Wednesday, November 15, 2006

Best Management Practices to Enhance Winter Shaded Creeping Bentgrass Golf Greens.

Christian Baldwin, Haibo Liu, Lambert McCarty, and Steven Long. Clemson Univ., Dept. Of Horticulture, Dept. Of Horticulture, Clemson, SC 29631, United States of America

Due to dramatic temperature variation in the warm climatic region of the transition zone, creeping bentgrass putting greens face many stresses and agronomic challenges year round, including shade.  To minimize shade damage, repeated trinexapac-ethyl (4-(cyclopropyl-a-hydroxy-methylene)-3,5-dioxy-cyclohexanecarboxylic acid ethyl ester) applications have proven beneficial in minimizing summer shade stress.  Currently, morning shade is considered more detrimental than afternoon shade, however, research studies are conflicting.  Therefore, a two-year replicated field study is in progress to evaluate the winter shade tolerance of ‘L93’ creeping bentgrass (Agrostis stolonifera var. palustris (Huds.) to various reduced light environments (55% and 95%), effect of morning vs. afternoon shade, effect of trinexapac-ethyl (TE) application on shade tolerance, and the effect winter shading has on turfgrass quality (TQ) during stressful summer months.  Data collection for each treatment includes visual TQ, total root biomass, total non-structural carbohydrates (TNC), clipping yield, chlorophyll content, daily light measurements (PPFD), and monthly canopy and soil temperature.  The 55% afternoon treatment maintained acceptable TQ throughout winter for both years.  Consistent bi-weekly TE applications during winter negatively impacted bentgrass growth and color, however, trinexapac-ethyl enhanced spring recovery from 95% winter shade damage.  Morning or afternoon shade minimally impacted parameters measured.