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.

Sulfur nutrition of temperate pasture species. I. Effects of nitrogen supply on the external and internal sulfur requirements of subterranean clover and ryegrass

1984 ◽  
Vol 35 (3) ◽  
pp. 379 ◽  
Author(s):  
MA Gilbert ◽  
AD Robson
Keyword(s):  
Sulfur Content ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nitrogen Supply ◽  
Nitrogen Application ◽  
Lolium Rigidum ◽  
Young Leaves ◽  
Glasshouse Experiment ◽  
Sulfur Nutrition

The effects of nitrogen supply on the external and internal sulfur requirements of subterranean clover (Trifolium subterraneum cv. Trikkala) and ryegrass (Lolium rigidum cv. Wimmera) were examined in a glasshouse experiment. Plants were grown for 28 and 42 days on a sulfur-deficient soil supplied with varying rates of sulfur. Nitrogen application increased the external requirement for sulfur of ryegrass by greatly stimulating growth and, to a lesser extent, sulfur content. Hence nitrogen application decreased sulfur concentrations in ryegrass. In subterranean clover there was relatively little effect of nitrogen application on the external requirement for sulfur because nitrogen did not greatly increase the sulfur content. Nitrogen application did not affect the external requirement for sulfur by changing the distribution of sulfur either between root and shoot or within shoots. The internal sulfur requirements, based either on sulfur concentrations or nitrogen to sulfur ratios, in the young leaves of both species were unaffected by nitrogen supply.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

1981 ◽  
Vol 32 (2) ◽  
pp. 257 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Root Growth ◽  
Growth And Development ◽  
Copper Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Growing Season ◽  
Internode Elongation ◽  
Plant Parts ◽  
Lateral Branches

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.

Zinc in subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of zinc supply on distribution of zinc and dry weight among plant parts

1982 ◽  
Vol 33 (6) ◽  
pp. 989 ◽  
Author(s):  
DJ Reuter ◽  
JF Loneragan ◽  
AD Robson ◽  
D Plaskett
Keyword(s):  
Zinc Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Physiological Age ◽  
Vegetative Development ◽  
Plant Parts ◽  
Zinc Concentrations ◽  
Complex Relationships ◽  
Lateral Branches

Effects of zinc supply on the distribution of zinc and dry weight among plant parts were examined during the first 55 days of vegetative development of Seaton Park subterranean clover grown in a zinc-deficient soil in a glasshouse. Symptoms of zinc deficiency first appeared in young trifoliate leaves. Zinc deficiency decreased the expansion of blades and petioles, delayed the development of leaves and lateral branches, depressed dry weights of roots and shoots, and increased the proportion of plant dry weight in roots and leaf blades. In each treatment and at each harvest, zinc concentrations varied widely amongst plant parts and with their physiological age. Plant parts also differed widely in the response of their dry matter and zinc concentrations to both zinc treatment and harvest time. It is suggested that these complex relationships explain why plant samples consisting of composite plant parts are not suitable for diagnosis of zinc deficiency. In the present experiment, zinc concentration in whole shoots was unsatisfactory for diagnosing zinc deficiency since concentrations were higher in young, zinc-deficient plants than in older, zinc-adequate plants. In young leaf blades of the same physiological age, zinc concentrations showed reasonably constant relationships with plant growth throughout the entire experiment. However, they varied two- to three-fold in leaves of different ages from the same plants. The results show the importance for diagnosis of zinc deficiency of selecting as a sample a single organ of defined physiological age. The youngest open leaf blade is recommended for diagnosis of zinc deficiency in subterranean clover.

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.

A comparison of the effects of autumn deferment and continous grazing on the growth of an annual pasture

1973 ◽  
Vol 13 (65) ◽  
pp. 669 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Shoot Apex ◽  
Plant Density ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Winter ◽  
Botanical Composition ◽  
Growing Seasons ◽  
Annual Grasses ◽  
One Year ◽  
Apex Height

The effects of deferred autumn grazing on a pasture comprising nearly equal proportions of subterranean clover (Trifolium subterraneum), capeweed (Arctotheca calendula) and annual grasses were measured over two growing seasons. Autumn deferment increased the survival of capeweed seedlings in both years and of clover in one year but had little effect on the annual grasses. Although there was more herbage present on the deferred plots in early winter, under later set stocking at normal levels by spring the amount of herbage present, plant density, botanical composition and seed numbers were similar on all plots. The accumulation of herbage under deferred grazing caused an elevation of shoot apex height in capeweed, but not in clover. When combined with subsequent intensive grazing, the number of capeweed plants surviving to flowering was sharply reduced. However, this management also resulted in a reduction in herbage production in spring.

