This trial was conducted as part of a series to evaluate the potential of a range of fallow registered residual herbicides and potential new options for management of common sowthistle. Management of common sowthistle in fallow is a major industry challenge with increasing levels of glyphosate resistance or tolerance. Although common sowthistle populations are typically scattered and at low densities, management alternatives including residual control are keenly sought.

The trial was conducted in a paddock near Bellata in Northern NSW that was fallowed from faba beans in 2020. Stubble levels were low and the paddock was sown to LRPB Lancer wheat in early May.
The majority of herbicide treatments were applied in late April and incorporated by sowing (IBS) 5 days later using a John Deere single disc planter on 38 cm row spacings. Rainfall totaling 11 mm was recorded 3-4 days after planting (3-4 DAP) with an additional 7 mm within the first fortnight. One herbicide was applied as a post sowing pre-emergent (PSPE) split application, 5 days after sowing and the remaining 3 treatments applied at an early post-emergent timing in wheat, at ~4 leaf crop stage.
Wheat establishment was assessed at 12 DAP when a majority of plants were already at ~1-2 leaf stage. The untreated population was ~96 plants/m2. Severe damage to crop emergence was apparent from a number of herbicides.
Treatments containing trifluralin (TriflurX or Bolta Duo) caused the greatest damage and reduced crop emergence by >90% (0-8 plants/m2). Rifle 440 (pendimethalin) and Luximax (cinmethylin) had less impact but still reduced emergence by ~50-60% (50 and 37 plants/m2). Diablo Duo (triallate and prosulfocarb) reduced emergence by ~15% (82 plants/m2). No other treatment had a significant impact on crop emergence although there was a non-significant trend to a ~10% reduction in emergence from both Boxer Gold (s-metolachlor plus prosulfocarb) treatments and Overwatch (bixlozone). There was no effect on crop emergence from Sakura or Dual Gold. A second assessment of emergence was not conducted, as there was no apparent change in crop emergence at later inspections.
Trace levels of paradoxa grass were apparent at 23 DAP when the in-crop treatments were applied but with no detection in the untreated. Paradoxa grass control was assessed in late June at 59 DAP with a density of ~0.7 plants/m2 in the untreated. All herbicides significantly reduced the weed counts under a low paradoxa grass density. Sakura, the split application of Boxer Gold, Luximax and all treatments containing trifluralin reduced paradoxa grass counts by >90%. Arcade 3 L/ha and Mateno Complete applied at 23 DAP also reduced paradoxa counts by >90%.
All treatments provided useful levels of suppression or control of paradoxa grass for ~3-7 weeks after application. All herbicides with paradoxa grass control claims provided >90% reduction in counts with encouraging activity from the split application of Boxer Gold, Luximax and Arcade 3 L/ha applied 23 DAP.
An effective commercial knockdown spray was applied shortly after the 59 DAP assessment. The site was inspected in August and October with no new paradoxa grass emergence in the untreated but trace levels where severe crop damage had occurred.
This trial however was an example where residual herbicide crop safety was very poor. The actual cause is unclear but may be due to a combination of early planting with very rapid seedling development (wheat to 2 leaf by 12 DAP) and the use of a single disc planter which failed to remove adequate soil from the planting furrow. Depth of planting was unfortunately not assessed but the rapid crop emergence would suggest planting seed was relatively shallow. Rainfall after planting was obviously a factor but the amounts were relatively low with ~8 mm at 3 DAP and ~3 mm at 4 DAP.
In this situation, with low paradoxa grass density, the treatments with the best combination of crop safety and paradoxa grass efficacy were Sakura, Mateno Complete and Arcade 3 L/ha.

Despite the trial being established in a paddock with a history of FTR, common sowthistle was the only weed to emerge over thefollowing 5 months. No data was generated on residual herbicide efficacy against FTR

This trial was established to evaluate the residual control of Feathertop Rhodes (FTR) grass in wheat. Stubble levels were extremely low with the paddock long fallowed from sorghum in 2019/20.
The majority of treatments were applied 3 days prior to planting (-3 DAP) and incorporated by sowing (IBS) using a commercial disc planter on 28cm row spacing. The post sowing pre-emergent treatment (PSPE) was applied 4 days after planting. No rainfall was recorded between the IBS and PSPE applications with ~24 mm recorded in the first 9 days after the PSPE application. The in-crop application was applied at a crop stage of 2-4 tillers, 57 days after planting (57 DAP) and received ~11mm of rain the following day.
A total of 175mm was received during the 5-month duration of the trial. Monthly totals of less than 10mm of rain were recorded in August and September with a total of ~65mm in October.
Wheat establishment was assessed at 18 DAP with ~104 pl

Ally applied as per label recommendations with a 9 month plant back period for pulses and canola grown on alkaline soils did not appear to have a negative effect on the growth of chickpeas, field peas, lentils, faba beans and canola.

