scholarly journals Developing a Petri dish test to detect resistance to key herbicides in Lolium rigidum

2021 ◽  
Author(s):  
Martina Badano Perez ◽  
Hugh J Beckie ◽  
Gregory R Cawthray ◽  
Danica E Goggin ◽  
Roberto Busi
Keyword(s):  
Weed Management ◽  
Technology Use ◽  
Petri Dish ◽  
Resistance Testing ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Management Interventions ◽  
Wide Range ◽  
Whole Plants ◽  
On Farm

AbstractOverreliance on herbicides for weed control is conducive to the evolution of herbicide resistance. Annual ryegrass (Lolium rigidum Gaud.) is a species that is prone to evolve resistance to a wide range of herbicide modes of action. Rapid detection of herbicide-resistant weed populations in the field can aid farmers to optimize the use of herbicides for their control. The feasibility of a portable agar-based test to rapidly and reliably detect annual ryegrass resistance to key herbicides such as clethodim, glyphosate, pyroxasulfone and trifluralin on-farm was investigated. The three research phases of this study show that: a) easy-to-interpret results are obtained with non-dormant seed from well-characterised susceptible and resistant populations, and resistance is detected as effectively as with traditional dose-response pot-based resistance assays. However, the test may not be suitable for portable use on-farm because of b) the low stability of some herbicides such as trifluralin and clethodim in agar and c) the tendency of seed dormancy in freshly-harvested seeds to confound the results. The agar-based test is best used as a research tool as a complement to confirm results obtained in traditional pot-based resistance screenings. Comprehensive agar test and / or whole-plant resistance tests by herbicide application at the recommended label rate (whole plants grown in pots) are the current benchmark for proactive in- and off-season resistance testing and should be promoted more widely to allow early detection of resistance, optimization of herbicide technology use and deploy appropriate weed management interventions.

scholarly journals Rapid On-Farm Testing of Resistance in Lolium rigidum to Key Pre- and Post-Emergence Herbicides

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1879
Author(s):  
Martina Badano Perez ◽  
Hugh J. Beckie ◽  
Gregory R. Cawthray ◽  
Danica E. Goggin ◽  
Roberto Busi
Keyword(s):  
Weed Control ◽  
Herbicide Resistance ◽  
Rapid Detection ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Herbicide Resistant ◽  
Primary Dormancy ◽  
Wide Range ◽  
Control Options ◽  
On Farm

Overreliance on herbicides for weed control is conducive to the evolution of herbicide resistance. Lolium rigidum (annual ryegrass) is a species that is prone to evolve resistance to a wide range of herbicide modes of action. Rapid detection of herbicide-resistant weed populations in the field can aid farmers to optimize the use of effective herbicides for their control. The feasibility and utility of a rapid 7-d agar-based assay to reliably detect L. rigidum resistant to key pre- and post-emergence herbicides including clethodim, glyphosate, pyroxasulfone and trifluralin were investigated in three phases: correlation with traditional pot-based dose-response assays, effect of seed dormancy, and stability of herbicides in agar. Easy-to-interpret results were obtained using non-dormant seeds from susceptible and resistant populations, and resistance was detected similarly as pot-based assays. However, the test is not suitable for trifluralin because of instability in agar as measured over a 10-d period, as well as freshly-harvested seeds due to primary dormancy. This study demonstrates the utility of a portable and rapid assay that allows for on-farm testing of clethodim, glyphosate, and pyroxasulfone resistance in L. rigidum, thereby aiding the identification and implementation of effective herbicide control options.

Influence of row spacing and cultivar selection on annual ryegrass (Lolium rigidum) control and grain yield in chickpea (Cicer arietinum)

2019 ◽  
Vol 70 (2) ◽  
pp. 140 ◽  
Author(s):  
Gulshan Mahajan ◽  
Kerry McKenzie ◽  
Bhagirath S. Chauhan
Keyword(s):  
Grain Yield ◽  
Cicer Arietinum ◽  
Weed Management ◽  
Integrated Management ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Row Spacing ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Narrow Row

