1. Terbyne® Xtreme® and Valor® provided the best residual control of common sowthistle as stand-alone residual herbicides and as mix partners with ‘grass active’ herbicides.
2. Group K, Group D and Flame® provided the best residual control of grass weeds as standalone residual herbicides and as mix partners.
3. Herbicide mixtures provided improved control over individual products and are likely to provide more wide-spectrum control of a range of weed species.

The trial was conducted in a paddock sown to wheat in 2020. Cereal stubble levels were high with visual assessment indicating ~70% groundcover prior to trial initiation.
Ten treatments were applied at the start of June, and 7 days later incorporated by sowing (IBS) using a commercial single disc planter on 50 cm row spacing. The post sowing pre-emergent treatments (PSPE) were applied directly after planting. Rainfall of ~5 mm was received 3 days after IBS application with ~15mm recorded in the first week after planting/ PSPE application. Total rainfall of only ~110 mm was received in the 4 months after planting. Inspection and assessment for weed emergence was conducted at ~4-6 week intervals from early July. The trial was concluded in early November.
Chickpea establishment was assessed at 30 days after planting (30 DAP) with ~22 plants/m2 in the untreated plots. There was no apparent effect on emergence from any herbicide treatment and no visual crop effects. No weeds were present at this assessment.
Insufficient paradoxa grass emerged during the trial to allow assessment. Common sowthistle (Sonchus oleraceus) was the only weed to emerge in sufficient numbers to allow a useful evaluation of residual efficacy.
Residual common sowthistle control was assessed at both 66 and 87 DAP. Trace levels were present at 66 DAP with <1 sowthistle/10m2 in the untreated, mainly at a 2 to 5 leaf stage. Significant (and complete control) was provided by Balance + Simazine, Balance + Terbyne Xtreme and the experimental treatment. Balance alone and Outlook were the only other treatments to provide >90% control.
By 87 DAP, the untreated sowthistle population was ~0.3/m2, mainly at the large rosette stage. Balance, Balance + Simazine, Balance + Terbyne, the experimental treatment and Outlook all provided significant control and reduced populations by >98%.
Under low weed densities, the commercial standards of Balance alone or in a tank mixture with either Simazine or Terbyne Xtreme provided complete common sowthistle control of populations emerging ~5 to 10 weeks after application. Complete control was also achieved by the experimental herbicide. Outlook also provided significant levels of control of common sowthistle but does not have label claim for this weed in chickpeas. No data was generated on the residual control of paradoxa grass.

• Chickpea seed yield responded to 50 kg N/ha applied 8 weeks after sowing at Grass Patch in 2020
• Higher rates did not increase yields when applied at 8 weeks after sowing or in a split application at 8 and 12 weeks after sowing.
• Within plot variation resulted in no significant difference in the gross margin.

• In 2009 47 ha of barley sown for feed at the break of the season sustained 300 ewes and lambs for 3 months during the period of late autumn-winter, a traditional period of pasture deficit.
• Hay freezing the forage crop ensures grass weeds are controlled.
• Use of strip grazing better utilises feed on hand and helps control erosion (especially around watering points).

• At Grass Patch in 2018 hybrid TT’s produced higher yields and gross margins than most of the OP TT canola variety ATR Bonito treatments.
• Retaining ATR Bonito seed ‘on-farm’ for 1, 2, 3 or 4 years produced similar yields, oil and higher gross margins than purchasing new OP seed.
• Using ATR Bonito seed stored for 4 years produced plants lacking in vigour and overall poorer performance than growing out and retaining seed each year or purchasing new commercial seed.

The ribbon sowing provided about 137kg/ha more yield, 0.6% less screenings and an average improvement to income of $35/ha; this will be a useful benefit when the system is used for shield spraying for grass.

• An east-west (E-W) sowing direction increased yield over north-south (N-S) sowing direction in an average season.
• The results showed a decline in yield due to weed competition, but no effect on weed competition due to row direction. Sowing in an E-W direction may give a yield benefit with no difference in weed seed set.
• The wider row spacing of 30 cm resulted in a yield reduction and greater weed biomass at harvest.
• There were no differences in yield with ribbon seeding with either 18 or 30 cm row spacings, but ribbon seeding reduced ‘weed’ biomass.

