Almost all sports and golf facilities in the southwestern desert areas overseed bermudagrass in the late summer/early fall in order to provide a green year round season play surface. This is necessary since bermudagrass growth and winter dormancy can severely limit performance of sports fields and golf course turfs for six months or longer, which often occurs in high use periods. In the last fifteen years, the natural conversion of ryegrass back to bermudagrass has become problematic due to any single or combination of the following: (1) widespread use of ryegrass cultivars which now tolerate high temperature stress, close mowing and produce high tiller densities, (2) clientele demand for high quality turf on a year round basis, and (3) inadequate response of newer ryegrasses to standard typical cultural management practices for transition. These issues often create a condition whereby transition from the overseed to bermudagrass produces an unacceptable turf surface. A number of scenarios arise where any of the following is possible: (1) ryegrass persists for an unacceptable length of time, (2) bermudagrass is weak and thin, or (3) ryegrass persists and then fails abruptly leaving a dead straw turf mat, often without bermudagrass regrowth.
