Effects of shading on growth characteristics of Poa pratensis and Festuca rubra during turf mature stage

The shade tolerance of 3 cultivars of Poa pratensis (Merit、NuGlade and K. B. G) and 2 cultivars of Festuca rubra (Boreal and Rubra)in turf mature stage were compared under different shading treatments including control without shading and shading rates of 22%, 45%, 66% and 83%. The results showed that the plant height firstly increased and then decreased with the increase of shading rates during turf mature stage. The plant height of different cultivars reached the maximum values under different shading rates treatments. However, the plant heights of Poa pratensis with 83% shading rate were significantly lower (P0.05) than that of corresponding cultivar under other shading rates treatments. The root length of Boreal under 22% shading rate treatment was significantly (P0.01) than that of Boreal under control treatment. The root length of the other 4 cultivars decreased with the increase of shading rates. The specific leaf weight (SLW) of all these 5 cultivars decreased under shading treatments and SLW under over 45% shading rate treatments were significantly less (P0.05) than that under control treatment. With the increase of shading rate, the dry weight of Poa pratensis shoot decreased whereas the dry weight of Festuca rubra shoot firstly increased and then decreased.