29 may 2018
RHP performs bio assays in order to check the plant safety of a substrate or substrate component. Such a growing test can also be used as a diagnostic tool, when problems occur in the culture. Watch the new RHP explanatory video.
A bio assay shows whether a substrate or substrate component is safe to use, which is especially important in professional horticulture. A bio assay is a growing test that involves growing the indicator crops lettuce, garden cress and kohlrabi. For a proper assessment of the growth results, a reference is made similar to the substrate to be tested in terms of physical aspects and nutrition. The germination and growth of the crops is analysed over the course of 2 to 3 weeks. This reflects the performance of the substrate.
A bio assay is also used as a diagnostic tool. Plants are used as an indicator, because it is impossible to determine all the risks with laboratory analyses. Several factors can influence the growth of a crop. If the bio assay points to a certain problem, further research can be done with a specific laboratory analysis.
If there is a certain risk known beforehand, then sometimes a different specific indicator crop is chosen for the bio assay instead of the standard indicator crops lettuce, garden cress and kohlrabi. Substrates such as expanded clay granules and pumice stone are too coarse to sow on. Then an extract with a nutrient solution is made of these substrates and tested in a specific test situation in which it is compared to a standard nutrient solution.
Take a look at the Knowledge base for more information concerning the bio assay.