scholarly journals A COMPARISON OF THREE PERENNIAL RYEGRASS CULTIVARS UNDER CATTLE GRAZING IN THE WAIKATO

1982 ◽  
pp. 118-124
Author(s):  
G.J. Goold
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Growth Rates ◽  
Cattle Grazing ◽  
Cultivar Differences ◽  
Organic Soils ◽  
Peat Soils ◽  
Friesian Cattle

Three perennial ryegrass cultivars (L&urn perennr L.), Grasslands 'Ruanui', Grasslands 'Nui' and Yates 'Ellett' were sown in two experiments on different peat soils at Moanatuatua. Both experiments were alternately mown and grazed with Friesian cattle after an establishment period on each soil. Ruanui swards, grown with white clover (Trfolium repens L.) were the least productive one both a partially-developed and a well-developed peat. "Ellett' and 'Nui' swards produced 28% and 20% more total DM than 'Ruanui' on a well developed peat and 16% and 5%, respectively, on a partially-developed peat, over a 21 cut period from September 1976-September 1979. Pasture growth rates were generally lower on the partially-developed peat and cultivar differences were minimized in this experiment. Peak sward growth rates occurred in December-January on both peat soils. Whereas all three ryegrass cultivar swards reached a peak growth rate of approximately 70 kg DM/ha/day on the partially-developed peat, and Ruanui and Nui reached similar levels on the developed peat, Ellett swards attained higher growth rates (90 kg DM/ha/day) on the more fertile peat. Sward growth rates of Ellett and Nui pastures were consistently higher than those of Ruanui in the autumn. Ellett pastures contained more ryegrass and less white clover than Ruanui swards with Nui being intermediate in grass and clover composition. The value of Ellett and Nui on fertile, organic soils in the Waikato is emphasised.

Pasture and the theory of diversification

2017 ◽  
Vol 57 (7) ◽  
pp. 1210 ◽  
Author(s):  
C. D. Lewis ◽  
C. K. M. Ho ◽  
B. R. Cullen ◽  
B. Malcolm
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Tall Fescue ◽  
Growth Rates ◽  
Dairy Farm ◽  
Biophysical Model ◽  
Seasonal Growth ◽  
Average Growth ◽  
High Rainfall

Diversifying farm activities can reduce the business risk of agricultural production. The aim of the present study was to investigate the effect of diversifying the types of dairy pastures sown on (1) the average seasonal growth rate (kg DM/ha/day) of pasture and (2) the variability of seasonal growth rate of pasture over time by diversifying the types of pastures grown on a dairy farm. This approach is similar to the approach used to assess the diversification of annual cropping activities, although repeated harvest of pasture by grazing animals and the seasonality of pasture DM production complicates the question. The question investigated was ‘How does substituting chicory (Cichorium intybus L.) or tall fescue (Festuca arundinaceae Schreb.) monocultures for a perennial ryegrass (Lolium perenne L.)–white clover (Trifolium repens L.) pasture in increasing proportions affect (1) the average growth rate (kg DM/ha.day) of pasture and (2) the variability of growth rate of pasture in each season?’. The biophysical model DairyMod was used to simulate 30 years growth of a mixed sward of perennial ryegrass and white clover and monocultures of chicory and tall fescue for two rain-fed locations in the high-rainfall zone of southern Australia. Including chicory in the pasture base had the potential to increase pasture growth rate during the summer–early autumn period compared with growing perennial ryegrass–white clover alone. This increase in pasture growth rate increased variability, and reduced growth rates in late autumn–winter and spring. The simulated growth rates of tall fescue and perennial ryegrass were strongly correlated in all seasons; hence, tall fescue did not reduce the variability of total DM. Further analysis would include price correlations and variability and consider the whole-farm implications. The analysis presented here for the high-rainfall zone showed that introducing alternative forages may have benefits in terms of increasing pasture growth rates at critical times of the production year, but the variability of the growth rate was not reduced.

scholarly journals Ewe reproductive performance and growth rate of suckling-lambs on endophyte-infected perennial ryegrass pasture

1999 ◽  
Vol 7 ◽  
pp. 19-26
Author(s):  
R.H. Watson ◽  
R.G. Keogh ◽  
M.F. Mcdonald
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
Reproductive Performance ◽  
Growth Rates ◽  
Ovulation Rate ◽  
Grazing Management ◽  
One Year ◽  
Lamb Growth

