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Sensitivity Test

What is a sensitivity test?

The sensitivity test is a bioassay to test the herbicide sensitivity of weed grasses before the use of herbicides. Thus, the success of a herbicide is ensured. Resistance can be identified at an early stage of evolution. Therefore, the sensitivity test is suitable for use as an early warning System. The test is applied to all conventional herbicide products for controlling grasses. It can be used for all herbicides in HRAC group A (FOPs / DIMs) , HRAC B (e.g. sulfonylureas etc.) and HRAC G (glyphosate).

When is the sensitivity test used?

The test is used to ensure the success of a planned herbicide Treatment. The weeds must be at least BBCH 14. The best time for use with winter crops is four weeks prior to application in late fall or four weeks prior to application in spring.

How long does the sensitivity test take?

A sensitivity Analysis takes 8-10 working days. The test is product-specific and requires preparation. Let us know which herbicides are to be tested about one week in advance. Upon receipt of your plant material, we start the investigations immediately.

What information does the sensitivity test provide and how do I benefit from this?

The test determines the sensitivity of a problematic grass population in your field to one or more products. On the one hand, you receive assistance in deciding what herbicides have the greatest efficacy and receive information as to whether the application rate of the herbicide can be reduced without risk. On the other hand, you find out if initial herbicide resistances are already occuring in your field. Thus, you can respond quickly and ensure a long-term plan for your herbicide strategy together with your advisor. Tailored herbicide management is worthwhile and helps you to use the limited number of products available for weed control sustainably. Long-term savings on herbicides and the avoidance of inefficient crossings due to resistance is the goal.

What type of sample material is required for the sensitivity test?

We need you to provide us with at least 100 live plants per test herbicide. The grasses are to be at least BBCH 14 and should be fully dig up with their root balls. Instructions on sampling and shipping plants as well as further Information are available below or you can contact us at (

Plant species that we can check using the sensitivity test:

  • blackgrass (Alopecurus myosuroides)
  • silky-bent grass (Apera spica-venti)
  • ryegrass (Lolium spp.)
  • brome grasses (Bromus spp.)
  • wild out (Avena fatua)

Please contact us for further information or queries.

The following videos provide instructions for sampling and shipment:


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