The resistance tests in the greenhouse are progressing. At the moment we are still testing wind grass, rye grass, and brome grass in addition to redroot. The first results are almost ready, but still need to be processed. In the case of redroot and ryegrass, resistance is found both in the active substance group A (ACCase inhibitors) and in the active substance group B (ALS inhibitors). Two things stand out independently from the weeds: 1) Resistances can also be detected in areas where only a few weed plants are left in the field after herbicide application, and 2) Resistances are not always the cause of high residual weeds in the field.
General connections between the area of origin of a sample and the potential mechanisms of resistance do not appear at first glance, but links to crop rotation and the resulting use of herbicides can be found.
