scholarly journals Changes in sward structure, plant morphology and growth of perennial ryegrass–white clover swards over winter

2021 ◽  
Author(s):  
C. Guy ◽  
T. J. Gilliland ◽  
D. Hennessy ◽  
F. Coughlan ◽  
B. McCarthy
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Plant Morphology ◽  
Winter Period ◽  
Stolon Length ◽  
Number Of Leaves ◽  
Trifolium Repens L ◽  
And Performance ◽  
Tiller Density ◽  
Sward Structure

White clover (Trifolium repens L.) is at a disadvantage to perennial ryegrass (Lolium perenne L.; PRG) due to its limited cold tolerance and low growth rates at colder temperatures, which can affect subsequent spring herbage dry matter (DM) availability. The effect of PRG ploidy on white clover morphology and growth over winter, and its subsequent recovery in spring and the following growing season, is poorly understood. The objective of this study was to compare the effect of white clover inclusion and PRG ploidy on sward structure, plant morphology and growth of PRG–white clover swards over winter. Four swards (diploid PRG only, tetraploid PRG only, diploid PRG–white clover and tetraploid PRG–white clover) were evaluated over a full winter period (November–February) at a farmlet scale. The PRG ploidy had no effect on herbage DM production, white clover content or tissue turnover (P > 0.05) over winter. However, white clover inclusion caused a significant decrease in herbage DM production (P < 0.001; −254 kg DM/ha) and tiller density (P < 0.001; −1,953 tillers/m2) over winter. Stolon mass was not affected by PRG ploidy (P > 0.05); however, stolon length and number of leaves per stolon were affected by PRG ploidy (P < 0.05). Including white clover in PRG swards can alter winter sward dynamics, potentially causing difficulties in subsequent spring management and performance due to the reduced over-winter growth rate when compared with PRG.

scholarly journals White clover plant morphology in Waikato dairy pastures

1993 ◽  
pp. 147-150
Author(s):  
S.L. Harris
Keyword(s):  
White Clover ◽  
Plant Morphology ◽  
Dry Weight ◽  
Plant Size ◽  
Plant Structure ◽  
Stolon Length ◽  
Number Of Leaves ◽  
Grazed Swards ◽  
White Clover Plant ◽  
Clover Plant

Seasonal changes in white clover plant morphology were investigated in Waikato dairy pasture. Plants were classified according to the degree of branching, 2nd-order plants comprising the bulk of the population (47%) throughout the year. There was a slightly greater proportion of lst-order plants than found in similar studies on sheep-grazed swards in Manawahr. Plant fragmentation occurred in late spring, increasing the proportion of lstorder plants. A corresponding decrease in plant size was observed, with minimum values measured for most characteristics, i.e., stolon, leaf and root dry weight (DW); stolon length, and number of leaves, roots and growing points. Overall, white clover plants in Waikato dairy pastures are considerably larger than plants in Manawatu sheep pastures. The trial highlighted that because white clover plants in spring are small, they are vulnerable to mismanagement in dairy pastures, just as has been demonstrated in pasture grazed by sheep. There were, however, some significant differences in white clover plant structure in dairy pastures compared with sheep-grazed swards. Keywords: dairy pasture, morphology, plant order, plant size, seasonal variation, Trifolium repens

Morphology of white clover (Trifolium repens L.) plants in pastures under intensive sheep grazing

1988 ◽  
Vol 111 (2) ◽  
pp. 273-283 ◽  
Author(s):  
J. L. Brock ◽  
M. J. M. Hay ◽  
V. J. Thomas ◽  
J. R. Sedcole
Keyword(s):  
White Clover ◽  
Plant Morphology ◽  
Dry Weight ◽  
Plant Size ◽  
Early Spring ◽  
Axillary Buds ◽  
Branching Order ◽  
Wide Range ◽  
Stolon Length ◽  
Total Plant