• There was no detectable direct effect of sowing direction this season at Minnipa with a mild spring.
• Using a narrow row spacing of 18 cm instead of 30 cm resulted in wheat yield increasing from 3 t/ha to 3.6 t/ha (19% increase).
• Light interception was very sensitive to sowing direction, and not having ‘weeds’ resulted in higher light within the canopy in the north-south direction compared to east-west.
• Knife point and ribbon seeding systems achieved similar crop establishment and crop performance.

• An east-west (E-W) sowing direction increased yield over northsouth (N-S) sowing direction in an average season.
• The results showed a decline in yield due to weed competition, but no effect on weed competition due to row direction. So sowing in an E-W direction may give a yield benefit with no difference in weed seed set.
• The wider row spacing of 30 cm resulted in a yield reduction and greater weed biomass at harvest.
• There were no differences in yield with ribbon seeding with either 18 or 30 cm row spacings, but ribbon seeding reduced ‘weed’ biomass.

• Contrary to expectations Russian Wheat Aphid pressure in Southern Australian cereal production seems low over the last years (2017, 2018). Dry and hot summer conditions seem to reduce green bridge survival of Russian Wheat Aphids.
• Barley grass and Brome grasses are major hosts (van Helden 2018) supporting RWA survival over summer. Their development will strongly depend on summer rainfall.
• Development of regional economic thresholds are in progress at trial sites throughout South Australia,Victoria, Tasmania, and New South Wales. Use of international thresholds are still advised until Australian thresholds are developed.
• Observations suggest that crop infestations occur in autumn on early growth stages, then persist over winter and can build up in spring, especially when plants are drought stressed.

• Managing herbicide resistance in ryegrass continues to be crucial in maintaining sustainable crop production on Lower Eyre Peninsula.
• Management strategies other than herbicides need to be deployed to ensure sustainable ryegrass control into the future.
• Windrow burning proved to be an effective method in reducing ryegrass seed numbers in 2015.
• Managing ryegrass on differing soil types will prove a challenge into the future.
• Information generated by this project will provide data to simulate how different management strategies can be used to manage ryegrass in a sustainable, cost effective way.

• Grower noted that Sakura mixed well in the tank and was easy to spray.
• Sakura reduced the numbers of barley grass across the site compared to the grower’s treatment. This was also evident down by the Summit trial where Sakura applied pre-emergent adjacent to the trial was giving better control of barley grass than Trifluralin 2 L ha with a post-emergent application of Monza® 25 g/ha.
• Sakura was safe to Calingiri wheat in this commercial trial.
• The yields presented were taken from close to the northern contour bank where there was higher numbers of barley grass in the crop to represent a good efficacy comparison.
• Based on this the Sakura treatment recorded a 110 kg/ha yield increase over the grower’s Trifluralin at 2 L/ha.
• This equals a $20.58 ROI above the grower’s program once herbicide and application costs were removed.

Using an effective knockdown with broad spectrum pre-emergent grass herbicide like Sakura can deliver excellent weed control, yields and return on investment not just in the year of application but in following seasons due to a reduction in the seed bank when combined with a complete integrated weed management program across the farm.

No damage to lentils was observed, but it should be noted that conditions were not conducive to herbicide damage.  Following label rates will ensure that the risk of damage is minimized.  Using a range of pre-plant and post-plant-pre-emergent herbicides will assist in reducing pressure on in-crop herbicides for grass weed control such as Clethodim (group A).  Rotating herbicide groups and sound manual methods such as wind row burning, chaff carts and fence line spraying will ensure that weed numbers are kept in check and “blow-outs” of weed numbers is minimised.