Two groups (n=39) of Romney breeding ewes were maintained under the same grazing management on either endophyte-infected (E+) or endophytefree (E-) perennial ryegrass pasture for two years (1997-1998) following a one-year equilibration period. The ewes were naturally mated in March each year and ovulation rate at 1st mating was measured, and conception and the number of lambs born and weaned were recorded. All ewes were weighed monthly and lamb growth rates were determined between birth and weaning. Mean mating date was delayed by 1.8 days (P

Mixed herb and legume pasture improves the growth of lambs post-weaning

2011 ◽  
Vol 51 (8) ◽  
pp. 717 ◽  
Author(s):  
K. P. Golding ◽  
E. D. Wilson ◽  
P. D. Kemp ◽  
S. J. Pain ◽  
P. R. Kenyon ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Growth Rates ◽  
Red Clover ◽  
Carcass Weight ◽  
Grass Species ◽  
Ewe Lambs

The potential of mixed herb and legume pastures to increase post-weaning growth rates of lambs in comparison to ryegrass-based pastures was evaluated. Unrestricted allowances of pasture treatments were offered to weaned, Romney lambs in consecutive autumns of 2007 and 2008. In Experiment 1 (2007), 300 ewe lambs were allocated for 64 days to one of four permanent sward mix treatments; chicory, plantain, red clover and white clover [herb/clover (n = 75)]; plantain, perennial ryegrass and white clover [plantain/pasture (n = 75)]; tetraploid perennial ryegrass and white clover [new pasture (n = 75)]; or diploid perennial ryegrass, other grass species and white clover [old pasture (n = 75)]. In Experiment 2 (2008), the first three pasture treatments from Experiment 1 were re-used (‘old pasture’ not used) with 168 wether lambs allocated for 35 days; herb/clover (n = 56); plantain/pasture (n = 56); and new pasture (n = 56). Unfasted liveweights of all lambs were recorded at weekly intervals and before slaughter. A sub-sample of 78 lambs from Experiment 2 was slaughtered to obtain the carcass weights, tissue depth (11 cm from the spine over the 12th rib) and commercial meat percentages. At the conclusion of Experiment 1 the herb/clover treatment lambs were heavier than the new pasture and plantain/pasture treatment lambs, which were heavier than the old pasture treatment lambs (47.4 vs 41.5 vs 41.5 vs 39.6 ± 0.4 kg, respectively) (P < 0.05). At the conclusion of Experiment 2 the herb/clover treatment lambs were heavier than the new pasture treatment lambs, which were heavier than the plantain/pasture treatment lambs (35.6 vs 32.8 vs 28.8 kg ± 0.4, respectively) (P < 0.05). In Experiment 1 a higher percent of herb/clover treatment lambs grew faster than 200 g/day (P < 0.001) than of the pasture/plantain, new pasture and old pasture treatment lambs (87 vs 4 vs 3 vs 0 percent, respectively). In Experiment 2 only the herb/clover lambs (71%) grew faster than 200 g/day (P < 0.05). In Experiment 2 herb/clover treatment lambs had heavier (P < 0.05) final carcass weight (15.7 ± 0.20 vs 14.8 ± 0.38 vs 14.6 ± 0.27 kg) compared with the plantain/pasture and new pasture lambs, respectively. It was demonstrated that a herb/clover mixed sward can increase post-weaning lamb liveweight gains during unrestricted feeding conditions compared with traditional perennial ryegrass-based pastures.

scholarly journals Lamb growth rates improve as goat to sheep ratio increases

1990 ◽  
pp. 115-118
Author(s):  
R.J. Townsend ◽  
J.E. Radcliffe
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Growth Rates ◽  
Plant Material ◽  
Grazing Management ◽  
Sheep Grazing ◽  
Lamb Growth