In 1978, a residual value trial in which it is possible to compare the effectiveness of previuos applied Mn with cuuently applied Mn.  The Mn sulfate at 15, 30 & 60 kg/ha in 1978 produced maximum seed yield. The 15 & 30 kg Mn sulfate applied in 1982 produced the same maximum seed yield as Mn applied in 1978.  However, the 15 kg/ha of Mn sulfate applied in 1978 & 1982 still resulted in 11 - 16% split seed compared to the nil Mn that had 40% split seed. THe 30 kg Mn sul /ha reduced split seed to <5%.

The Mn concentration in whole shoot was 34 mg/kg; indicating Mn deficiency The Mn concentration in whole shoots with 15 kg Mn sul/ha was similar (80 mg/kg) for 1978 and 1982 applications.

THese results suggest that the residual value of soil applied Mn is greater than originally thought 

• Tested effect of rates, methods of application and residual effects of zinc oxide on hybrid maize XL45.
• Zinc was either broadcast or drilled at initial rates of 0, 5.6, 11.3 or 38 kg Zn/ha and 0 or 5.6 kg Zn/ha in subsequent seasons.
• In most seasons, treatment with zinc almost doubled grain yields.
• Broadcasting and working in was more effective than drilling zinc with the fertilizer.
• Residual effects of the initial 5.6, 11.2 and 38 kg Zn remained evident throughout the 6 years and the higher rates continued to produce highest yields.

Rates nil to 5 kg Zn/ha applied in 1970. Results for 1977.

Zn applied in 1970 barely detectable although application of plain super at 250 kg/ha /yr since 1970 maintain Zn levels for near maximum yield of pasture..

The author indicated the following:  

Suggestion that results indicated need to reassess the Zn requirement of a wide on inherently Zn deficient soils. This is particularly so in the absence of Zn via the Zn impurities in super from traditional sources of rock phosphate. It maybe highly likely that some future date we may have to rely on low Zn containing Zn phosphates .  Unless more information is obtained in advanced there could be serious losses due to Zn deficiency some time in the future.

Residual effects from soil nitrogen can be observed in the following cereal crop whcih makes a good case for utilising pulse innoculants

• Residual subsoil zinc improved root growth and grain yield of wheat in a pot experiment.
• Canola genotypes did not differ in their effects on the following wheat.
• A greater proportion of wheat zinc was located in grain where subsoils had received zinc (but it should be noted that these pots had received 3 times the total zinc of the surface zinc pots).

Residual herbicides can be an effective management tool in providing an extended period of weed control but careful consideration must be given to potential crop selection limitations, or crop loss, that their application may impose.

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.

• This trial yielded 3.4 t/ha without fertiliser but there were still good responses to nitrogen (N) and phosphorus (P). The application of both nutrients increased yields up to 4.5 t/ha.
• There was a 0.6 t/ha response to 80 kg N/ha and a 0.7 t/ha response to 24 kg P/ha.
• 24 kg P/ha applied in both years produced 0.4 to 0.5 t/ha more than where 16 kg P/ha applied both years.
• Residual responses to N and P applied in 2011 were not significant.
• NS 41 applications increased protein from about 12.3% to 13.3%. Hectolitre weights were about 77 kg/hl and screenings averaged 1%.
• The most profitable treatment over the two years of the trial was 24 kg/ha (136 kg/ha Double Phos) applied both years.

• Residual effects of high rates of nitrogen, sulfur and phosphorus applied to canola could be detected in soil tests prior to seeding wheat in the following season.
• Nitrogen applied to the wheat crop had a much larger impact (1 t/ha grain yield increase) than carryover effects of nitrogen applied to the canola crop (up to 0.6% grain protein concentration increase).
• Phosphorus rates applied to canola influenced the yield of the following wheat crop only when no P was applied to the wheat, with no difference in yield when 27 kg P/ha was applied at seeding of the wheat.
• Growers in WA’s high rainfall zone are unlikely to see meaningful carryover effects in the cereal phase from high rates of nutrition applied to canola the year prior. They should, therefore, continue to focus on expected responses in the current year only when determining the most profitable rates of fertiliser to apply to their crops.

