Evaluation of the effect of day length on morphological and physiological indices of Bermudagrass (Cynodon dactylon [L.] Pers.) and Tall Fescue (Festuca arundinacea Schreb.) Turfgrasses in field conditions

It is estimated that 20 to 25 percent of all turfgrasses are maintained under some shades, whether from building or trees. Shade affects plant growth by influencing light intensity, quality, and duration. Given the importance of turfgrasses in the beauty of the environment surrounding human beings, so far enough research has not been done to understand the morpho-physiological properties of the turfgrasses under different day length conditions. For this purpose, a field experiment was conducted to determine the effect of day length on some morphological and physiological characteristics of two turfgrass genera in a split plot study based on a randomized complete block design with four replications in research farm of the Department of Horticultural Sciences, College of Agriculture, Shiraz University. Day length at three levels including long day length (16 hours), intermediate day length (12 hours), and short day length (8 hours) were considered as the main factor and two turfgrasses genera (Festuca arundinacea Schreb. and Cynodon dactylon [L.] Pers.) were considered as sub plots. The results showed that short day causes decreasing tiller density, fresh and dry weight of shoot, fresh and dry weight of root, and chlorophyll and starch contents and led to increasing leaf area and superoxide dismutase, peroxidase, and ascorbate peroxidase enzymes activities. Also, results showed that long day causes increasing tiller density, fresh and dry weight of shoot, fresh and dry weight of root and chlorophyll and starch contents and led to decreasing leaf area and superoxide dismutase, peroxidase and ascorbate peroxidase enzymes activities. Festuca arundinacea turfgrass compared with Cynodon dactylon turfgrass showed more resistance to decrease in day length. Regarding the possibility of increasing the period of light in parks and stadiums, in cold seasons when turfgrasses turn yellow, increasing photoperiod leads to improvement of the green color and increasing the efficiency of turfgrasses.