New Work On Poa Annua Biotypes From Golf Greens.

Annual bluegrass (Poa annua L.) is a troublesome weed in intensively managed turf.  As the intensity of golf turf management increases, so do populations of perennial biotypes of annual bluegrass.  Annual bluegrass patches, which may represent different biotypes, are commonly observed to differ in regards to color, texture, and number of seed heads.  It is not known whether these visual differences are promoted by management strategies, and/or whether morphologically diverse annual bluegrasses respond differentially to control programs. For this study, annual bluegrass plugs were collected from greens at the Lexington Country Club and The University Club of Kentucky. The samples were collected based on their having one of two appearances while on the same green: 1.) dark green, with few to no flower heads (“dark” biotype) or 2.) light green, with numerous flower heads ("light" biotype).  Herbicide and plant growth regulator treatments were applied to the plugs both in the field and the greenhouse to investigate potential differential responses among the annual bluegrass biotypes to the chemicals.