• In 2007, herbicides applied to burnt stubble were more effective than those applied to slashed stubble. In 2008, there was no effect of stubble management on efficacy or crop safety.
• All herbicide treatments gave adequate control ofryegrassin both years, but TriflurX® 1.5L/ha + Avadex Xtra® 1.6L/ha gave the best control in both 2007 and 2008.
• Improved control of ryegrass did not increase yield, and the most profitable treatments were the lower rates of trifluralin.
• Standing stubble substantially increased grain yield relative to slashed stubble (0.41 and 0.47t/ha in 2007 and 2008 respectively).

• The combination of stubble burning and post-emergent use of a Group A herbicide has effectively controlled ryegrass in plots continuously cropped for 21 years at Condobolin.
• This combination worked well in both cultivated and direct drilled systems.

Tedera did not have enough biomass to take in any of the two samples in August and November, which was due to frost damage.Balansa and Serradella produced the same amount of biomass, and both were more productive than ryegrass. However, it was observed that ryegrass was severely grazed by kangaroos, so samples were not reflective of what the true biomass would normally be.

In-paddock surveys were conducted in 197 paddocks over the summers of 2019-20 and 2020-21 to identify the diversity and abundance of summer weed species present across the GRDC Western region. The surveys covered the 6 agro-ecological zones (Agzones).

Physical surveys were conducted from late January to early April 2020 and mid November to mid-March 2020-21. The development of SARS-Cov-2 complicated the final stages of the first season’s surveys preventing several properties from being surveyed.  Surveys in the second season were dictated by timing of rainfall, and tight accommodation availability in some areas.

In the 2019-20 summer patchy rain was received in mid-January north of Dalwallinu and east of Esperance, with more widespread patchy rain occurring mid-February. Some areas remained dry until late March. The 2020-21 summer saw a large fall of rain in the northern and south-eastern zones in early November then patchy rain through the summer then more widespread rain fell mid-March. Rain received in November and March was accompanied by high temperatures.

Over the two surveys 57 broadleaf, 16 grass and one monocotyledon weed species and 13 volunteer crop and pasture species were identified. Volunteer crop and pasture species tended to be the most abundant and have the highest incidence confirming what Michael et al (2010) observed in their 2006 paddock survey. Eight weed species identified in 2019-20 were not found in 2020-21. Eleven weed species found in 2020-21 were not found during the previous survey.

Weed abundance and diversity varied between Agzones and years.

Barley, wheat and annual ryegrass were consistently the most frequent grass species followed by the native grass species stink grass (Eragrostis cilianensis) and small burrgrass (Tragus australiensis). Grass diversity is generally lower than that of broadleaves, although inter-zone variability is less. Grass abundance was lower in 2020-21. Agzone 1 was the least diverse with four grass species while Agzone 4 was the most diverse with 12 species.

Feathertop Rhodes grass (Chloris virgata) was not found in-paddock despite increasing along roadsides across the cropping zone in the past decade.

The six most abundant broadleaf weeds were capeweed, mintweed, paddy melon, Afghan melon, small-flowered mallow and caltrop while annual ryegrass, stink grass and small burrgrass were the most common grass weeds.

 Weeds that were found in 5 or 6 of the Agzones were considered widespread, and likely to have fewer specific requirements for germination and establishment compared with other less common species.

There appears to be a geographic trend in the distribution of some summer weeds. Species that had a more northern distribution include tarvine (Boerhavia coccinea), sandplain (blue) lupin (Lupinus cosentinii), button grass (Dactyloctenium radulans) and mulla mulla (Ptilotus polystachyus). Species more common towards the south included blackberry nightshade (Solanum nigrum), flaxleaf fleabane (Conyza bonariensis), common sowthistle (Sonchus oleraceus) and common heliotrope (Heliotropium europaeum).

Paddock management can influence abundance of species and to a lesser extent species diversity. While little paddock management data was gathered it was noted that a failure to control early emerging summer weed species in spring resulted in large weeds which are difficult to control in summer.