• During 2013, in canola crops sown on time that achieved target plant populations, it appears that late burning and/or cultivation of previous crop stubbles improved yield.
• The cost of burning stubble needs to be considered both in terms of dollar labour cost and lost nutrients.
• Potential impact on fallow efficiencies following the canola crop need to be better understood. Burning stubbles may have a fit in paddocks where windrows are being burnt for grass seed control or stubbles are too heavy for seeders to get through.
• The cost of cultivation needs to account for both cost of the operation as well as the risk soil erosion, and the possibility of producing drier seedbed conditions at sowing time.
• CWFS proposes to do further trials in the next two years. Remember this report represents only one year (2013) of data from trials at Rankins Springs, Wirrinya and Tullamore.

• During 2013, in canola crops sown on time that achieved target plant populations, it appears that late burning and/or cultivation of previous crop stubbles improved yield. • The cost of burning stubble needs to be considered both in terms of dollar labour cost and lost nutrients. Potential impact on fallow efficiencies following the canola crop need to be better understood. Burning stubbles may have a fit in paddocks where windrows are being burnt for grass seed control or stubbles are too heavy for seeders to get through. • The cost of cultivation needs to account for both cost of the operation as well as the risk soil erosion, and the possibility of producing drier seedbed conditions at sowing time. • CWFS proposes to do further trials in the next two years. Remember this report represents only one year (2013) of data from trials at Rankins Springs, Wirrinya and Tullamore.

Sowing feed into dwindling lucerne stands; either barley or the newer forage ryecorn varieties resulted in increased weight gains of lambs when compared with those lucerne stands where annual grasses were becoming more dominant allowing lambs to be finished quicker prior to the onset of grass seeds
• Oversowing with Scope CL provides a flexible option in the grazing system with the ability to graze for feed in a seed free environment, or to lock up for grain if seasonal conditions are favourable 
• Heavy stocking rates (and possibly small paddocks or strip grazing methods) are needed to keep newer
forage ryecorn varieties grazed down to maintain feed quality and maximise grazing benefits.

• Feathertop Rhodes grass seed viability was reduced by more than 99% after feeding through sheep.
• A low level of viable seeds (<1%) can still be detected 12 days after feeding, therefore, if sheep graze feathertop Rhodes grass, they should be quarantined for at least 8 days in order to prevent seed spread.

• 18 cm (7”) systems showed better plant establishment in a drier seeding than the 30 cm (12”) system.
• Higher seeding rates resulted in higher grain yield but also higher screenings and lower protein.
• Grass weeds were lower in the higher seeding rate and in the 18 cm row spacing indicating crop competition is a non-chemical weed reduction method.
• Single row or spread row seeding boots showed little differences in plant establishment, grain yield and quality or grass weed competition.

• Reducing row spacing to 18 cm from 30 cm increased grain yield of wheat by more than 0.5 t/ha in 2015 and 2016.
• Increasing seeding rate also increased grain yield in 2015 and 2016.

• Late grassy weed dry matter was 65% lower, and barley grass weed seed set was 57% lower, with a higher seeding rate.
• 18 cm row spacing had 42% lower grass weed dry matter than 30 cm row spacing.
• Single row or spread row seeding boots showed little differences in plant establishment, grain yield and quality or grass weed competition.

• 18 cm (7”) systems showed better plant establishment in a drier seeding than the 30 cm (12”) system.
• Higher seeding rates resulted in higher grain yield but also higher screenings and lower protein.
• Grass weeds were lower in the higher seeding rate and in the 18 cm row spacing indicating crop competition is a non-chemical weed reduction method.
• Single row or spread row seeding boots showed little differences in plant establishment, grain yield and quality or grass weed competition.

Legumes are an important tool in a perennial sward to supply a nitrogen source and maintain production. Serradella can be successfully established and persist in an established perennial pasture; this includes persisting as part of a crop/pasture rotation in perennials.

In the more favorable year of 2013 serradella biomass and pod production was higher. There is a yield penalty for serradella when sown into perennials, the penalty though will vary depending on the seasonal conditions. Perennials are still actively growing in March and April before the cooler weather starts to suppress their growth and they become less competitive. An indecisive Autumn break can allow active perennials to deplete moisture reserves that would normally allow germinating serradella to survive. These results clearly demonstrate the advantage of a successful early germination and establishment, although an indecisive break and low rainfall year will exaggerate the yield penalty when serradella is sown into perennials. Additionally, the suppressive effect of a grass selective on perennial growth may reduce competition with annual pasture species and can be used as a tool to increase annual legume production.

