Effects of Neotyphodium lolii infection and sowing rate of perennial ryegrass (Lolium perenne) on the dynamics of ryegrass/subterranean clover (Trifolium subterraneum) swards

2000 ◽  
Vol 51 (1) ◽  
pp. 47 ◽  
Author(s):  
P. E. Quigley
Keyword(s):  
Perennial Ryegrass ◽  
Plant Density ◽  
Production Systems ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Third ◽  
Neotyphodium Lolii ◽  
Sheep Production ◽  
Tiller Density

There is no clear rationale for use of endophyte-infected or endophyte-free seed of perennial ryegrass when sowing pasture in Australia. This research was undertaken to clarify the importance of ryegrass endophyte in temperate pasture systems. A field experiment was conducted to study the dynamics of perennial ryegrass/subterranean clover swards in response to (a) endophyte infection in perennial ryegrass seed, (b) the sowing rate of this seed, and (c) the cultivar of subterranean clover. A higher density of perennial ryegrass seedlings established from seed infected with the endophyte Neotyphodium lolii (E+) than with endophyte-free (E−) seed and there was a significant interaction with the sowing rate. At the highest sowing rate of 16 kg/ha, about 25% more seedlings emerged in the E+ than the E− treatment. The size of individual ryegrass plants at establishment was reduced as sowing rate increased, but endophyte had no effect on their size. The slopes of the curves describing ryegrass tiller density relationships with sowing rate were similar for both endophyte treatments in the first 2 years but were different in the third year. Between the first and third years, tiller density in the E+ plots sown at the lowest rate increased by up to 1000/m2, whereas in E− plots the corresponding increase was only 250/m2. Such changes have not previously been demonstrated. This difference is believed to be due to the superior ability of E+ plants to recover after extended dry periods. At higher sowing rates, neither endophyte treatment led to increased tiller densities between the first and third years. The presence of N. lolii had no effect on plant density of subterranean clover during the 3 years of the experiment. In the second year, the 3 clover cultivars tested had similar patterns of reductions in plant density in response to increased sowing rate of the ryegrass in the previous year, but these patterns did not persist into the third year. Although dry matter (DM) yield of herbage in the third year was not responsive to initial sowing rate, the E+ treatment was still significantly higher than the E−. The cultivar of subterranean clover had little effect on companion ryegrass, and total DM production was insensitive to cultivar of clover. The use of endophyte-infected seed is desirable in order to maintain long-term density of perennial ryegrass in sheep-production systems in Australia.

Tactical versus continuous stocking for persistence of perennial ryegrass (Lolium perenne L.) in pastures grazed by sheep in south-western Victoria

1999 ◽  
Vol 39 (3) ◽  
pp. 265 ◽  
Author(s):  
R. A. Waller ◽  
P. E. Quigley ◽  
G. R. Saul ◽  
G. A. Kearney ◽  
P. W. G. Sale
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seedling Recruitment ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fold Increase ◽  
Early Summer ◽  
Lolium Perenne L ◽  
Western Victoria ◽  
Tiller Density