In both years the majority of fleabane, wireweed (Polygonum aviculare) and jersey cudweed (Pseudognaphalium luteoalbum) were large plants that had established in spring in the previous winter crop having not been controlled prior to harvest. Wireweed and jersey cudweed were more likely to be found in canola, pea and vetch stubbles.

This project has raised the question of the effect on stubble cover on summer weed germination. Most research has looked at the effects of stubble on weed growth and seed yield. This suggests there is a need for some research on effects of crop stubbles on a selection of important summer weeds.

This research has shown that a wide range of climatic and environmental factors dictate the occurrence for specific weeds. The differences between Agzones in abundance and species mixtures suggest management messages need to be zone-specific to a degree. The high prevalence of crop volunteers (3 of the top 6 most abundant species) encourages a focus on volunteer management across the region.

Differences in the surveys between years shows the importance of multi-year projects involving weeds. Ideally this project would have run for a third season to help remove any bias from highly variable summer seasons. This would also give additional information on how different weed species react to different seasonal conditions.

Other outcomes include the training of five early career Department of Primary Industries & Regional Development agronomists in weed identification and survey technique. They now have increased skills in in weed identification, particularly experience with the wide range of useful weed identification resources.

• Yield Prophet- the crop simulation model- is a great tool for assessing crop risk and predicting potential yields.
• For renovating overgrazed perennial pasture paddocks, the sowing of cereals is a low risk strategy.
• Pasture establishment is extremely difficult in the Mallee in years with limited spring rainfall.
• Cereal biomass production may be greater by an order of 10 times than either perennial or leguminous pastures in the first year of establishment.
• Best pasture options for a June sowing in terms of biomass in the first year of establishment are either forage brassica or Italian Ryegrass

• In 2016 only 40% of the barley grass was greater than 17 cm tall and had the potential to be collected by early swathing, or 60% of the barley grass seed had already shed or was below harvest weed seed collection height.
• Sampling of the swathed paddock area showed slightly better barley grass weed seed collection using swathing than from the rest of the paddock which was harvested normally.
• Seed capture at both swathing and harvest is higher with annual ryegrass than with barley grass.

• Annual ryegrass (ARG) establishment and seed head numbers increased significantly under the faba bean herbicide strategies used in 2016
• There were no significant differences between herbicide strategies in 2016, with the legacy of past years’ management strategies not creating any difference in yields this year
• Over the five years of the trial, RT Canola in 2014 was been the best option to maintain ARG seed head numbers
• ARG seed head numbers increased by 35% in 2016 following the high cost weed strategy (strategy C) in combination with HWS prototype mill
• ARG seed head numbers increased by 148% (low cost, strategy A) and 171% (mid cost, strategy B) in 2016
• Effects of pre-harvest desiccations in 2016 will not be evidenced until emergence in 2017 

• Canola and peas only produced half the yield of wheat, but barley performed very well.
• Ryegrass is becoming a problem in wheat on wheat plots.
• Pastures performed well where seed reserves had been increased in 2011.
• All options had good soil moisture (40mm) at the start of the season.

The results of this study suggests:

• Whilst the streaming of UAN modestly reduced annual ryegrass N percentage in the tissue, no difference in annual ryegrass biomass or seed production was evident.
• Nitrogen placement did not affect Wheat biomass accumulation (NDVI results), however modest differences in Canopy closure percentage existed. UAN rate and timing however had a greater effect on wheat biomass (NDVI results and wheat biomass cut) and percent canopy closure.
• UAN rate, UAN timing (plus interaction of UAN timing and placement) were found to have significantly affected Radiation interception of the crop in the absence of weeds.
• Nitrogen placement affected the yield and protein content of the grain produced.