• On average in the Mediterranean Mallee environment, sub-tropical grasses grow best during late spring and early summer when soil temperatures are rising and soil moisture is available.
• Unless significant rain occurs after December, the growth rate of sub-tropical grasses is typically low in the period December to April.
• Subtropical grasses are dormant in the winter months, so weed control measures are relatively easy and the inclusion of annual medics may be possible.
• The standing fodder of sub-tropical grasses can potentially be carried over for grazing later in summer.

After six years of running the Systems Site comparing farming systems it has become clear that the critical issues are as follows.

Conserving soil water into dry seasons, which can be achieved using either mechanical in a conventional system or chemical means in a reduced till or no till system (assuming there is enough stubble to protect the soil surface from evaporation).

Since the introduction of Frame and Yitpi (CCN resistant wheats) CCN has not been a problem.

Take-all and Pratylenchus neglectus appear to more closely correlate to specific areas in a paddock rather than levels changing because of crop choice or the rotation (field peas did lower Pratylenchus levels). Certainly there did not appear to be any influence of farming system on these two soil borne diseases.

Weed levels have not changed markedly over the duration of the trial and there were no differences between systems after six years. Brome grass is now present at the site at very low levels whereas it was not recorded in 1999 and 2000.

Wind erosion susceptibility and risk is lowest in the No Till plots because of good stubble cover and aggregation of soil particles. The three other systems all had plots which were moderately susceptible to wind erosion, primarily as a result of low stubble cover.

Using current technology and sampling intensity it is not possible to pick up changes in soil available nitrogen levels between different farming systems.

Soil changes in soil biological characteristics are currently being assessed and will be reported by the BCG update in February 2006.

• The majority of sites had a soil pH less than pH 5.0 (CaCl2) which will reduce crop and pasture productivity and reduce profitability.
• Soils should be sampled at 0-5 and 5-10 cm rather than 0-10 cm. There is often an ‘acid throttle’ that is missed if sampling at 0-10 cm.
• Soils that have been limed will acidify over time. An application of lime every 5-6 years may be necessary to keep the soil pH above pH 5.0 (CaCl2).
• Deep rooted perennial grass dominant pastures can be less acidifying than annual pastures.

Results from the Northern Agricultural Region have shown that crops can be sown over subtropical perennial grasses without jeopardizing persistence of the perennial base. However, perennial grasses vary in their tolerance to in-crop herbicides and crop yield is dependent on effective weed control, adequate fertility and moisture, and winter dormancy (or suppression) of the perennial pasture.

Pasture cropping systems can also lift overall biomass production, improve the feed value of stubbles, provide out of season fodder, and reduce the likelihood of wind erosion and groundwater recharge on deep sandy soils.

The application of additional nitrogen can lead to greater biomass in both the annual crop and perennial pasture. However, this is dependent on seasonal conditions and the economics of applying additional nitrogen needs to be considered carefully on low moisture holding, infertile, sandy soils in the Northern Agricultural Region.

• Light interception at midday was significantly higher under east-west sowing compared with north-south.
• It is plausible that sowing direction may influence weed seed set.
• To establish a competitive crop against weeds and maximise yields, growers should aim for the narrowest row spacing to suit their system.

• Light interception at midday was significantly higher under east-west sowing compared with north-south.
• It is plausible that sowing direction may influence weed seed set.
• To establish a competitive crop against weeds and maximise yields, growers should aim for the
  narrowest row spacing to suit their system.

In this trial both summer sowing and conventional seeding after the break of the season resulted in the successful establishment of serradella into perennial grass pastures. All treatments resulted in serradella seed yields greater than 600 kg/ha, which has set them up for good legume regeneration in subsequent years. The yellow serradella experimental line (87GEH72.1a) shows considerable promise as a companion legume for perennial grasses in this environment. It flowers earlier than Margurita French serradella and has a hard seed breakdown pattern more suitable for summer sowing than current yellow serradella varieties (Yelbini*, Charano* and Santorini*).  Both summer sowing and conventional sowing of annual legumes into perennial grasses after the break require good weed control. Herbicide options and the impact of perennial grass suppression require further investigation. Weed seed set control in the year prior to establishment is recommended.

