Evaluation of Zoysia Under Natural Tree Shade.

‘Meyer’ zoysiagrass (Zoysia japonica Steud.) is commonly planted on home lawns and golf courses in the transition zone; however, poor shade tolerance limits its widespread use. This study was conducted to determine effects of shade on growth and development among seven Zoysia genotypes over a three-year period. The study was initiated in June 2010 at the Rocky Ford Turfgrass Research Center in Manhattan, KS. Soil type was a Chase silt loam (fine, montmorillonitic, mesic, Aquic, Argiudolls). Zoysia genotypes were sodded in 0.37 m² plots and arranged in a randomized complete block with five replications under silver maple (Acer saccharinum L.) shade. Genotypes included ‘Zorro’ [Zoysia matrella (L.) Merr.], ‘Emerald’ (Z. matrella × Z. tenuifolia Willd. ex Thiel), ‘Meyer’, Chinese common (Zoysia japonica Steud.), and experimental progeny 5313-46 ('Zorro' × 'Meyer'), 5321-18 ('Emerald' × 'Meyer'), and 5321-45 ('Emerald' × 'Meyer'). ‘Zorro’ and ‘Emerald’ experienced winter injury which negatively affected their performance. Tiller numbers decreased 50% in ‘Meyer’ from June 2010 to June 2012, but declines in 'Emerald' × ‘Meyer’ progeny were 4% for  5321-18 and 28% in 5321-45.   In general, by the third year of evaluation, progeny of 'Emerald' × 'Meyer' had higher quality ratings and greater tiller numbers than 'Meyer', and may one day provide more shade-tolerant cultivar choices for transition zone turf managers.