SummaryThere has been little study on the growth and morphology of individual plants constituting the population of white clover in mixed swards under grazing. Such information is required if the mechanisms governing plant productivity and persistence are to be understood.Intact white clover plants were sampled from intensively sheep-grazed pastures under set stocking, rotational grazing, and a combination of both systems, by taking turves (250 × 250 mm), and washing out the plants, every month for a year. Characters measured for every stolon of each plant were: presence of a growing point; numbers of leaves, roots and axillary buds; stolon length. Total plant leaf and stolon dry weight were also recorded. Plants were classified according to degree of branching, and the contribution of each branching order to the population determined.There were strong seasonal variations in plant size (leaf and stolon dry weight, stolon length, and numbers of stolons and leaves per plant) which showed a significant decrease in spring with recovery over the following summer. This was paralleled by a rapid increase in the proportion of less branched plants (1st and 2nd branching order) in the population from 60 to 80% in spring, as higher-order plants broke up into smaller- and lower-ordered plants at this time. Numbers of roots per plant increased over winter to peak in early spring then declined in the following summer-autumn. While system of grazing management had no significant effect on branching structure of plants, it had a large effect on plant dry weight; rotationally grazed plants were 2·5 times larger than set stocked plants (0·182 cf. 0·073 g respectively).Other general features of plant morphology were that each successive order of branch stolons was shorter and length before branching was less than that of their preceding parent stolon. The highest branching order observed was 6th order. There was no relationship between branching and numbers of roots; in branched plants only 55% of stolons were rooted regardless of plant order, but rooted stolons accounted for 85% of total stolon length and carried 62, 48 and 90% of the leaves, growing points and axillary buds per plant, respectively.Comparison with other studies suggests that the processes outlined in this report may be common to white clover growth under grazing over a wide range of favourable environments.

Effects of chitin amendment of soil on microorganisms, nematodes, and growth of white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.)

1996 ◽  
Vol 22 (3) ◽  
pp. 221-226 ◽  
Author(s):  
S. U. Sarathchandra ◽  
R. N. Watson ◽  
N. R. Cox ◽  
M. E. di Menna ◽  
J. A. Brown ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Trifolium Repens ◽  
Lolium Perenne L ◽  
Trifolium Repens L

scholarly journals GRAZING MANAGEMENT OF PERENNIAL RYEGRASS/ WHITE CLOVER PASTURE IN-LATE SPRING

1982 ◽  
pp. 80-84 ◽  
Author(s):  
C.J. Korte
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Accumulation Rate ◽  
Grazing Intensity ◽  
Late Spring ◽  
Grazing Management ◽  
Tiller Density ◽  
Tiller Dynamics ◽  
Clover Pasture

The patterns of herbage accumulation and the tiller dynamics of a "Grasslands Nui" perennial ryegrass dominant pasture were compared under two grazing intensity treatments in late spring. Rank stemmy herbage developed with lax grazing whereas dense leafy pasture developed with close grazing. Dead herbage and uneaten stems in rank pastures shaded photosynthetic tissue. Leafy swards had a higher herbage accumulation rate and a higher tiller density than stemmy swards. Methods of achieving leafy pasture on farms by combinations of hard grazing, forage conservation and mechanical topping are discussed briefly.

scholarly journals Milksolids production from different combinations of perennial ryegrass and white clover cultivars: I Trial design and pasture performance

2001 ◽  
pp. 91-96 ◽  
Author(s):  
J.P.J. Eerens ◽  
J.R. Crush ◽  
S.L. Woodward ◽  
K.A. Macdonald ◽  
W.A. Carter
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Block Design ◽  
Late Summer ◽  
First Year ◽  
Endophyte Infection ◽  
Commercial Sources ◽  
Tiller Density ◽  
Clover Content

A whole-farm systems comparison of combinations of perennial ryegrass and white clover cultivars rotationally grazed by dairy cows over two complete seasons evaluated improvements in perennial ryegrass and white clover cultivars resulting from plant breeding efforts. There were four treatments comprised of two ryegrass mixtures and two clover mixtures in a 2 x 2 factorial design, each replicated three times in a randomised block design giving 12, self-contained 4-ha farmlets each stocked at three multiparous Friesian cows/ ha. All pastures were sown in April 1998, using seed obtained through commercial sources, with a high endophyte (>70% endophyte infection) specification for the ryegrass cultivars. A grow out test, carried out after sowing, showed that two of the ryegrass cultivars used in the mix of older cultivars (80R) had less than 70% endophyte infection (Ellett 50%, Nui 62%, Yatsyn 94%) resulting in an average endophyte infection of 69% for that mix. The mix of newer ryegrass (98R) cultivars had an average endophyte infection of 92% (Aries HD 91%, Bronsyn 98%, Samson 87%). While seedling densities (ryegrass and clover) were similar for all mixtures at the start, from late summer of the first year onward, tiller densities were around 30% lower (due to predation of endophyte-free plants and tillers by the Argentine stem weevil) in the 80R treatment. The lower tiller density opened up the sward at an opportune time for clover expansion, which the newer clover cultivars (98C) Sustain and Challenge converted into a higher clover production than from the older clover cultivars (60C) Huia and Pitau. The 80R treatment had a greater spring surplus requiring more conservation than the 98R treatment, which had a more even growth distribution over the year. Differences in endophyte infection levels had a major impact on pasture composition, especially clover content; reducing the endophyte level of seed sown from 90% to 70% may create an opportunity to increase the clover content and quality of young pastures in the Waikato. Keywords: cultivars, dairying, endophyte, perennial ryegrass, tiller density, white clover

scholarly journals Plant responses to defoliation and relationships with pasture persistence

