Initially there was disease evident at the site (14% on top 4 leaves at Z22) . The disease was found to predominantly yellow spot, with some septoria nodorum blotch also present (75:25). The disease continued to progress up the canopy and there were significant differences between fungicide treatments when disease was assessed at Z22, Z39 and Z65. There were no statistically significant yield differences, probably due to the dry spring, only approximately 60 mm of rain fell in the 8 weeks after flag leaf emergence. Average yield was 1.1 t/ha. Previous DAFWA research has found that at least 80 mm of rain needs to fall in this period for a Z39 flag leaf fungicide application to be profitable. While there were no significant yield impacts from the fungicide treatments there were significant grain quality results (see Table in attached document). The double spray strategy of applying fungicide at Z22 and Z39 gave the best disease control throughout the season. It, along with the Z39 spray on its own, were the best treatments for high hectolitre weight and lowest screenings.

• Flagship and Buloke are new malting variety alternatives to Schooner and the Sloop varieties and segregation options for these varieties will increase during 2008. Flagship has the advantage of CCN resistance and more developed markets, whilst Buloke has the advantage of higher yields.
• Hindmarsh, Fleet and Keel are the highest yielding feed varieties. Choice between these varieties will be based on the relative importance of test weight (Hindmarsh superior), resistance to the spot form of net blotch (Keel and Fleet superior), resistance to leaf rust (Hindmarsh and Fleet superior), and tolerance to deep sands (Fleet and Hindmarsh superior).

Leaf rust, net blotch and barley scald were evident in the trial. The average yield response as a result of spraying with a fungicide was 900 kg/ha. Controlling leaf disease with the use of a fungicide significantly increased grain retention, reduced screenings and increased test weights. There was no significant effect on grain protein.

There are 2 commercially available varieties, namely Fleet and Capstan that performed very well in the trial. The effect of a foliar fungicide to control leaf disease (scald and spot form of net blotch) gave on average an additional 340 kg/ha yield which was cost effective on most varieties, even in a very low disease pressure situation.

At Conmurra there was significant net blotch. In this case GairdnerPlus produced greater grain yields of better quality grain than Gairdner. No other diseases were recorded. At Frances, no significant disease was noted and higher yielding varieties were
Capstan, Flagship and Gairdner.

This research highlights how important a tactical approach to STNB management is in the medium rainfall zone.  In dry seasons there is lower disease pressure, resulting in a potentially expensive fungicide strategy which can be marginal in returns.  Conversely, where there is high disease pressure usually from wet conditions early in the season, then a double spray strategy can improve grain quality, yield and returns to the grower.

Where growing barley on barley, growers should budget for a fungicide spray at Flag-1 every year to protect the top 3 leaves in the canopy.  Where conditions are wet early post emergent (especially if stubble is retained) allowing early disease pressure and high yield potential then a fungicide spray at Z31-Z32 can reduce disease pressure and protect the canopy until the Flag-1 spray is applied.

Under high disease pressure situations (wet conditions early post emergent) removing stubble prior to sowing barley on barley can reduce inoculum levels and the build up of early disease pressure.  This will also help to reduce the selection pressure for fungicide resistance.

Where there is a dry start to the season and a slow build up of disease then stubble management has minimal impact on the buildup of STNB levels.

Burning barley stubble prior to planting barley on barley has shown to increase yield buy between 325 and 400kg in 2017 and 2015. While removing stubble can reduce early disease pressure, not all the yield increase can be accounted for by disease.  Other factors are involved that may require additional work to understand (N mineralization, allelopathic impacts of stubble or improved seed bed).  Where erosion risk is low growers should consider burning to remove barley stubble if planting consecutive barley crops.

We feel that there is no further work required to investigate the hypothesized link between STNB levels and pre-harvest head loss.

Growers, advisors and the wider barley industry are the key beneficiaries of this research.  Being able to manage disease to maintain grain quality, yield and economic returns to the grower is critical for a competitive barley industry.

This research highlights how important a tactical approach to STNB management is in the medium rainfall zone.  In dry seasons there is lower disease pressure, resulting in a potentially expensive fungicide strategy which can be marginal in returns.  Conversely, where there is high disease pressure usually from wet conditions early in the season, then a double spray strategy can improve grain quality, yield and returns to the grower.

Where growing barley on barley, growers should budget for a fungicide spray at Flag-1 every year to protect the top 3 leaves in the canopy.  Where conditions are wet early post emergent (especially if stubble is retained) allowing early disease pressure and high yield potential then a fungicide spray at Z31-Z32 can reduce disease pressure and protect the canopy until the Flag-1 spray is applied.

Under high disease pressure situations (wet conditions early post emergent) removing stubble prior to sowing barley on barley can reduce inoculum levels and the build up of early disease pressure.  This will also help to reduce the selection pressure for fungicide resistance.

Where there is a dry start to the season and a slow build up of disease then stubble management has minimal impact on the buildup of STNB levels.

Burning barley stubble prior to planting barley on barley has shown to increase yield buy between 325 and 400kg in 2017 and 2015. While removing stubble can reduce early disease pressure, not all the yield increase can be accounted for by disease.  Other factors are involved that may require additional work to understand (N mineralization, allelopathic impacts of stubble or improved seed bed).  Where erosion risk is low growers should consider burning to remove barley stubble if planting consecutive barley crops.

We feel that there is no further work required to investigate the hypothesized link between STNB levels and pre-harvest head loss.

Growers, advisors and the wider barley industry are the key beneficiaries of this research.  Being able to manage disease to maintain grain quality, yield and economic returns to the grower is critical for a competitive barley industry.

