Infection studies with Cercospora zebrina on pasture legumes in Western Australia

1985 ◽  
Vol 25 (4) ◽  
pp. 850 ◽  
Author(s):  
MJ Barbetti
Keyword(s):  
Medicago Sativa ◽  
Western Australia ◽  
White Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Disease Development ◽  
High Humidity ◽  
Inoculum Level ◽  
Pasture Legumes ◽  
Ornithopus Compressus

The effects of inoculum level, and temperature and humidity regimes on the development of Cercospora blackstem disease (caused by Cercospora zebrina) in subterranean clover (Trifolium subterraneum) were investigated. Mycelial fragments were an effective and reliable inoculum. The incidence, severity, and the rate of disease development increased with increasing period of high humidity after inoculation and with increasing concentrations of inoculum. Disease was greatest at 18/13� (12/12 h, day/ night), followed by 21/16�C, and then l5/10�C While all cultivars of T. subterraneum sprayed with hyphal fragments of C. zebrina became infected, Trikkala and Larisa showed some resistance. Of the alternative pasture legumes, lucerne (Medicago sativa), medic (M. littoralis, M. truncatula), drooping-flowered clover (T. cernuum), strawberry clover (T. fragiferum), rose clover (T. hirtum) and white clover (T. repens) were all susceptible; only serradella (Ornithopus compressus) was resistant.

Breeding and farming system opportunities for pasture legumes facing increasing climate variability in the south-west of Western Australia

2012 ◽  
Vol 63 (9) ◽  
pp. 840 ◽  
Author(s):  
C. K. Revell ◽  
M. A. Ewing ◽  
B. J. Nutt
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming System ◽  
Annual Rainfall ◽  
The South ◽  
Pasture Legumes ◽  
South West ◽  
Annual Medics ◽  
Phosphorus And Potassium

The south-west of Western Australia has experienced a declining trend in annual rainfall and gradual warming over the last 30 years. The distribution of rainfall has also changed, with lower autumn rainfall, patchy breaks to the season, and shorter springs. This has important implications for the productivity of legume pastures in the region, which is dominated by annual species, particularly subterranean clover (Trifolium subterraneum L.), annual medics (Medicago spp.), serradella (Ornithopus spp.), and biserrula (Biserrula pelecinus L.). For annual pasture legumes, appropriate patterns of seed softening and germination behaviour, efficiency of phosphorus and potassium uptake, responses to elevated levels of atmospheric CO2, and drought resistance of seedlings and mature plants will assume increasing importance. While these traits can be targeted in pasture breeding programs, it will also be important to exploit farming system opportunities to optimise the annual legume component of the feed base. These opportunities may take the form of incorporating strategic shrub reserves and grazing crops to allow for pasture deferment in autumn–winter. Perennial forages may become more important in this context, as discussed in terms of the development of the perennial legume tedera (Bituminaria bituminosa var. albomarginata C.H. Stirton).

Occurrence of bean yellow mosaic virus in subterranean clover pastures and perennial native legumes

1994 ◽  
Vol 45 (1) ◽  
pp. 183 ◽  
Author(s):  
SJ McKirdy ◽  
BA Coutts ◽  
RAC Jones
Keyword(s):  
Mosaic Virus ◽  
Western Australia ◽  
White Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Bean Yellow Mosaic Virus ◽  
Yellow Vein ◽  
Yellow Mosaic Virus ◽  
South West ◽  
Clover Yellow Vein Virus

In 1990, infection with bean yellow mosaic virus (BYMV) was widespread in subterranean clover (Trifolium subterraneum) pastures in the south-west of Western Australia. When 100 leaves were sampled at random per pasture, the virus was detected by ELISA in 23 of 87 pastures and incidences of infection ranged from 1 to 64%. BYMV was present in all seven districts surveyed, but highest incidences of infection occurred in the Busselton district. In smaller surveys in 1989 and 1992, incidences of infection in pastures were higher than in 1990, and ranged up to 90%. In 1992, when petals from 1703 samples of 59 species of perennial native legumes from 117 sites were tested by ELISA, only 1% were found infected with BYMV. The infected samples came from 5/7 districts surveyed. Species found infected were Kennedia prostrata, K. coccinea, Hovea elliptica and H. pungens. Representative isolates of BYMV from subterranean clover and native legumes did not infect white clover systemically confirming that clover yellow vein virus (CYVV) was not involved. It was concluded that BYMV infection was present in many subterranean clover pastures, but normally at low incidences, except in epidemic years such as 1992. Also, perennial native legumes are unlikely to act as major reservoirs for reinfection of annual pastures each year. In areas of Australia with Mediterranean climates where perennial pastures are absent, persistence of the virus over summer is therefore by some other method than infection of perennials.