Annual ryegrass (ARG) (Lolium rigidum Gaudin) is a problematic weed for chickpea (Cicer arietinum L.) production in Australia. Understanding the critical period of control of ARG in chickpea is important for developing effective integrated management strategies to prevent unacceptable yield loss. Experiments were conducted over 2 years at the research farm of the University of Queensland, Gatton, to evaluate the effect of chickpea row spacing (25 and 75cm) and cultivar (PBA Seamer and PBA HatTrick) and ARG infestation period (from 0, 3 and 6 weeks after planting (WAP), and weed-free) on ARG suppression and grain yield of chickpea. Year×treatment interactions were not significant for any parameter, and none of the treatment combinations showed any interaction for grain yield. Average grain yield was greater (20%) with 25-cm than 75-cm rows. On average, PBA Seamer had 9% higher yield than PBA HatTrick. Average grain yield was lowest in season-long weedy plots (562kg ha–1) and highest in weed-free plots (1849kg ha–1). Grain yield losses were lower when ARG emerged at 3 WAP (1679kg ha–1). Late-emerged ARG (3 and 6 WAP) had lower biomass (4.7–22.2g m–2) and number of spikes (5–24m–2) than ARG that emerged early; at 0 WAP, weed biomass was 282–337g m–2 and number of spikes 89–120m–2. Compared with wide row spacing, narrow row spacing suppressed ARG biomass by 16% and 52% and reduced number of spikes of ARG by 26% and 48% at 0 WAP and 3 WAP, respectively. PBA Seamer suppressed ARG growth more effectively than PBA HatTrick, but only in the season-long weedy plots. Our results imply that in ARG-infested fields, grain yield of chickpea can be increased by exploring narrow row spacing and weed-competitive cultivars. These cultural tools could be useful for developing integrated weed management tactics in chickpea in combination with pre-emergent herbicides.

Losses of the digestible components of annual ryegrass (Lolium rigidum Gaudin) during senescence

1990 ◽  
Vol 41 (4) ◽  
pp. 719 ◽  
Author(s):  
RA Ballard ◽  
RJ Simpson ◽  
GR Pearce
Keyword(s):  
Chemical Composition ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Stem Internode ◽  
Whole Plants ◽  
Grass Sward ◽  
Stem Leaf

Changes in the digestibility and chemical composition of a L. rigidum cv. Wimmera sward sown in May, 1985 were measured from 21 d pre-anthesis (9 Oct.) until 69 d after anthesis (7 Jan.) when the plants were dead. Max. yield of 11.7 t DM/ha was reached 8 d pre-anthesis. The in vitro DM digestibility (IVDMD) of whole plants decreased from 58% at anthesis to 36% 69 d after anthesis. This was associated with a decrease in the IVDMD of stem, leaf blades and sheaths. In the 3rd stem internode, which was considered representative of the stem, the loss of digestible yield was due to loss of DM soluble in neutral detergent (NDS). The NDS consisted mainly of non-structural carbohydrates. Similar losses of NDS contributed to loss of digestibility in the uppermost leaf blade and leaf sheath. The digestibility of NDS was generally 80-95% but in the leaf blade this declined to 45% as NDS was mobilized during leaf senescence. NDF digestibility of the stem declined from 35% at anthesis to 19% when dead; corresponding values for the uppermost leaf blade were 83 and 54%, resp., and for the leaf sheath 46 and 37%, resp. These characteristics of a senescing grass sward are discussed in relation to options for improving digestibility of dead grass pastures.

scholarly journals The Remarkable Journey of a Weed: Biology and Management of Annual Ryegrass (Lolium rigidum) in Conservation Cropping Systems of Australia

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1505
Author(s):  
Ali Ahsan Bajwa ◽  
Sajid Latif ◽  
Catherine Borger ◽  
Nadeem Iqbal ◽  
Md Asaduzzaman ◽  
...  
Keyword(s):  
Weed Management ◽  
Production Systems ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Integrated Weed Management ◽  
Annual Ryegrass ◽  
Grain Production ◽  
Competitive Growth ◽  
Lolium Rigidum ◽  
Negative Impacts

Annual ryegrass (Lolium rigidum Gaud.), traditionally utilised as a pasture species, has become the most problematic and difficult-to-control weed across grain production regions in Australia. Annual ryegrass has been favoured by the adoption of conservation tillage systems due to its genetic diversity, prolific seed production, widespread dispersal, flexible germination requirements and competitive growth habit. The widespread evolution of herbicide resistance in annual ryegrass has made its management within these systems extremely difficult. The negative impacts of this weed on grain production systems result in annual revenue losses exceeding $93 million (AUD) for Australian grain growers. No single method of management provides effective and enduring control hence the need of integrated weed management programs is widely accepted and practiced in Australian cropping. Although annual ryegrass is an extensively researched weed, a comprehensive review of the biology and management of this weed in conservation cropping systems has not been conducted. This review presents an up-to-date account of knowledge on the biology, ecology and management of annual ryegrass in an Australian context. This comprehensive account provides pragmatic information for further research and suitable management of annual ryegrass.

Evaluation of seedling allelopathy in 453 wheat (Triticum aestivum) accessions against annual ryegrass (Lolium rigidum) by the equal-compartment-agar method

2000 ◽  
Vol 51 (7) ◽  
pp. 937 ◽  
Author(s):  
H. Wu ◽  
J. Pratley ◽  
D. Lemerle ◽  
T. Haig
Keyword(s):  
Root Growth ◽  
Weed Management ◽  
Wheat Seedling ◽  
Weed Suppression ◽  
Integrated Weed Management ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Allelopathic Potential ◽  
Allelopathic Activity ◽  
Agar Method

