The quarantine pathogen, Clavibacter michiganensis subsp. michiganensis (Cmm), is one of the most important bacterial pathogens affecting tomatoes. The quarantine status and the devastating disease symptoms caused by Cmm are problematic for many parties. Even though resistance/tolerance breeding is one of the most important and successful ways to manage diseases, other paths can also be walked to manage disease symptoms. We developed a new and an efficient way to screen big tomato populations in vitro and used it to fine map the QTL on chromosome 7. Furthermore, susceptibility (S) gene, WAT1, reduced disease symptoms. Lastly, alternative approaches were applied to reduce Cmm disease symptoms by applying grafting and utilizing biocontrol agens. In conclusion, we developed a new protocol that could ease disease screening, fine mapped the QTL on chromosome 7, found a potential new tolerance against Cmm by using S-gene and tested two alternative approaches to minimize wilting symptom.