Foliar and Granular Nitrogen for Creeping Bentgrass.
Poster Number 709
Wednesday, November 6, 2013
Tampa Convention Center, East Hall, Third Floor
L. Patrick Conard, Crop, Soil and Environmental Sciences, Auburn University, Auburn University, AL and Elizabeth A. Guertal, Crop, Soil and Environmental Sciences, Auburn University, Auburn, AL
Creeping bentgrass (A. stolonifera) has long been used in the transition zone of the United States as a putting green surface. However, summer heat and humidity will thin turf and reduce root growth, and so many golf course superintendents include foliar N fertilization in their maintenance regime as a means to supply N to stressed turf. However, information regarding N timing and N rates is lacking, especially in the humid southeast US. The objective of this work was to examine combined and separate effects of foliar N rate and timing of irrigation on the color, quality, shoot density, root growth, and percent N content of ‘Penn A-4’ creeping bentgrass. Conducted over 2 years, the experiment consisted of 4 N rates (0.5, 1.0, 2.0, and 4.0 g m-2) and 3 N application methods (Granular – watered after application, Foliar – watered after application, and Foliar – no water after application), all replicated 4 times on a ‘Penn A-4’ putting green. Collected data included weekly color and quality, clipping yield and N content at 1 and 3 weeks after application, quarterly shoot and root density, and twice-yearly carbohydrate content. The highest N rate was needed to achieve maximum color and quality ratings, except in the summer, when application of foliar N (without a following irrigation) reduced turf quality via foliar burn. For best turf color and quality (especially when granular sources were used) the monthly rate of 4.0 g m-2 would likely maintain constant N levels within the plant and consistent turf color if applied twice throughout the month at 2.0 g m-2.