Creeping bentgrass response to plant growth regulating substances and annual bluegrass competition

Creeping Bentgrass (Agrostis stolonifera var. palustris (Huds.) Farw.) is the most widely used cool-season turf grass used for putting greens in North America. Frequently it becomes invaded with a persistent weed, annual bluegrass (Poa annua L.). Studies were conducted on a predominately annual bluegrass area managed as a putting green to attempt to quantify the impacts of plant growth regulator, seeding rate" and season on the success of introducing creeping bentgrass. Also, the impact of plant growth regulating substances on creeping bentgrass overall quality and seasonal rootmass production was evaluated. It was observed that creeping bentgrass does not become well established when overseeded into annual bluegrass regardless of plant growth regulator applications or season. Additionally 1I plant growth regulator application, following seedling emergence reduced creeping bentgrass seedling populations. Competition from established annual bluegrass and close frequent cutting were deemed reasons for lack of creeping bentgrass establishment success. Creeping bentgrass turf was maintained at a high level of quality with plant growth regulating substances. The use of the plant growth regulator trinexapac-ethyI reduced clipping production and was not detrimental to root production. Propiconizole application increased clippings and controlled Sclerotinia dollarspot. The application of a proprietary biostimulator material (3D) enhanced creeping bentgrass green color and generally increased rootmass over untreated turf.