Potato brown rot is an important quarantine disease, caused by Ralstonia solanacearum race 3 biovar 2, Phylotype II, sequevar 1. Cow pea and maize crops, cultivated in clay soil, supported the highest survival of the biocontrol agent, Stenotrophomonas maltophilia under green house conditions. Meanwhile, the biocontrol agent disappeared quickly from soil cultivated with tomato or non-cultivated soil. The survival of S. maltophilia in soil had a significant negative correlation with potato brown rot incidence, as expressed by wilt severity, area under disease progress curve (AUDPC) as well as the count of pathogen in soil, rhizospher and crown area of potato plants. The amino acid analysis in root exudates of crops under investigation showed high ratio of asparagine, glutamine, and methionine (sulfur containing amino), in both cow pea and maize plants and high percentage of arginine and lysine in tomato root exudates. Tomato plants which considered as host for pathogen containing amino acids in their root exudates that act as attractant signals that made the pathogen more survived in soil. It can be concluded that cow pea and maize are recommended crops to be used for crop rotation with potato. The two crops are able to colonize S. maltophilia bacteria as biocontrol agent, in their rhizosphere that support establishment of the biocontrol agent and hence sustainable control for bacterial wilt of potato.