Turf quality and reliability in varieties of four turfgrass species in contrasting Italian environments

Abstract

Turf quality is a complex character of fundamental importance in turfgrass evaluation. It takes into account aesthetic and functional aspects, and depends on several individual components which may vary with time. The use of a synthetic and simple quality score is necessary when evaluating large numbers of varieties. The quality of 110 turfgrass varieties belonging to four species (Lolium perenne, Poa pratensis, Festuca arundinacea and F. rubra) was assessed in the second and third years of growth at three Italian locations, i.e. Lodi (Po Valley, continental climate), Perugia (central Italy, sub-Mediterranean climate) and Foggia (southern Italy, Mediterranean climate), using a visual score ranging from 9 (outstanding turf) to 1 (very poor turf). A randomized block design with three replicates was used, with varieties of the same species being blocked to facilitate the comparison within species. On average, F. rubra had the lowest turf quality score in summer, whereas the other species had the lowest quality score in winter and the highest quality score in summer and autumn. Components of variance were large for genotype (i.e. variety) main effects in all species. A variety · location interaction was found in F. arundinacea and higherorder interactions were also found for P. pratensis and F. rubra. Genotype · environment effects were small relative to genotypic effects in L. perenne. Variety · year interactions were small in all cases, whereas variety · location and variety · season interactions were greater. Stability of turf quality across sites, seasons and years was measured for each variety in terms of environmental variance, i.e. the variance of score values across sites, years and seasons. Mean scores and stability values of varieties were integrated into an index of reliability that estimated the lowest score value expected in 0AE80 of cases. For each species, a small subset of highly reliable varieties could be identified. Implications of the results for the testing and breeding of varieties in Italy are discussed.

Bazı Kamışsı Yumak Çeşitlerinin Serin İklim Ekolojik Koşullarında Yeşil Alan Performanslarının Belirlenmesi

“…This study supports the results of prior research [12,13,16,25,26] carried out in Tokat. Furthermore, the results are in line with many studies [10,11,14,15,17,18,19] carried out in ecologies with similar cool climatic conditions as Tokat. However; the study results were higher and more favorable when compared to a study carried out in Izmir [7,8,20,21,22,23,24] a city located in the Mediterranean climate zone with exceptionally hotter summers.…”

Adaptability of Newly Improved Creeping Bentgrass (Agrostis stolonifera L.) Genotypes in a Mediterranean Environment

“…Turf grass color scores may also help to define the most appropriate alternative to select, particularly with regard to the seasons in which turf color is considered of special significance (Morris and Sherman, 2000;Salman et al, 2011). The higher turf color scores of genotype B, D and E during the summer season which is the least favourable period of the year for growth of many cool season turf grasses in the mediterranean environment, were mainly due to comparatively greater color retention, heat and drought tolerance of above mentioned experimental grass material (Russi et al, 2004). Among the cover scores of all creeping bentgrass genotypes tested in the experiment, genotypes B, C, E and the control cultivar had highest scores in various seasons of the experimental years and over two years of average.…”

“…In contrast, all the turf grass genotypes and the control variety had reduced adaptability during the summer and the winter seasons in both years might be attributed to the heat and drought stress in the summer and respectively cold stress in the winter. These stress factors arising from weather conditions of the summer and winter seasons under the mediterranean environment have generaly restrictive effect on plant growth and development particulary for some cool season grasses (Russi et al, 2004;Sheng et al, 2005;Demiroglu et al, 2010).…”

“…usually assessed monthly or seasonally on a scale ranging from 1 to 9 are highly regarded variables in the USA and the European national tests (Morris and Sherman, 2000). Despite their limitations, turf quality, color, cover and weed infestation traits of turf remain as fundamental characteristics used by turf researchers because the process is much less time-consuming than the alternative options based on individual traits and can, therefore, be easly assessed several times a year (Russi et al, 2004).…”

Effects of Nitrogen Fertilization on Some Turfgrass Characteristics of Perennial Ryegrass (Lolium perenne L.)

“…Russi at al. [26] concluded that the turfrass quality is largely dependent on the genotype and environment interaction.…”