2011 ◽  
Vol 15 ◽  
pp. 39-46
Author(s):  
G.R. Edwards ◽  
D.F. Chapman
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Plant Morphology ◽  
Farming Systems ◽  
Plant Responses ◽  
Plant Interactions ◽  
Trade Offs ◽  
Competition For Light ◽  
Grazing Systems

The effects of defoliation on plant morphology and the structure of perennial ryegrass and white clover populations are reviewed with reference to the persistence of yield in sown pastures. Maintenance of high densities of perennial ryegrass tillers and white clover stolons is fundamental to persistence. Tiller and stolon population densities are subject to within- and between-year variation, and are strongly influenced by defoliation management through processes such as competition for light, and size-density trade-offs mediated by self-thinning processes. Spring is a time when high tiller/stolon appearance and death rates occur simultaneously. Spring is also the time when clover populations undergo rapid structural change as large clover plants fragment to release small, unbranched plants with limited ability to compete for light with grasses. The central role of reproductive stem development in perennial ryegrass for summer survival of tillers and autumn re-establishment of tiller populations also highlights the importance of defoliation management during the spring for population persistence. Examples of the application of tactical defoliation management in spring, and at other times of the year, to manipulate stolon and tiller densities are presented. In some instances, such tactics may improve animal production potential, as well as the persistence of new cultivars. It is notable that the New Zealand literature on this topic is mostly more than 15 years old. Recent changes in farming systems and plant genotypes (e.g. tetraploidy in perennial ryegrass, late flowering perennial ryegrass) may require a reanalysis of established principles and practices related to defoliation x plant interactions in grazed pastures to ensure best possible pasture yield persistence and profitability of grazing systems. Keywords: grazing management, perennial ryegrass, persistence, population dynamics, white clover

PASTURE COMPOSITION UNDER MIXED SHEEP AND GOAT GRAZING ON HILL COUNTRY

1984 ◽  
pp. 160-166
Author(s):  
D.A. Clark ◽  
M.P. Rolston ◽  
M.G. Lambert ◽  
P.J. Budding
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Trifolium Repens ◽  
Accumulation Rate ◽  
Botanical Composition ◽  
Lolium Perenne L ◽  
Hill Country ◽  
Agrostis Tenuis ◽  
Trifolium Repens L

Hill country pasture was grazed by the following ratios of goats and sheep from 1979-l 983: 100% goats (Goat 100). 66% goats and 34% sheep (Goat 66)) 33% goats and 67% sheep (doat 33), 100% set-stocked sheep (Sheep 100) and 100% mobstocked sheep. Changes in botanical composition, herbage mass and herbage accumulation rate were measured by sample dissection, visual estimation and trimmed exclosure cages respectively on three slope classes (banks, slopes and tracks). Pastures grazed by goats developed Yorkshire fog IHolcus lanatus)- white clover (Trifolium repens L.) associations with strong white clover growth on all slope classes unlike sheep-grazed pastures which contained little white clover and were dominated by perennial' ryegrass (Lolium perenne L.) and browntop (Agrostis tenuis Sibth.). The herbage mass of 3000, 1830, 1410 kg DM/ha on banks, slopes and tracks respectively for Sheep 100 pastures contrasted with that on the Goat 100 pastures of 2030, 3750 and 4300 kg DM/ha. White clover was enhanced on all slope classes in the Goat 100 treatment. Annual herbage accumulation was greater on the Goat 100 than Sheep 100 pastures, 13.9 and 11.2 t DM/ha respectively. There was a close association between increased annual white clover accumulation and tofal herbage accumulation. The complementary nature of sheepandgoatgrazing behavioursuggeststhe possibility of increased meat and fibre production from mixed grazing. The implications of these results for future research are discussed. Keywords: Sheep, goats, herbage mass, herbage accumulation rate, botanical composition, slope classes, white clover (Trifolium repens L.), perennial ryegrass (Lolium perenne L.), Yorkshire fog (Holcus lanatusl, browntop (Agrostis tenuis Sibth.).

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