Co-occurrence of anAphanomycessp. andPhytopththora clandestinain subterranean clover pastures in the high rainfall areas of the lower south-west of Western Australia

2008 ◽  
Vol 37 (1) ◽  
pp. 74 ◽  
Author(s):  
Xuanli Ma ◽  
Hua Li ◽  
T. O'Rourke ◽  
K. Sivasithamparam ◽  
M. J. Barbetti
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
High Rainfall ◽  
South West ◽  
Lower South

Taxonomic and pathogenic characteristics of a new species Aphanomyces trifolii causing root rot of subterranean clover (Trifolium subterraneum) in Western Australia

2010 ◽  
Vol 61 (9) ◽  
pp. 708 ◽  
Author(s):  
Tiernan A. O'Rourke ◽  
Megan H. Ryan ◽  
Hua Li ◽  
Xuanli Ma ◽  
Krishnapillai Sivasithamparam ◽  
...  
Keyword(s):  
New Species ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Molecular Characteristics ◽  
Root Pruning ◽  
High Rainfall ◽  
South West ◽  
A New Species

Subterranean clover (Trifolium subterraneum) is grown extensively as a pasture legume in agronomic regions with Mediterranean-type climates in parts of Africa, Asia, Australia, Europe, North America and South America. Root diseases of subterranean clover, especially those caused by oomycete pathogens including Aphanomyces, Phytophthora and Pythium, greatly reduce productivity by significantly decreasing germination, seedling establishment, plant survival and seed set. For this reason, experiments were conducted to determine the species of Aphanomyces causing root disease on subterranean clover in the high-rainfall areas of south-west Western Australia. The effects of flooding, temperature and inoculum concentration on the development of root disease on subterranean clover caused by this Aphanomyces sp. were also investigated as was its host range. Morphological and molecular characteristics were used to identify the pathogen as a new species Aphanomyces trifolii sp. nov. (O’Rourke et al.), which forms a distinct clade with its nearest relative being A. cladogamus. A. trifolii caused significant lateral root pruning as well as hypocotyl collapse and tap root disease of subterranean clover. The level of disease was greater in treatments where soil was flooded for 24 h rather than for 6 h or in unflooded treatments. The pathogen caused more disease at 18/13oC than at lower (10/5oC) or higher (25/20oC) temperatures. The pathogen caused more disease at 1% inoculum than at 0.5 or 0.2% (% inoculum : dry weight of soil). In greenhouse trials, A. trifolii also caused root disease on annual medic (M. polymorpha and M. truncatula), dwarf beans (Phaseolus vulgaris) and tomatoes (Solanum lycopersicum). However, the pathogen did not cause disease on peas (Pisum sativum), chickpea (Cicer arietinum), wheat (Triticum aestivum), annual ryegrass (Lolium rigidium) or capsicum (Capsicum annuum). A. trifolii is a serious pathogen in the high-rainfall areas of south-west Western Australia and is likely a significant cause of root disease and subsequent decline in subterranean clover pastures across southern Australia.

The effects of different cultivars of subterranean clover (T. subterraneum L.) on sheep reproduction in the South-west of Western Australia

1970 ◽  
Vol 21 (2) ◽  
pp. 359 ◽  
Author(s):  
HL Davies ◽  
RC Rossiter ◽  
R Maller
Keyword(s):  
Western Australia ◽  
Uterine Prolapse ◽  
Subterranean Clover ◽  
Conception Rate ◽  
The South ◽  
Progressive Decline ◽  
South West ◽  
Conception Rates

The cultivars Dwalganup, Geraldton, Yarloop, Woogenellup, and Mt. Barker were each grazed continuously by Merino and Merino x Border Leicester ewes from April 1963 to November 1967. There was a progressive decline in the proportion of Merino ewes conceiving on the three high oestrogen cultivars Dwalganup, Geraldton, and Yarloop; crossbred ewes showed a decline on Dwalganup and Yarloop. For neither breed of sheep was the decline in conception rate significant on the two low oestrogen cultivars Woogenellup and Mt. Barker. The incidence of uterine prolapse was higher on the high oestrogen cultivars. The percentage lambs marked in 1967 was only 50% for the high oestrogen cultivars (excluding the crossbred ewes on Geraldton), compared with 93% for the low group. Conception rates were significantly related to the concentration of the isoflavone formononetin in the clover leaves.