The survival of perennial ryegrass (Lolium perenne L.) plants was studied in sheep pastures in south-western Victoria during the dry summer of 1996–97. Recruitment of perennial ryegrass seedlings into the pasture sward was also monitored in the autumn–winter periods in 1997 and 1998. The objective was to investigate whether a tactical stocking strategy, consisting of variable length summer, autumn and winter rotations and continuous stocking in spring, might increase perennial ryegrass tiller survival and seedling recruitment in the autumn, compared with continuous stocking all year. The grazing strategies were compared on 2 contrasting pastures: an upgraded pasture [sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year as applied fertiliser] and a naturalised perennial ryegrass pasture receiving 6 kg P/ha.year. Paddocks were grazed by Border Leicester × Merino ewes, mated to a terminal sire so as to lamb in September. Perennial ryegrass tiller density was higher on the upgraded pasture with a mean density of 7750 tillers/m2 in early summer which declined to zero live tillers by mid summer. Live tillers began to reappear before the opening rains and then increased after the rain. Mean tiller density in the upgraded pasture declined over the 2 summers, with only 2050 tillers/m2 being present 2 months after the opening rains in 1998. There were no effects (P>0.05) of pasture type or grazing strategy on the number of tagged tillers that survived the summer period. Only 12% of the vegetative tillers, randomly tagged in December 1996, survived to May 1997. More than half of the tillers (56%) that produced a seedhead produced daughter tillers which survived the dry summer–autumn period. A significant (P<0.05) interaction between grazing strategy and pasture type occurred with the number of perennial ryegrass seedlings that had established 4 weeks after the opening rains in 1997. There was a 5–11-fold increase in seedling numbers which regenerated in the tactically stocked, upgraded pasture compared with the other treatments. Seedling recruitment was considerably lower in the autumn of 1998, due presumably to an overall decline in perennial ryegrass density relative to annual grasses in 1997. A second experiment investigated the effect of excluding sheep from grazing at anthesis until seedhead maturation or until the opening rains, together with a mechanical seed dislodgment treatment at seed maturity. All exclusion treatments increased seedling recruitment 4–7-fold, compared with continuous stocking. The results suggest a possible mechanism by which perennial ryegrass density can be increased without expensive reseeding.

Studies on competition for sulfur between subterranean clover and annual ryegrass. III. Effects of plant density and nitrogen supply

1984 ◽  
Vol 35 (1) ◽  
pp. 75 ◽  
Author(s):  
MA Gilbert ◽  
AD Robson
Keyword(s):  
Interspecific Competition ◽  
Sulfur Content ◽  
Plant Density ◽  
Average Length ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Leaf Length ◽  
Nitrogen Supply ◽  
Competitive Situation ◽  
Lateral Branches

The effects of plant density and supplies of nitrogen and sulfur on competition for sulfur between subterranean clover (Trifolium subterraneum cv. Trikkala) and ryegrass (Lolium rigidum cv. Wimmera) were studied in a glasshouse experiment over a period of 40 days. Irrespective of the density or proportion of each species in the mixture, changes in the supply of nitrogen and sulfur did not cause interspecific competition for sulfur. For subterranean clover, sulfur application increased the number of lateral branches, petiole length and shoot yield. Sulfur application had similar effects on ryegrass, but only at the high level of nitrogen supply. Nitrogen application increased leaf length and tiller number of ryegrass, and increased yield and sulfur content of shoots of both species. In swards where both species were in equal proportions, increasing the overall density from 10 to 30 plants/pot (i.e. from 497 to 1490 plants/m2) did not affect botanical composition or result in interspecific competition, but increased the degree of intraspecific competition. As density increased, the number of branches (tillers), the yield and the sulfur content per plant of each species decreased. Increasing plant density increased the average length of subterranean clover petioles, but had no effect on the average length of ryegrass leaves. When the ryegrass density in mixed swards was low, increasing the density of subterranean clover plants resulted in interspecific competition to the detriment of ryegrass. This competitive situation was considered to be due to competition for light, as it was not alleviated by the addition of sulfur and nitrogen.

Growth of skeleton weed (Chondrilla juncea L.) as affected by growth of subterranean clover (Trifolium subterraneum L.) and infection by Puccinea chondrillina Bubak and Syd

1975 ◽  
Vol 26 (6) ◽  
pp. 975 ◽  
Author(s):  
RH Groves ◽  
JD Williams
Keyword(s):  
Leaf Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Competition ◽  
Leaf Number ◽  
Root Weight ◽  
Large Reduction ◽  
Plant Parts ◽  
Chondrilla Juncea