• In a non-wetting sand, sowing on-row allowed seedlings to germinate in a wetter soil, with increased competitiveness against weed and disease pressures resulting in significant advantages in crop establishment and biomass production.
• Sowing on-row in sands or loam that did not express non-wetting did not capture the same level of benefits.
• Sowing crops on or very near last year’s crop row greatly suppressed grass weed populations and reduced brome grass seed set by over 70% compared to inter-row seeding.
• Early sowing in the last week of April instead of the third week of May helped to overcome the dry spring conditions and resulted in yield benefits of 28% at Loxton and up to 13% at Karoonda.
• When sowing crops on last year’s row, the potential for higher stubble borne pathogen (Take-All and Fusarium) inoculum and a greater likelihood of N tie-up after opening rains needs to be considered. However, impacts on rhizoctonia disease depend upon inherent biological fertility of soil.

• In a non-wetting sand, sowing on-row allowed seedlings to germinate in a wetter soil, with increased competitiveness against weed and disease pressures resulting in significant advantages in crop establishment and biomass production.
• Sowing on-row in sands or loam that did not express non-wetting did not capture the same level of benefits.
• Sowing crops on or very near last year’s crop row greatly suppressed grass weed populations and reduced brome grass seed set by over 70% compared to inter-row seeding.
• Early sowing in the last week of April instead of the third week of May helped to overcome the dry spring conditions and resulted in yield benefits of 28% at Loxton and up to 13% at Karoonda.
• When sowing crops on last year’s row, the potential for higher stubble borne pathogen (Take-All and Fusarium) inoculum and a greater likelihood of N tie-up after opening rains needs to be considered. However, impacts on rhizoctonia disease depend upon inherent biological fertility of soil.

• In a non-wetting sand, sowing on-row allowed seedlings to germinate in a wetter soil, with increased competitiveness against weed and disease pressures resulting in significant advantages in crop establishment and biomass production.
• Sowing on-row in sands or loam that did not express non-wetting did not capture the same level of benefits.
• Sowing crops on or very near last year’s crop row greatly suppressed grass weed populations and reduced brome grass seed set by over 70% compared to inter-row seeding.
• Early sowing in the last week of April instead of the third week of May helped to overcome the dry spring conditions and resulted in yield benefits of 28% at Loxton and up to 13% at Karoonda.
• When sowing crops on last year’s row, the potential for higher stubble borne pathogen (Take-All and Fusarium) inoculum and a greater likelihood of N tie-up after opening rains needs to be considered. However, impacts on rhizoctonia disease depend upon inherent biological fertility of soil.

This trial has demonstrated the impact poor nozzle selection and water rates can have on herbicide efficacy. Farmers generally only use one nozzle type for all post emergent herbicide applications and water rates tend to be lower than optimal. It was found that increasing the water rate and selecting a nozzle with a fine droplet pattern and good coverage gave best results for contact herbicides and those poorly translocated within the plant (Group A herbicides eg. Verdict 520). For herbicides that move readily through the plant, coverage is not as essential allowing larger droplet size nozzles to be used without losing efficacy. For smaller grass targets it is even more important to have the correct water rate and nozzle type. Understanding how herbicides work, modes of action and movement within the plant will allow for better water rate and nozzle selection leading to more cost effective weed control and less off target impact.

This trial has demonstrated the impact poor nozzle selection and water rates can have on herbicide efficacy. Farmers generally only use one nozzle type for all post emergent herbicide applications and water rates tend to be lower than optimal. It was found that increasing the water rate and selecting a nozzle with a fine droplet pattern and good coverage gave best results for contact herbicides and those poorly translocated within the plant (Group A herbicides eg. Verdict 520). For herbicides that move readily through the plant, coverage is not as essential allowing larger droplet size nozzles to be used without losing efficacy. For smaller grass targets it is even more important to have the correct water rate and nozzle type. Understanding how herbicides work, modes of action and movement within the plant will allow for better water rate and nozzle selection leading to more cost effective weed control and less off target impact.

