Competitive ability of creeping bentgrass cultivars and their potential for renovating existing putting greens through interseeding

Golf is a key industry that generates jobs, commerce, economic development, and tax revenues for communities throughout the United States. A survey conducted in Iowa showed that golf generated 769.6 million dollars in total economic output while providing over 10,000 jobs to the state. The integrity of turf swards is routinely compromised by invasion from annual bluegrass (Poa annua L.), and higher levels of inputs are needed to maintain acceptable quality. New cultivars of creeping bentgrass (Agrostis stolonifera L.) offer improved agronomic characteristics and are better able to resist invasion from annual bluegrass. The overall objective of this research was to evaluate the culture of creeping bentgrass cultivars and assess the practice of interseeding as a means of converting existing putting greens to recently developed cultivars. Recently developed cultivars of creeping bentgrass possess finer leaf texture and more upright leaf architecture. These morphological characteristics allow for increased shoot densities. Results from our research suggest that a greater number of shoots hinders the plant\u27s ability to recuperate from injury. Our work also demonstrated that cultivars of creeping bentgrass displayed varying lateral spread rates and stolon and internode lengths. Growth analysis revealed that low shoot density cultivars allocate more dry matter into stolons than leaves. Difference in dry matter partitioning could partially explain differences in lateral spread among cultivars of creeping bentgrass. Higher shoot density cultivars may be better suited for areas where low populations of annual bluegrass are desired. Alternatively, lower shoot density cultivars may be better suited for areas where mechanical damage is frequent and recuperative potential is important. The vegetative characteristics should be matched with desired site usage requirements for optimum performance when selecting cultivars of creeping bentgrass. The ability of established facilities to utilize recently developed cultivars is limited as few conversion methods exist. Current renovation methods require a facility to incur significant financial loss. Interseeding has been proposed as an alternative conversion method with less financial burden. Germination studies showed that recently developed cultivars of creeping bentgrass possess greater vigor and may be better suited for interseeding compared with older cultivars. Our interseeding studies suggest that the level of maintenance and overall quality of the putting surface influence the success of conversion. Conversion through interseeding in this study was not successful when the plots were maintained under golf course conditions. Interseeding was only successful when conditions of the putting green were allowed to deteriorate below acceptable levels. The overall conditioning of the putting surface in order to permit interseeding needs to be weighed against the cost of a traditional conversion when deciding on a renovation program