Development of disease caused by Phytophthora cinnamomi in mature Xanthorrhoea australis

2001 ◽  
Vol 49 (2) ◽  
pp. 209 ◽  
Author(s):  
M. J. Aberton ◽  
B. A. Wilson ◽  
J. Hill ◽  
D. M. Cahill
Keyword(s):  
Phytophthora Cinnamomi ◽  
Central Area ◽  
Sharp Decline ◽  
Disease Symptoms ◽  
Stem Apex ◽  
The Past ◽  
Open Forest ◽  
Eastern Australia ◽  
Mineral Transport ◽  
Dead Plant

Over the past 30 years, heathland and open forest communities in south-eastern Australia dominated by Xanthorrhoea australis R.Br. have been severely affected by disease caused by Phytophthora cinnamomi Rands. The disease has caused a sharp decline in numbers of individuals within populations of X. australis; however, the etiology of the disease is unclear. The characteristics and disease symptoms induced by P. cinnamomi were analysed within nine mature X. australis plants that had been removed from the field. Seven plants showed typical disease symptoms that ranged from chlorotic leaves through to plant death. Plants showing disease symptoms had different numbers of infected roots, ranging from 0% in one dead plant, 40% infected roots in a plant showing yellowing of leaf tips and 67 and 86%, respectively, in two plants with severe chlorosis. There was variation within the roots, with some infected close to the stem while others were infected at more distal regions. Within stems of all plants, P. cinnamomi was difficult to isolate but was found in the desmium and stem apex and was associated with massive lesions within the central area of the stem. The symptoms of disease in X. australis are caused by a combination of damage to tissues of the roots and stem that may lead to a reduction in water and mineral transport throughout the plant.

An early pliocene pollen assemblage from Lake Tay, south-western Australia, and its phytogeographic implications

1981 ◽  
Vol 29 (3) ◽  
pp. 277 ◽  
Author(s):  
AN Bint
Keyword(s):  
Regional Differentiation ◽  
Pollen Spectrum ◽  
Pollen Assemblage ◽  
Early Pliocene ◽  
The Past ◽  
South West ◽  
Open Forest ◽  
Short Period ◽  
Eastern Australia ◽  
Warm Temperate

Pollen assemblages indicate an Early Pliocene age for sediments in the Lake Tay area, south-west of Norseman, W.A. They also show unexpected similarities to assemblages of the same age from south-eastern Australia and suggest that regional phytogeographic differentiation of the flora of southern Australia was less pronounced in the Early Pliocene than usually supposed. This implies that considerable regional differentiation of southern Australian floras has taken place in a relatively short period, principally during the past 4 or 5 million years. Although the dominant elements in the pollen spectrum indicate a warm temperate open-forest with a lake edge or marsh component, small numbers of the pollen of Nothofagus (brassii-type) and some podocarpaceous conifers are also present. These suggest a wetter climate and may have derived from small stands surviving in refugia on high country to the east or south of Lake Tay.

scholarly journals How To Invest Your IRAs In Profitable Real Estate IRAs

2011 ◽  
Vol 2 (11) ◽  
Author(s):  
Raj Kiani ◽  
M.A. Sangeladji
Keyword(s):  
Real Estate ◽  
Interest Rates ◽  
Retirement Savings ◽  
Sharp Decline ◽  
The Public ◽  
Individual Retirement Accounts ◽  
The Past ◽  
Retirement Accounts ◽  
Roth Ira ◽  
Investment Advisers

Since the inception of Individual Retirement Accounts (IRAs) in 1974, the public has been advised strongly by bankers, accountants (CPAs), and investment advisors that the best strategy for IRA holdings is investment in stocks or bonds.  Unfortunately, with the sharp decline in the market value of stocks and the bottoming out of interest rates in the past years, most IRA funds have performed very poorly and investors have witnessed how drastically their retirement savings lost their accumulated value.  During these years, apparently, not many investment advisers have bothered to consider other alternative ways for investing accumulated IRAs and pension funds.  There is, in fact, another viable investment alternative that offers both safety and a considerable growth rate.  That is real estate IRAs.  The purpose of this paper is to explain (a) why the traditional and Roth IRA should be invested in real estate, b) the steps involved in establishing a sound real estate IRA, (c) the restrictions and the dos and don’ts of investing in a real estate IRA, and (d) the tax and penalty consequences of incorrect investment in a real estate IRA.

