Phenotypic Plasticity and Turf Performance of Zoysiagrass in Response to Reduced Light Intensities

Abstract

Understanding phenotypic plasticity and patterns of biomass allocation of turfgrass under shade is needed for better turfgrass management and the development of cultivars that persist under shade. The objectives of this study were to (i) compare turf performance and determine the relationship between the phenotypic plasticity in growth, biomass allocation and turfgrass quality (TQ) under different light intensities under greenhouse condition; and (ii) assess the turf establishment and performance in response to moderate shade under field conditions in zoysiagrass (Zoysia spp.). A greenhouse experiment evaluated 11 cultivars under four shade levels. Plasticity in leaf extension rate (LER) had a positive relationship with the plasticity in clipping dry weight (CDW, R2 = 0.31), total dry weight (TDW, R2 = 0.16), and TQ (R2 = 0.32), indicating less decline in TQ was associated with more biomass allocated to shoot growth and/or more biomass storage during the study period. Under 90% shade, cultivars JaMur (plasticity in TQ = −0.12), Empire (−0.13), El Toro (−0.16), Palisades (−0.17), and BA‐305 (−0.21) were identified as the top performers with less decline in TQ and higher turf performance index (TPI). Cultivar Emerald demonstrated a low reduction in TDW and no plasticity in LER, indicating a different shade response mechanism compared to BA‐305. A separate field experiment evaluated eight cultivars under full sun and 63% shade. The moderate shade resulted in limited variation and results on cultivar difference in shade tolerance were inconclusive. Nonetheless, cultivars BA‐189, Shadow Turf, and Empire had faster establishment than Emerald.