Many people have problems with bahiagrass in their centipede lawns. Bahiagrass is the grass that shoot up the long stems that have a V shaped seedhead. Seeing bahiagrass in a centipede lawn is an eyesore to many people.
There are several good options for control of bahiagrass in centipede lawns. One option is to apply a chemical with the active ingredient: metsulfuron methyl. There are numerous products that contain metsulfuron methyl. Two products that can be used that contain metsulfuron methyl are Manor and Blade. These would need to be applied at a rate of .25-.5 ounces per acre in order to kill bahiagrass. 1/3 ounce per acre would be a good rate to go with. Sprayers will need to be properly calibrated for this application. You will also need to add some nonionic surfactant at a rate of .25% or 32oz/100gal. Metsulfuron will also control other summer weeds including lespedeza.
Another option for controlling bahiagrass in home lawns is to use a chemical with the active ingredient called sethoxydim. The trade name of one product that contains sethoxydim is Segment. This product will also kill crabgrass in centipede along with other grass-weeds. Make sure to use the rate listed on the label for this product.