A new biotype of bluegreen aphid (Acyrthosiphon kondoi Shinji) found in south-eastern Australia overcomes resistance in a broad range of pasture legumes

2012 ◽  
Vol 63 (9) ◽  
pp. 893 ◽  
Author(s):  
A. W. Humphries ◽  
D. M. Peck ◽  
S. S. Robinson ◽  
T. Rowe ◽  
K. Oldach
Keyword(s):  
Breeding Program ◽  
Severe Damage ◽  
South Eastern ◽  
Pasture Legumes ◽  
Eastern Australia ◽  
Two Populations ◽  
Pasture Legume ◽  
South Eastern Australia

A new bluegreen aphid biotype (BGA, Acyrthosiphon kondoi Shinji) has been found in south-eastern Australia that causes severe damage and mortality in seedlings of previously resistant pasture legume cultivars. Populations of BGA collected at Urrbrae and Binnum, SA in 2009 caused 100% mortality in 29 cultivars of annual and perennial Medicago spp. and annual Trifolium spp. Delaying inoculation from the first trifoliate to the 6–8 trifoliate stage and removing susceptible genotypes from experiments had no impact on reducing mortality from 100% in previously resistant barrel medics. A half-sib family of lucerne from the SARDI breeding program has maintained resistance to the Urrbrae 2009 BGA. A detailed study of the virulence of BGA populations collected from Toowoomba (Qld), Tamworth, Howlong (NSW), Launceston (Tas.), Colebatch, Kimba, Urrbrae and Vivonne Bay (SA) in 2010–11 on 33 pasture legumes provides evidence of new virulent BGA being widespread, despite these populations causing less severe damage and mortality than the two populations collected in 2009.

Performance and weed-suppressive potential of selected pasture legumes against annual weeds in south-eastern Australia

2019 ◽  
Vol 70 (2) ◽  
pp. 147 ◽  
Author(s):  
Sajid Latif ◽  
Saliya Gurusinghe ◽  
Paul A. Weston ◽  
William B. Brown ◽  
Jane C. Quinn ◽  
...  
Keyword(s):  
Subterranean Clover ◽  
Weed Suppression ◽  
Weed Species ◽  
Mixed Stands ◽  
South Eastern ◽  
Pasture Legumes ◽  
Eastern Australia ◽  
Weed Suppressive Ability ◽  
Weed Infestation ◽  
South Eastern Australia

Mixed farming systems have traditionally incorporated subterranean clover (Trifolium subterraneum L.) and lucerne (Medicago sativa L.) as key components of the pasture phase across south-eastern Australia. However, poor adaptation of subterranean clover to acidic soils, insufficient and inconsistent rainfall, high input costs, soil acidification and the emergence of herbicide-resistant weeds have reduced efficacy of some traditional clover species in recent years. To overcome these challenges, numerous novel pasture species have been selectively improved and released for establishment in Australia. Despite their suitability to Australian climate and soils, limited knowledge exists regarding their weed-suppressive ability in relation to establishment and regeneration. Field trials were therefore conducted over 3 years in New South Wales to evaluate the suppressive potential of selected pasture legume species and cultivars as monocultures and in mixed stands against dominant annual pasture weeds. Pasture and weed biomass varied significantly between pasture species when sown as monocultures, but mixtures of several species did not differ with regard to establishment and subsequent weed infestation. Arrowleaf clover (T. vesiculosum Savi.) and biserrula (Biserrula pelecinus L.) cv. Casbah showed improved stand establishment, with higher biomass and reduced weed infestation compared with other pasture species. Generally, weed suppression was positively correlated with pasture biomass; however, yellow serradella (Ornithopus compressus L.) cv. Santorini exhibited greater weed suppression than other pasture legumes while producing lower biomass, thereby suggesting a mechanism other than competition for resources affecting weed-suppressive ability. Over the period 2015–17, arrowleaf clover and biserrula cv. Casbah were generally the most consistent annual pasture legumes with respect to yearly regeneration and suppression of annual pasture weed species.

