Rooting in a Creeping Bentgrass Putting Green in Response to Spring and Summer Coring

Understanding root growth response of creeping bentgrass (Agrostis stolonifera L.) to coring will help golf course superintendents maintain high quality putting green turf. The objective of this field study was to examine the effects of coring on summer rooting in young creeping bentgrass grown on a sand-based root zone and maintained as a putting green. The study was initiated on 7-mo-old 'Providence' creeping bentgrass in 2006 and compared spring (SP) only coring, spring plus three summer (SU) corings (SP + SU) and a noncored control through 2007. The minirhizotron imagining technique was used to measure total root count (TRC) and total root length (TRL) from late spring to late summer. The percentage of the TRC in the surface 0- to 6-cm root zone depth averaged over measurement dates was 48 to 53% and 33 to 44% among all treatments in 2006 and 2007, respectively. Greater TRC were observed in 2006 with 28, 51, and 50% lower TRC's found in SP + SU, SP only, and noncored plots in 2007, respectively. Spring + SU coring generally reduced TRC and TRL at various root zone depths and dates during the first year of establishment. In 2007, greater TRC and TRL were observed throughout the 0-to 24-cm root zone in SP + SU cored compared to SP only and noncored plots. Th us, SP + SU coring in the second study year promoted creeping bentgrass root growth and/or longevity, but coring during the first summer of establishment reduced rooting.