Influence of the critical phase of stem elongation on yield and forage quality of perennial ryegrass genotypes in the first reproductive growth

2017 ◽  
Vol 205 ◽  
pp. 23-33 ◽  
Author(s):  
I. Ullmann ◽  
A. Herrmann ◽  
M. Hasler ◽  
F. Taube
2006 ◽  
Vol 46 (1) ◽  
pp. 45 ◽  
Author(s):  
K. Sinclair ◽  
W. J. Fulkerson ◽  
S. G. Morris

The influence of regrowth time on the forage quality of prairie grass (Bromus willdenowii Kunth. cv. Matua), perennial ryegrass (Lolium perenne L. cv. Dobson) and tall fescue (Festuca arundinacea Schreb. cv. Dovey) was determined under non-limiting soil nutrient and moisture growth conditions. In a glasshouse, individual plants of each species were arranged in separate mini-swards and were defoliated at 6, 10 and 14 weeks after sowing to a stubble height of 60 mm for perennial ryegrass and tall fescue and 90 mm for prairie grass. Following defoliation at 14 weeks, selected individual plants were cut to the previous stubble height as each new leaf per tiller was fully expanded, to provide leaf material for nutrient analysis, until prairie grass, perennial ryegrass and tall fescue had attained 6–8, 5 and 3 leaves/tiller, respectively. The concentration of leaf phosphorus (P) decreased from 6.6 to 5.9 g/kg dry matter (DM) in prairie grass, increased from 5.9 to 6.9 g/kg DM in perennial ryegrass, and initially increased to 8.8 g/kg DM and then decreased to 8.4 g/kg DM in tall fescue. The mean potassium (K) content in perennial ryegrass was 29.6 g/kg DM and was not significantly affected by duration of regrowth, whereas K content in prairie grass and tall fescue fell from 51.7 to 43.6 g/kg DM and from 55.5 to 47.9 g/kg DM, respectively, after the first leaf per tiller formed. Calcium levels increased with regrowth in all species and at the completion of regrowth were 5.8, 3.8 and 3.4 g/kg DM in prairie grass, perennial ryegrass and tall fescue, respectively. The magnesium (Mg) and sodium (Na) content of perennial ryegrass showed no change throughout the regrowth period and had measured values of 2.5 and 2.8 g/kg DM, respectively. For tall fescue, the concentration of leaf Mg decreased from 0.30 to 0.24 g/kg DM, whereas the Na concentration increased from 1.2 to 2.1 g/kg DM. The Mg content of prairie grass remained constant at 2.0 g/kg DM, whereas the Na content increased from 2.7 to 4.3 (g/kg DM). While the crude protein content of all grasses declined over the regrowth period, values remained over 200 g/kg DM, well above the recommended content for lactating cows. The leaf water-soluble carbohydrate (WSC) of prairie grass and perennial ryegrass increased over the regrowth period from 29.7 to 43.9 g/kg DM and from 25.9 to 72.5 g/kg DM, respectively, whereas tall fescue showed no change at 55.6 g/kg DM. The change in in vitro organic matter digestibility (OMD) with age was 125 and 44 (g/kg DM) for tall fescue and perennial ryegrass, respectively. The OMD of prairie grass decreased following the onset of stem elongation at the 5-leaves/tiller stage of regrowth from 824 to 756 g/kg DM. In this glasshouse study, the pattern of change in K and Ca content was the same as observed in the field but the absolute content, including that of Na, was greatly elevated, particularly in prairie grass. In terms of nutrient content capability, N, P and K were readily taken up by these C3 grasses, while the uptake of Mg and Na appear to reflect genetic differences between species. The differences in forage quality as determined under optimal growth conditions in this study, as compared with field grown forage, are presumed to indicate possible soil nutrient deficiencies in field situations.


2000 ◽  
Vol 40 (8) ◽  
pp. 1059 ◽  
Author(s):  
W. J. Fulkerson ◽  
J. F. M. Fennell ◽  
K. Slack