Lambs were rotationally grazed with ewes in a 'sheep only' system and with low, medium, and high proportions,of wether goats from October to March on dryland perennial ryegrass-white clover pastures in Canterbury. Lambs grazed with ewes and goats until they were weaned; then they grazed ahead of other stock. Treatment ratios of adult stock on a per head basis were 3 ewes:1 goat ('low goats'), 3 ewes:2 goats ('medium goats') and 3 ewes:3 goats ('high goats'). The ewe:lamb ratio was 1:1.35 on all treatments. Lamb growth rates (g/day) were 152 for 'sheep only', and 169, 185 and 203 for low, medium and high goat treatments respectively. As each treatment lamb reached a target draft weight, it was replaced by a lighter lamb for finishing. In comparison with the 'sheep only' treatment, an extra 1.6 lambs/ha were drafted off the 'medium goat' and an additional 2.6-lambs/ha off the 'high goat' treatment by the end of January. Increasing the proportion of goats:ewes increased the supply of white clover in pastures especially after lambs were weaned. Examination of faecal plant material showed 30% clover in the diet of lambs in a 'sheep only' system, increasing as the goat:sheep ratio increased to 60% clover in the 'high goat' treatment. Keywords white clover, perennial ryegrass, goats, sheep,grazing management, diet, lamb

Genotypic differences in seed growth rates of Phaseolus vulgaris L. I. General characteristics, seed coat factors and comparative roles of seed coats and cotyledons

2000 ◽  
Vol 27 (2) ◽  
pp. 109 ◽  
Author(s):  
Melinda Thomas ◽  
Louise Hetherington ◽  
John W. Patrick
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Dry Matter ◽  
Cultivar Differences ◽  
Phaseolus Vulgaris L ◽  
Surface Areas ◽  
Parenchyma Cells ◽  
Absolute Growth ◽  
Cultivar Variation ◽  
Seed Coats

Developing seeds of four cultivars of Phaseolus vulgaris L., raised under glasshouse conditions, exhib-ited a 4-fold range in rates of storage product accumulation by their cotyledons. These growth rate differences were established during seed expansion. Patterns of dry matter distribution were consistent with absolute growth rates of cotyledons being an inherent property of developing seeds and not limited by photoassimilate supply. Seed surface areas and cotyledon volumes exhibited a 3.2-fold cultivar difference and were the principal components contribut-ing to cultivar variation in cotyledon absolute growth rates. The remaining cultivar variation was attributable to a 1.3- fold difference in dry matter fluxes, expressed on a seed surface area basis. Seed coats reflected these properties in terms of fluxes of dry matter released for cotyledon storage and surface areas supporting these fluxes. Seed coat surface areas correlated with estimates of total plasma membrane areas of ground parenchyma cells that are respon-sible for photoassimilate release. Cultivar differences in these membrane areas largely arose from variation in cell size. Coat turgor pressures correlated positively with dry matter fluxes imported into cotyledons. In contrast, sucrose concentration in bulk saps extracted from seed coats was identical across three cultivars but was positively related to growth rate in the remaining cultivar. Overall, these data suggested that cultivar dry matter fluxes were determined by variation in transport conductances for symplasmic movement through the post-sieve element pathway and for release across the plasma membranes of ground parenchyma cells. Comparable sucrose concentrations were found in seed apoplasmic saps across cultivars, and cultivar differences in absolute growth rates of in vitro cultured coty-ledons were retained. Together, these observations support the conclusion that cotyledons intrinsically express geno-typic variation in rates of dry matter transport comparable to those set independently by seed coats.

scholarly journals Modelling Carbon Fluxes as an Aid to Understanding Perennial Ryegrass (Lolium perenne) Root Dynamics

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 236
Author(s):  
Arif Robin ◽  
Louis Irving ◽  
Edith Khaembah ◽  
Cory Matthew
Keyword(s):  
Root Growth ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Growth Rates ◽  
Plant Performance ◽  
Seasonal Effects ◽  
Cultivar Differences ◽  
Root Turnover ◽  
Root Dynamics ◽  
Maintenance Respiration

Despite the importance of roots in determining plant performance, the factors controlling their development and longevity remain poorly understood. Grass morphology is based on repeating units called phytomers, with each capable of producing one leaf, one daughter tiller, and one or more roots. We developed a phytomer-based understanding of root birth, growth and senescence in Lolium perenne, using a modeling approach to explore seasonal effects on root turnover dynamics, and to explore cultivar differences in these processes. Similar to leaves, roots exhibit a clear progression from initiation, growing for approximately seven phyllochrons, with growth rates strongly influenced by environmental conditions. In spring, the phyllochron decreased over the experiment, while it increased in autumn. In spring, C availability exceeding maintenance respiratory requirements allowed root growth at each phytomer position, with a 70/30 split between maintenance and growth. Under C-deficient conditions in autumn, this split was approximately 80/20, with growth limited to younger phytomer positions, while older roots were more susceptible to starvation-induced senescence due to their high C requirements for maintenance respiration.

