Tuesday, November 14, 2006
171-2
Rooting in a Creeping Bentgrass Putting Green in Response to Summer Irrigation.
Jinmin Fu and Peter H. Dernoeden. University of Maryland, 2804 Schubert Dr, Silver Spring, MD 20904-6881
Frequent versus infrequent irrigation are two common irrigation practices for most golf course managers in the mid-Atlantic region during summer months. The objectives of this 2005 field study were to examine how quality and rooting respond to light and frequent (LF) versus deep and infrequent (DI) irrigation in ‘Southshore’ creeping bentgrass (Agrosis stolonifera L) putting green turf. Root measurements were obtained using the minirhizotron imaging technique. Soil moisture level usually was lower in DI-irrigated plots (average of 16.6 % over 12 dates), when compared to LF-irrigated plots (average of 19.4 %) despite frequent thunderstorms. No differences in turf quality, however, were found between the two regimes during most of the experimental period. Significant irrigation effects on rooting mainly were observed between 4.1 and 23.0 cm soil depths. Deeply and infrequently irrigated bentgrass generally had a longer root length, larger root surface area and greater volume at 4.1 to 10.8 cm soil depths, when compared to LF-irrigated creeping bentgrass. Deeply and infrequently irrigated bentgrass, however, usually had shorter root length, smaller root surface area and less root volume at 18.9 to 23.0 cm soil depths, when compared to LF-irrigated bentgrass. When data were analyzed over the entire root system, DI-irrigated bentgrass had 6.4 to 12.7% longer total root length on two out of three monitoring dates versus LF-irrigated bentgrass. There were, however, no significant differences in root volume or surface area between irrigation regimes, when data were summed over all root depth measurements.