The influence of wheat density and spatial arrangement on annual ryegrass, Lolium rigidum Gaudin, competition

1985 ◽  
Vol 36 (3) ◽  
pp. 361 ◽  
Author(s):  
RW Medd ◽  
BA Auld ◽  
DR Kemp ◽  
RD Murison
Keyword(s):  
Field Experiments ◽  
Spatial Arrangement ◽  
Triticum Aestivum L ◽  
Yield Reduction ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Yield Model ◽  
Common Trend ◽  
South Wales ◽  
Crop Density

The influence of wheat (Triticum aestivum L.) planting arrangement and density on the competitive effect of the weed, annual ryegrass (Lolium rigidum Gaudin), was examined in field experiments over three climatically contrasting years on the central western slopes of New South Wales. Results for three experiments conformed to a common trend. Geometrical arrangement of the crop (rectangularities of 1 to 6.4) at any one of a range of crop densities had no significant effect (P > 0.05) on ryegrass competition, expressed as relative wheat grain yield reduction. However, the effect of ryegrass was substantially reduced by increasing wheat sowing density from 40 or 75 to 200 plants m-2. In analysing models of weed competition a reciprocal yield model (I/ Y = 0.0092 + 0.0037X, r2= 0.89) predicted yield reduction (Y, as per cent of weed-free controls), especially when used with the ratio of weed density to crop density (X), with residual sums of squares lower than for other models.

Herbicide Application Strategies for the Control of Rigid Ryegrass (Lolium rigidum) in Wide-Row Faba Bean (Vicia faba) in Southern Australia

2012 ◽  
Vol 26 (2) ◽  
pp. 284-288 ◽  
Author(s):  
Samuel G. L. Kleemann ◽  
Gurjeet S. Gill
Keyword(s):  
Faba Bean ◽  
Field Experiments ◽  
Control Strategies ◽  
South Australia ◽  
Yield Reduction ◽  
Lolium Rigidum ◽  
Herbicide Application ◽  
Spike Density ◽  
Herbicide Resistant ◽  
Rigid Ryegrass

Two field experiments were undertaken at Roseworthy, South Australia from 2006 to 2007 to evaluate the performance of herbicide application strategies for the control of herbicide-resistant rigid ryegrass in faba bean grown in wide rows (WR). The standard farmer practice of applying postsowing PRE (PSPE) simazine followed by POST clethodim to faba bean grown in WR provided consistent and high levels of rigid ryegrass control (≥ 96%) and caused a large reduction (P < 0.05) in spike production (≤ 20 spikes m−2) as compared with nontreated control (560 to 722 spikes m−2). Furthermore, this herbicide combination resulted in greatest yield benefits for WR faba bean (723 to 1,046 kg ha−1). Although PSPE propyzamide used in combination with shielded interrow applications of glyphosate or paraquat provided high levels of rigid ryegrass control (≥ 93%), these treatments were unable to reduce ryegrass spike density within the crop row (20 to 54 spikes m−2) to levels acceptable for continued cropping. Furthermore, a yield reduction (13 to 29%) was observed for faba bean in treatments with shielded application of nonselective herbicides and could be related to spray drift onto lower leaves. These findings highlight that shielded interrow spraying in WR faba bean could play an important role in the management of rigid ryegrass in southern Australia. However, timing of shielded interrow applications on weed control, crop safety, and issues concerning integration with more effective early-season control strategies require attention.

Evaluating the double knockdown technique: sequence, application interval, and annual ryegrass growth stage

2007 ◽  
Vol 58 (3) ◽  
pp. 265 ◽  
Author(s):  
Catherine P. Borger ◽  
Abul Hashem
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Growth Stages ◽  
Annual Ryegrass ◽  
Application Time ◽  
Lolium Rigidum ◽  
Single Application ◽  
Herbicide Application ◽  
Leaf Stage ◽  
The Difference

