Developmental characteristics of grass varieties in relation to their herbage production

1980 ◽  
Vol 94 (1) ◽  
pp. 125-136 ◽  
Author(s):  
I. Davies

SummaryThe length and weight per unit length of individual internodes of mature reproductive tillers of S. 24 and S. 23 perennial ryegrass and S. 345 and S. 143 cocksfoot were examined under three manurial treatments. At the lower level of nitrogen application successive internodes generally increased in length from the base upward. With additional nitrogen there was an increased proportion of tillers in which internodes near the base of the stem were longer than those immediately above them; lateheading tillers were most affected.Nitrogen increased the weight per unit length of upper internodes of all four varieties; the effect was most marked in S. 23 ryegrass. In the two ryegrasses, nitrogen reduced the weight per unit length of the basal internode.At maturity the upper internodes had lower dry-matter digestibility values than the lower. Nitrogen reduced the dry-matter digestibility of upper and lower internodes.The results are discussed in relation to selection criteria in variety synthesis.

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
E. Malinowska ◽  
K. Jankowski

The aim of this paper is to evaluate the effect of different doses of spent mushroom substrate and cow slurry on sugar content and digestibility of hybrid alfalfa and grass mixtures. The main factors were different doses of organic material: mushroom substrate and slurry, and the following legume grass mixtures: M1-orchard grass (Dactylis glomerata), perennial ryegrass (Lolium perenne), and hybrid alfalfa (Medicago x varia T. Martyn); M2-orchard grass, hybrid alfalfa; M3-perennial ryegrass, hybrid alfalfa. In each growing season, the mixtures were harvested three times during three years of their full use. Sugar content and dry matter digestibility were determined with near-infrared spectroscopy (NIRS) using the NIRFlex N-500 spectrometer. Of all fertilizer treatments, the application of mushroom substrate at a dose of 20 t·ha−1 in combination with 40 m3 of slurry resulted in the best forage quality with its highest digestibility. In the mixture of perennial ryegrass and hybrid alfalfa increasing doses of mushroom substrate with decreasing doses of slurry lowered soluble sugar content and digestibility.


1984 ◽  
Vol 103 (3) ◽  
pp. 659-669 ◽  
Author(s):  
D. Reid

SummaryIn studies of the seasonal distribution of nitrogen fertilizer dressings on grassland using conventional experimental designs it is usually not possible to separate the true effects of an individual fertilizer dressing on the yield at a particular cut from the residual effects of previous dressings. An experiment is described which was designed to allow separation of the direct and residual effects, with certain restrictions, for a system involving five cuts and five possible fertilizer dressings per season on perennial ryegrass swards. From the results obtained over two harvest years on swards on two adjacent sites equations were derived relating the dry-matter and crude-protein yields of herbage to the rate of nitrogen application at five dressings in the season. Predictions of yield distribution patterns from the equations are compared with observed yields from various sequences of nitrogen dressings included in previous experiments at this Institute. Examples are also given of the prediction of sequences of nitrogen dressings required to obtain certain patterns of yield distribution.


1978 ◽  
Vol 90 (3) ◽  
pp. 447-457 ◽  
Author(s):  
D. Reid

SummaryIn a 3-year experiment on a sward of S. 23 perennial ryegrass 21 rates of nitrogen fertilizer ranging from 0 to 897 kg/ha were applied annually on plots cut three, five or ten times per year. The cutting dates within each frequency were decided on the basis of herbage growth stage. Four-parameter exponential curves fitted to the herbage yield data show that the pattern of response to nitrogen application in the five cuts per year treatment was markedly similar to that reported for a previous experiment (Reid, 1970). Alterations in the cutting frequency affected the pattern of dry-matter yield response to nitrogen, but not that of crude-protein yield response. The combined effects of cutting frequency and nitrogen rate are illustrated by response surfaces fitted to the dry-matter yield results using an extension of the equation for the curves fitted to the individual frequency results. These surfaces show that as the number of cuts per year was increased the total yield and the response to nitrogen decreased, but the response was maintained to an increasingly high nitrogen rate. The practical implications of the results are discussed in relation to intensive grazing managements for dairy cows.


2017 ◽  
Vol 3 (1) ◽  
pp. 61-66
Author(s):  
Xuezhao Sun ◽  
Linda Krijgsman ◽  
Garry C. Waghorn ◽  
Holly Kjestrup ◽  
John Koolaard ◽  
...  

