Chemical treatments have proven successful when dealing with dallis grass. Use repeat applications of an herbicide such as MSMA or MSMA + Sencor. Apply 2 lbs per acre every seven to 10 days, limiting it to four applications in one season.
Pulling out the young plants can also save your grass. Remove them before they form rhizomes or set seed. You can also dig out mature plants, but they are more likely to regrow.
Because dallis grass spreads so quickly, precautionary tactics can cut down on the spread. Clean lawnmowers that are used in contaminated sites, and don't use soil from those areas for other plantings.