ROOT AND SHOOT PERFORMANCE OF THREE CREEPING BENTGRASS CULTIVARS AS AFFECTED BY NITROGEN FERTILITY^*

Abstract

Cultivar selection and nitrogen (N) fertility significantly influence the performance of creeping bentgrass (Agrostis palustris Huds.) in warmer regions of the United States. This study was conducted to determine the effects of N on root and shoot growth of three creeping bentgrass cultivars. The effect of three N rates (195.3, 390.6, and 586.0 kg N/ha year) on the total root length density (TRLD), deep root length density (DRLD), visual shoot quality, shoot density, and root to shoot ratio (RSR) of ‘Crenshaw’, ‘L93’, and ‘Penncross’ creeping bentgrass were evaluated in the University of Georgia Rhizotron at Athens, GA. Over the 19 month study, cultivar type and N rate significantly affected root and shoot growth with slight interaction. Crenshaw and L93 showed greater TRLD, DRLD, and visual shoot quality than Penncross at the 390.6 kg N rate. RSR was significantly influenced by N rate but not cultivar type. Both L93 and Crenshaw possessed significantly higher RSR at the 195.3 kg N rate than the 586.0 kg N rate.