2001 ◽  
Vol 41 (1) ◽  
pp. 45 ◽  
Author(s):  
J. L. Jacobs ◽  
F. R. McKenzie ◽  
G. N. Ward ◽  
G. Kearney

A study in south-western Victoria determined effects of 3 perennial ryegrass (Lolium perenne L.) cultivars (Vedette, Impact and Nevis) with differing maturities, duration of lock up and nitrogen (N) application on the dry matter yield and nutritive characteristics of pasture for silage. Treatments were cultivar (3), N (0 and 50 kg N/ha) and duration of lock up (5–10 weeks) arranged in a completely randomised design in 3 by 5 m plots replicated 3 times. Plots were mown to a uniform height (5 cm) on 14 September 1998 (first day of lock up) and 1 week later N was applied as urea (46% N) at either 0 or 50 kg N/ha to the respective plots. Weekly sampling commenced on 19 October (week 5 of lock up), and continued until 23 November. For each treatment and harvest date, dry matter yield and botanical composition were determined, and samples of total pasture and the ryegrass fraction were collected and chemically analysed for dry matter digestibility, concentrations of crude protein, neutral detergent fibre, water-soluble carbohydrates and minerals. Metabolisable energy was derived from dry matter digestibility. All pasture types were predominantly ryegrass (>90%) with no differences in the nutritive characteristics of total pasture swards or the respective ryegrass fraction. Nitrogen at 50 kg N/ha significantly (P<0.05) increased dry matter yield for all cultivars. Metabolisable energy (MJ/kg DM) of the pasture declined with time for all treatments, with Vedette having a significantly (P<0.05) greater rate of decline than the other cultivars. Vedette reached early ear emergence about 3 weeks earlier (week 7) than the other cultivars. The harvestable metabolisable energy yield (MJ/ha) at ear emergence was highest for Impact, followed by Nevis and Vedette. In conclusion, there is potential to use later-maturing cultivars of ryegrass in south-eastern Australia to allow for later harvesting of forage for silage, while maintaining metabolisable energy and maximising dry matter yields. Furthermore, the use of N fertiliser can also increase dry matter yields without impinging on pasture quality provided the time between N application and harvest date does not exceed 5–6 weeks.


1998 ◽  
Vol 38 (8) ◽  
pp. 821 ◽  
Author(s):  
K. F. Smith ◽  
R. J. Simpson ◽  
R. N. Oram ◽  
K. F. Lowe ◽  
K. B. Kelly ◽  
...  

Summary. Two lines of perennial ryegrass (Lolium perenne L.), cv. Aurora and breeding line Ba 11351, from the United Kingdom with elevated concentrations of water-soluble carbohydrates in the shoot were compared with the standard cultivars, Ellett, Vedette and Kangaroo Valley, in pure grass swards under irrigation at Kyabram, Victoria, and Gatton, Queensland, and under natural rainfall at Condah, Victoria, during 1995–97. Near infrared reflectance spectroscopy was used to predict the water-soluble carbohydrate, crude protein, in vitro dry matter digestibility, neutral and acid detergent fibre, and Klason lignin concentrations of the perennial ryegrass herbage. Herbage yield and water-soluble carbohydrate differed between cultivars at each site at most harvests, with the high water-soluble carbohydrate lines usually yielding less and having higher water-soluble carbohydrate concentrations than the 3 standard cultivars. However, the high water-soluble carbohydrate lines also had higher water-soluble carbohydrate concentrations at harvests where their yield was equal to the standard cultivars. The other nutritive value traits differed significantly at more than half of the 32 harvests: the high water-soluble carbohydrate lines had higher crude protein and dry matter digestibility, and lower neutral detergent fibre, the neutral detergent fibre containing less acid detergent fibre and lignin than did the standard cultivars. The high water-soluble carbohydrate lines were more susceptible to crown rust during spring and summer than the standard cultivars at Kyabram and Gatton: heavy infections reduced yield, water-soluble carbohydrate, dry matter digestibility and crude protein. Higher water-soluble carbohydrate may depend on only a few genes, as does rust resistance and it seems likely that high yielding, high water-soluble carbohydrate cultivars can be developed by recombination and selection.


