Can chrysanthemums be grown in any other way than in the open ground? To answer this question, ErfGoed teamed up with Delphy, Van Iperen and Deliflor to conduct a study on the cultivation floor of the company from Moerkapelle. Director Hugo Paans and head of research Cock van Bommel report that the first trial was positive: ‘We harvested some good, heavy stems last week. We gave the bunches of flowers to our colleagues and residents of the local care home.’
Chrysanthemum growers have been looking for alternative growing methods for a long time. Experiments with cultivation on water have been in progress for several years, for example. In the trial initiated by ErfGoed, it was decided to use a layer of humus taken from the greenhouse of a chrysanthemum grower on the cultivation floor. Van Bommel: ‘Growers have invested heavily in their soil so not using it would be a missed opportunity.’ ErfGoed believes that the relatively thin layer of soil also makes it much easier to maintain the quality of the humus, for example by using bio-stimulants and other soil improvers.
Paans and Van Bommel believe that the ErfGoedFloor delivers a number of other important benefits. ‘First of all, you can use it to create a closed system and eliminate emissions to the subsurface. And obviously, as well as the environmental benefit, you also save on the cost of water and fertilisers that can be reused.’ Another important advantage is the fact that the shallow layer means much less disinfection is needed when changing crops. ‘The fact that disinfection is much more effective allows growers to make the most of biological crop protection.’
Paans and Van Bommel think it is still much too early to say whether growing chrysanthemums on a cultivation floor has the future. Paans: ‘A delegation from the national Chrysanthemum Committee visited the trial in mid-October. They were struck by the vitality of the plants. A number of policy officers from the branch organisation LTO Glaskracht also seem to think this emission-free cultivation method is promising. They also mentioned other cut flowers that can be harvested once, such as Lisianthus, as an option. Van Bommel: ‘I’m sure there are possibilities. That’s why we want more studies. A new trial will start with the Baltica variety in week 47, with 40 plants per square metre. In a change from the last trial, we will now be using intensive lighting. In addition, fertilisation will be monitored closer by taking samples more often. And as well as using humus from growers, we will also be organising a trial with a dedicated soil mixture.’
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