Growth of skeleton weed (Chondrilla juncea, form A) and subterranean clover (Trifolium subterraneum) was studied in a glasshouse experiment in which the species were grown alone or together and the resultant effects of shoot and root competition assessed. The leaf number and weight of plant parts of C. juncea were reduced by competition vith subterranean clover, especially when shoots of the two species were competing. The leaf area of C. juncea was reduced, especially when roots of the two species were growing together. Puccinia chondrillina on C. juncea rosettes reduced leaf number, leaf area, and weight of plant parts. Subterranean clover grown with C. juncea infected with P. chondrillina further reduced the size and weight of the weed. The large reduction in leaf area and root weight of C. juncea (form A) plants in the presence of both subterranean clover and P. chondrillina suggests that growth of this form of C. juncea in Australia will be greatly reduced in pastures containing these species. In the long term, densities of this form may possibly be so lowered that a significant level of control will be reached in a cereal cropping-pasture system.

scholarly journals Feasibility of grazing sheep production systems using long-term economic indicators and the methodology of the soil expectation value

2014 ◽  
Vol 51 (2) ◽  
pp. 149
Author(s):  
Thayla Sara Soares Stivari ◽  
Rafael Felice Fan Chen ◽  
Augusto Hauber Gameiro ◽  
Alda Lúcia Gomes Monteiro ◽  
Camila Raineri ◽  
...  
Keyword(s):  
Production Systems ◽  
Economic Indicators ◽  
Expectation Value ◽  
Soil Expectation Value ◽  
Grazing Sheep ◽  
Sheep Production

Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 1. Importance of initial perennial density on their persistence and recruitment, and on the presence of weeds

2007 ◽  
Vol 58 (2) ◽  
pp. 113 ◽  
Author(s):  
B. S. Dear ◽  
J. M. Virgona ◽  
G. A. Sandral ◽  
A. D. Swan ◽  
B. A. Orchard
Keyword(s):  
Plant Density ◽  
Seedling Recruitment ◽  
Initial Density ◽  
Basal Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Annual Rainfall ◽  
Curvilinear Relationship ◽  
Initial Population ◽  
South Wales

The influence of initial plant density on the changes in the populations of 3 perennial pasture species, lucerne (Medicago sativa L.), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), and phalaris (Phalaris aquatica L.), over a 3-year pasture phase was examined in the wheatbelt of southern New South Wales. The perennials were sown at 5 rates in combination with subterranean clover (Trifolium subterraneum L.) at 2 locations, Kamarah [430 mm average annual rainfall (a.a.r.)] and Junee (550 mm a.a.r). The range in initial plant populations for lucerne, phalaris, and wallaby grass was 4–74, 8–94, and 2–20 plants/m2, respectively, at Kamarah and 11–120, 9–149, and 6–48 plants/m2 at Junee. When sown at higher densities, the density of lucerne and phalaris declined curvilinearly over the 3 years at both sites. At the 3 lower densities, phalaris populations remained constant at both sites. Lucerne, in contrast, declined over all densities at both sites except at the lowest density at the wetter site (Junee). The rate of decline in lucerne was negatively related (R2 = 0.75) to initial density at Junee, but not at Kamarah. The density of the native grass, wallaby grass, increased with time at both sites through seedling recruitment. The invasion of experimental plots by the summer weed Eragrostis cilianensis (All.) Vign. ex Janchen (stinkgrass) was restricted by lucerne and phalaris, with a negative curvilinear relationship between perennial density and E. cilianensis seedlings in both environments (R2 = 0.65–0.70). In contrast, wallaby grass was ineffective at suppressing E. cilianensis. By the third year, phalaris had significantly higher herbage yields in spring than lucerne and wallaby grass at both sites and phalaris yield was independent of density. Lucerne yields at this time increased with density only at the wetter site (R2 = 0.64), but wallaby grass yields responded to increasing density at both sites (R2 = 0.27–0.59). The experiment demonstrated that establishing higher initial perennial populations of lucerne and phalaris, which did not recruit during the experiment, will result in the maintenance of higher populations over the life of a 3–4 year pasture phase despite proportionally higher rates of plant loss. The size of the initial population was less critical for wallaby grass, which was able to increase in density through recruitment. High initial populations are likely to be an advantage for suppressing weeds in swards of perennial species with limited ability to increase their basal area, such as lucerne and wallaby grass, but will be less beneficial for species such as phalaris, which can compensate by greatly increasing its basal area at lower densities.