Allelopathy has been receiving world-wide attention for its potential in integrated weed management. A newly developed screening bioassay, the ‘equal-compartment-agar method’ (ECAM), was used to evaluate seedling allelopathy against annual ryegrass in a collection of 453 wheat accessions originating from 50 countries. Significant differences in allelopathic potential were found in this worldwide collection, inhibiting root growth of ryegrass from 9.7% to 90.9%. Wheat seedling allelopathy also varied significantly with accessions from different countries. Wheat allelopathic activity was normally distributed within the collection, indicating the involvement of multiple genes conferring the allelopathic trait. Of the 453 wheat accessions screened, 2 distinct groups were identified. Condor-derivatives were more allelopathic than Pavon-derivatives, with an average inhibition of root growth of ryegrass by 76% and 46%, respectively. Research was further extended to investigate the near isogenic lines derived from Hartog (Pavon-derivative) and Janz (Condor-derivative). Hartog and its backcrossed lines were less allelopathic than Janz and its backcrossed lines, inhibiting root length of ryegrass by 45% and 81%, respectively. These results strongly indicate that wheat allelopathic activity might also be controlled by major genes, depending on the particular populations. The present study demonstrates that there is a considerable genetic variation of allelopathic activity in wheat germplasm. It is possible to breed for cultivars with enhanced allelopathic activity for weed suppression.

A quarter of a century of monitoring herbicide resistance in Lolium rigidum in Australia

2019 ◽  
Vol 70 (3) ◽  
pp. 283 ◽  
Author(s):  
J. C. Broster ◽  
J. E. Pratley ◽  
R. H. L. Ip ◽  
L. Ang ◽  
K. P. Seng
Keyword(s):  
Herbicide Resistance ◽  
Acetolactate Synthase ◽  
Resistance Testing ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Epsp Synthase ◽  
Testing Service ◽  
South Wales ◽  
Significant Incidence ◽  
Random Survey

Charles Sturt University has operated a commercial herbicide resistance testing service since 1991, following a random survey of the South West Slopes region of New South Wales that identified significant incidence of herbicide resistance in annual ryegrass (Lolium rigidum Gaud.). Other surveys of cropping regions of southern Australia conducted at that time also found a significant incidence of resistance. In the subsequent 25-year period, the testing service has received samples from the majority of the southern Australian cropping belt. Overall, 80% of samples tested were resistant to acetyl-CoA carboxylase (ACCase) inhibiting aryloxyphenoxypropionate and phenylpyrazole herbicides, 56% to acetolactate synthase (ALS) inhibiting herbicides, and 24% to ACCase-inhibiting cyclohexanedione herbicides. The incidences of resistance to inhibitors of photosynthesis at PSII, tubulin-formation inhibitors, and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase inhibiting herbicides have remained <10% of samples tested. The relationships between many herbicide groups and subgroups are discussed, as is the variability in resistance incidence and the forms of cross or multiple resistance for each state. This paper builds on an earlier publication of 14 years of testing history. At >5000 samples, the size and geographical spread of this dataset allows for valuable analyses of the relationships present in herbicide-resistant populations of annual ryegrass.

Alleviation of dormancy in annual ryegrass (Lolium rigidum) seeds by hydration and after-ripening

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 968-975 ◽  
Author(s):  
Robert S. Gallagher ◽  
Kathryn J. Steadman ◽  
Andrew D. Crawford
Keyword(s):  
Seed Germination ◽  
Relative Humidity ◽  
Germination Rate ◽  
Dormancy Release ◽  
Annual Ryegrass ◽  
Dormant Seed ◽  
Lolium Rigidum ◽  
Time Model ◽  
Treatment Regimens ◽  
Two Populations

The effect of hydration (priming) treatment on dormancy release in annual ryegrass seeds from two populations was investigated. Hydration duration, number, and timing with respect to after-ripening were compared in an experiment involving 15 treatment regimens for 12 wk. Seeds were hydrated at 100% relative humidity for 0, 2, or 10 d at Weeks 1, 6, or 12 of after-ripening. Dormancy status was assessed after each hydration treatment by measuring seed germination at 12-hourly alternating 25/15 C (light/dark) periods using seeds directly from the hydration treatment and seeds subjected to 4 d postpriming desiccation. Seeds exposed to one or more hydration events during the 12 wk were less dormant than seeds that remained dry throughout after-ripening. The longer hydration of 10 d promoted greater dormancy loss than either a 2-d hydration or no hydration. For the seed lot that was most dormant at the start of the experiment, two or three rather than one hydration event or a hydration event earlier rather than later during after-ripening promoted greater dormancy release. These effects were not significant for the less-dormant seed lot. For both seed lots, the effect of a single hydration for 2 d at Week 1 or 6 of after-ripening was not manifested until the test at Week 12 of the experiment, suggesting that the hydration events alter the rate of dormancy release during subsequent after-ripening. A hydrothermal priming time model, usually used for modeling the effect of priming on germination rate of nondormant seeds, was successfully applied to dormancy release resulting from the hydration treatments.

Sign in / Sign up

Export Citation Format

Share Document