Root Weight, Nonstructural Carbohydrate Content, and Shoot Density of High-density Creeping Bentgrass Cultivars

Limited information is available on the performance under temperate conditions in the United States of recently released cultivars of creeping bentgrass (Agrostis stolonifera L.) with high shoot density for use on golf course putting greens. Fifteen cultivars were established in Aug. 1996 on a greens mix with high sand content to compare their seasonal weights and total nonstructural carbohydrate (TNC) contents. The cultivars were maintained at 3.1 mm height of cut. Shoot density counts were taken during Apr., July, and Oct. 1998. Root weights and nonstructural carbohydrate levels were assessed monthly from June 1997 through Nov. 1998. A cultivar group contrast between the high shoot density cultivars (`Penn A1', `Penn A2', `Penn A4', `Penn G1', `Penn G2', and `Penn G6') and the standard cultivars (`Penncross', `Crenshaw', `Southshore', `DF-1', `Procup', `Lopez', `SR1020', and `Providence') revealed that the former averaged 342.9 and 216.1 more shoots/dm2 on two of the three sampling dates. Root dry weights did not vary significantly (P ≤ 0.05) among the cultivars. Performing a contrast between new high shoot density cultivars and standard cultivars revealed greater root dry weight in the former during Mar. and May 1998. Differences (P ≤ 0.05) in TNC were observed on two of the 18 sampling dates, but no trends were evident.