Crops in greenhouses receive water to grow. But growers often add other substances to that water, such as fertilizers, crop protection agents or cleaning agents (to keep the water system clean). Certainly the latter agents can damage the crop if the water concentrations are too high. But the question is: what is too high? The Greenhouse Horticulture Business Unit at Wageningen University & Research is developing a measurement method to unambiguously determine the damage limit (the critical concentration) of used substances.
Dutch horticulture is working on emission-free greenhouses, in other words: greenhouses that do not emit harmful substances (nitrogen, plant protection products) to, for example, surface water. It is important to know which added substances are absorbed by the crop or broken down by the water. Substances that continue to circulate in the drain water can accumulate to toxic values for the plant.
For an emission-free cultivation, it is therefore crucial to know what the critical concentrations are of commonly used substances. To this end, WUR first investigates a number of cleaning and disinfectants (such as hydrogen peroxide, ozone and chlorine bleach) and growth enhancers. It is then examined whether the so-called fytotoxkit is a useful method. Hereby seeds from different crops are germinated in a solution with a agent. This way it can be measured at which concentration damage occurs.
This project receives financial support from the Topsector Tuinbouw & Uitgangsmaterialen. Within the Topsector, business, knowledge institutions and the government work together on innovations in the field of sustainable production of healthy and safe food and the development of a healthy, green living environment. From the business community, Glastuinbouw Nederland (through collective financing from the Kennis In Je Kas Foundation) and Agrozone are participating in the project. Other participants are welcome.