Whilst the streaming of UAN modestly reduced annual ryegrass (ARG) N percentage in the tissue, no difference in annual ryegrass seed production was evident. Due to the dry conditions in 2019, the application of supplementary UAN did not significantly increase wheat canopy closure or yield. Interestingly, UAN placement did affect the total nitrogen uptake in the ryegrass population, potentially increasing ARG competitiveness. Banding UAN to the crop row was found to increase ARG N uptake. As seeding systems provide herbicide free bands on otherwise herbicide treated soil for safe wheat establishment it was found that the majority of ARG emerged from these crop rows. Concentrating N applications to these regions may have inadvertently increased the N uptake in ARG. This study was conducted in York over the 2018 and 2019 seasons. A multi- environment trial analysis for the combined data to be completed.

• The herbicide treatment had a significant effect on annual ryegrass (ARG) plant density. Trifluralin only reduced ARG spike density by 20% compared to the untreated control, whereas Boxer Gold caused a 73% reduction in ARG spike density.
• Barley sown on 25 cm row spacing resulted in a 38% less ARG seed production compared to the 37.5 cm row spacing treatment.
• Barley sown using the splitter seed boot treatment had 32% lower ARG seed production than the narrow seed boot treatment.
• It was still profitable to control ARG with effective herbicide treatments. Based on cash grain price of feed barley of $250/t in 2019, Trifluralin would be expected to increase the gross margin by $32/ha as compared $71/ha increase for Boxer Gold.

 

The herbicide treatment had a significant effect on annual ryegrass (ARG) plant density (P<0.001) in this field trial at Minnipa. Favourable rain events in May were highly suitable for the activity of both pre-emergent herbicides investigated in this trial. Averaged across the row spacing and seed boot treatments, Trifluralin and Boxer Gold reduced ARG plant density by 20% and 90%, respectively. The density of ARG spikes was significantly influenced by the row spacing (P<0.001), seed boot treatment (P=0.027), and the herbicide treatment (P<0.001). The 25cm row spacing had 20% lower ARG spike density than the 37.5cm row spacing treatment. The splitter seed boot treatment had 12% lower ARG spike density than the narrow seed boot treatment. Trifluralin only reduced ARG spike density by 20% compared to the untreated control, whereas Boxer Gold caused a 73% reduction in ARG spike density. ARG seed production was also significantly affected by the row spacing (P=0.003), seed boot (P=0.01), and the herbicide treatment (P<0.001). The normal (25 cm) row spacing set 38% less seed than the wide row spacing. The splitter seed boot treatment also had 32% lower ARG seed set compared to the narrow seed boot. ARG produced 4792 seeds/m2 in the untreated control, which was reduced by 11% by Trifluralin and 69% by Boxer Gold. Presence of ARG at 262 plants/m2 in the untreated control, reduced barley grain yield by 8% compared to Trifluralin or 16% compared to Boxer Gold. However, it was still profitable to control ARG with effective herbicide treatments. Based on cash grain price of Feed Barley of $250/t in 2019, Trifluralin would be expected to increase the gross margin by $32/ha as compared $71/ha increase for Boxer Gold.

• Barley crop establishment was significantly reduced in the wider row spacing treatments. This is most likely due to increased crop intra-row competition rather than fertiliser toxicity from reduced seed bed utilisation (SBU) as fertiliser was banded for crop safety and crop establishment was similar for the two seed boot treatments.
• Herbicide treatments achieved varying levels of annual ryegrass (ARG) control with Trifluralin reducing ARG plant density by 30%, Overwatch 67% and Boxer Gold 88% compared to untreated control (1092 ARG plants/m2).
• Improved crop competition in narrower row spacing was reflected in 28% lower ARG seed set in the 25cm row spacing than the wider 37.5cm row spacing. Even though Boxer Gold reduced ARG seed set by 86% compared to the control, ARG was still able to produce 4787 seeds/m2. Such a high level of ARG seed production is likely to have a serious impact on crops grown next year.

