Seasonal Wear Tolerance and Recovery in the 2005 NTEP Kentucky Bluegrass Test.

Kentucky bluegrass (Poa pratensis L.) cultivar recommendations for sports fields based on the specific season of play would be useful. The objective of this study was to assess the wear tolerance and recovery of Kentucky bluegrass in spring, summer, and fall. One-hundred twenty-one entries, including those of the 2005 NTEP Kentucky Bluegrass Test, were established in September 2005 on a Nixon loam in North Brunswick, NJ. Eighteen passes of simulated wear were applied in October 2006 (fall), July 2007 (summer), and April 2008 (spring). Plots were visually rated for fullness of turfgrass canopy before wear (C_BW), immediately after wear (C_W) and 20 days after wear (C_20DAW). Canopy retention immediately after wear was calculated as: C_W- C_BW. The redevelopment of the turfgrass canopy during recovery was assessed as: C_20DAW-C_W. Analysis of variance was performed on data arranged in a randomized complete block design. Entries were replicated three times in each season; replications were nested within season (spring, summer, and fall). Kentucky bluegrass had the least C_W after spring wear (summer=fall>spring); however, C_W- C_BW was ranked as: spring>fall>summer. Seasons did not differ for C_20DAW; however, C_20DAW-C_W was as follows: spring>summer=fall. While low C_W after spring wear was due to incomplete green-up, C_20DAW-C_W after spring wear was considerable (relative to summer and fall) due to rapid spring growth. 'Julia', CPP 822, CP 76-9068, had the best C_W and C_20DAW after spring, summer, and fall and were ranked the highest for canopy retention after two or more seasons. The poorest C_W for all three seasons was exhibited by DLF 76-9075.  The following had the poorest canopy retention in two or more seasons: MSP 3722, RAD-504, H94-305,  DP 76-9081, 'Kenblue', PST-101-73, 'Volt', 'Glenmont', A97-1560, 'Shamrock', SPTR 2959, BAR VV 9634, A99-2377, H98-701, A99-3122, 'Mystere', Bd 99-2103, 'Corsair', 'Reveille', STR 2485, and PST-109-752.