• P fertilisers applied in 2006 did not improve grain yield in 2007, even at the high P rate (18 kg P/ha).
• In terms of residual value, there was no difference between granular and fluid P.
• 2007 applied fluid P (TGMAP) at 6 kg P/ha increased dry matter at GS30 from fresh granular P and control treatments.
• Soil testing is a useful tool for estimating P status in the soil.

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.

2020 Key message:

• The ability to make the best use possible out of rainfall and stored soil moisture continues to be the largest driver of crop and pasture production on the Eyre Peninsula.
• Being able to measure what plant-available soil moisture is present at any time of the year, not only at soil moisture probe points but across the landscape offers the potential to improve productivity and limit risk.
• In the next 12 months, tools such as an improved platform (website/app) to display soil moisture probe information will be rolled out.
•  
• 2021 Key message
• Out of season rainfall and stored soil moisture were found to be key factors in driving grain yields across most farming systems on the Eyre Peninsula in 2021. 
• Collating and interpreting information from a range of sources including plant available water, previous grain yields and soil testing across the landscape can maximise returns and reduce risk. 
• Improving knowledge of soil characteristics can add considerable valueto monitoring soil moistue probes.  

• Grain shattering is a significant cause of grain yield loss in wheat, accounting for 11–13% of the variability in grain yield in this experiment.

• Genetic variation exists for grain shattering in Australian wheat varieties.

• However, grain shattering is also controlled by the environment, and this will influence choice of variety.

• Almost 20% of all stored grain insects collected had strong resistance to phosphine.
• Rusty grain beetle resistance is the most serious, as it is beyond label rates to control.
• Strong resistance in lesser grain borer is the main problem in New South Wales; rice weevil in South Australia.

• Approximately 3% of all stored grain insects collected had strong resistance to phosphine – a marked reduction from 18% in 2016.
• Improved hygiene is the probable reason for the observed reduction in resistance.
• Rusty grain beetle resistance remains the most serious issue as it is not controlled by current label rates.

• It was not surprising that no response to sulphur was obtained, when we consider that the KCI sulphur level in the soil rose from 5-7 mg/kg before bed forming to 16 mg/kg after bed forming. 
• For further discussion please see the attached trial report.

  Key findings:

Yield in the presence of crown rot was generally barley > bread wheat > durum across both sowing times, but significant differences were evident between varieties.

• Barley, bread wheat and durum varieties differ in their extent of yield loss from crown rot and their actual yield and grain quality (screenings) in the presence of this disease.
• However, all varieties are susceptible to crown rot infection and will not significantly reduce inoculum levels for subsequent crops. Variety choice is not a sole solution to crown rot.

Conclusions

• Sowing date and variety maturity choice is a balance between frost risk and terminal heat stress in the northern grain region. Both can have a significant impact on grain yield. No frost damage was evident at this site in 2014 with either sowing time but terminal heat stress did occur which was more severe during grain filling with the second sowing time. A three week delay in sowing time resulted in an average 24% reduction in yield across the winter cereal entries.  Later sowing pushed grain-fill too far into hotter conditions. This can reduce yield by itself but if there is also an underlying issue with crown rot then delayed sowing significantly exacerbates the expression of this disease with negative impacts on both yield and grain quality.

  Varieties do differ in their extent of yield loss from crown rot and in their relative yield in the presence of high levels of infection, which is often referred to as tolerance. This is a function of a varieties level of partial resistance to infection but appears to also interact with its environmental adaptation and maturity relative to the timing of stress (moisture and heat) which exacerbates the expression of crown rot. Generally quicker maturing barley, durum and bread wheat entries were higher yielding in the presence of crown rot infection in this trial. This does not necessarily mean that these varieties have improved levels of resistance to crown rot infection but rather their quicker maturity allowed them to minimize stress during grain filling relative to longer season entries, reducing the expression of crown rot.

  If forced into planting a cereal crop in a high crown rot risk situation then some barley varieties may provide a yield advantage over bread wheat in that season, as long as early stress does not occur. Some of the newer bread wheat varieties do appear to be closing this gap to some extent. Barley tends to yield better in the presence of crown rot infection due to its earlier maturity relative to bread wheat, providing an escape mechanism which reduces its exposure to moisture stress during the critical grain filling stage. However, a key message is that this decision is only potentially maximising profit in the current season. Growing barley over bread wheat will not assist with the reduction of crown rot inoculum levels as barley is very susceptible to infection. Significant yield loss is still occurring in the best of the barley and bread wheat varieties in the presence of high crown rot infection. Variety selection can improve yield in the presence of crown rot, though all varieties still suffer yield loss, which can maximise profit in the current season but this will not reduce inoculum levels for subsequent crops. Winter cereal crop and variety choice is therefore not the sole solution to crown rot but rather just one element of an integrated management strategy to limit losses from this disease.