Transfer of nitrogen from three pasture legumes under periodic defoliation in a field environment

1976 ◽  
Vol 16 (83) ◽  
pp. 863 ◽  
Author(s):  
JR Simpson
Keyword(s):  
White Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Nitrogen Transfer ◽  
Soil System ◽  
Nitrogen Input ◽  
Nitrogen Yield ◽  
Pasture Legumes ◽  
Plant Soil ◽  
Nitrogen Inputs

Subterranean clover (Trifolium subterraneum), white clover (T. repens) and lucerne (Medicago sativa) were each grown in association with cocksfoot (Dactylis glomerata) for three years in field microplots with periodic removal of herbage. The three legumes produced quite different effects on the nitrogen uptake of the grass and the nitrogen content of the underlying soil. The total nitrogen input to the plant-soil system by subterranean clover was only about half that by either of the two perennial legumes. However, subterranean clover continually donated the most nitrogen to the grass. White clover also increased the nitrogen yield of the grass during the second year, but in the third year, severe competition caused a 45 per cent mortality of grass plants and nitrogen transfer was reduced. Both clovers released about 40 per cent of their apparent nitrogen inputs, distributed between the grass and the soil ; thus soil nitrogen under white clover increased by 160 kg N ha-1 year-1. Lucerne put the most nitrogen into the system but produced only transient increases in grass nitrogen yield. Twenty-one per cent of the apparent nitrogen input of lucerne was donated to the soil.

Wether bioassay of annual pasture legumes. I. Oestrogenic activity in Medicago tribuloides Desr. var. Cyprus* relative to four strains of Trifolium subterraneum L.

1964 ◽  
Vol 15 (4) ◽  
pp. 520 ◽  
Author(s):  
AJ Millington ◽  
CM Francis ◽  
NR McKeown
Keyword(s):  
Western Australia ◽  
Large Scale ◽  
Agricultural Research ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Barrel Medic ◽  
Pasture Legumes ◽  
Waite Agricultural Research Institute ◽  
Wide Range ◽  
Seed Increase

The grazing of pasture swards of Cyprus barrel medic and of four strains of subterranean clover resulted in increases of wether teat length similar to those produced by injections of a synthetic oestrogen, diethylstilboestrol. Oestrogenic activity of the medic, as measured by increase in wether teat length, was less than that of the Yarloop and Dwalganup strains of subterranean clover, but similar to that of the Mt. Barker strain. Coumestrol appears to be the principal oestrogenic substance in the medic. The coumestrol contents of Cyprus and commercial barrel medics were similar but varied at different localities. The low coumestrol content of the subterranean clovers suggests that it is not an important oestrogen in this species. ____________________ *Cyprus barrel medic. During the joint FAO–CSIRO collecting expedition in 1950–1951, J. F. Miles collected barrel medic, C.P.J. 13914, in Cyprus, and portion of the seed was passed to D. Symon at the Waite Agricultural Research Institute, Adelaide. A programme, commenced in 1950, to extend the legume belt into the lower rainfall districts of Western Australia, indicated the need for an earlier-flowering medic, and Symon suggested testing the Cyprus introductjon. Encouraging results from sward tnals conducted by the Institute of Agriculture, University of Western Australia, resulted in a programme of seed increase and large-scale commercial production of the Cyprus strain. The Cyprus strain flowers 4 weeks earlier than the commercial and 5 weeks before M. tr ibuloides 173, and is proving a very satisfactory legume on a wide range of soils in Western Australia.

Effects of pH and aluminium on the growth of temperate pasture species. I. Temperate grasses and legumes supplied with inorganic nitrogen

1991 ◽  
Vol 42 (3) ◽  
pp. 559 ◽  
Author(s):  
DC Edmeades ◽  
FPC Blamey ◽  
CJ Asher ◽  
DG Edwards
Keyword(s):  
White Clover ◽  
Festuca Arundinacea ◽  
Trifolium Pratense ◽  
Inorganic Nitrogen ◽  
Red Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Pasture Legumes ◽  
Effects Of Ph

