Germination and Establishment of Ten Turfgrass Species As a Response to Various Levels of Phosphorus Fertilizer.

Phosphorus (P) is very important for turfgrass seed germination and establishment.  However, runoff of P can cause environmental problems.  Little information is available about the P requirement of commonly used cool-season turfgrasses at germination and establishment stage.  This greenhouse study was conducted to test the germination and establishment of Kentucky bluegrass (KB) ‘Park’ and ‘Bewitched’; Perennial ryegrass (PR) ‘Stellar’, and ‘Panther GLS’; Tall fescue (TF) ‘Turf Saver w/RTF’ and ‘KY-31’; Creeping bentgrass (CB) ‘Penncross’ and ‘T1’; and Creeping red fescue (CF) ‘Navigator’ and ‘Smirna’ as affected by different P levels.  Calcium superphosphate was added to a sand-based root zone to create P levels of 0, 5, 15, 45, 75, and 100 mg Kg^-1.  Cool season grass species/cultivars were seeded at 100 kg ha^-1 (KB), 300 kg ha^-1 (PR), 400 kg ha^-1 (TF), 50 kg ha^-1 (CB), and 200 kg ha^-1 (CF) adjusted by pure living seed (PLS) ratio.  The results showed that the germination date, seedling density, and root/shoot ratio were affected by P levels as well as species/cultivars.  Clipping yield was the highest at 45 mg Kg^-1 for KB and CB, and at 75 mg Kg^-1 for PR, TF, and CF.  Root/shoot ratio was the highest for KB, TF, and CF at 5 mg Kg^-1, while highest for PR and CB at 15 mg Kg^-1.  Germination date was earliest at 15 mg Kg^-1 but delayed as P levels increased for most species.  Based on these results, further study is needed to evaluate species, cultivar, and PLS effects on P requirements in cool-season grasses.