Persistence of several annual legumes in mixtures under continuous grazing in the south west of Western Australia

1974 ◽  
Vol 14 (70) ◽  
pp. 632 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Medicago Truncatula ◽  
Western Australia ◽  
Subterranean Clover ◽  
The Other ◽  
Annual Rainfall ◽  
Annual Legumes ◽  
South West ◽  
Continuous Grazing ◽  
Average Annual Rainfall ◽  
Average Rainfall

Two experiments are described: one in the wheatbelt in areas receiving 320 and 400 mm average annual rainfall, and the other in a medium rainfall area with an average rainfall of 640 mm. In the first experiment various combinations of barrel medic (Medicago truncatula) and cupped (Trifolium cherleri) and rose clovers (T. hirtum) with subterranean clover (T. subeterraneum) were grown at four sites. Each site was continuously grazed by sheep for periods ranging from three to five years. At all sites subterranean clover became dominant within a few years of establishment. The second experiment involved rose and subterranean clovers in ungrazed pure swards and mixed swards which were either grazed or ungrazed. Grazing was continued for three years. Grazing had a profound effect on the composition of the mixture: whereas subterranean clover dominated the grazed sward, in the absence of grazing rose clover over-topped the subterranean clover and dominated the mixture. The success of subterranean clover in grazed mixtures is attributed largely to relative inaccessibility to the grazing animal, particularly of seedlings but also of seeds.

Single and coastal superphosphates are equally effective as sulfur fertilisers for subterranean clover on very sandy soils in high rainfall areas of south-western Australia

2003 ◽  
Vol 43 (9) ◽  
pp. 1117
Author(s):  
M. D. A. Bolland ◽  
J. S. Yeates ◽  
M. F. Clarke
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Maximum Yield ◽  
Sandy Soils ◽  
Subterranean Clover ◽  
Water Soluble ◽  
Single Superphosphate ◽  
Suitable Alternative ◽  
High Rainfall ◽  
Coastal Superphosphate

To reduce leaching of phosphorus (P) from fertilised pastures to shallow estuaries in the high rainfall (>800 mm annual average) areas of south-western Australia, and to supply extra sulfur (S) for subterranean clover (Trifolium subterraneum L.) in pasture, 'coastal superphosphate' was developed as a possible alternative P and S fertiliser to single superphosphate. Coastal superphosphate is made by adding phosphate rock and elemental S to single superphosphate as it comes out of the den before granulation. It has about 3 times more sulfur (S) and one-third the water-soluble P content than single superphosphate. Four long-term (5-year) field experiments were conducted in south-western Australia to compare the effectiveness of single and coastal superphosphate as S fertilisers for subterranean clover pasture grown on very sandy soils that are frequently S deficient after July each year due to leaching of S from soil. Seven different amounts of S were applied as fertiliser annually. Fertiliser effectiveness was assessed from clover herbage yield and S concentration in dried herbage. Fertiliser nitrogen was not applied in these experiments as this was the normal practice for pastures in the region when the research was conducted.Both coastal and single superphosphates were equally effective per unit of applied S for producing dried clover herbage and increasing S concentration in herbage. Previous research on very sandy soils in the region had shown that coastal superphosphate was equally or more effective per unit of applied P for production of subterranean clover herbage. It is, therefore, concluded that coastal superphosphate is a suitable alternative S and P fertiliser for clover pastures on very sandy soils in the region. The concentration of S in dried clover herbage that was related to 90% of the maximum yield (critical S) was about 0.20–0.35% S during August (before flowering) and 0.15–0.20% S during October (after flowering).

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 alfalfa mosaic and subterranean clover red leaf viruses in legume pastures in Western Australia

1995 ◽  
Vol 46 (4) ◽  
pp. 763 ◽  
Author(s):  
SJ McKirdy ◽  
RAC Jones
Keyword(s):  
Western Australia ◽  
Alfalfa Mosaic Virus ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Transmission ◽  
Enzyme Linked Immunosorbent Assay ◽  
The South ◽  
Potential Threat ◽  
South West ◽  
Burr Medic

When leaf samples were collected from 94 Trifolium subterraneum (subterranean clover) pastures from six districts in spring 1993 in the south-west of Western Australia and tested by enzyme-linked immunosorbent assay, no alfalfa mosaic virus (AMV) or subterranean clover red leaf virus (SCRLV) was detected. In contrast, when 21 irrigated T. repens (white clover) pastures from one district (Bunbury) were sampled and tested in January (summer) 1994, AMV was detected in 16, with eight having infection levels >86%, while SCRLV was found in seven at infection levels of <12%. When a further five T. repens pastures were tested for AMV in October (spring) 1994, the virus was found in all with incidences up to 100%. None of the T. repens pastures with high levels of AMV infection had been resown with T. repens within the last 20 years, whereas those resown within the last five years had little or no infection. AMV was detected in 9/91 annual medic (Medicago spp.) pastures from seven wheatbelt districts sampled in spring 1991 or 1993; a single pasture of M. polymorpha (burr medic) cv. Serena was 21% infected, but the other eight infected ones had <3%. AMV seed transmission was detected in 1/19 commercial seed stocks of M. polymorpha harvested in 1991-93. AMV infection was followed over a 12-year period in M. murex (murex medic) cv. Zodiac seed stocks. It persisted readily through successive seed harvests during this period. It is concluded that infection with AMV and SCRLV is currently not a threat to T. subterraneum pastures in the south-west of Western Australia and that AMV seems not to be one in wheatbelt annual medic pastures provided these are sown with healthy medic seed. In contrast, AMV poses a potential threat to the productivity of irrigated T. repens pastures. SCRLV is also sometimes present in T. repens pastures, but was not found at serious levels.