• 10 chickpea genotypes were grown in the field with and without added zinc.
• Zinc sulphate was applied to the soil at sowing and later as a foliar spray at the start of flowering.
• Zinc fertilisation increase shoot dry matter by 13% at maturity.
• There were differences between cultivars in zinc efficiency.
• Gains in yield by improved to sink efficiency are possible in chickpeas.
•  The ranking of cultivars was consistent between sites and in pot studies in the glasshouse.
•  Significant responses to zinc fertiliser confirmed that zinc deficiency was a limitation to chickpea yield.

• 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.

• Chickpea seed yield responded to 25-50 kg N/ha applied 18 weeks after sowing at Ridely in 2020
• Yield responses were not large enough to pay for the cost on applied nitrogen.
• Kabuli variety Gen090 produced similar yields to desi variety CBA Captain

• The critical zinc concentration in shoots ranged from 22 to 29 mg /kilogram across the 5 durum varieties.
• There was no difference in shoot zinc concentration of the 5 varieties within any of the zinc treatments, ranging from 0.025 to 5 mg / kilogram of soil.
• There was some evidence that zinc sensitive genotypes were more likely to suffer from crown rot.

• Applying 100 kg N/ha 8 weeks after sowing increased yield, but did not lead to increased gross margins
• Trial site was flooded in August – treat results with caution

• The Italian ryegrass responded well to phosphorus additions in the range of 15-60 kg P/ha and required the higher rates to be applied unless nitrogen, potassium and sulphur were also included.
• In regard to the addition of potassium, the relatively wet year meant there was unexpectedly no negative affect on plant establishment by banding potassium fertiliser in the soil at sowing which is generally not recommended.

• Applying nitrogen to lentil had no positive effect in 2020

Potassium levels are low in this soil and this site should have been responsive to applied potassium, however due to seasonal and soil conditions there where no differences between treatments in this trial. The very dry June-August had a marked impact on crop growth, particularly tillering. This can be seen by the lack of differences in the head counts taken in September. Very hot conditions in early August also affected flowering in wheat and limited any response in grain yeild with later rains. Soil penetrometer readings in the paddock near the trial site showed hard pan and this in conjunction with the pH and Aluminium levels below 10cm would have restricted root growth and limited the wheat plants ability to access soil miosture at depth during the dry winter period. Without yield responses to applied treatments, crop return decreased as fertiliser rates increased.

• Wtih three continuous wheat years, all the varieties were very responsive to 120kg N/ha. 
• Increasing seed density is a good management tool for weeds in wheat. At this site, yields increased with increasing seed density without a reduction in grain quality.

• Short season variety, Condo yielded the highest (5.75 t/ha).
• There was no significant difference between applying 40 + 40 kg N/ha (5.77 t/ha) split application and the single 80 kg N/ha (5.75 t/ha).

• Responses to Zn were measured in terms of seed yield, yield components and growth.
• Responses differed between varieties. In terms of yield response to Zn.
• Forrest is extremely responsive; Dare, Dodds and Bragg are moderately responsive; and Lee and Ruse are relatively tolerant of Zn deficiency.

• The 12 barley varieties were, on average 26%, higher yielding than the 4 wheat varieties in this experiment.
• the fast developing wheat varieties Emu Rock and Condo generally reached anthesis around the same date as the slow developing barley varieties Navigator, Oxford and Urambie.
• Long season barley varieties such as Oxford and Urambie performed well for early sowing (24 April) but most barley lines had their highest yield from main season sowing (12 May).
• The four early season wheat varieties generally had better yield from main season sowing than from early sowing. 

• Wheat yields were improved by using a combination of N,P,K,Mg,S,Zn fertilisers.
• Canola yields were improved by using a combination of N,P,S and Zn fertilisers.
• Gross margins suggested balanced crop nutrition could improve farm profitability despite dry conditions and high fertiliser prices.

