Competition ability of selected amenity varieties of Festuca rubra in mixture with Deschampsia caespitosa

The aim of the research was to evaluate the competition capacity and find suitable proportion of different types of Festuca rubra and Deschampsia caespitosa in grass mixtures for decorative lawns. A field experiment with Deschampsia caespitosa cv. Kometa in monoculture or in mixtures with Festuca rubra L. varieties Viktorka (ssp. trichophylla), Barborka (ssp. commutata) and Petruna (ssp. rubra) was established in Větrov in 2007. The sowing rate was 40 000 viable seeds per m² (0, 25, 50 or 75% of F. rubra). The sward was mown at 3 cm. The number and weight of tillers of the turf components were evaluated during three years. The highest number of tillers (on average 63.3 thousand/m²) and weight of the dry aboveground phytomass (on average 196 g/m²) were found with F. rubra ssp. trichophylla. Its particular tillers had the lowest dry weight (0.32 g/100 tillers). The lowest number of tillers (32.9 thousand/m²) and low weight of dry aboveground phytomass (134 g/m²) showed mixtures with F. rubra ssp. rubra, whose tiller weight was relatively high (0.42 g/100 tillers). The size of F. rubra tillers was not influenced either by the mixture composition or by vegetation years. The number of F. rubra tillers was not significantly different in the third and first vegetation year. The number of D. caespitosa tillers in monoculture decreased during the years from 45 to 30 thousand/m², but the weight of dry aboveground phytomass increased significantly from 233 g/m² to 318 g/m². Poor competition of D. caespitosa was found in the mixture with F. rubra ssp. commutata (on average 4% of total number of tillers and 7% of the total weight of the dry aboveground phytomass). F. rubra ssp. trichophylla was less competitive and the least competition with D. caespitosa was found in F. rubra ssp. rubra, After three years the proportion of D. caespitosa in mixtures with F. rubra ssp. rubra significantly increased to 36% of the total number of tillers and to 55% of the total weight of phytomass. Mixtures of D. caespitosa and F. rubra ssp. rubra were found to be promising for low input lawns.