Quantifying a Daily Light Integral for Establishment of Warm-Season Cultivars on Putting Greens.

A major constraint for successful ultradwarf bermudagrass [Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt Davy] putting green establishment is a reduced-light environment (RLE) because of the overall poor shade tolerance of bermudagrass. Currently, no research studies have determined the light requirement for warm-season putting green cultivar establishment. Research was conducted to determine a daily light integral (DLI) requirement for successful bermudagrass and zoysiagrass [Zoysia matrella (L.) Merr.] putting green establishment. This field trial was initiated in June 2013 and repeated in 2014 at the Foil Plant Science Research Center in Starkville, MS. Four bermudagrass cultivars (Champion, TifEagle, MiniVerde, and MSB-285) and one zoysiagrass cultivar (Diamond) were established under full sunlight (control) and under 30, 55, and 80% full-day shade (reduction of total light) using a neutral density, polyfiber black shade cloth. Daily light integrals averaged across both years resulted in a DLI of 42.26, 31.92, 22.04, and 13.48 mol m-2 d-1for full sunlight and 30, 55, and 80% shade treatments, respectively. Based on the dose-response curves, the DLI requirements to reach a mean predicted cover of 70% for Champion, Diamond, MiniVerde, MSB-285, and TifEagle were 27.1, 42.3, 28.1, 38.2, and 30.1 m-2 d-1, respectively. Although Diamond is a shade-tolerant cultivar, its high light requirement noted in this study likely is due to previously reported slow establishment rates. The predicted DLIs generated from this research can assist a golf course superintendent's decision-making regarding altering the light environment in locations where these putting green cultivars will be established. [ABSTRACT FROM AUTHOR]