Spraying small ryegrass with translocated herbicides such as Roundup, the droplet spectrum is not as critical as what was first thought. When spraying Roundup during the time of year when drift is a problem, which occurs mainly at sowing during autumn, nozzles which produce droplets which drift less such as the Air Inducted nozzles (AI) can be used (in our trials water rates were kept at 60L/ha).

Spraying small ryegrass with translocated herbicides such as Roundup®, the droplet spectrum is not as critical as what was first thought.  When spraying Roundup during the time of year when drift is a problem, which occurs mainly at sowing during autumn, nozzles which produce droplets which drift less such as the Air Inducted nozzles (AI) can be used (in our trials water rates were kept at 60L/ha).

Higher rates of Spray.Seed provided significantly greater levels of final ryegrass, radish, canola and lupin control.

• Summer sowing into perennial grasses is showing some promise, but the results are inconsistent.  We need to develop guidelines for the required soil conditions (including soil fertility) and there is a need to reduce weed competition by controlling the seed-set of annual pasture weeds in the preceding year.
• Results from these trials plus a range of other summer sowing sites demonstrate that serradella pods need to be drilled for successful establishment. Broadcasting pod is not a reliable alternative.
• The experimental line of yellow serradella (72.1A) was slow to establish in the first year at Badgingarra but has has really gone ahead in the second year.  This yellow serradella is unique in having a very different hard seed breakdown pattern compared with the commercial yellow serradella varieties (i.e. Yelbini, Charano, Santorini) and is suitable for ‘summer sowing’.  It is earlier flowering (80 to 90 days compared to 105 to 115 for Margurita) and yellow serradella is hardier than French serradella.
• Summer sowing using pod avoids the need for de-hulling, so seed is cheaper, but higher sowing rates are required.  Consequently the concept relies to a large extent on farmers being able to source or to produce their own hard-seeded serradella pod at low cost

• The results for summer sowing into an established perennial grass pasture were encouraging in a season with minimal spring rainfall. The results were negatively impacted by the low rainfall in spring. Drilling pod was more successful than broadcasting pod and then using animals to trample it into the soil.
• This was the first summer sowing trial into perennial grasses in WA so it is too early to develop recommendations, but it appears that you need to use 20 to 40 kg pod/ha to achieve a good seedbank. The mid-March sowing time is at the end of the ‘sowing window’ for summer sowing. Sowing in early February is desirable to maximize the time for hardseed breakdown.
• With summer sowing using pod rather than seed there is no need for de-hulling, so there is a cost saving per kilogram, but higher sowing rates are required as the seedlings need to compete with annual grasses, broadleaf weeds as well as the perennial grasses. The summer sowing method requires relatively high sowing rates and the concept relies to a large extent on farmers producing hard-seeded serradella pod on-farm at a low cost.After these promising results in 2010, similar trials will be undertaken in 2011 with local producers.

• The results for summer sowing into an established perennial grass pasture were encouraging in a season with minimal spring rainfall.  The results were negatively impacted by the low rainfall in spring.
• Drilling pod was more successful than broadcasting pod and then using animals to trample it into the soil.  This was the first summer sowing trial into perennial grasses in WA so it is too early to develop recommendations, but it appears that you need to use 20 to 40 kg pod/ha to achieve a good seedbank.  The mid-March sowing time is at the end of the ‘sowing window’ for summer sowing.  Sowing in early February is desirable to maximize the time for hardseed breakdown.
• With summer sowing using pod rather than seed there is no need for de-hulling, so there is a cost saving per kilogram, but higher sowing rates are required as the seedlings need to compete with annual grasses, broadleaf weeds as well as the perennial grasses.  The summer sowing method requires relatively high sowing rates and the concept relies to a large extent on farmers producing hard-seeded serradella pod on-farm at a low cost.
• After these promising results in 2010, similar trials will be undertaken in 2011 with local producers.

For most effective weed control of heliotrope an early applied residual herbicide such as Glean, Ally or Atrazine (be careful with plant backs for different crops!) is most effective. For grass and heliotrope control later in the season, weeds have to be sprayed before they are fully grown and flowering.