The herbicide treatment had a significant effect on annual ryegrass (ARG) plant density (P<0.001) in this field trial at Minnipa. Favourable soil moisture in early May was suitable for the activity of both pre-emergent herbicide treatments investigated in this trial. Averaged across the row spacing and seed boot treatments, Boxer Gold + Trifluralin and Sakura + Avadex reduced ARG plant density by 71% and 72%, respectively. The density of ARG spikes was significantly influenced by the row spacing (P<0.001), seed boot treatment (P=0.002), and the herbicide treatment (P<0.001). The 25cm row spacing had 43% lower ARG spike density than the 37.5cm row spacing treatment. The splitter seed boot treatment had 35% lower ARG spike density than the narrow seed boot treatment. Boxer Gold + Trifluralin reduced ARG spike density by 68% compared to the untreated control, whereas Sakura + Avadex caused a 70% reduction in ARG spike density. ARG seed production was also significantly affected by the row spacing (P<0.001), seed boot (P=0.003), and the herbicide treatment (P<0.001). The normal (25 cm) row spacing set 53% less seed than the wide row spacing. The splitter seed boot treatment also had 39% lower ARG seed set compared to the narrow seed boot. There was a 73% reduction in ARG seed production in the normal row spacing and splitter boot treatment compared to wide row spacing with single seed boot treatment. ARG produced 15483 seeds/m2 in the untreated control, which was reduced by 62% by Boxer Gold + Trifluralin and 67% by Sakura + Avadex. This level of ARG seed production would be more than adequate to allow problematic weed establishment in crops grown next year. Therefore, growers need to consider integration of harvest weed seed control or other management tactics for ARG management. Presence of ARG at 76 plants/m2 in the untreated control, reduced wheat grain yield by 29% compared to Boxer Gold + Trifluralin or 30% compared to Sakura + Avadex.

• While large differences in seedbed utilisation (SBU) were achieved with row spacing and seed boot treatments (7.9 – 22.1% SBU), it had a smaller impact on ARG suppression in this trial compared to previous trials.
• Averaged across the row spacing and seed boot treatments, Boxer Gold (850 ARG plants/m2), Overwatch (118 ARG plants/m2) and Sakura (422 ARG plants/m2) reduced ARG plant density by 49%, 93% and 75%, respectively compared to the untreated control (1680 ARG plants/m2).
• The 25cm row spacing had 17% lower ARG spike density than the 37.5cm row spacing treatment (P=0.007).
• Boxer Gold reduced ARG spike density by 58% compared to the untreated control, whereas Overwatch and Sakura caused an 84% and 82% reduction in ARG spike density, respectively.
• Grain yield in the 25 cm row spacing treatment (5.979 t/ha), was 14% greater than the yield in 37.5 cm row spacing treatment (5.243 t/ha).

• Despite visual differences there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or winter when soils are water logged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild raddish populations did not increase because of grazing, although the sites only had low levels of infestation to being with. However, farmer observations do not support this and further work is needed.

• Despite visual difference there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or in winter when soils are waterlogged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild radish populations did not increase because of grazing, altough the sites only had low levels of infestation to begin with. However, farmer observations do not support this and further work is required.

• Despite visual differences there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or winter when soils are waterlogged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild raddish populations did not increase because of grazing, although the sites only had low levels of infestation to begin with. However farmer observations do not support this and further work is required.

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Each stubble incorporation prior to sowing lead to better weed control in the crop as we were able to create an early germination of ryegrass. 
• There was considerable difference in soil moisture and its distribution through the profile at establishement.
• Straw length at harvest was the biggest drawback in incorporating and establishment.
• Previous trial cropping areas, on other parts of the padock, still showed up the biggest difference in the crop's establishment.