Applying glyphosate followed by a mixture of paraquat + diquat in the same season for pre-planting weed control may reduce the risk of developing resistance to either herbicide. Glasshouse and field experiments at Merredin and Beverly, Western Australia, were conducted over 2 seasons to determine the best herbicide application sequence, growth stage of annual ryegrass at which to apply the 2 herbicides, and application time and interval to be allowed between applications for optimum control of annual ryegrass (Lolium rigidum Gaud.). Annual ryegrass plants were treated at 3 growth stages with either glyphosate 540 g a.i./ha alone, paraquat + diquat 250 g a.i./ha alone, glyphosate followed by paraquat + diquat 250 g a.i./ha, or paraquat + diquat 250 g a.i./ha followed by glyphosate 540 g a.i./ha (the double knockdown treatment). The herbicides were applied at different times of the day, with varied intervals between herbicides when applied in sequence. The glasshouse experiment showed that herbicides in sequence more effectively killed annual ryegrass plants at the 3–6-leaf stage than a single application of either herbicide. Field experiments showed that applying glyphosate followed by paraquat + diquat provided 98–100% control of annual ryegrass plants when applied at the 3- or 6-leaf stage in 2002 and at all 3 growth stages in 2003. Generally, the sequence of paraquat + diquat followed by glyphosate was less effective than the reverse sequence, although the difference was not large. Averaged over 2 seasons, herbicides in sequence were most effective when the first herbicide was applied at the 3- or 6-leaf stage of annual ryegrass. An interval of 2–10 days between applications of herbicides was more effective than 1 day or less. The application time did not significantly affect the efficacy of double knockdown herbicides on annual ryegrass plants under field conditions.

A decade of monitoring herbicide resistance in Lolium rigidum in Australia

2006 ◽  
Vol 46 (9) ◽  
pp. 1151 ◽  
Author(s):  
J. C. Broster ◽  
J. E. Pratley
Keyword(s):  
Herbicide Resistance ◽  
Cultural Practices ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Herbicide Resistant ◽  
South Wales ◽  
Australian State ◽  
Group B ◽  
Random Survey ◽  
Group D

Charles Sturt University commenced herbicide resistance monitoring in 1991. A random survey in 1991 to determine the level of resistance in annual ryegrass (Lolium rigidum) to selective herbicides across the south-west slopes region of New South Wales found that 30% of samples were resistant to at least 1 herbicide. A subsequent survey of commercially available ryegrass seed found that 58% of these samples were resistant to at least 1 herbicide. As a result of these findings, a commercial testing service was established and has since received samples from a large proportion of the southern Australian cropping belt. Seventy-seven percent of samples tested were resistant to Group AI, 40% to Group B and 22% to Group AII herbicides. Lower levels of resistance were found to Group D (8%), Group C (1%) and Group M (0.4%) herbicides. The correlation between resistance in Group AI and AII herbicides was lower than expected given that these herbicides are considered to have the same mode of action. Within the Group AI herbicides the observed response of the samples was consistent across herbicide formulations. Resistance to clethodim varied from observed responses to other Group AII herbicides. The variation in resistance levels (and degree of multiple resistance) in each Australian state is discussed in relation to environmental conditions and cultural practices. The size of this dataset allows for the analysis of the relationships present among herbicide resistant annual ryegrass.

Effect of time sowing and cultivar on the development and grain yield of irrigated wheat in the Macquarie Valley, New South Wales

1992 ◽  
Vol 32 (3) ◽  
pp. 345 ◽  
Author(s):  
JL Cooper
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Moisture Stress ◽  
Frost Damage ◽  
Yield Reduction ◽  
Detectable Effect ◽  
South Wales ◽  
Wide Range

Field experiments over 2 seasons in the Macquarie Valley of central New South Wales compared yields under irrigation of 5 wheat varieties with a wide range of maturities sown from 8 April to 27 August.Early maturity wheats (Yecora and Avocet) sown prior to 6 May suffered frost damage, while the winter wheats (WW33G and Burgas) sown after 29 July were not fully vernalised and most tillers failed to produce heads. There was a curvilinear relation between time of sowing and grain yield. Excluding the treatments which suffered frost damage, the earliest time of sowing (8 April) produced the highest yield, with a 6.4% yield reduction between 8 April and 8 May. The yield reduction increased with later sowing date: 13.3, 19.3, and 26.5% during May, June, and July. Anthesis in mid September produced the highest yields for all varieties. Treatments which flowered earlier than mid September suffered frost damage. For each day later than 15 September that anthesis occurred, the mean yield fell by 1.3% or about 68 kg/ha.day. Date of anthesis had no detectable effect on the rate of individual grain growth (1.3 mg/grain.day), but the later anthesis occurred, the shorter the duration of grain development and the lower the final grain weight. Rising temperatures, not moisture stress, seems to be the factor causing the decline in yield with late sowing. This experiment was irrigated to eliminate moisture stress but the decline in yield was similar to that reported for dryland crops.

scholarly journals Impact and Control of Powdery Mildew on Irrigated Soybean Varieties Grown in Southeast Australia

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 514 ◽  
Author(s):  
Mathew Dunn ◽  
Luke Gaynor
Keyword(s):  
Powdery Mildew ◽  
Grain Yield ◽  
Field Experiments ◽  
Effective Control ◽  
Yield Reduction ◽  
South Wales ◽  
Severity Of The Disease ◽  
High Level ◽  
Disease Pressure ◽  
And Control

