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.

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).

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.

Subterranean clover mottle virus infection of subterranean clover: widespread occurrence in pastures and effects on productivity

1992 ◽  
Vol 43 (7) ◽  
pp. 1597 ◽  
Author(s):  
JM Wroth ◽  
RAC Jones
Keyword(s):  
Systemic Infection ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Transmission ◽  
Dry Weight ◽  
Widespread Occurrence ◽  
Transmission Rates ◽  
Type Isolate ◽  
Growing Seasons ◽  
South West

In 1989 and 1990, infection with subterranean clover mottle sobemovirus (SCMV) was widespread in subterranean clover ( Trifolium subterraneum L.) pastures in the south-west of Western Australia. The virus was detected in 61% of the pastures sampled and incidences of infection ranged from 1 to 50%. The virus was more common in old pastures than in pastures resown with newer cultivars during the preceeding 5 year period. When 12 isolates of SCMV were inoculated to subterranean clover plants grown in the glasshouse, symptoms varied from mild to severe. SCMV isolates P23 and F4 decreased the herbage dry weight of cw. Daliak and Woogenellup grown in plots as spaced plants by 81-88% while the Type isolate caused losses of 92%. By contrast, losses were 37-49% with cv. Karridale, a cultivar in which systemic infection was either delayed or prevented during winter. Infection decreased seed yield by c. 90% in cvv. Karridale and Woogenellup with all three isolates; seed weight was decreased 21-55%. A small proportion of cv. Woogenellup transplants outgrew the infection in new shoots during late spring to produce abundant healthy foliage. SCMV seed transmission rates in seed collected from infected transplants of cv. Woogenellup were 0.06, 0.07 and 0.43% for the Type, P23 and F4 isolates respectively. It was concluded that SCMV was present in most pastures, but at low incidences, and that it persists in them from year to year. Extended growing seasons and hard grazing are likely to increase its incidence.

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.

Comparison of the phosphate requirements of burr medic and yellow serradella with subterranean clover in the low rainfall wheatbelt of Western Australia

1992 ◽  
Vol 32 (8) ◽  
pp. 1077 ◽  
Author(s):  
BH Paynter
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Yield Response ◽  
Absolute Maximum ◽  
Absolute Yield ◽  
Burr Medic ◽  
Internal Efficiency

Burr medic (Medicago polymorpha) and yellow serradella (Ornithopus compressus) were compared with subterranean clover (Trifolium subterraneum) in their response to freshly topdressed phosphate in the low rainfall wheatbelt of Western Australia. Species were compared on the amount of applied phosphorus (P) required for 90% maximum yield and the ratio of their curvature coefficients from the Mitscherlich relationship between P applied and absolute yield. On marginally acidic, medium-textured soils, burr medic had a higher external shoot requirement for applied P than subterranean clover. Relative differences between the species were affected by season, initial concentration of bicarbonate-extractable P in the soil (0-10 cm), and timing of plant harvest during the growing season. Burr medic generally achieved a higher absolute maximum yield at each harvest, a larger absolute yield response, and a larger percentage response to applied P than subterranean clover. There was no difference between burr medic and subterranean clover with respect to the internal efficiency of P use for shoot production. For seed production, the external requirements of burr medic and subterranean clover for applied P were similar according to the criterion of P required at 90% maximum yield, but burr medic had a higher requirement if curvature coefficient was the criterion for comparison. Burr medic also had a higher internal efficiency of P use for seed production than subterranean clover. On an acidic, light-textured soil, yellow serradella had a lower requirement for applied P than subterranean clover, according to both criteria for all harvests in 2 separate years.

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.

Survey of feral honey bee (Apis mellifera) colonies for Nosema apis in Western Australia

2007 ◽  
Vol 47 (7) ◽  
pp. 883 ◽  
Author(s):  
Rob Manning ◽  
Kate Lancaster ◽  
April Rutkay ◽  
Linda Eaton
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Western Australia ◽  
Honey Bees ◽  
Nosema Apis ◽  
The South ◽  
South West ◽  
Feral Populations ◽  
Significant Difference

The parasite, Nosema apis, was found to be widespread among feral populations of honey bees (Apis mellifera) in the south-west of Western Australia. The location, month of collection and whether the feral colony was enclosed in an object or exposed to the environment, all affected the presence and severity of infection. There was no significant difference in the probability of infection between managed and feral bees. However, when infected by N. apis, managed bees appeared to have a greater severity of the infection.

scholarly journals Our New Cathedrals: Spirituality and Old-Growth Forests in Western Australia

2006 ◽  
Vol 3 (1) ◽  
Author(s):  
David Worth
Keyword(s):  
Social Movements ◽  
Western Australia ◽  
The State ◽  
The South ◽  
Old Growth ◽  
The Past ◽  
South West ◽  
Old Growth Forests ◽  
Heated Debate ◽  
Policy Proposals

Over the past 30 years in Western Australia (WA), there has been heated debate about the future use of the remaining karri and jarrah forests in the south-west of the State. This debate revolves around policy proposals from two social movements: one wants to preserve as much of the remaining old-growth forests as possible, and an opposing movement supports a continued

scholarly journals "Payneham Vale": integrated whole farm Planning

2003 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
R. S. Watkins
Keyword(s):  
Western Australia ◽  
Natural Vegetation ◽  
The South ◽  
Farm Planning ◽  
South West ◽  
The 1950S ◽  
Supplementary Feed ◽  
Eucalyptus Wandoo

IN 1908, Ron's grandfather, Issac Gray, took up an uncleared block of land 15 km north of Frankland in the south-west of Western Australia (see Fig. 1, Hobbs 2003). During that time he ran a few cattle in the bush and clearing of the native woodlands of Wandoo (white gum) Eucalyptus wandoo, J arrah E. marginata and Marri (Redgum) E. calophylla was slow and tedious. Ron's parents took over the farm in 1947, and with the advent of the bulldozer, clearing of Watkin's property and surrounding district began in earnest during the 1950s. Clearing continued as fast "as money permitted", until almost the last natural vegetation was knocked down in 1978 (Fig. 1). Annual pastures with some cropping (for supplementary feed) were the main source of fodder for sheep and cattle.

A new Altivasum Hedley, 1914 (Turbinellidae, Vasinae) from the coast of southern Western Australia

The Festivus ◽  
2020 ◽  
Vol 52 (3) ◽  
pp. 212-217
Author(s):  
Merv Cooper ◽  
Stephen Maxwell
Keyword(s):  
New Species ◽  
Western Australia ◽  
The South ◽  
South West ◽  
Geographically Isolated

This paper presents a new Altivasum found off Jurien Bay, Western Australia at 60 m. This new species expands our understanding of the distribution, and in particular extends the northern range of Altivasum, in the South-west Marine Region. Altivasum pauladellaboscae n. sp. is more rhomboidal than A. hedleyi Maxwell and Dekkers, 2019, which is elongated, and has the formation of tubular spines on the shoulder of axial fold on the later whorls of the spire; these spines are not formed in A. pauladellaboscae n sp. Altivasum pauladellaboscae n sp. differs from A. profundum Dekkers and Maxwell, 2018 in having acute shoulder nodules. The South Australian, A. flindersi Verco, 1914 lacks the fibriated subsutural band found in A. pauladellaboscae n. sp. Altivasum clarksoni Maxwell and Dekkers, 2019 is geographically isolated and morphologically distinct, being more elongated and fibriated. This paper brings the number of described Altivasum species to five

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