Tall Fescue and Bermudagrass Cultivar Response to Drought Stress at the Germination Growth Stage.

Seed germination is perhaps the most critical and sensitive stage in the life cycle of a plant. A key factor for germination and subsequent establishment is adequate water.  Examining and developing screening techniques to identify drought tolerant lines at the seedling stage is an important step for plant breeders.  Therefore, the objectives of this research trial were to determine if the use of polyethylene glycol (PEG-6000) is an effective tool to screen for water stress for turfgrass seed germination and to determine potential cultivar differences within each species tested.  Bermudagrass (Cynodon spp.) cultivars selected included ‘Casino Royale’, ‘Hollywood’, ‘Northshore’, ‘Riviera’, and ‘Transcontinental’.  Tall fescue (Festuca arundinacea L.) cultivars included ‘Jaguar 4G’, ‘Quest’, ‘Summer’, and ‘Sundial’.  Water stress levels were developed using PEG-6000.  For bermudagrass, seed was subjected to 0 (control), -2.5, -5.0, and -7.5 MPa, while tall fescue water stress treatments included 0 (control), -1.0, -2.0, -3.0, -4.0, -5.0, and -7.0 MPa.  Bermudagrass final germination percentage (FGP) and daily germination rate decreased with increasing rates of PEG-6000.  When averaged across cultivars, the -2.5 MPa water stress treatment decreased FGP 57% compared to the control.  Regarding bermudagrass cultivars, at the -5.0MPa treatment, Hollywood had 39% greater seed germination compared to Transcontinental.  For tall fescue cultivars, Jaguar 4G had 39% lower RDGR compared to the other tall fescue cultivars 7 days after seeding.  Results from this research trial indicate PEG-6000 is an effective technique for screening turfgrass cultivars that require less water for seed germination.  This study also identified cultivars that would have a competitive advantage during the establishment phase if water is a limiting factor.