Current weed control in sugar beet is characterized by three to four post-emergence herbicide applications. The optimal date for the application is mostly defined by the development of the weed species in the field, which can only be controlled in the cotyledon stage by the approved herbicides. If weeds are larger, application rates must be increased. Higher application rates as well as sub-optimal weather conditions at the time of the herbicide application may cause growth depression or plant damage. Often this cannot be seen in the field, because there is no opportunity for comparison to a non-treated plot. If herbicide-stress symptoms are visible, the question arises, whether this will finally cause yield loss or not. Therefore a two-year study on the effects of herbicide applications on yield and quality of sugar beet was conducted. Herbicides were applied as single products as in mixtures. Application rates were increased up to four times higher than common to induce specific stress. Development of yield and quality during the vegetation period was determined by periodic harvests.