The trials located at Miling and Kojonup in the grainbelt of Western Australia investigated combinations of canola variety (hybrid or open pollinated), crop row spacing (25 or 50cm) and canola seeding rate (20, 35 or 50 plants/m2). The average seedbank at the Miling and Kojonup sites were 3,630 seeds/m2 and 23,240 seeds/m2 respectively.  Annual ryegrass (ARG) establishment was reduced in hybrid canola treatments seeded at narrower 25 cm row spacing. Decreasing crop row spacing (from 50 to 25cm) and increasing canola seeding rate (from 20 to 50 plants/m2) was found to reduce ARG establishment in the absence of herbicides. At the Kojonup site, ARG seed production was reduced by hybrid varieties (Trophy) and higher plant densities (50 plants/m2). However due to the low rainfall at the Miling site, no interactions were identified. Canola yield in this study was increased in hybrid variety (Trophy) treatments especially at higher seeding rates (50 plants/m2). Interestingly, however, canola seeded at the wider row spacing (50cm) consistently out yielded the corresponding variety and seeding rate combination at the narrower 25cm row spacing. This study conducted two trials in 2018 (Mingenew and Cunderdin) and 2019 (Miling and Kojonup). Multi- environment trial analysis for the combined 2018 and 2019 data to be completed.

Annual ryegrass (ARG) establishment was reduced in hybrid canola treatments, treatments with increased seed size and higher seeding rates. However, no interaction between these factors existed. At the Kojonup site, ARG seed production was reduced by hybrid varieties (Trophy). Due to the low rainfall at the Miling site, no interaction between treatments were identified. Canola yield in this study was increased in the hybrid variety (Trophy) treatments especially at higher seeding rates (50 plants/m2). In the absence of ryegrass, increased canola seed size also increased canola yield. This study conducted two trials in 2018 (Mingenew and Cunderdin) and 2019 (Miling and Kojonup). Multi- environment trial analysis for the combined 2018 and 2019 data to be completed.

The results of this study suggest:

• Increasing the canola seeding rate of both OP and Hybrid varieties increased the crops potential competitiveness by increasing early biomass (NDVI) and % radiation interception.
• Increasing canola row spacing increased the crops light interception.
• At Cunderdin, the greatest decrease in ARG establishment in response to canola seeding rate occurred where both OP and Hybrid canola varieties were sown at wider (50cm) row spacing’s.
• The Mingenew site had a significantly higher weed density, reducing the trials competitive effect on ARG density, biomass, and seed production. Sites with lower weed seed banks will be identified in 2019.

At the Mingenew site, canola yield was higher in open pollinated variety (Bonito). At Cunderdin, no effects were identified.

The results of this study suggests:

• Crop emergence was affected by pollination type (greater in open pollinated var. Bonito), increased seeding rates and increased seed size at both the Cunderdin and Mingenew sites, with seed size and seeding rate interactions at Mingenew.
• Weed densities were reduced by seed size and seeding rates at Cunderdin. No significant decreases were identifies at Mingenew due to the high weed densities.
• Ryegrass biomass was reduced by Pollination type (reduced in the open pollinated var. Bonito), increased seed size at both the Cunderdin and Mingenew sites. Seeding rate was found to reduce ryegrass biomass at the Cunderdin site.
• Canola yield was increased by increasing seeding rate and seed size in both weedy and weed free situations at the Cunderdin and Mingenew sites.

In 2019, the three trial sites experienced vastly different rainfall and crop germination patterns. The Kojonup site had good soil moisture throughout the growing season resulting in a rapid crop germination. The York and Miling sites however were seeded into completely dry conditions with the wheat germination in the TOS 1 treatments occurring more than six weeks after seeding. The bioassay experiment showed that at all sites, Sakura was the most persistent herbicide. This was evident in the field results where the persistence and activity of Sakura resulted in lower ryegrass emergence, lower seed production and a higher wheat yield. Furthermore, the results showed that at the Kojonup site, which was sown into excellent soil moisture, Trifluralin was also very effective.

The TOS response was variable; the first time of seeding showed better weed control and wheat yields at Miling and York whereas the delayed time of seeding was advisable at the moist Kojonup site. It was also found that increasing the wheat density increased crop competition which in turn reduced ryegrass emergence, ryegrass biomass and ryegrass seed production for all herbicide treatments studied. 

• A combination of dry sowing and a pre-emergent herbicide choice yields greater than the standard sowing time.
• The seed production of ARG at the end of the season correlates with the pre-emergent herbicide soil persistence.
• Increasing crop seeding rates may affect ARG seed production at some sites.

