The present invention relates to the use of the ALS inhibitor herbicides for controlling unwanted vegetation in ALS inhibitor herbicide tolerant Beta vulgaris plants, more especially, present invention relates to the use of ALS inhibitor herbicides for control of unwanted vegetation in Beta vulgaris, preferably in sugar beet growing areas in which the Beta vulgaris, preferably sugar beet comprise mutations in the ALS gene where the tryptophan at position 569 in the encoded ALS enzyme is substituted by another amino acid (preferably by leucine), and a mutation in the ALS gene where the proline at position 188 in the encoded ALS enzyme is substituted by another amino acid (preferably by serine).