1998 ◽  
Vol 38 (3) ◽  
pp. 219 ◽  
Author(s):  
J. L. Jacobs ◽  
F. R. McKenzie ◽  
S. E. Rigby ◽  
G. Kearney

Summary. This study aimed to define the effect of differing rates of nitrogen application and lock up length on harvested material for silage in south-western Victoria. At 2 sites in south-western Victoria, 140, 3 by 2 m plots of predominantly perennial ryegrass pasture were randomly allocated, within 4 replicate blocks. Five nitrogen fertiliser rates (0, 25, 50, 75, 100 kg N/ha) in combination with 7 lock up lengths were randomly allocated to the 35 plots within each replicate. Nitrogen was applied 1 week after initial lock up (September 10, site 1; September 12, site 2) and harvesting commenced 3 weeks after initial lock up. For each treatment and harvest date, dry matter yield and botanical composition were determined and samples of total pasture and the ryegrass fraction were collected and chemically analysed for dry matter digestibility, crude protein, neutral detergent fibre, water-soluble carbohydrates and mineral content. Metabolisable energy was derived from dry matter digestibility. Increasing rates of nitrogen increased herbage dry matter yield regardless of length of lock up. The yield response was greatest 8 weeks after initial lock up at both sites (site 1, 26 kg DM/kg N; site 2, 14.9 kg DM/kg N). Subsequent regrowth of pasture was increased by nitrogen application over shorter lock up lengths (weeks 3 and 4). Botanical composition was unaffected by treatment during the harvesting period or in the subsequent autumn. Application of nitrogen gave rise to a linear increase in pasture metabolisable energy and crude protein content at both sites until week 5. Thereafter, this response diminished and by week 8 there was a decrease in metabolisable energy and crude protein content. Neutral detergent fibre content was relatively unaffected by nitrogen application until week 8 of the study, at which point there was a linear increase. Application of nitrogen reduced the water-soluble carbohydrate content of pastures throughout the sampling period. It is concluded that application of nitrogen to a mixed sward locked up for silage can increase dry matter yield and, provided pasture is harvested before ryegrass ear emergence, can also have a positive effect on metabolisable energy and crude protein. Given that the decision for removing paddocks from the grazing rotation is based upon pasture growth and stocking rates, the use of nitrogen fertilisers on higher stocked farms could lead to increased dry matter yield over shorter lock up periods. On farms with lower stocking rates shorter lock up periods may allow for pastures to be returned to the grazing rotation earlier, or provide the opportunity for a second harvest of pasture for silage.


2017 ◽  
Vol 155 (10) ◽  
pp. 1633-1645 ◽  
Author(s):  
N. BYRNE ◽  
T. J. GILLILAND ◽  
N. McHUGH ◽  
L. DELABY ◽  
A. GEOGHEGAN ◽  
...  

SUMMARYConventionally perennial ryegrass evaluations are conducted under simulated grazing studies to identify varieties with the best phenotypic performance. However, cut-plot environments differ greatly to those experienced on commercial farms as varieties are not exposed to the same stress levels in test environments. It could be argued that plot-based testing regimes provide little direction to plant breeders in the development of advanced varieties. Varietal phenotypic performance needs to be quantified in ‘commercial’ situations. The objective of the current study was to evaluate the phenotypic performance of a range of perennial ryegrass varieties under commercial farm conditions. Monocultures of 11 Irish Recommended List perennial ryegrass varieties were sown on 66 commercial farms throughout Ireland where performance was evaluated over a 3-year period from 2013 to 2015, inclusive. A linear mixed model was used to quantify variety effects on grassland phenotypic performance characteristics. No significant variety effect was estimated for total, seasonal or silage herbage production. Despite the lack of variety effects, pairwise comparisons found significant performance differences between individual varieties. Grazed herbage yield is of primary importance and was shown to be correlated strongly with total production (0.71); Grazed herbage yield differed significantly by variety, with a range of 1927 kg dry matter (DM)/ha between the highest and lowest performing varieties. Sward quality (dry matter digestibility [DMD]) and density were influenced by variety with a range of 44 g/kg DM for DMD and 0.7 ground score units between the highest and lowest performing varieties. Results of the current study show that on-farm evaluation is effective in identifying the most suitable varieties for intensive grazing regimes, and the phenotypic variance identified among varieties performance for many traits should allow for improved genetic gain in areas such as DM production, persistence and grazing efficiency.


Sign in / Sign up

Export Citation Format

Share Document