Herbage yield and composition of Kentucky bluegrass (Poa pratensis L.) cultivars under two harvest systems

Abstract

) is a naturalized species commonly found in the permanent grasslands of eastern Canada, its contribution to sward output is not well defined. Six Kentucky bluegrass cultivars originating from Norway, Germany and North America, and a timothy (Phleum pratense L.) cultivar, were grown under two harvest systems at two locations to determine yield and herbage composition. All cultivars persisted over 3 production years. Dry matter yields of bluegrass cultivars were similar to those of timothy, ranging from 7.87 to 9.76 t ha -1 in Charlottetown, Prince Edward Island, and from 3.64 to 4.79 t ha -1 in Normandin, Quebec. Yields of broadleafed genotypes from Europe were superior in year 1. However, the warm and dry growing conditions of year 3 favoured the narrow-leafed genotypes. Mean tiller density of Kentucky bluegrass was 6440 m -2 ; timothy had a mean tiller density of 3040 m -2 . Forage quality attributes of Kentucky bluegrass were similar to those of timothy. Cultivar differences in fibre and mineral concentrations were consistent across years and locations and may provide selection criteria in breeding programs. Greater harvest frequency increased the total nitrogen concentration of herbage and tiller density but had no effect on yield. Kentucky bluegrass is a persistent, valuable forage grass species with good potential for use in pasture and as conserved forage in eastern Canada. ) est l'espèce acclimatée la plus répandue dans les prairies permanentes de l'Est du Canada, mais la contribution de cette espèce à la productivité de la prairie n'est pas bien définie. Six cultivars de pâturin des prés provenant de la Norvège, de l'Allemagne et de l'Amérique du Nord et un cultivar témoin de fléole des prés (Phleum pratense L.) ont été évalués, à deux endroits, pour leur potentiel de rendement en matière sèche (MS) et leur qualité fourragère sous une régie de paissance simulée et d'ensilage. Tous les cultivars ont bien persisté au cours des trois années de production. Les rendements moyens en MS ont varié de 7.87 à 9.82 t ha -1 à Charlottetown et de 3.74 à 4.79 t ha -1 à Normandin, rendements similaires à ceux obtenus avec la fléole des prés. Les rendements en MS des génotypes tardifs à feuilles larges du Nord et du centre de l'Europe ont été supérieurs lors des deux premières années de production à Charlottetown et seulement à la première année à Normandin. Cependant, les conditions de croissance chaudes et sèches qui ont prévalu au printemps et au début de l'été lors de la troisième année ont favorisé les génotypes à feuilles étroites résistant à la sécheresse. La densité moyenne de talles du pâturin des prés a été de 6500 talles m -2 soit un peu plus que deux fois celle observée la fléole des prés, 3040 talles m -2 . Les valeurs de paramètres de qualité fourragère du pâturin des prés ont été semblables à celles obtenues avec la fléole des prés. Les différences dans la concentration en fibre et en éléments minéraux, entre les cultivars, ont été constantes à travers les années et les endroits et peuvent servir comme c...

Evaluation of Quantitative and Qualitative Traits of Wild Ecotypes of Forage Grasses

“…For all grass species, there were not any differences in mean nutrient content between wild ecotypes and cultivars. Our results are consistent with Dürr et al (2005) who did not find any clear distinction among cultivars for being "high" or "low" in minerals. Similarly, mean values of Ca / P and K / (Ca + Mg) ratio did not show any significant differences between the wild ecotypes and the cultivars.…”

“…In accordance with our results, Bovolenta et al (2008) found only limited variation in mean CP content at eight grass species of alpine pastures. The highest CP content was recorded in Poa pratensis L., comparing to Festuca rubra L. and Phleum pratense L. Similarly, Dürr et al (2005) found Poa pratensis L. as having the highest total N content. In our study, the mean CP content was 144.72 and 136.53 g/kg in the wild ecotypes and the cultivar of Phleum pratense L., respectively, which contrasts to Nordheim-Viken et al (2009) who reported that Phleum pratense L. is rich in CP.…”

“…Similar studies conducted with several alternative grasses in Austria showed that DM yield of monocultures of cultivar Festuca rubra L. were 12.3 t/ha and 13.6 t/ha, respectively (Grais et al 2011). Dürr et al (2005) observed differences in yield potential of Poa pratensis L. cultivars between two sites in Canada. The DM yields of Poa pratensis L. cultivar grown under T a b l e 7 Dry mater (DM) yield, the content of CP, fibre, P, K, Ca, Mg and the ratios of Ca / P and K / (Ca + Mg)…”

Improving potassium acquisition and utilisation by crop plants

“…1). In addition, genetic variation in herbage K concentration has been reported in several grass and clover species, which have been studied principally because of the negative economic consequences of grass tetany in ruminant animals when their diets contain high K : (Ca + Mg) ratios (Asher and Ozanne, 1977;Smith et al, 1999;Baligar et al, 2001;Kunelius et al, 2003;Dürr et al, 2005;Christian et al, 2006;El-Nashaar et al, 2009).…”

Fructan accumulation and transcription of candidate genes during cold acclimation in three varieties of Poa pratensis

“…The contrasting modes of reproduction facilitate the high polyploidy levels and unusual chromosome numbers (x = 7, 2n = 28-147) observed in P. pratensis (Speckmann and van Dijk, 1972). P. pratensis shows persistence and resilience to cold and seasonal drought (Kanneganti and Kaffka, 1995) and good performance under frequent and close defoliation (Bryan et al, 2000;Durr et al, 2005). Contemporary fructan research is mainly focused on a few plant species including barley, wheat and ryegrass, and despite being a type species for the grass family (Poaceae), little is known about the fructan metabolism in P. pratensis.…”