A grazing study was conducted, over a 3-year period (1997–99), on the subtropical north coast of New South Wales, Australia, to compare the yield of prairie grass (Bromus willdenowii cv. Matua), tall fescue (Festuca arundinacea cv. Vulcan) and perennial ryegrass (Lolium perenne cv. Yatsyn), on a well-drained red krasnozem soil at Wollongbar Agricultural Research Institute (WAI) and on a heavy clay soil at Casino. The effect of grazing interval (equivalent to the time taken to regrow 1.5, 2.5 or 4 leaves/tiller) in spring, and forage quality of prairie grass in winter and spring was also assessed. At both sites, the dry matter (DM) yields of prairie grass over the establishment year and in year 2 were significantly (P<0.001) higher than for the other 2 grass species (mean for 2 years over the 2 sites was 23.8, 8.9 and 7.7 t DM/ha for prairie grass, ryegrass and tall fescue, respectively). In year 3, there was no production of tall fescue or ryegrass at the WAI site while prairie grass produced 11.3 t DM/ha although this was obtained from natural seedling recruitment after the sward was sprayed with a herbicide in February of that year. At the Casino site, ryegrass and tall fescue still made substantial growth in year 3 (3.1 and 2.1 t DM/ha for ryegrass and tall fescue, respectively) but this was significantly below the yields of prairie grass (5.5 t DM/ha). More frequent grazing of prairie grass in spring (equivalent to 1.5 leaves/tiller of regrowth) led to significantly (P<0.05) less plants surviving summer and less seedling recruitment in the following autumn. The annual yield of the 1.5 leaf treatment was significantly (P<0.05) lower than the remaining treatments but only in the third year of the study. Analysis of prairie grass forage samples, taken in June (vegetative sward) and November (reproductive sward), gave magnesium values of less than 0.2% DM which is below the concentration found in ryegrass and that recommended for dairy cattle. The Ca : P and K : (Ca + Mg) ratios in prairie grass improved, as a forage for dairy cows, with regrowth time up to 5 leaves/tiller. Metabolisable energy remained constant with regrowth time in June at 10.8 MJ/kg DM but fell significantly in November from 10.7 MJ/kg DM, immediately post-grazing, to 9.2 MJ/kg DM at the 4.5 leaves/tiller stage of regrowth. In contrast to observations in ryegrass, the water-soluble carbohydrate content of forage samples of prairie grass taken in November showed a substantial increase with regrowth time to over 12% DM at the 3 leaves/tiller stage of regrowth. The high productivity and forage quality of prairie grass obtained over a 3-year period suggests this grass species could be a suitable temperate perennial grass for subtropical dairy pastures. An appropriately long grazing interval in spring seems critical to optimise plant survival over summer and for adequate seed set for seedling recruitment the following autumn. If summer weeds and/or grasses invade to a significant extent, the large seedbank of prairie grass provides the opportunity to spray out the pasture in summer and rely on seedling recruitment to establish a new sward in autumn. The forage quality of prairie grass in winter and spring is similar to perennial ryegrass but the magnesium levels are substantially lower and stock grazing this type of pasture for extended periods would need to be supplemented with this mineral.


2015 ◽  
Vol 154 (6) ◽  
pp. 1002-1014 ◽  
Author(s):  
I. ULLMANN ◽  
A. HERRMANN ◽  
M. HASLER ◽  
D. CAI ◽  
F. TAUBE

SUMMARYPhenological development and its variation during reproductive growth have important effects on the yield and quality of forage grasses. In perennial ryegrass (Lolium perenne L.) genetic variation in heading date is well recognized, but there are no reliable studies about the variability in the length of the stem elongation phase. To determine the variation in phenological traits of single plants of perennial ryegrass genotypes, a field trial was conducted over three growing seasons (2011–2013) using plant material from eight different ecotype populations, sampled from old permanent grassland swards in Northern Germany. In addition to the phenological stages of jointing, heading and flowering, the critical phase of stem elongation was considered as a new phenological trait. It was hypothesized that the length of the critical phase between jointing and heading differs significantly among genotypes and thus offers a new tool for selecting for specific purposes, e.g. adaption to changing climatic conditions, cutting or grazing as well as yield and quality. The study revealed significant genotypic variation in the observed traits, which was highest for the critical phase (GCV = 0·21). Moderate heritability in jointing (h2 = 0·72) revealed a large environmental impact. In contrast, high heritability (h2 > 0·86) in heading, flowering and the critical phase imply a strong genetic effect. Moderate to high genotypic and phenotypic coefficients of correlation revealed a substantial linkage among the phenological traits. Results are discussed in the context of providing different approaches and strategies in forage crop production, especially with regard to regional weather conditions and future climate change. Significant differences among the tested ecotype populations indicate that existing diversity in permanent grassland can provide source material for further progress in grass breeding.


Crop Science ◽  
1991 ◽  
Vol 31 (1) ◽  
pp. 147-150 ◽  
Author(s):  
A. W. Lenssen ◽  
E. L. Sorensen ◽  
G. L. Posler ◽  
D. L. Stuteville
Keyword(s):  

2021 ◽  
Author(s):  
Agnieszka Konkolewska ◽  
Patrick Conaghan ◽  
Dan Milbourne ◽  
Michael Dineen ◽  
Susanne Barth ◽  
...  

1998 ◽  
Vol 38 (1) ◽  
pp. 45-62 ◽  
Author(s):  
Edward Glenn ◽  
Rene Tanner ◽  
Seiichi Miyamoto ◽  
Kevin Fitzsimmons ◽  
John Boyer

Sign in / Sign up

Export Citation Format

Share Document