The effect of phosphate supply on the growth and botanical composition of annual type pasture

1964 ◽  
Vol 15 (1) ◽  
pp. 61 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Field Experiments ◽  
Total Yield ◽  
Indirect Evidence ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Residual Effects ◽  
Phosphate Deficiency ◽  
Phosphate Supply ◽  
High Phosphate

The results of two long-term field experiments and two 1-year experiments are reported. In three of these, severe phosphate deficiency was present initially. At high phosphate supply, the annual total yield was not significantly related to age of pasture over periods of 10–13 years. At intermediate and low supply, yields relative to high phosphate supply increased significantly with time; these increases are believed to demonstrate residual effects of phosphate. Indirect evidence for nitrogen accretion from clover under severely phosphate-deficient conditions is presented. Sward components—in the long term—responded differentially to phosphate supply. With very low phosphate, erodium (Erodium botrys (Cav.) Bertol.) and flatweed (Hypochoeris glabra L.) were dominant; whereas with high phosphate, cape-weed (Cryptostemma calendula (L.) Druce) and ripgut brome grass (Bromus rigidus Roth)—or else barley grass (Hordeum leporinum Link)—were dominant. Subterranean clover (Trifolium subterraneum L.), though present under these extremes, was relatively more plentiful at intermediate levels of supply. However, at "steady state" conditions, the range in clover content was fairly narrow (from c. 20 to 40%). The significance of these findings to a sheep infertility problem ("clover disease") of subterranean clover-dominant pastures is discussed.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 2. Ryegrass persistence and botanical composition

2001 ◽  
Vol 41 (8) ◽  
pp. 1109 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Grazing Pressure ◽  
Botanical Composition ◽  
Average Mass ◽  
Gravelly Soil ◽  
Western Victoria

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of continuous stocking. Tactical stocking consisted of variable-length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on ryegrass persistence and pasture botanical composition are presented in this paper. The perennial ryegrass component of the sward decreased from an average mass of 1000 kg dry matter/ha on the upgraded pasture and 400 kg dry matter/ha on the typical pasture in spring 1996 to 100 kg dry matter/ha and <50 kg/ha for the 2 pasture types, respectively, in spring 1998. This occurred irrespective of the grazing system imposed. The decline of ryegrass was attributed to several factors including the very dry 3-year period, summer rainfall events that caused ryegrass buds to break dormancy then die when dry conditions resumed, the gravelly soil type where the experiment was located, and the high grazing pressure used. A number of species became more prevalent in the pastures as the ryegrass disappeared. Silver grass (Vulpia spp.) increased 4–5-fold on all treatments. By the fourth year, barley grass (Hordeum leporinum) and Bromus spp. had increased significantly with tactical stocking compared with continuous stocking. Capeweed (Arctotheca calendula L.) and Erodium spp. increased on both the continuously stocked and upgraded pastures. The subterranean clover component was maintained across all treatments over the 4 years, indicating that tactical stocking did not adversely affect clover persistence. Since ryegrass declined irrespective of treatment, the tactical stocking system used in this study cannot be recommended for improving ryegrass persistence.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production

2001 ◽  
Vol 41 (8) ◽  
pp. 1099 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Soil Fertility Status ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter ◽  
Stocking Rates