The Import of a Narrative : The Role of Aesthetics and Discursive Elements in Fabricating Change in the Centre of São Paulo

2021 ◽  
Author(s):  
Beatriz Kalichman ◽  
Beatriz Rufino
Keyword(s):  
New York ◽  
New York City ◽  
Real Estate ◽  
York City ◽  
Central Area ◽  
Sao Paulo ◽  
Urban Transformation ◽  
São Paulo ◽  
The Past

This chapter examines the use of aesthetic and discursive elements in the production of a narrative about República, a district in the central area of São Paulo (Brazil) that has been transformed through a real estate boom in the past ten years. We focus on newly built studio apartments, and on the efforts to differentiate them from the quitinetes, apartments with similar features built in the 1950s and 1960s that have been heavily stigmatized. We situate our analysis of this purposeful urban transformation within a context intertwined with urban marketing, publicity, and image making. Our research shows the strong presence of an industrial aesthetic in the area, which we understand as being a deliberate echo of the gentrification process that took place in SoHo in New York City in the 1970s.

Relationship between the Southern Oscillation Index and Australian sugarcane yields

1994 ◽  
Vol 45 (7) ◽  
pp. 1557 ◽  
Author(s):  
I Kuhnel
Keyword(s):  
Southern Hemisphere ◽  
Southern Oscillation Index ◽  
Southern Oscillation ◽  
Significance Testing ◽  
The Past ◽  
Northern Areas ◽  
Eastern Australia ◽  
North Eastern ◽  
Sugarcane Yield ◽  
The Relationship

This study examines the relationship between the Southern Oscillation Index and the sugarcane yield anomalies at 27 mills in north-eastern Australia (Queensland) for the period 1950-1989. The major results of this work indicate that the SO1 alone seems to have only a limited value as predictor of total sugarcane yields over large areas (i.e. the whole of Queensland). However, on a smaller scale, the SO1 appears to be a useful indicator of yields for the northern sugarcane districts. In these northern areas, the highest correlations with the SO1 are reached during the southern hemisphere spring and summer months 6 to 11 months prior to the harvest. They are negative and explain about 40% of the total variance. They also suggest that a positive SO1 during the spring and summer months tends to be followed by lower-than-normal yields at the following harvest and vice versa. This signal is rather robust and withstands rigorous significance testing. Moreover, it appears that the relationship between the SO1 and the sugarcane yields has been relatively strong and stable for the past 40 years, but weakened substantially during the 1930-1940 period.

Pathogenic Variability in Australian Isolates of Phytophthora cinnamomi

1993 ◽  
Vol 41 (6) ◽  
pp. 721 ◽  
Author(s):  
MJ Dudzinski ◽  
KM Old ◽  
RJ Gibbs
Keyword(s):  
Phytophthora Cinnamomi ◽  
Growth Period ◽  
Species Variation ◽  
Eucalyptus Marginata ◽  
Disease Symptoms ◽  
Horticultural Crops ◽  
Damage Reduction ◽  
Single Clone ◽  
Pathogenic Variability ◽  
Stable Characteristic

