"Fixed-value cultivation is outdated"

"Our intention is to help the grower and make production more efficient. By knowing how the plant feels and how the plant reacts, you can control it more precisely," says Michèle Varrewaere of Belgian startup 2Grow. "Sensors provide early detection if there are any problems with the plant. You detect stress before visual symptoms are visible." By optimizing the cultivation, the company ultimately wants to contribute to an ambitious goal: reducing the earth’s area used for vegetable production to 1%.

For this project, they opted to measure the sap flow and the diameter of the plant stem. With this the root pressure can be determined, and thus the functioning of the plant. Olivier Begerem, also of 2Grow, explains: "In the morning, the perspiration, the evaporation, begins. At that time, the roots are not yet able to supply sufficient water to the plant, but the internal reserves of the stem are used. So the stem shrinks. At the end of the day, the evaporation drops and the plant can supplement its internal reserves, and the stem diameter increases again."

Thanks to the measurements and the immediately generated graphs with the measurement data, much more information about the plant can be found. "Whether it is vegetative or generative or how water management is doing," Michèle gives as example. "And a deviation in the rhythm can indicate stress. By looking at the climate settings and the sap flow / diameter measurements, we can review, analyze and correct each action separately. With this optimization we would be able to increase production, increase quality and improve taste."

"This way, we can adjust the settings according to the perspective of the plant itself," Olivier adds. "Every greenhouse has other cultivars, other settings and another grower, there are so many variables. The straightforward cultivation based on a fixed value is outdated. An extra insight into how the plant really feels about these settings seems indispensable to us and we want to focus on this, a means of communication with the plant."

Currently, the sensors are being hung in various greenhouses. For example, they are at tomato nurseries Stoffels and Den Berk and at the pepper greenhouses of Gemapa and VGT. "We let growers try out the sensors for 7 days, free of charge. Often, growers see the added value and want to keep the sensors," according to Michèle. What’s special about the arrangement with 2Grow is that a grower does not buy the sensors but secures a kind of user license for a fixed period. As a result, the costs are relatively low: from 2,040 euros for a one-year subscription with 1 set (170 euros per set per month) to 4,680 euros for one year working with 3 sets (130 euros per set per month). On average, a grower uses one set per greenhouse and per crop.

Notable also is that the information from the sensors is not exclusively for the growers, but is also interpreted by 2Grow. "That's to convert the data into readable language, but also because we are working on artificial intelligence. With artificial intelligence, we would make a network of all the data from across Belgium and the rest of the world, producing models to control an ideal plant. This way we could send advice to the grower, with a possibility for automation towards the future."

The sensors and the cultivation strategy were developed by two researchers from the University of Ghent. The startup 2Grow was established as distributor for the system. The company focuses on more techniques for modern cultivation. They are also working on the development of LED lights to replace traditional HPS lights. "But it's a challenge to develop affordable and efficient lighting," says Michèle.