Can a good chrysanthemum still be grown at a lower average temperature in the greenhouse? The Greenhouse Horticulture and Flower Bulbs Business Unit of Wageningen University & Research and Delphy Improvement Center are investigating this in the project Perfect Chrysant. Researchers are also looking at the effect of relative humidity and CO2 on energy needs. Researcher Marcel Raaphorst: "In recent years, less energy has been used in the cultivation of chrysanthemum. We are looking for what the next step is."
The project Perfect Chrysantemum (which started in 2017) investigates whether it is possible to achieve good, high-quality production with lower energy consumption. For example, the effect of dehumidification and the reuse of heat from condensation was examined. In addition, the effects of LED light (less energy consumption, but also less heat emissions from the lamps) and the use of far-red light (which can influence the flowering speed of a chrysanthemum) were investigated.
Raaphorst: "When we started, the average energy consumption in chrysanthemum cultivation was 28 natural gas equivalents per square meter per year. That has since fallen to 24 natural gas equivalents. This is partly due to the energy crisis, but also because growers themselves are actively looking to reduce their energy consumption. The knowledge from this project will help them with that."
Since 2017, research has been conducted in a 1,000 square meter greenhouse at the Delphy Improvement Center (which is located next to WUR in Bleiswijk). The greenhouse is divided into two departments of 500 m2 each. The effects on crop growth at a lower temperature, higher relative humidity and a lower CO2 dosage are now being examined. In addition, it is being tested whether cultivation without steaming is possible. If the soil can be made more resistant to soil fungi and nematodes, steaming would be less necessary and that would save a lot of energy.
Raaphorst: "In the 1980s I was a chrysanthemum grower myself. At that time I was very active in limiting my energy consumption. As a researcher, I now enjoy contributing to even more energy-efficient cultivation of chrysanthemums."
The project Perfect Chrysantemum is financed by the Kas als Energiebron program, ChrysantNL and a number of suppliers.
Source: wur.nl