Reliability of paddock sampling for the organisms (Anguina funesta and Clavibacter toxicus) responsible for annual ryegrass toxicity

1993 ◽  
Vol 33 (7) ◽  
pp. 861 ◽  
Author(s):  
IT Riley ◽  
JM Stanton ◽  
AGP Brown
Keyword(s):  
Western Australia ◽  
Recent History ◽  
Annual Ryegrass ◽  
Population Densities ◽  
Testing Service ◽  
Reliable Tool ◽  
History Of ◽  
Annual Ryegrass Toxicity

An examination of within-paddock distribution of the nematode (Anguina funesta) and bacterium (Clavibacter toxicus) responsible for annual ryegrass toxicity (ARGT) was undertaken to determine the reliability of farmer-collected samples in determining the risk of ARGT. Areas in Western Australia with a recent history of ARGT outbreaks were selected for study. The results indicate that the distribution of ARGT organisms is patchy in paddocks with low population densities, but as the populations grow they spread throughout the paddock. Populations are not likely to reach toxic levels before they become widespread in the paddock. Farmer-collected samples processed by the ARGT Testing Service procedure were found to be a reliable tool for the management of ARGT in Western Australia.

Dilophospora alopecuri and decline in annual ryegrass toxicity in Western Australia

1994 ◽  
Vol 45 (4) ◽  
pp. 841 ◽  
Author(s):  
IT Riley
Keyword(s):  
Western Australia ◽  
Soil Samples ◽  
Annual Ryegrass ◽  
Biological Factors ◽  
The South ◽  
Population Densities ◽  
Important Contributor ◽  
Annual Ryegrass Toxicity

Biological factors contributing to the decline in the incidence of annual ryegrass toxicity (ARGT) in Western Australia were investigated. Annual ryegrass and soil samples were collected in the area where ARGT outbreaks first occurred in Western Australia, an area where the incidence of ARGT has markedly declined. The nematode vector, Anguina funesta, was found in 68% of samples, whereas the toxigenic bacterium, Clavibacter toxicus, was detected in fewer than 2% of samples. The population densities of the nematode were low, but other attributes assayed were normal. The fungus, Dilophospora alopecuri, also associated with A. funesta, was found at 58% of the sampling sites. The abundance of D. alopecuri suggests that it is an important contributor to decline in ARGT. Therefore, the distribution of D. alopecuri in Western Australia was determined in the following season. D. alopecuri was common in the southerly range of A. funesta, but absent in the northerly range where ARGT outbreaks are still common. In the south, D. alopecuri appears to have displaced C. toxicus and reduced A. funesta populations. The findings suggest that there is potential to use D. alopecuri to control ARGT

Development of annual ryegrass toxicity

1983 ◽  
Vol 34 (6) ◽  
pp. 653 ◽  
Author(s):  
BA Stynes ◽  
AF Bird
Keyword(s):  
Electron Microscope ◽  
Plant Growth ◽  
Western Australia ◽  
Growth Stage ◽  
Maximum Level ◽  
Annual Ryegrass ◽  
Physiological Aging ◽  
Bacterial Inhibition ◽  
Annual Ryegrass Toxicity ◽  
Experimental Plots

Ryegrass pasture, containing seed galls induced by Anguina agrostis and colonized by Corynebacterium rathayi, was harvested from experimental plots near Katanning in Western Australia. Plant growth stage, numbers of emerged inflorescences and numbers of galls present were estimated for 10 harvests collected at weekly intervals, commencing 22 September when the first inflorescences had emerged. The concentration of toxin (corynetoxins) at each harvest was estimated using a bacterial inhibition bioassay. Levels of toxin were up to 459 �g per m2 pasture prior to and during anthesis, but the concentration increased rapidly during the final four harvests (corresponding to ripening) and reached a maximum level of 6292 �g m-2. A possible relationship between toxicity and the presence of ultramicroscopic particles observed in the galls was investigated. Galls from each harvest were sectioned and examined under the electron microscope. Particles were not found in galls sampled prior to anthesis, but were found in galls from the last four harvests. From these results, the production of toxin appears to be related to physiological aging of the plant and may also be related to the accumulation of particles.

The distribution and importance of annual ryegrass toxicity in Western Australia and its occurrence in relation to cropping rotations and cultural practices

1980 ◽  
Vol 31 (3) ◽  
pp. 557 ◽  
Author(s):  
BA Stynes ◽  
JL Wise
Keyword(s):  
Western Australia ◽  
Cultural Practices ◽  
Annual Ryegrass ◽  
Four Seasons ◽  
Annual Ryegrass Toxicity

Surveys in Western Australia showed annual ryegrass toxicity to occur on 152 farms in an area around Gnowangerup measuring c. 100 km by 150 km and on 18 farms in four other isolated areas. The disease has spread rapidly during the last 10 years, and has been favoured by practices aimed at pasture improvement in alternating crop-pasture rotations. In the last four seasons, between 76 and 95 % of all stock mortalities due to ryegrass toxicity occurred on fields grazed in the season following a cropping year. Under these conditions, ryegrass is dominant in the pasture, and infection levels are highest. Burning these fields in autumn reduces the level of infection and makes the pasture relatively safe to graze in this season.

Physiologic Measures In Patients with PTSD with and Without A Recent History of Alcohol Abuse

2007 ◽  
Author(s):  
Eileen Ahearn ◽  
Mary Mussey ◽  
Catherine Johnson ◽  
Amy Krohn ◽  
Timothy Juergens ◽  
...  
Keyword(s):  
Alcohol Abuse ◽  
Recent History ◽  
History Of

Fictive Mode, ‘Journey to the West’, and Transformation of Space: ‘Ali Mubarak’s Discourses of Modernization

2007 ◽  
Vol 4 (3) ◽  
pp. 331-358
Author(s):  
WEN-CHIN OUYANG
Keyword(s):  
Cultural Transformation ◽  
Recent History ◽  
Theoretical Principle ◽  
Time And Space ◽  
The West ◽  
Arab Culture ◽  
History Of ◽  
Journey To The West

I begin my exploration of ‘Ali Mubarak (1823/4–1893) and the discourses on modernization ‘performed’ in his only attempt at fiction, ‘Alam al-Din (The Sign of Religion, 1882), with a quote from Guy Davenport because it elegantly sums up a key theoretical principle underpinning any discussion of cultural transformation and, more particularly, of modernization. Locating ‘Ali Mubarak and his only fictional work at the juncture of the transformation from the ‘traditional’ to the ‘modern’ in the recent history of Arab culture and of Arabic narrative, I find Davenport's pronouncement tantalizingly appropriate. He not only places the stakes of history and geography in one another, but simultaneously opens up the imagination to the combined forces of time and space that stand behind these two distinct yet related disciplines.

Mission Tracks in the Bush

2019 ◽  
Vol 3 (1-2) ◽  
pp. 103-124
Author(s):  
Gemma Tulud Cruz
Keyword(s):  
Nineteenth Century ◽  
Western Australia ◽  
South Australia ◽  
Nation Building ◽  
Cultural Encounters ◽  
History Of

Christian missionaries played an important role in the Australian nation building that started in the nineteenth century. This essay explores the multifaceted and complex cultural encounters in the context of two aboriginal missions in Australia in the nineteenth century. More specifically, the essay explores the New Norcia mission in Western Australia in 1846-1900 and the Lutheran mission in South Australia in 1838-1853. The essay begins with an overview of the history of the two missions followed by a discussion of the key faces of the cultural encounters that occurred in the course of the missions. This is followed by theological reflections on the encounters in dialogue with contemporary theology, particularly the works of Robert Schreiter.

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