Powdery mildew—caused by the fungus Erisyphe diffusa (syn. Microsphaera diffusa)—was first observed in commercial soybean crops in southern New South Wales (NSW), Australia, in 2011. Its detection raised concerns that soybean production might be constrained if the severity of the disease reached the levels observed in northern Australia. Field experiments were conducted over four consecutive seasons to examine the response of three soybean cultivars—Djakal, SnowyA and the breeding line N005A-80—to two fungicides and two fungicide application regimes. The cultivar Djakal was identified as having a high level of resistance to powdery mildew. The severity of infection symptoms varied between seasons. The most severe symptoms were observed during the 2014–2015 season which resulted in the largest grain yield reduction of 20% for the cultivar SnowyA. All fungicide treatments provided a significant reduction in the severity of symptoms, with the split application of tebuconazole and both the single and split applications of tebuconazole + prothioconazole providing the most effective control of the disease. Few other grain yield effects were found, even when strong disease control was achieved. This was a suspected result of the consistent late-in-the-season onset of the disease. Few differences were observed among the treatments in terms of lodging severity, date of physiological maturity, or grain oil and protein concentrations. It was concluded that both fungicides provided effective control of powdery mildew. However, when disease pressure is low, application might not be warranted in southern NSW.

Comparative growth of wheat, barley, and annual ryegrass (Lolium rigidum) in monoculture and mixture

1996 ◽  
Vol 47 (3) ◽  
pp. 449 ◽  
Author(s):  
RD Cousens
Keyword(s):  
Coastal Plain ◽  
Yield Loss ◽  
New South ◽  
Growth Dynamics ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Leaf Production ◽  
South Wales ◽  
Wheat Sensitivity ◽  
Biomass Reduction

The growth and development of wheat, barley, and annual ryegrass (Lolium rigidum Gaud.) were studied in monoculture and in additive mixtures at two sites of contrasting climate and soil type in New South Wales. Although smaller, annual ryegrass paralleled the behaviour of the two cereals in monoculture in all respects. The phenological development of all three species was more rapid at the wheatbelt site (Forbes) than on the coastal plain (Camden); yield loss was also greater at Forbes. The early growth rate of barley was greater than that of wheat or ryegrass at both sites. As a result, barley was more able to suppress ryegrass in mixtures and to maintain its yield than wheat. Sensitivity analysis of a growth simulation model suggested that the early rate of leaf production was likely to be influential in determining the magnitude of biomass reduction at anthesis; relative phenological development and height growth dynamics appeared to have little effect.

Annual ryegrass and volunteer cereal control in lupins using selective post-emergent herbicides

1995 ◽  
Vol 35 (8) ◽  
pp. 1141 ◽  
Author(s):  
A Chambers ◽  
G Code ◽  
G Scammell
Keyword(s):  
Triticum Aestivum ◽  
Avena Sativa ◽  
Relative Effectiveness ◽  
Triticum Aestivum L ◽  
Lupinus Angustifolius ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Target Species ◽  
North Eastern

The relative effectiveness of herbicides from the aryloxyphenoxypropionate (fop) and cyclohexanedione (dim) chemical families for the control of volunteer wheat (Triticum aestivum L.), oats (Avena sativa), triticale (Triticum x Secale) and annual ryegrass (Lolium rigidum Gaud.) in narrow-leafed lupins (Lupinus angustifolius) were evaluated over a 3-year period near Rutherglen in north-eastern Victoria. Herbicides tested included diclofop-methyl, fluazifop-pethyl, haloxyfop, propaquizafop, quizalofop-p-ethyl, clethodim, cycloxydim, sethoxydim, and mixes of fluazifop-p-ethyl + diclofop-methyl, and fluazifop-pethyl + sethoxydim. Effective grass control needed to prevent disease carryover is defined as greater than 98%. Haloxyfop at 78 g a.i./ha and clethodim at 120 g a.i./ha consistently gave greater than 98% control of all target species. Quizalofop-p-ethyl at 12 g a.i./ha gave greater than 98% control of volunteer cereals but annual ryegrass control ranged from 83.7 to 44.1%. Cycloxydim at 100 g a.i./ha produced similar oat and ryegrass control to that of 563 g a.i./ha diclofop-methyl. Sethoxydim at 93 g a.i./ha, gave significantly (P < 0.05) better control of annual ryegrass than the recommended rates of diclofop-methyl, fluazifop-p-ethyl and propaquizafop. The addition of 47 g a.i./ha sethoxydim to 32 g a.i./ha fluazifop-p-ethyl significantly improved ryegrass control than low rates of fluazifop-p-ethyl alone.

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 &lt;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 &gt;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.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

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