Studies on competition for sulfur between subterranean clover and annual ryegrass. II. Interrelation of nitrogen supply and soil temperature

1984 ◽  
Vol 35 (1) ◽  
pp. 65 ◽  
Author(s):  
MA Gilbert ◽  
AD Robson
Keyword(s):  
Soil Temperature ◽  
Sulfur Content ◽  
Subterranean Clover ◽  
Nitrogen Supply ◽  
Annual Ryegrass ◽  
Nitrogen Application ◽  
Lolium Rigidum ◽  
Sulfur Deficiency ◽  
Sulfur Supply ◽  
Better Than

The effects of soil temperature (7, 13, 19 and 25�C) end supplies of nitrogen and sulfur on growth and competition between subterranean clover ( Triticum subterraneum cv. Trikkala) and ryegrass (Lolium rigidum cv. Wimmera) were examined in a glasshouse experiment over a period of 62 days. Soil temperature influenced competition for sulfur in mixtures of species supplied with nitrogen fertilizer. When the sulfur supply was low, there was no competition between the species at temperatures of 7 and 13�C. However, at 19 and 25�C ryegrass suppressed the yield and sulfur content of subterranean clover. When sulfur was applied to the mixture, nitrogen application did not result in competition at any temperature. When nitrogen supply was low, the yield and sulfur content of ryegrass were poor compared with those of subterranean clover. However, this did not result in competition between the species at low or high levels of sulfur supply. In both species, yield and sulfur content increased, and sulfur concentration decreased with increasing soil temperature. Hence there were severe symptoms of sulfur deficiency in plants grown with added nitrogen at 19 and 25'C, and no symptoms in plants grown at lower temperatures. While both species had the same optimum temperature range for growth (between 19 and 25�C), ryegrass grew relatively better than subterranean clover at lower temperatures.

scholarly journals Nitrogen content in plant biomass from subterranean clover (Trifolium subterraneum L.) and cocksfoot (Dactylis glomerata L.) grown under different inorganic nitrogen supply

2015 ◽  
Vol 52 (3) ◽  
pp. 114-119
Author(s):  
Viliana Vasileva ◽  
Konstantina Kocheva ◽  
Janet Mincheva ◽  
Georgi Georgiev ◽  
Anna Ilieva ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Plant Biomass ◽  
Inorganic Nitrogen ◽  
Dactylis Glomerata ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nitrogen Supply ◽  
Dactylis Glomerata L

Effect of cultivar, sowing time, and density on the growth of subterranean clover in winter

1997 ◽  
Vol 48 (7) ◽  
pp. 977 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune ◽  
W. D. Bellotti
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Subterranean Clover ◽  
Leaf Size ◽  
Trifolium Subterraneum ◽  
Early Spring ◽  
Dry Matter Yield ◽  
Sowing Time ◽  
Area Index ◽  
Sward Height

In winter and early spring in Mediterranean environments, animal production is often limited by the low herbage availability associated with low growth rates and short swards, which result in low intake. In the present study, 26 subterranean clover (Trifolium subterraneum) cultivars were evaluated for herbage availability early in the season. There were large variations in dry matter yield (0·3-0·7 g/plant), sward height (2·9-9·3 cm), and leaf area index (1·0-5·1) among cultivars after 70 days of growth, indicating a possibility for selection of cultivars based on these parameters. Increasing plant density from 460 to 4600 plants/m2 increased dry matter yield from 88·5 to 362·8 g/m2 and sward height from 2·6 to 8·3 cm at Day 60. Early sowing increased dry matter yield, sward height, petiole length, leaf number, and leaf size by 13, 6, 32, 10, and 23%, respectively, after 70 days of growth. These results indicate that new pastures should be established early if soil moisture is adequate, and that the time of the season break has an important influence on early growth of pastures and, consequently, on the budgeting of feed in farming practice.

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.

Simazine mixtures for control of annual grasses in pastures

1993 ◽  
Vol 33 (3) ◽  
pp. 319 ◽  
Author(s):  
A Leys ◽  
B Plater
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Bromus Diandrus ◽  
South Wales ◽  
Annual Grasses ◽  
Excellent Control ◽  
Seed Yields

The effectiveness of tank mixes of simazine plus paraquat, and simazine plus fluazifop-P, for control of annual grass weeds in subterranean clover (Trifolium subterraneum L.) pastures was compared in 6 field experiments in southern New South Wales between 1989 and 1991. Mixtures of simazine (500-750 g a.i./ha) plus very low rates of paraquat (40-60 g a.i./ha) gave better than 90% control of vulpia [Vulpia bromoides (L.) S. F. Gray and V. myuros (L.) C. C. Gmelin], barley grass (Hordeum leporinum Link), annual ryegrass (Lolium rigidum Gaud.), and great brome (Bromus diandrus Roth) and were at least as effective as mixtures of simazine plus fluazifop-P (53-106 g a.i./ha). Subterranean clover plant density was not affected by any treatment. Excellent control of grasses caused increased subterranean clover dry matter yields at 1 site and no differences at another site. In weed-free conditions, 12 of 21 herbicide treatments damaged subterranean clover (severe leaf burn and retarded growth) and significantly (P<0.05) reduced dry weight, but this was not reflected in subsequent seed yields.

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