Geographic variation in the advertisement call of Crinia signifera (Anura:Myobatrachidae) on Kangaroo Island and across southern south-eastern Australia

2008 ◽  
Vol 56 (4) ◽  
pp. 223 ◽  
Author(s):  
Murray J. Littlejohn
Keyword(s):  
Geographic Variation ◽  
Pulse Number ◽  
Advertisement Call ◽  
Regional Study ◽  
South Eastern ◽  
Island Sample ◽  
Eastern Australia ◽  
Continental Islands ◽  
Two Populations ◽  
South Eastern Australia

The male advertisement call of anuran amphibians has a major role in mate choice, and regional variation in this attribute can act as an indicator of speciation and a marker for genetic differentiation. As part of a regional study of geographic variation in the male advertisement call of Crinia signifera across south-eastern Australia and adjacent larger continental islands, samples of advertisement calls from two populations on Kangaroo Island and two populations on the adjacent Fleurieu Peninsula were compared. Four call attributes were considered: pulse number, call duration, pulse rate and dominant frequency. Pulse number is considered the most reliable for comparative purposes because it is not influenced by effective temperature or audio recording and analysis. The two island populations (central and eastern, ~24 km apart) differ significantly in pulse number, with contact but no overlap of interquartile ranges. The eastern sample differs markedly from those on the nearby Fleurieu Peninsula – which are both similar to the more distant central island sample. Geographic variation in pulse number in these four samples and 11 others from two recent publications is then interpreted in the light of land bridges and lower temperatures of the late Pleistocene and early Holocene.

Genesis of an Inverted Treeline Associated With a Frost Hollow in South-Eastern Australia

1988 ◽  
Vol 36 (6) ◽  
pp. 655 ◽  
Author(s):  
DM Paton
Keyword(s):  
Inversion Layer ◽  
Valley Floor ◽  
Severe Damage ◽  
Leaf Injury ◽  
South Eastern ◽  
Eucalyptus Viminalis ◽  
Naturally Occurring ◽  
Dead Trees ◽  
Eastern Australia ◽  
South Eastern Australia

A catastrophic frost in the Bonang valley, Victoria (alt. 660 m), during Aug. 1982 caused severe damage to naturally occurring trees growing within a contour-related inversion layer. All eucalypts and acacias on the valley floor and up to 6 m above it on the lowest slopes were either killed outright or suffered complete crown loss. Between 6 and 25 m above the valley floor, tall Eucalyptus viminalis. trees escaped damage if their crowns were positioned well above the inversion layer. Neighbouring trees of the slightly shorter original codominant E. radiata were so severely damaged that they were either killed or survived crown destruction only by production of trunk epicormics. Despite being wholly positioned within the inversion layer, the shorter trees of E. pauciflora generally survived without much damage, although leaf injury continued to develop for several years in some trees. Results of the final assessment 5 yr after the frost indicate that the lowest surviving E. viminalis trees, together with severely damaged E. radiata. trees, now constitute an inverted treeline separating forest above from dead trees and grassland below. This treeline is related to the 666 m contour, 6 m above the valley floor, and forms a very abrupt boundary because of the predominance of large undamaged trees of E. viminalis. The consequences of this rare catastrophic frost have implications for subalpine ecology in south-eastern Australia, especially the genesis and stability of inverted treelines.

Cross-host compatibility of commercial rhizobial strains for new and existing pasture legume cultivars in south-eastern Australia

2021 ◽  
Author(s):  
Jessica L. Rigg ◽  
Ashlea T. Webster ◽  
Deirdre M. Harvey ◽  
Susan E. Orgill ◽  
Francesca Galea ◽  
...  
Keyword(s):  
South Eastern ◽  
Eastern Australia ◽  
Pasture Legume ◽  
South Eastern Australia

Population ecology of the velvet gecko,Oedura lesueuriiin south eastern Australia: Implications for the persistence of an endangered snake

2008 ◽  
Vol 33 (7) ◽  
pp. 839-847 ◽  
Author(s):  
JONATHAN K. WEBB ◽  
DAVID A. PIKE ◽  
RICHARD SHINE
Keyword(s):  
Population Ecology ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Combining management and breeding advances to improve field pea (Pisum sativum L.) grain yields under changing climatic conditions in south-eastern Australia

Euphytica ◽  
2011 ◽  
Vol 180 (1) ◽  
pp. 69-88 ◽  
Author(s):  
L. S. McMurray ◽  
J. A. Davidson ◽  
M. D. Lines ◽  
A. Leonforte ◽  
M. U. Salam
Keyword(s):  
Pisum Sativum ◽  
Climatic Conditions ◽  
Field Pea ◽  
Grain Yields ◽  
South Eastern ◽  
Pisum Sativum L ◽  
Eastern Australia ◽  
South Eastern Australia
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