Effect of defoliation frequency on an irrigated perennial pasture in northern Victoria. 1. Seasonal production and sward composition

1997 ◽  
Vol 48 (6) ◽  
pp. 811 ◽  
Author(s):  
A. R. Lawson ◽  
P. W. G. Sale ◽  
K. B. Kelly
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Early Spring ◽  
Defoliation Frequency ◽  
Clover Content ◽  
Pasture Yield ◽  
Clover Pasture ◽  
Ryegrass Growth

A field experiment was carried out to investigate whether changes in winter and post-winter defoliation frequency would increase the white clover content of an irrigated perennial ryegrass–white clover pasture in northern Victoria. Pastures defoliated every 4 weeks during winter had higher white clover growing point (stolon apices with at least 2 nodes) density at the end of winter than pastures defoliated every 8 weeks or those receiving a single defoliation after 16 weeks, but these differences did not affect the clover content in the spring. Reasons for this are suggested. Pastures defoliated at 8-week intervals in winter were the most productive over winter{early spring. Less frequent defoliation (4 v. 2 weeks) during the post-winter, September–May period reduced white clover growing point and perennial ryegrass tiller densities. However, the white clover growth rate during this period was increased by less frequent defoliation, whereas the ryegrass growth rate was reduced, resulting in an increase of 10% in the white clover content, and a 1·9 t dry matter (DM)/ha increase in total DM produced. This higher clover content and pasture yield during spring–autumn with less frequent defoliation has important implications for the management of irrigated perennial pastures for the dairy industry in northern Victoria.

scholarly journals THE PERFORMANCE OF FRIESIAN STEERS GRAZING 'GRASSLANDS ROA' TALL FESCUE PASTURES ON PEAT SOILS IN THE WAIKATO

1979 ◽  
pp. 130-137
Author(s):  
G.J. Goold ◽  
F.C.C. Hupkensvan der Elst
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Growth Rates ◽  
Total Yield ◽  
Peat Soils ◽  
Daily Growth ◽  
Stocking Rates

Legume-based pastures of perennial ryegrass ('Grasslands Ruanui + Nui') and 'Grasslands Roa' tall fescue were established on semideveloped peat soils near Hamilton in autumn 1975. Pastures were grazed with yearling Friesian steers at equal stocking rates from August until March during the years 1976 to 1979. Roa tall fescue swards substantially outyielded those of perennial ryegrass in January, February and March with an overall total yield advantage of some 21%. As a result, in most months, steers grazing Roa were offered approximately 15% more DM, which was utilized with similar efficiency to ryegrass (67% tall fescue and 69% ryegrass). Steer liveweight gains per head and per hectare were 10% higher on Roa tall fescue pastures, with average daily growth rates being 0.74 kg/head and the 3-year mean total LWG/ha being 970 kg from the tall fescue pasture.

scholarly journals REGULATION OF APPLE FRUIT GROWTH RATE BY TURGOR PRESSURE?

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 625e-625 ◽  
Author(s):  
Douglas D. Archbold
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Osmotic Potential ◽  
Turgor Pressure ◽  
Apple Fruit ◽  
Fruit Growth ◽  
Cultivar Differences ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Carbohydrate Levels

Maintenance of positive cell turgor is an essential factor in cell, and fruit, expansion. Since apple fruit partition carbohydrates between the starch and soluble pools to maintain turgor, variation among cultivars in this osmoregulatory aspect may play an important role in defining cultivar-specific fruit growth rates. Cultivar-specific apple fruit growth rates were determined over a 6 week period following June drop during 2 seasons. Fruit water relations parameters and carbohydrate levels were also measured. Although cultivar differences were evident, generally, fruit absolute growth rate increased, relative growth rate (RGR) declined, water potential and osmotic potential declined, and turgor potential increased as the season progressed. Soluble carbohydrate levels increased over 6 weeks, while starch levels fluctuated. Soluble carbohydrates contributed 50 to 90% of the osmotic potential. RGR was not correlated to either turgor potential or the relative allocation of carbohydrates between the soluble and starch pools. Thus, although positive turgor was maintained, factors other than turgor per se determine fruit growth rate.

Sign in / Sign up

Export Citation Format

Share Document