Forty-two isolates of Phytophthora cinnamomi were obtained from native vegetation and horticultural crops within Australia. They represented a broad spectrum of geographical and host origins, both mating types, and all identified Australian isozyme genotypes. All isolates were tested for their pathogenicity to a single clone of Eucalyptus marginata by inoculation of soil in which plants were growing. Differences in pathogenicity were expressed as extent of root damage, reduction of plant growth, period to first visible disease symptoms and time to plant death. Significant variation between isolates was detected. Pathogenicity was unrelated to mating type and isozyme properties. A subset of these 42 isolates encompassing a range of virulence gave generally consistent rankings for pathogenicity variates when re-inoculated twice into plants derived from the original clone. This suggests that pathogenicity is a relatively stable characteristic. Detection of differences in susceptibility to P. cinnamomi between three selected E. marginata. clones was influenced by the pathogenicity of isolates. Only the more pathogenic isolates were useful in this regard. Seedling stems of five eucalypt species were inoculated with virulent and less virulent isolates of P. cinnamomi. This method detected variation in both pathogenicity in the fungus and susceptibility in the host species. Variation in pathogenicity within Australian populations of P. cinnamomi should be taken into account by the choice of isolates of proven virulence when selecting for resistance in trees and other woody hosts.

Atmospheric dust accession in South-Eastern Australia.

Soil Research ◽  
1971 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
PH Walker ◽  
AB Costin
Keyword(s):  
Particle Size ◽  
Organic Content ◽  
Alpine Soils ◽  
The Past ◽  
Eastern Australia ◽  
Australian Alps ◽  
Central Regions ◽  
Median Diameter ◽  
Strong Winds ◽  
High Organic Content

Reddish dust, transported by strong winds from the dry central regions of Australia, is periodically deposited in the humid eastern part of the continent. Dust sampled in snow on the Australian alps during 1968 is comparable in amount with accession reported earlier in the 1900's in New Zealand and Melbourne. The dust reported here has a median diameter of 4 pm, relatively high organic content, and mineralogy in the less than 2 pm fraction dominated by illite and kaolin. The rate of dust accession during the past was probably sufficient to have modified alpine soils. In particular, snow patch soils have a particle size and mineralogy consistent with dust enrichment. A much lower rate of dust accession seems to occur at present in Canberra on the Southern Tablelands.

Foraging ecology of the horseshoe bat, Rhinolophus megaphyllus (Rhinolophidae), in eastern Australia

2004 ◽  
Vol 31 (4) ◽  
pp. 403 ◽  
Author(s):  
Chris R. Pavey ◽  
Chris J. Burwell
Keyword(s):  
Prey Capture ◽  
Foraging Ecology ◽  
Light Trap ◽  
Foraging Strategy ◽  
Flying Insects ◽  
Open Forest ◽  
Eastern Australia ◽  
Wide Range ◽  
Horseshoe Bat ◽  
Conservation Concern

The foraging ecology of the eastern horseshoe bat, Rhinolophus megaphyllus, was examined at five sites spread along 2100 km of its Australian distribution in coastal Queensland. Foraging strategy and prey-capture behaviour of light-tagged bats were similar across sites. Bats were observed foraging during continuous flight at all sites, whereas perch hunting was observed (rarely) at only one site. Bats captured insects by aerial hawking, with a single record of gleaning. In rainforest bats spent most time close to vegetation whereas openings were favoured in open forest/woodland. Only flying insects were captured and, although a wide range of taxa was taken, Lepidoptera (all sites) and Coleoptera (all sites except one) were the primary prey. Occurrence in faeces of Lepidoptera, Coleoptera, and other taxa combined, varied across sites and across seasons, but there was no three-way interaction between taxon, site and season. Comparison of insect taxa in faeces with those captured in a light-trap set at foraging grounds indicated that insects were selectively captured by R. megaphyllus. The foraging ecology of R. megaphyllus is similar to that of other horseshoe bats in its relative stability across a large geographic range. Although the species is currently not of conservation concern in Australia, aspects of its foraging ecology suggest that it may become regionally threatened in areas with high levels of vegetation clearance.

