Responses of turf‐type hybrid bermudagrasses to drought stress

Abstract

Bermudagrasses (species of Cynodon Rich.) are among the most widely used warm‐season turfgrasses in the southern and transition zones of the United States. However, the growth and quality of turfgrass in various regions are increasingly compromised by insufficient rainfall or inadequate irrigation. Therefore, identifying drought‐resistant turfgrass cultivars is crucial for maintaining sustainable landscapes and conserving water resources amidst the increasing frequency of drought events. The objective of this study was to determine the responses of four hybrid bermudagrass ( Cynodon dactylon × C. transvaalensis ) genotypes (Tifway, DT‐1[TifTuf ® ], OKC 1131 [Tahoma 31 ® ], and experimental selection TifB16117) to drought stress. Grasses were grown in PVC tubes measuring 63.0 cm deep and 10.2 cm in diameter under controlled greenhouse conditions. After full establishment, irrigation water was held off for testing turf quality (TQ), leaf firing, normalized difference vegetation index, percentage green cover, chlorophyll index, relative vertical growth, electrolyte leakage (EL), and evapotranspiration (ET). The study included two experimental runs with a duration of 25 and 28 days, respectively. Significant variations were noted among different parameters in both experiments, revealing how different genotypes respond to drought stress. In particular, TifB16117 emerged as a standout performer, demonstrating greater drought resistance compared to other genotypes, including the widely used TifTuf. It maintained exceptional TQ and exhibited reduced EL, revealing its robust adaptability under drought stress. Throughout the study, TifB16117 exhibited higher ET rates under drought conditions, reflecting its ability to sustain transpiration for a longer duration. These findings suggest that effective root water absorption plays a critical role in enhancing the drought resistance of bermudagrasses. Tifway demonstrated weaker performance under drought conditions compared to TifTuf. TifTuf, despite a higher evapotranspiration rate, outperformed varieties with lower rates during drought. TifB16117 demonstrated drought resistance comparable to or better than TifTuf.