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.

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.

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.

Target‐site resistance to trifluralin is more prevalent in annual ryegrass populations from Western Australia

2021 ◽  
Author(s):  
Jinyi Chen ◽  
Qin Yu ◽  
Mechelle Owen ◽  
Heping Han ◽  
Eric Patterson ◽  
...  
Keyword(s):  
Western Australia ◽  
Target Site ◽  
Annual Ryegrass ◽  
Target Site Resistance

An enzyme-linked immunosorbent assay for the detection of Rathayibacter toxicus, the bacterium involved in annual ryegrass toxicity, in hay

2006 ◽  
Vol 57 (7) ◽  
pp. 731 ◽  
Author(s):  
A. M. Masters ◽  
A. R. Gregory ◽  
R. J. Evans ◽  
J. E. Speijers ◽  
S. S. Sutherland
Keyword(s):  
Monoclonal Antibody ◽  
Immunosorbent Assay ◽  
Specific Antigen ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Annual Ryegrass ◽  
Capture Assay ◽  
Large Numbers ◽  
Soluble Polysaccharide ◽  
Annual Ryegrass Toxicity

An enzyme-linked immunosorbent assay (ELISA) for Rathayibacter toxicus is described. The development of a monoclonal antibody for a specific antigen from R. toxicus and a polyclonal antibody raised against the same R. toxicus preparation enabled a capture assay format. The assay is specific for a soluble polysaccharide produced by the bacterium and was found to be sensitive enough to detect antigen equivalent to less than one gall per kilogram of hay. The applicability of the assay to samples of pasture or hay is demonstrated. Cost-effective testing of large numbers of samples for the presence of R. toxicus is possible with the ELISA. This will assist stockowners, hay producers, and hay exporters in the management of the risk of annual ryegrass toxicity.

Control of the nematode associated with annual ryegrass toxicity

1983 ◽  
Vol 34 (4) ◽  
pp. 403 ◽  
Author(s):  
AC McKay ◽  
JM Fisher ◽  
AJ Dube
Keyword(s):  
Subterranean Clover ◽  
Good Control ◽  
Parasitic Fungus ◽  
Annual Ryegrass ◽  
Pasture Management ◽  
Pasture Production ◽  
Second Stage ◽  
Before And After ◽  
Legume Growth ◽  
Annual Ryegrass Toxicity

To control the nematode Anguina funesta (considered by some to be A. agrostis), the vector in annual ryegrass toxicity, pasture management treatments were applied before and after gall initiation. Before gall initiation, the herbicides paraquat and diclofop methyl were used to remove ryegrass. These treatments gave good control of the nematode, but reduced pasture production in winter when feed is generally scarce. Diclofop methyl had no detrimental effect on legume growth, and was more effective on actively growing ryegrass than was paraquat, which severely retarded subterranean clover. Desiccating the ryegrass heads, with mechanical topping or the desiccant herbicide paraquat, after gall initiation, but before hatching of the second-stage juveniles ( J2s ) , gave good control of the nematode population. The main limitations with mechanical topping are that the ryegrass heads must be tall enough to cut before the J2s hatch and not all paddocks are suitable for topping. With paraquat, the main limitations are that treated material was susceptible to weathering and there was less regrowth to set seed. Oxamyl, a systemic nematicide applied after gall initiation, had no effect on the nematode, nor had spraying pasture with the nematode parasitic fungus Verticillium sp.

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