• The combination of Triazine Tolerant (TT) and Roundup Ready (RR) herbicide provided superior control of ryegrass and wild radish over individual chemistry treatments.
• Canola is an important rotational winter crop however, with increasing herbicide resistance across multiple chemistries in WA, growers are experiencing increasingly limited options with the current herbicide tolerance technologies available.
• Hyola RT® Technology allows the combination of strong knockdown and residual broad-spectrum herbicides from different herbicide groups and modes of action, targeting a wide range of weed species.
•  Hyola RT® will provide an important role in addressing the increasing Clethodim resistance problem.
• RT® dual herbicide tolerant Hybrids have now demonstrated their value as a new competitive integrated weed management (IWM) tool, also providing increased convenience and flexibility of in-crop weed control.

Results from the initial establishment season have again confirmed the ability of hardseeded legumes to grow and set seed under adverse seasonal conditions.  The value of indeterminate pattern of growth in facilitating additional seed set was also shwon with biserrula where following late spring rain, an additional round of seed set resulted in a more than doubling of overall seed production.Bladder, with a slightly deeper root system, and gland clover which is early maturing also showed b etter capacity to produce seed in challenging condition s compared to subterranean clover.  With production of a seed bank critical for pasture performance  in subsequent years, the performance of hardsseded legumes was very encouraging.

• Early sowing of barley may be an effective way of controlling ryegrass growth and limiting seed set.
• Results in wheat are more variable than for barley: at Wanilla, mid-May seemed the optimal time of sowing to reduce ryegrass with less effect obvious at Yeelanna.
• Higher seeding rates also followed the same trend, with little ryegrass suppression benefit seen in wheat but a benefit evident in barley.
• Increasing seeding rate did not improve wheat yields significantly however barley (Fleet) did seem to benefit from higher seeding rates when sown late (mid-June).

• Early sowing of barley may be an effective way of controlling ryegrass growth and limiting seed set.
• Results in wheat are more variable than for barley: at Wanilla, mid-May seemed the optimal time of sowing to reduce ryegrass with less effect obvious at Yeelanna.
• Higher seeding rates also followed the same trend, with little ryegrass suppression benefit seen in wheat but a benefit evident in barley.
• Increasing seeding rate did not improve wheat yields significantly however barley (Fleet) did seem to benefit from higher seeding rates when sown late (mid-June).

• Tonic plantain and Grouse chicory are worth considering as summer forages, with the Tonic plantain likely to persist through the following winter and longer. Although not tried, Italian ryegrass (or perennial ryegrass) could be oversown for more winter feed. In this trial, winter feed production from Tonic plantain and sub clover was excellent, no doubt partially due to the high sub clover seed reserves and partially due to the high soil fertility on Tremaine’s.
• Banquet tetraploid hybrid perennial ryegrass could be considered for a medium term high quality pasture for finishing lambs/weaners in high fertility paddocks, with controlled rotational grazing over summer.

Trifluralin appears to be the best pre-emergent ryegrass herbicide for wheat.

Trifluralin and related Group D herbicides are effective in controlling Group A herbicide resistant ryegrass, however when they are consistently used without other control practices resistance will develop. Ryegrass with Group D (trifluralin) resistance is already common in some areas.

A thorough understanding of trifluralin application techniques can be the difference between poor and excellent ryegrass control. It can also help achieve target plant establishment. This demonstration showed an increase in ryegrass control when up to 3L/ha trifluralin was applied. Rates above 3L/ha trifluralin did not result in additional ryegrass control. The influence of water rates was minimal due to the lack of stubble residue which shows that water rates of 50L/ha are acceptable in situations where there is very little residue from the previous crop.

The yields of the different Trifluralin treatments and sowing depths ranged from 1.5 to 2.1 t/ha.

Inversion ploughing of water repellent sands can significantly reduce repellence and increase critical components of grain yield.

Deep ripping in the presence of problem background ryegrass can stimulate ryegrass emergence and worsen weed competition with the crop.

The strength of the subsoil resource (i.e. clay component) appears important in sustaining the crop production potential and realisation of grain yield improvement.