• Five representative sites with no history of copper application were selected on each of five main soil types in the district.
• Four treatments (replicated 4 times) were established; Nil and 75 g/ha of foliar copper applied at Zadox scale 23, 41 and 23 + 41.
• Anthesis and harvest dry matter production and grain yield were determined by quadrat cuts of 3mL/plot. Al, A2 and 81 horizon soil samples were taken for chemical analysis • Copper application resulted in a significant increase in grain yield on soil types 2 and 5, attributable to significant increases in grain weight on soil type 5, and grain number per head on soil type 2.
• These soils were geologically the oldest of the five tested and had the lowest average level of EDTA copper.
• Time of application was not important and a second application did not increase yield further.
• There were no early symptoms of Cu deficiency on any sites and foliar application of copper at tillering produced no change in either visual appearance or anthesis dry matter production.
• Deficiency symptoms only became apparent at stem elongation when two sites displayed minor wilting.
• In addition to identifying the two soil types with suboptimal copper supply to wheat, this experiment highlights the pitfalls of relying on visual detection of copper deficiency.
• Areas of subliminal but significant copper deficiency may go undetected by farmers who rely on this method.

• Trial sowing at 11 June was later than optimal but plant growth was showing strong response to nitrogen (N) and some response to potassium (K) at 28 August.
• By harvest, Mace wheat showed significant grain yield response to nitrogen application but potassium response had moderated.
• No significant differences were seen from Cu application.
• Late sowing decreased yield potential from the start. Harvest yields ranged from 2 to 3 t/ha, with maximum yield and $/ha return at 80 kg N/ha and 12.5 kg K/ha.

• A field trial was conducted at Pthara in 2009. Twenty-four wheat breeding lines from various Australian breeding companies were selected and sown at three times of sowing in a randomised block design with three replications.
• At this site, most of the AH varieties achieved more than 13% protein at all sowing times times except TOS1.

There was a significant difference in response to irrigation on the flat ground and raised beds (Table 2). Grain yields on the flat ground only increased slightly with irrigation and this was not significant. On the raised beds there was a progressive increase in yield with increasing irrigation although there was not statistically significant difference between the two irrigated treatments. Initial examination of data from Gopher tubes shows greater drying of the soil profile on raised beds.

The Jibberding site showed a positive and linear response to increasing P with no PR-70.

• Significant increases in dry matter at GS30 were found in wheat. Fluid P increased dry matter from the control by 49%, whereas only 19% increase was found when P was supplied as a granule
• There was an increase in dry matter from the application of P for both Barley (20%) and Oats (35%). There was no difference in dry matter between the granular and fluid products.
• There was no difference in terms of grain yield from P application compared to the control of each crop type.

1. Chickpea yields increased by over 900 kg/ha on deep banded phosphorus (P) applied at 40 kg P /ha; representing a 300 % increase over the zero P treatments.
2. Chickpea yields were not responsive to deep applied potassium bands.

1. 20% yield response to deep-placed phosphorus at the highest rate in the third year of production.
2. No significant response to deep-placed potassium.

1. Mungbeans did not respond to deep phosphorus treatments.
2. Mungbeans had a 15% yield response to deep potassium treatments.
3. After 3 years of cropping the return on investment to 20 kg deep banded phosphorus is 1.6 and 100 kg deep banded potassium is 1.7.

1. Wheat at Condamine and late barley at Jimbour West both had yield increases with starter and deep-P independently.
2. Chickpea at both Roma sites had no effect of starter or deep-P on grain yield, with little in-crop rain restricting yield potential.
3. Potassium (K) had no yield effect on late barley at Jimbour West.

• Wheat yields in the poor, medium and good zones in response to low, medium and high inputs respectively did not differ significantly in 2011.
• Over a 3 year wheat-canola-wheat rotation there has been no measured production benefit from applying 6 kg/ha of P on the good soil type as opposed to nil P on a shallow constrained soil.

• 4 kg/ha of P as a blanket application increased grain yields and gross margins over nil P in all 3 soil zones, however applying a variable rate to the medium soil zone of 8 kg P/ha improved gross margins over the 4 kg/ha rate.

• In a good growing season, wheat performed equally well in zones identified as good, medium or poor however they achieved only 50% of their yield potential water use efficiency.

• Annual medic plant establishment density limited by 2008 drought, mice and possibly a false break.
• Pasture production restricted by low plant numbers but increased by 2010 P applications.

• In an above average season a high input system was the “best bet”.
• Variable rate had reduced production but at a lower risk.

• Sowing in early June 2009 resulted in wheat yields on 3 soil types being similar but only achieving 50% of potential water use efficiency.

• After two good seasons a variable rate approach is as profitable as a low input blanket approach and more profitable than a standard blanket approach.

• The profitability of VRT, excluding capital outlay, was just better than standard practice over the last two seasons at Minnipa.
• The long term impacts of reducing inputs and any consequent yield reductions in above average seasons are yet to be determined.

• WI3806-1 is an early maturing line equivalent to Keel in the good years and better in the bad ones.
• Very early maturing barley varieties will provide farmers with more cropping options.