Trials with Lisianthus on substrate finished

Published on
January 12, 2017

From 2014 to 2016, we performed thirteen trials with Lisianthus cultivation on substrate on an area of 1000 m2 of the Delphy Improvement Centre. The aim was to limit the emissions of CO2 (less soil steaming, more energy-efficient cultivation), nutrients (recirculation of drainage water with closed water loops) and pesticides (hygienic cultivation).

Initially it seemed possible to grow fungicide free, without failure caused by soil fungi. Thus it seemed as if the substrate could remain free of soil fungi with a short steam treatment. After six crops, growth failure by soil fungi (Fusarium oxysporum) still turned out to become a problem. At the thirteenth cultivation, the scrap percentage had increased to more than 15%, even after intensive spraying with fungicides. At the unsprayed boxes, the scrap percentage then was even up to 40%. The scrap percentage was almost identical for the different types of substrate and lighting intensities. Because we also haven’t found an improved production on substrate, the growers have become reluctant to foresee a successful future for Lisianthus on substrate.

Some crops showed more tipburn than in commercial farms. Tipburn has sometimes been ascribed to the abundant growth on coir substrate and sometimes to the 50% lower use of energy. However, we did not find a correlation between the use of heat or lighting on the one hand and the occurrence of tipburn on the other. Lighting did have a clear influence on production. In the winter period, 1% more PAR light gave even more than 1% more production. In the summer period this was only 0.5% more production. This is consistent with previously carried out photosynthesis research. At the recycling of drainage water the composition of nutrients remained stable. In the course of the cultivation, the EC increased, but the sodium concentration remained at an acceptable level. Thus the scrap problem remains the main hurdle, before Lisianthus on substrate can be grown successfully in practice.

This research is largely funded by the programs Greenhouse Horticulture Waterproof, Greenhouse as a Source of Energy and by the knowledge cooperation Lisianthus.