, I can see that on my screen. Sensiplant therefore servers as an alarm. Sensiplant has the advantage that I save time, but also that I receive more insights, and that I can limit risks.

You have invested in the system, how do you think you will earn back the costs?
Firstly through time savings. I am pressed for time, and it is therefore handy that I now have more time available. But if you are under pressure, you also make more mistakes. Sensiplant prevents me from giving water to the wrong section, or from forgetting to give water to any section. If for instance one batch wilts, that causes enormous damage.

The risk of a lack of water is highest in the flowering season. There are some 4000 plants in one section. If these are dry for one day, this has negative results for quality. You don’t actually have to throw the plants away, but you can only then sell them as A2 quality. That cuts yields considerably!

A good example for this comes from the time shortly after we installed the Sensiplant system. We found out that a crop section didn’t have any water. I ordered for section 14C to receive water. That day, an electrician was working on site. He moved the section to 14B. Sensiplant showed us that these plants didn’t receive any water.

What are your experiences with the co-operation with and support from Hoogendoorn Growth Management?
The system was installed on our site for tests. The system didn’t run quite perfectly to start with. There were problems with the sensor signals, as there is a lot of metal in the greenhouse which caused interference. Placing the system in the correct spot took a lot of additional time and consideration. Hoogendoorn was extremely open for questions and suggestions.

Do you think growers can install Sensiplant themselves?
Installing Sensiplant is not very complex. The most important point is the positioning of the receivers. You are dealing with radio waves. If you put the system into an iron cage, this interferes with the signal. That was a learning curve for us – to know what factors you have to take into account. You don’t need a lot of technical expertise for this though.

At one time for instance, a row of carts was placed in front of the sensor, so that no signal came from the sensor any longer. We didn’t think of this beforehand. The same applies to the installation of the receivers. You have to try this a number of times to achieve the ideal position.

Do you have any requests for the system in future?
Obviously there are small improvements I would like to see. Hoogendoorn is constantly optimising the software, so these requests will be considered in an updated version.

At the moment, Sensiplant doesn’t have a link to an irrigation computer yet. I would have one request for the future, that you can irrigate based on sensor measurements. For instance, if the sun comes out and the measurements of several sensors falls below a certain value, the irrigation computer should automatically start up. This development however also depends on the irrigation computer supplier.

Currently, the use of Sensiplant is still extremely suitable to learn something, to find out how it works and to fully trust the sensors. Trust in the product is included in this. The values I see on my screen agree with my perceptions in the crop. Values are stable, but complete trust into automatic growing still has to grow. I will still take a walk around the greenhouse to have a look, just to be on the safe side.

Would you advise other growers to use Sensiplant?
Yes, but that does depend on their type of crop and the regularity of irrigation. For growers with plants who are very sensitive to irrigation, Sensiplant is an excellent tool. If you irrigate several times a day, and irrigation takes a lot of time, your investment in Sensiplant is quickly returned. For crops not needing that much water, Sensiplant of course remains a reliable means of control. Greenhouses keep increasing in size, with more and more crop sections, and you have to check them all as to how they are. With Sensiplant you save time and avoid risks!