A flowing solution culture experiment was conducted in which four temperature pasture grasses and 11 temperate pasture legumes were grown in solutions of low ionic strength for 29 days at six aluminium (Al) levels with average Al3+ activities {Al3+} of 1.0, 5.1, 5.9, 9.9, 20.8, 41.6 8M at pH 4.5. Growth of these species was also measured at pH 5.5 in the absence of Al. In the absence of added Al, lucerne (Medicago sativa) cv. Hunter River and phalaris (Phalaris aquatica) cv. Grasslands Maru grew better at pH 5.5 than at 4.5. The reverse was so for ryegrass (Lolium perenne) cv. Grasslands Nui and subterranean clover (Trifolium subterraneum) cv. Tallarook. Increasing the pH from 4.5 to 5.5 had no effect on the growth of the other 11 species and cultivars tested. Micromolar activities of Al (<10 8M) markedly reduced the growth of all species. Four groups were tentatively identified in terms of their tolerance to Al. The two cultivars of ryegrass and the two red clover (Trifolium pratense) cultivars, together with Lotus corniculatus cv. Maitland, were relatively sensitive to Al. A 50% reduction in total dry matter (TDM) was associated with {Al3+} of 2-3 8M. The four white clover (Trifolium repens) cultivars, tall fescue (Festuca arundinacea) cv. Grasslands Roa, phalaris cv. Grasslands Maru, and Lucerne cv. Hunter River were intermediate in their tolerance, with {Al3+} of 3-5 8M reducing TDM by 50%. The two subterranean clover cultivars were more tolerant to Al than white clover (50% TDM reduction at 5-6 8M {Al3+}. Lotus pedunculatus CV. Grasslands Maku was exceptional in its tolerance to Al. Its growth was unaffected by {Al3+} up to 5 8M and 50% growth reduction was associated with {Al3+} of 7 8M The results of this study emphasize the need to conduct solution culture experiments at realistic solution concentrations and ionic strengths when examining the effects of Al on plant growth.

Competition among seedlings of perennial grasses, subterranean clover, white clover, and annual ryegrass in replacement series mixtures

2000 ◽  
Vol 51 (3) ◽  
pp. 377 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
White Clover ◽  
Plant Competition ◽  
Perennial Grass ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Maximum Likelihood Estimates ◽  
Annual Ryegrass ◽  
Replacement Series ◽  
Successful Establishment

Seedlings of 3 perennial grasses, Danthonia linkii Kunthcv. Bunderra, D. richardsonii Cashmore cv. Taranna(wallaby grasses), and Phalaris aquatica L. cv. Sirosa,were each grown in replacement series mixtures with seedlings ofTrifolium repens L. (white clover),Trifolium subterraneum L. var. brachycalycinum (Katzn.et Morley) Zorahy & Heller cv. Clare (subterraneanclover), and Lolium rigidum L. (annual ryegrass). Plantswere sown 5 cm apart in boxes (45 by 29 by 20 cm) at a density of 307plants/m2. Maximum likelihood estimates were usedto derive parameters of a non-linear competition model using the dry matterweights of perennial grasses and competitors at 3 harvests, approximately 168,216, and 271 days after sowing. Intra-plant competition was examined inmonocultures of each species, grown at plant spacings of 2, 5, and 8 cm apartwith plants harvested at the above times.Competition occurred in all perennial grass–competitor mixtures, exceptin those of each perennial grass with white clover and thephalaris–subterranean clover mixture (Harvest 1) and those withD. richardsonii and phalaris grown with white clover(Harvest 2). For D. richardsonii (Harvests 1 and 2) andD. linkii (Harvest 1 only) grown with white clover andthe phalaris–subterranean clover (Harvest 1), the two species in themixture were not competing. In the phalaris–white clover mixture, eachspecies was equally competitive (Harvests 1 and 2). These differences incompetition and aggressiveness reflected differences in individual plantweights in monocultures where there was an effect (P < 0.05) of species ondry matter weight per box, but no significant effect of plant spacing.These data indicated that for successful establishment,D. richardsonii and D. linkiishould not be sown in swards with either subterranean clover or white clover,or where populations of annual ryegrass seedlings are likely to be high.Phalaris was more compatible with both white clover and subterranean clover,but aggressively competed with by annual ryegrass.

Response of defoliated swards of subterranean clover and yellow serradella to superphosphate applications

1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland
Keyword(s):  
Field Experiment ◽  
Sandy Soil ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Herbage Yield ◽  
Ornithopus Compressus ◽  
The Relationship

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.