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.

• The survey received 224 responses from growers aligned with the different farming systems groups participating in this project.
• 39% of the grower respondents identified barley grass as having a medium to high impact on their cropping systems.
• 40% of the grower respondents feel that barley grass emergence patterns have changed over the last 10 years and that it now emerges later in the season.

51% of growers thought barley grass had become more common in their cropping paddocks. Some of the factors responsible for the increase in barley grass include delayed emergence and early seed-set, low efficacy of pre-emergence herbicides, particularly during dry starts to seasons, resistance to group A herbicides, continuous cereals in the system and wide crop row spacing

• 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.

• Substantially better brome control and seed set reduction is possible by using pre-emergence options other than trifluralin.
• The costly Sakura+Avadex treatment is likely to be the most effective.
• Consistency of performance of all pre-emergence herbicides for brome remains a problem
• On-row seeding on non-wetting sand showed that it can substantially improve early crop emergence.
• One reason for this is the likely wetter surface soil in rows at time of seeding.
• Seasonal conditions such as the long-wet season of 2016 will affect efficacy of both pre-emergence herbicides and the impact of additional crop competition on brome seed set suppression.
• Maintaining low seedbanks and having alternative options for weed seed control when faced with a risk of ‘blowouts’ in brome seed set is important given the chance of particularly poor control in some seasons.

• Substantially better brome control and seed set reduction is possible with pre-emergence options other than trifluralin.
• The costly Sakura+Avadex treatment is likely to be the most effective.
• Consistency of performance of all pre-emergence herbicides for brome remains a problem
• On-row seeding on non-wetting sand can substantially improve early crop emergence in part due to increased surface soil water accumulation in rows at time of seeding.
• Seasonal conditions such as the long wet season of 2016 will affect efficacy of both pre-emergence herbicides and the impact of additional crop competition on brome seed set suppression.
• Maintaining low seedbanks and having alternative options for weed seed control when faced with a risk of ‘blowouts’ in brome seed set is important given the chance of particularly poor control in some seasons.

• The later seeding had very poor crop establishment, resulting in significantly higher brome seed production (115% more panicles) than early seeding, but seeding time did not interact with herbicide treatment effects.
• Only the treatments including Sakura resulted in significantly (P<0.01) better brome control than trifluralin alone (measured by number of panicles/m2).
• Sakura alone resulted in 55% less brome panicles than trifluralin alone, and Sakura + Avadex resulted in 72% less brome panicles than trifluralin alone.
• Sakura’s extended residual soil activity, which can restrict root growth of brome, combined with the dry spring, was probably responsible for the reduced seed set.
• Substantially better brome control and seedset reduction is possible by using pre-emergence options other than trifluralin. The additional herbicide cost needs to be evaluated against the better level of control, including the longer-term seedbank 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.  

This demonstration clearly showed that by adding a small amount of barley (16kg/ha) to serradella when re-seeding, early winter feed for livestock can be significantly increased.  However, as the photos from early September indicate, the serradella growth in spring can be held back due to competition from the barley. Increasing the frequency and intensity of grazing would help, as would the application of a grass selective herbicide to kill the barley in early spring when feed is becoming abundant. If the season was very poor, the barley might be left to increase total pasture production and groundcover for summer.  

• The highest yielding treatment was Calibre (RAC2721) sown on 28 April, achieving just over 4.6t/ha.
• Yields of over 4t/ha were consistently achieved by mid-slow to slow maturing spring wheats sown on 14 April and quick to mid maturing spring wheats sown 28 April. This coincided with flowering occurring during August.
• Despite being sown onto field pea stubble with 75kg N/ha applied, high yielding (4+ t/ha) treatments rarely met APW1 protein specifications, indicating that at these high yields greater nitrogen applications are required to achieve premium milling grades.

• 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.

• Wheat yields were significantly reduced by competition from barley and brome grass.
• The use of knockdown post sowing but pre-emergent provided excellent control of the grass weeds, which translated into a yield benefit.
• The trends in control of grass weeds and yield benefits in barley were similar to the results seen in wheat.