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of year-around continuous stocking. Tactical stocking consisted of variable length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on herbage production and stocking rate are presented in this paper. Herbage production was similar between the treatments, but tactical stocking significantly increased herbage mass during the growing season (P<0.05) compared with continuous stocking. In spring each year, the herbage mass generally exceeded 3000 kg dry matter/ha in tactically stocked paddocks and averaged 500–900 kg dry matter/ha higher than the mass on continuously stocked paddocks. This enabled the year-round stocking rate to be increased by an average of 9% over the 4 years of the experiment. We considered that the stocking rates could not be further increased, despite the higher herbage mass in spring, as stock reduced the dry herbage to a low residual mass by the opening rains in autumn. In contrast, stocking rates averaged 51% higher on the upgraded pasture compared with the typical pasture over the 4 years of the experiment. This indicates that pasture improvement and soil fertility status have a much greater impact on productivity than changes to grazing method. However, tactical stocking was able to increase the sustainability of prime lamb production on upgraded pastures in a dry summer climate, by maintaining herbage cover on the paddocks over the summer–autumn period.

The interrelation of age, permeability and viability of subterranean clover seeds

1969 ◽  
Vol 9 (40) ◽  
pp. 513
Author(s):  
JA Carpenter
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Small Samples ◽  
Long Term Storage ◽  
Common Effect ◽  
Seed Content ◽  
The Common ◽  
Term Storage

The proportions of impermeable seeds, and the viability of permeable and impermeable seeds were measured in samples of Trifolium subterraneum seed that had been stored in a laboratory for up to 34 years. Viability of permeable seed decreased from 99 per cent after storage for 1 year to 8 per cent after 30 years. On the other hand, all impermeable seeds were viable for 1 to 5 years, and 83 per cent were viable after 30 years. The impermeable seed content of the older seed lots was generally higher than that of the younger ones. This difference was related to the high retention of impermeability of the seeds during storage, and to changes in the severity of threshing methods. The impermeable seed content was also correlated positively but poorly with the viability of both permeable and impermeable seeds, independent of the age of the seed. These associations are probably due to the common effect of the environment on all these variables during seed ripening. A small varietal component in each variable was detected. The implications of these data for the long-term storage of small samples of seed are discussed.

Effect of grazing strategy, ryegrass overdrilling and herbicide application on vulpia content, tiller density and seed production in perennial pastures

2008 ◽  
Vol 48 (5) ◽  
pp. 632 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
R. D. Cousens ◽  
...  
Keyword(s):  
Soil Seed Bank ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Integrated Approach ◽  
Annual Rainfall ◽  
Herbicide Application ◽  
Effective Strategies ◽  
Annual Grasses ◽  
Western Victoria ◽  
Tiller Density

Vulpia species C.C. Gmel. are annual grass weeds that can reduce the productivity of perennial pastures throughout southern Australia. To develop more effective strategies to manage vulpia, a 3-year experiment was established in western Victoria (average annual rainfall: 625 mm) comparing different methods currently used to control this weed. Overdrilling perennial ryegrass (Lolium perenne L.) seed and simazine application treatments were applied to phalaris (Phalaris aquatica L.) pastures that were set-stocked or rotationally grazed (either as a four-paddock or strategic rotation) with Merino ewes. The content of vulpia, subterranean clover (Trifolium subterraneum L.) and other annual grasses as a proportion of total dry matter increased, and the proportion of phalaris decreased in most grazing treatments throughout the experiment. The mean vulpia content was lowest and the phalaris content was highest in the four-paddock rotation, whereas vulpia content was greatest and phalaris content was lowest under set-stocking. Simazine application in June with or without ryegrass overdrilling reduced the number of vulpia tillers/m2 in 2000 and 2001 and vulpia panicle production in 2000, although vulpia populations increased to pretreatment levels in herbicide-treated swards by 2002. The number of vulpia seeds in the soil seed bank was not affected by any of the treatments. The most effective treatment was a combination of ryegrass overdrilling and herbicide application in the four-paddock, rotationally grazed pastures. This experiment highlights the need for an integrated approach to manage vulpia since relying on herbicide application alone is ineffective. This is particularly the case when competitive pasture species are unable to adequately utilise available resources and prevent a recovery in vulpia populations.

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