• Trifluralin was very effective, reducing ryegrass numbers by 60 percent.
• The use of oilseeds and pulse crops provided the opportunity to effectively control resistant ryegrass using different chemistries (even within Group A - dims).
• Cutting hay is a profitable option with low risk and importantly very effective in reducing ryegrass if managed correctly.

• Velocity and Precept selective herbicides are based on a new active pyrasulfotole.
• This is a new mode of action on broadleaf weeds in cereals in Australia (Group H).
• Velocity and Precept showed excellent crop safety.
• Broad spectrum and reliable broadleaf weed control.

The efficacy of Select and Aramo in controlling ryegrass when sprayed under different weather conditions was investigated. It appears that neither bright sunshine nor overcast conditions affected the efficacy of these two products.

• Site background weed levels increased total weed competition levels to very high numbers
  masking differences between genotypes for grain yield. However genotype differences still
  occurred for competition score and final ryegrass tiller numbers in the low ryegrass
  treatment.
• Limited findings suggests there is variation in the current chickpea genotype for competition
  with ryegrass, particularly in reducing tiller numbers. Tall types (CICA512) and types with
  wide branching angles (Sonali) were generally more competitive than short and narrow
  branching angle types.
• The concept trial had limited success in 2007 due to trial methodology and site selection
  issues. Further refinements to trial methodology are required for 2008. These are:
  o Lower rye grass numbers (40 and 100 plants per sq.m) are required than those used
  in 2007 (adapted from work undertaken in wheat).
  o A site with very low background weed numbers is essential due to limited herbicide
  options available.
  o The ability of the chickpea variety to reduce ryegrass tiller numbers is likely to be a
  greater assessment of the competitive rating of the variety than its grain yield.
• A number of lines with a greater variation in vigour, plant height and plant shape (degree of
  angle of branches) than those evaluated in 2007 have been selected from advanced breeding trials in 2007 for assessment in 2008.

• Although chickpea yields were higher than previous years, the rapid finish to the season
  favoured earlier flowering and maturing varieties such as GenesisTM079 and Sonali.
• Ryegrass competition at 31 and 86 plants/m2 reduced chickpea grain yield by 31% and 56%, respectively. Similarly, at Turretfield ryegrass at 41 plants/m2 corresponded to 33% yield loss, and 62% at 123 plants/m2.
• Similarities between moisture stresses caused by lack of finishing rainfall in 2009 and from
  competition with ryegrass meant that the same varieties yielded well with or without  ryegrass competition eg GenesisTM079.
• Breeder’s line “Chickpea 4” recorded the lowest yield loss from ryegrass competition at both
  sites (9% at the low ryegrass density at Hart), and also displayed 35% better tiller suppression than other varieties at Hart.
• Early vigour appeared an important trait in chickpea for improved competivness with ryegrass, plant height was a disadvantage, but further work is required on a larger set of
  phenotypes and in a more favourable growing season.
• Some ambiguous results in 2009 (eg PBA Slasher and Chickpea 2) may be due to the
  unfavourable seasonal conditions for chickpea production which prevailed in SA last year.
  However they do indicate the need for more work in a more favourable growing season, and
  potentially on a larger set of phenotypes.

• Ryegrass and broadleaf weeds such as toadrush and capeweed are the main weeds to control in oat crops on the rising hill country in hte southern Wimmera.
• In this trial, the most cost effective option to control these weeds was Diuron and Glean applied at the 3-leaf stage of the oats.

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Nitrogen application timing produced no significant differences to grain yield.
• Grain yield was reduced by 12% with the presence of ryegrass.
• Crop sensors were able to accurately measure crop dry matter.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

To effectively establish windrows requires forward planning and potentially slows harvest tand increases harvest costs. Burn as early as conditions allow. Make it a priority job. Small rainfall events may germinate weeds in burnt areas that require attention before the whole paddock area.

Early sowing resulted in excessive vegetattive growth and also provided excelelnt conditions for ryegrass that proved difficult to control.