• There was a significant step up in 2013 wheat yields from rotations which included a one year break previously compared to where there had been a two year break.
• The break crop benefit of a one year break may only last one season if grass weeds are a significant factor.
• Large break crop benefits of 0.5-1.25 t/ha were achieved following a two year non-cereal break phase compared to continuous wheat.
• The benefit of a two year break had little to do with the phases chosen for those two breaks.
• The eight most profitable crop sequences over a three year period in this trial had two year breaks in them.

• ‘Compass type’ varieties with good early vigour, combined with a prostrate growth habit are the best competitors (Compass, Fathom, Scope CL, RGT Planet).
• ‘Hindmarsh type’ and ‘Urambie type’ varieties with very slow early vigour are poor competitors (Hindmarsh, Spartacus CL, Urambie).
• In the presence of grass weeds there was an average of 0.9t/ha yield loss across all barley varieties.
• Three years of data has reinforced that certain varieties can be used as a non-herbicide option for grass weed control.

•  Yields were significantly higher under narrow row spacing, but sowing direction had no influence on yield.
• Weeds had a significant effect on yield, but the scale of yield penalty (t/ha yield loss) did  not alter with row spacing or sowing direction in 2015.
• Weeds established faster where row spacings were wider, however by late tillering, all treatments had similar weed numbers and biomass levels.

• Yields were significantly higher under narrow row spacing, but sowing direction had no influence on yield.
• Weeds had a significant effect on yield, but the scale of yield penalty (t/ha yield loss) did not alter with row spacing or sowing direction in 2015.
• Weeds established faster where row spacings were wider, however by late tillering, all treatments had similar weed numbers and biomass levels.

Sowing early gave best crop competition with brome grass. Select a variety with high early vigour to suppress brome grass seed set. Select a variety with a short growing season when crop-topping brome.

• 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.

• 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.

• Our standard package of 100 kg 18:20/ha at seeding under the seed row (to avoid fertiliser toxicity), Jockey-treated seed, endosulfan and simazine pre-seeding, a follow up spray of atrazine and a grass herbicide mid-season, and two top-ups of nitrogen during the season (50 kg N/ha as broadcast urea each time) gave us a clean, high yielding and good quality crop with no pests or diseases.
• There was no evidence that extra management options provided any further benefits to canola performance (ie a fungicide spray, B fertiliser or use of a growth regulant) under the conditions of last year’s trial.
• However, it would appear that we may have been a bit generous with our N and P inputs in the standard package because we could halve the mid-season N rate and not suffer any yield or quality loss. Additionally, leaving out P altogether had little impact so a rate lower than 20 kg P/ha may have been the best compromise last year.
• There seems little reason to change from a management strategy of plenty of N at seeding (providing you can avoid seedling toxicity by separating the N and the seed) followed up by an early season top-up. Delayed aapplications of N produced yields or quality no better than our standard.

• 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.  

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

Please see attached trial report for results.

• 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.  

In 2014, an estimated 61 per cent of the seed bank germinated throughout the season, enabling a rapid reduction of the wild radish population and having a positive effect on grain yield. However, due to the long dormancy of the seed (six to eight years), 100 per cent control would be needed to eradicate the entire seed bank.

Approximately 30 per cent of the seed bank germinated as a result of summer rainfall; best practice is to make the most of seasons that deliver a summer break to get a good knockdown.

Aim to control 100 per cent of seed set by using multiple cultural, chemical and mechanical practices to eradicate the seed bank and stop resistance development.

• All treatments were safe to the crop except for Sakura 118 g/ha + Sencor 150 g/ha which resulted in biomass reduction at all assessments.
• This was in part due to a couple of rows being sown into the inter row that contained herbicide which re-sulted in the death of some plants.
• This mixture would not be recommended on conventional wheat. An overall crop bio-mass rating was taken 106 DAA rated Sakura 118 g/ha as 100% with the other treatments benchmarked against it.
• The crop was water stressed at this time. Inspection of the crop heads found they were not filling to potential with small grain and empty husks common across the trial.