Climate- and Refrigeration
Technology, our specialisation

HZPC: exploring the possibilities of LED lighting for potato growing

For HZPC, Nijssen converted two cold stores into phytotrons for research. The phytotrons are used for research into plant-pathogen interactions and for plant physiological research on potatoes.

“Hardly any structural research has been done into the effects of LED growth lighting on potato cultivation,” says Roberto Miglino, Plant Pathologist at HZPC Research in the Frisian village Metslawier. The refrigeration system offers the possibility of cooling, heating, drying and humidifying the air in the phytotrons. The wide range in temperature and humidity makes it possible to simulate a large number of climate conditions. The rooms are equipped with the Signify Dynamics growth lighting in which each color can be adjusted separately.

Nijssen realiseert fytotrons voor HZPC Nijssen fytotron voor research in aardappelteelt HZPC


Light spectrum calibrated on site

"We want to investigate the influence of the LED light spectrum on potato cultivation," explains Roberto Miglino. “Can we make plants grow or flower faster? Can we stimulate root formation or tuber formation? ”That requires extremely precise control of the lighting. For more certainty in the research results, Signify has again calibrated the lighting on site, at a specific height above the plants. This ensures that the light intensity offered to the plants is precisely known. Nijssen included this calibration in the control. This makes it possible to control the spectrum with great precision and to log with great accuracy.

Lighting integrated in control

The Automation department of Nijssen has linked the Signify control module to the Nijssen control, so that climate conditions, day-night rhythm and light intensity can be controlled on the same screen. The growth lighting is mounted on lifting frames that are adjustable in height. This way the lighting can be kept at a constant distance from the crop.

Nijssen Control System regelt fytotrons HZPCNijssen Control System met uitgebreide grafiekenmodule voor HZPC


Pathogenic research requires phytotron

Roberto Miglino himself is particularly concerned with plant-pathogen interactions. "The development of pathogen-resistant varieties is an important research direction for HZPC. Much of this research takes place in greenhouses, but that gives the best results in the March-September period. The rest of the year the temperature and amount of light is not sufficient for certain plant-pathogen tests. A more difficult problem that we encounter is that it is insufficiently possible to achieve really constant conditions in a greenhouse. This is crucial for research into pathogens, because they thrive in specific circumstances. For example, powder scab caused by the pathogen Spongospora subterranea f. sp. subterranea for example a temperature of 15-16 degrees. You really need a phytotron to get temperature, humidity and lighting precisely controlled to decimal places.”

Custom refrigeration system

The conditions in the rooms are realized by a tailor-made refrigeration system based on two Bitzer compressors and the entire installation is controlled via the Nijssen Control System. The advantage of a custom designed cooling installation is that all settings of control valves, condenser and compressors are visible in the control. All parameters such as various pressures and temperatures in the cooling circuit are also monitored in real time. This makes it easier to make diagnoses and to optimize the efficiency and operation of the cooling installation remotely.

Limousine among the phytotrons

"With this setup we have the limousine among the phytotrons," Roberto Miglino says. “You really need it in the research phase. And the fact that hardly any information is available about the potato cultivation under LED light means extra risk and uncertainty for us. That is why we now opt for maximum flexibility in growth conditions. We also work closely with Signify. Signify has defined one light recipe concept for potatoes. We use that as a starting point for our research. Once the optimum conditions are clear, for example, you could opt for more specific lighting for production purposes."

Nijssen realiseert fytotrons voor HPZC met ledverlichting in verstelbare hijsmodulesNijssen ontwerpt koelinstallatie op maat voor HZPC



Founded in 1898, and rooted in Dutch soil, HZPC has grown to become the international market leader in potato breeding, seed potato trade and product concept development. HZPC offers innovative potato varieties that are optimized for local growing conditions. The company shares knowledge and focuses on solutions that respond to the climatic, cultural and commercial challenges within the food industry. With over 400 employees in 15 different countries, and exports to more than 90 countries, HZPC contributes to the availability of responsible food and the well-being of millions of people worldwide.


Completion: Autumn 2019