Reproduction in sympatric lizards: comparison of two species of Ctenotus (Scincidae) in south-eastern Australia

2004 ◽  
Vol 52 (6) ◽  
pp. 649 ◽  
Author(s):  
Jennifer E. Taylor
Keyword(s):  
Sexual Maturity ◽  
New South ◽  
Early Spring ◽  
Reproductive Characteristics ◽  
Sparse Vegetation ◽  
South Wales ◽  
Open Forest ◽  
Eastern Australia ◽  
Testis Volume ◽  
Myall Lakes

The scincid lizards Ctenotus robustus and C. taeniolatus occur sympatrically in regenerating, sand-mined areas in the Port Stephens–Myall Lakes region, coastal New South Wales, Australia. They are absent from the unmined open forest of the area. The reproductive characteristics of these two species were compared. Males reached sexual maturity at a smaller snout–vent length (SVL) than females in C. robustus (72 mm v. 78 mm) and C. taeniolatus (49 mm v. 52 mm). Males were reproductive from August to December and maximum testis volume in both species occurred in early spring; minimum testis volume was recorded in early autumn. Females of both species contained yolking follicles or eggs from October to January (spring–summer). Clutch size in C. robustus (4–9) did not differ significantly from that in C. taeniolatus (2–7) when SVL was accounted for. Both species laid eggs in nests dug 4–5 cm deep in open sandy areas with sparse vegetation, and nesting requirements might explain their absence from open forest. At hatching, C. robustus averaged 35.9 mm SVL and C. taeniolatus averaged 29.9 mm SVL. Hatchlings of both species were at field sites from mid-January to early April. Overall, reproductive characteristics of C. robustus and C. taeniolatus were generally similar.

scholarly journals Soilborne Phytophthora and Pythium Diversity From Rhododendron in Propagation, Container, and Field Production Systems of the Pacific Northwest

Plant Disease ◽  
2020 ◽  
Vol 104 (6) ◽  
pp. 1841-1850
Author(s):  
Jerry E. Weiland ◽  
Carolyn. F. Scagel ◽  
Niklaus J. Grünwald ◽  
E. Anne Davis ◽  
Bryan R. Beck ◽  
...  
Keyword(s):  
Disease Control ◽  
Pacific Northwest ◽  
Root Rot ◽  
Production Systems ◽  
Phytophthora Cinnamomi ◽  
Phytophthora Species ◽  
Pythium Species ◽  
Disease Etiology ◽  
The Past ◽  
Field Systems

Rhododendron root rot is a severe disease that causes significant mortality in rhododendrons. Information is needed about the incidence and identity of soilborne Phytophthora and Pythium species causing root rot in Pacific Northwest nurseries in order to better understand the disease etiology and to optimize disease control strategies. The last survey focusing solely on soilborne oomycete pathogens in rhododendron production was conducted in 1974. Since then, advances in pathogen identification have occurred, new species may have been introduced, pathogen communities may have shifted, and little is known about Pythium species affecting this crop. Therefore, a survey of root-infecting Phytophthora and Pythium species was conducted at seven nurseries from 2013 to 2017 to (i) document the incidence of root rot damage at each nursery and stage of production, (ii) identify soilborne oomycetes infecting rhododendron, and (iii) determine whether there are differences in pathogen diversity among nurseries and production systems. Rhododendrons from propagation, container, and field systems were sampled and Phytophthora and Pythium species were isolated from the roots and collar region. Root rot was rarely evident in propagation systems, which were dominated by Pythium species. However, severe root rot was much more common in container and field systems where the genus Phytophthora was also more prevalent, suggesting that Phytophthora species are the primary cause of severe root rot and that most contamination by these pathogens comes in after the propagation stage. In total, 20 Pythium species and 11 Phytophthora species were identified. Pythium cryptoirregulare, Pythium aff. macrosporum, Phytophthora plurivora, and Phytophthora cinnamomi were the most frequently isolated species and the results showed that Phytophthora plurivora has become much more common than in the past. Phytophthora diversity was also greater in field systems than in propagation or container systems. Risks for Phytophthora contamination were commonly observed during the survey and included placement of potting media in direct contact with field soil, the presence of dead plants that could serve as continuous sources of inoculum, and the presence of excess water as a result of poor drainage, overirrigation, or malfunctioning irrigation equipment. In the past, research on disease development and root rot disease control in rhododendron focused almost exclusively on Phytophthora cinnamomi. More research is needed on both of these topics for the other root-infecting species identified in this survey.

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