The transference of nitrogen from pasture legumes to an associated grass under several systems of management in pot culture

1965 ◽  
Vol 16 (6) ◽  
pp. 915 ◽  
Author(s):  
JR Simpson
Keyword(s):  
White Clover ◽  
Subterranean Clover ◽  
Experimental Period ◽  
The Other ◽  
Temporary Increase ◽  
Winter Period ◽  
Pasture Legumes ◽  
Perennial Legumes ◽  
Intact Root ◽  
Pot Culture

The extent of underground transference of nitrogen from three pasture legumes, each growing in association with a grass, has been studied in pot culture under several systems of management during the first 12–18 months after sowing. The three legumes performed quite differently. Subterranean clover did not release any nitrogen until senescence and then produced a rapid transference. White clover was competitive for nitrogen until the autumn-winter period. Lucerne released nitrogen gradually over the whole experimental period. Frequent defoliation of the legumes reduced competition for nitrogen by white clover but also reduced transference from the other legumes. Killing the perennial legumes produced only a small temporary increase in transference. Wilting and temporary drying treatments also reduced the transference. Thus there was no evidence that the nitrogen transference from lucerne was due to a shedding or decay of nodules induced by defoliation; it could equally well be due to direct excretion of nitrogen from the intact root system. The significance of the results in pasture establishment in infertile areas is discussed.

Flower initiation in pasture legumes. I. Factors affecting flower initiation in Trifolium subterraneum L.

1955 ◽  
Vol 6 (2) ◽  
pp. 211 ◽  
Author(s):  
Y Aitken
Keyword(s):  
Low Temperature ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Cold Period ◽  
Effect Of Temperature ◽  
Flower Initiation ◽  
Temperature Level ◽  
Factors Affecting ◽  
Pasture Legumes ◽  
Precise Knowledge

The value of the annual legume Trifolium subterraneum L. (subterranean clover) in Australian agriculture warrants more precise knowledge of factors affecting flowering and prolific seeding. The effect of temperature and photoperiod on flower initiation in early and later flowering varieties has been investigated in an effort to determine the geographical limits of the use of subterranean clover in Australia. At any time of sowing, the length of the growing season of a variety depends greatly on the variety's response to the temperature level and to the photoperiod of the first few weeks after germination. In all varieties of subterranean clover so far examined flower initiation is accelerated by a period of low temperature. In the later varieties, flower initiation is prevented by an insufficient period of low temperature. The length of the necessary cold period is shortened under longer photoperiod. Early varieties are early flowering because they do not require so long a cold period or so low a temperature as late varieties.

Effects of pH and aluminium on the growth of temperate pasture species. II. Growth and nodulation of legumes

1991 ◽  
Vol 42 (5) ◽  
pp. 893 ◽  
Author(s):  
DC Edmeades ◽  
FPC Blamey ◽  
CJ Asher ◽  
DG Edwards
Keyword(s):  
White Clover ◽  
Trifolium Pratense ◽  
Inorganic Nitrogen ◽  
Red Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Lotus Corniculatus ◽  
Culture Solution ◽  
Solution Ph ◽  
Lotus Pedunculatus

Ten temperate pasture legumes inoculated with appropriate rhizobia were grown for 31 days in flowing solution culture. Solution ionic strength was approximately 2700 8M and contained inorganic nitrogen (150 , 8M NO3-) only at the commencement of the experiment. Solution pH was maintained at 4.5, 5.0, 5.5 and 6.0. Also, five aluminium (Al) treatments were imposed, with nominal Al concentrations of 0, 3, 6, 12 and 24 8M (2.5, 7.1, 8.3, 11.2 and 24.7 8M Al measured) at pH 4.5. Solution pH <6 . 0 markedly reduced total dry mass (TDM) in all cultivars of white clover (Trifolium repens) cvv. 'Grasslands Pitau, Huia, G18 and Tahora' and red clover (Trifolium pratense) cvv. 'Grassland Turoa and Pawera', and to a lesser extent in the two subterranean clover (Trifolium subterraneum) cvv. 'Tallarook and Woogenellup'. In contrast, solution pH had no effect on the growth of Lotus corniculatus cv. Maitland, while Lotus pedunculatus cv. Maku grew best at pH 4.5. Lotus pedunculatus cv. Maku grew best in solution where the sum of the activities of the monomeric Al species {Alm} was maintained at 5.9 8M. The growth of all other species was decreased with Al in solution, a 50% reduction in TDM being associated with c. 6 8M {Alm] for white clover and subterranean clover, and c. 3 8M in red clover and Lotus corniculatus cv. Maitland.

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