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.

Bunch rot of Rhine Riesling grapes in the lower south-west of Western Australia

1980 ◽  
Vol 20 (103) ◽  
pp. 247 ◽  
Author(s):  
MJ Barbetti
Keyword(s):  
Botrytis Cinerea ◽  
Western Australia ◽  
Aureobasidium Pullulans ◽  
Grape Berry ◽  
Complete Elimination ◽  
South West ◽  
Wide Range ◽  
Bunch Rot ◽  
Lower South

A bunch rot disorder of Rhine Riesling grapes was investigated during the 1976-77 and 1977-78 seasons in south-west of Western Australia. Fungi isolated from immature berries at or just after flowering were not identical to those isolated from rotting berries at harvest. A wide range of fungi, including Aureobasidium pullulans (de Bary) Arnaud, Botrytis cinerea Pers. ex Fr., Rhizopus, Aspergillus, Penicillium and Alternaria spp., was isolated from rotted berries at harvest. More than 98% of rotting berries showed berry splitting or cracking, or both, at the pedicel end of the grape. Berry thinning of bunches by hand resulted in the almost complete elimination of berry splitting and cracking and a corresponding decline in bunch rot levels. The yield of unrotted bunches from the thinned vines was more than twice that for the unthinned ones; however, thinning reduced overall total vine yields by 63% compared with yields from unthinned vines.

Grazing winter and spring wheat crops improves the profitability of prime lamb production in mixed farming systems of Western Australia

2017 ◽  
Vol 57 (10) ◽  
pp. 2082 ◽  
Author(s):  
E. Hussein ◽  
D. T. Thomas ◽  
L. W. Bell ◽  
D. Blache
Keyword(s):  
Simulation Model ◽  
Western Australia ◽  
Spring Wheat ◽  
Subterranean Clover ◽  
Supplementary Feeding ◽  
Cereal Crops ◽  
Wheat Varieties ◽  
High Rainfall ◽  
Mixed Farming ◽  
Short Period

Grazing immature cereal crops, particularly different varieties of wheat, has become widely adopted in the high rainfall areas of southern Australia. Recently, there has been growing interest in applying this technology in drier parts of the mixed farming zones of Western Australia. A modelling study was conducted to examine farm business returns with or without the grazing of immature wheat (winter and spring varieties) in different locations of Western Australia (Merredin, Wickepin and Kojonup), representing the low to high rainfall (319–528 mm) cropping regions, respectively. A combination of APSIM (crop simulation model) and GrassGro (pasture and livestock simulation model), were used to evaluate the changes in farm gross margins with the grazing of cereal crops at three locations of Western Australia. The results of the study showed that grazing the two wheat varieties (dual-purpose winter and spring) at the high rainfall location increased the profitability of the livestock enterprise by 2.5 times more than grazing crops at both low rainfall locations (P < 0.05). Across all years and sites, the average supplementary feeding costs were reduced by the inclusion of grazed winter (12%) and spring (2%) wheat crops in the lamb production system. The comparative reduction in the cost of supplementary feeding varied between locations and by crop variety within locations, due to both the frequency and average duration of the grazing of wheat crops in these regions, and the farm-stocking rate that was chosen. Both wheat varieties were grazed frequently at the lowest rainfall site (68% and 30% of years for winter and spring wheat varieties respectively), whereas grazing spring wheat was less frequent at the higher rainfall location and averaged 16% of years due to a greater difference in the relative availability of wheat crops versus pasture for grazing among regions. The grazing model assumed that there were abundant productive mixed ryegrass and subterranean clover pasture in the farming system. Overall, this study suggests that both winter and spring wheat crops are likely to supply green feed during the winter feed shortage (April–July) and reduce supplementary feed requirements for a short period of time in some seasons. The value of grazing crops is likely to be higher on farms with poorer soils and less productive pastures.

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