• Favourable climatic conditions in 2021 resulted in the increased prevalence of a range of cereal diseases across NSW, especially the wheat leaf diseases stripe rust, septoria tritici blotch (STB) and yellow leaf spot (YLS).
• In combination with increased cereal stubble loads produced in 2021, pathogen levels are likely to be elevated again in 2022.
• Predicted La Niña conditions over summer will maintain or increase the risk of stripe rust in 2022.
• Multiple stripe rust pathotypes were prevalent across NSW in 2021. Keep up to date with the latest varietal resistance ratings.
• Minimise disease impacts in 2022 by using an integrated approach to management.
• NSW DPI plant pathologists can assist with correct diagnosis and advice on appropriate management options.

• A Predicta B sample taken from the site indicated a medium risk of rhizoctonia although patches did not express during the season.
• Early establishment across the site was severely impacted by non-wetting affected all plots across the trial with the worst of it commencing around plot 215 and increasing in severity throughout replicate 3.  Early dry conditions further staggered the crop emergence.
• Good rains through late July and into early August ensured the crop was growing well albeit patchy across the trial with high levels of disease present at both the Z31 and Z39 applications. Only 48.9 mm of rain fell from the second Z39 application to the end of October reducing the benefits to yield of the different fungicide treatments.
•  Increasing variability in the trial due to the sub-soil issues from plot 215 into replicate 3 was a significant factor. Yield data should be treated with caution due to the variability of the site with disease control is the most accurate assessment of treatment efficacy.

• Control of net form net blotch using effective fungicides resulted in yield increases of up to 1.0 t/ha compared to nil treatments.
• Two strategic fungicide applications during early-mid growth stages (before end of August) – suppressed disease development and provided control comparable to four applications made every 2-4 weeks from early August.
• Tilt, Amistar Xtra, Opera and Prosaro were effective for control of net form of net blotch.

• Control of net form net blotch using effective fungicides resulted in yield increases of up to 1.0 t/ha compared to nil treatments.
• Two strategic fungicide applications during early-mid growth stages (before end of August) – suppressed disease development and provided control comparable to four applications made every 2-4 weeks from early August.
• Tilt, Amistar Xtra, Opera and Prosaro were effective for control of net form of net blotch.

Seed-applied fungicide had no significant effect on plant establishment, yield or grain quality (Refer Table 2). Visual differences in disease levels were not present between the fungicide treatments. Spot Form of Net Blotch was present at low levels in the trial and Leaf Scald was present at very low levels.

• Spot form of net blotch (SFNB) is a foliar disease of barley threatening production of the susceptible variety Gairdner.
• Fungicides may play an important role in achieving control over this disease

• Baudin produced a statistically higher yield than Gairdner under all treatment regimes.
• The dry growing season lead to a very low disease presence in the plots.
• Under non-experimental cropping situations, foliar fungicide sprays would not have been applied in the absence of disease; however, in this trial the cost of foliar applications were not returned through improved yield.

• A combination of old and new technology is being used to detect and analyse airborne fungal spore patterns affecting cereal and pulse grain crops.
• Intense spore showers were detected for blackspot of field pea and NFNB of barley, but negligible for YLS of wheat, at the experimental site at Hart during the 2013 season.
• Spore dispersal patterns of blackspot of field pea fitted with Blackspot Manager predictions.

• Fungicide spray significantly reduced the disease severity of spot type net blotch (STNB) in barley in Muntadgin in 2017.
• There was no yield penalty from not applying fungicide in the 2017 growing season in Muntadgin.
• There was no economic benefit from fungicide spray for controlling STNB in Muntadgin in 2017.

At the time of first visit (30th May), plants were at ~3 leaf stage and no foliar disease was evident.  Seedling establishment showed no spatial differences, with average emergence of >100 plants / m2 in all treatments except those with triadimenol seed treatment where >20% reduction in emergence was noted.

Minimal foliar disease was evident at 7th July (~Z31) assessment, minor levels of Stagonospora nodorum (septoria nodorum blotch) (SNB) were evident in the lower canopy but severity was too low for fungicide differences to be assessed.  

Trace levels of powdery mildew (PM) were evident on stems and lowest canopy leaves of untreated plots at booting (27th July) when the second foliar spray was applied. Development of PM was slow and on 15th September (~Z69) average severity in untreated controls was <1% leaf area affected on top 3 leaves, with infection primarily restricted to Flag-2 (Table 1).

PM was also present on heads and stems at low severity at this time, however the distribution of disease, particularly on heads, was patchy across the trial making differentiating between treatments difficult. At this time only the booting foliar spray provided consistent significant reduction in incidence of powdery mildew on stems and leaves.

SNB was present at low levels throughout the season, assessments at head emergence (23rd August) showed a small but significant effect of foliar treatments (Z31 and Z45) and flutriafol and Uniform in-furrow on necrotic leaf area. Assessments 3 weeks later at Z69 indicated that flutriafol in-furrow, triadimenol seed dressing and both foliar spray timings were providing a small reduction (~8-15% leaf area) in necrosis associated with SNB infection (Table 1).

With late and patchy onset of PM, yield responses to fungicides were 0-320kg/ha, with only the flutriafol in-furrow treatment having significantly greater yield than the untreated control, this response is likely due to the reduction of SNB rather than any effect on powdery mildew. Neither foliar spray timing gave significant yield response. Reduced emergence in triadimenol treated plots resulted in a 15% yield reduction (Table 2).

At two other sites (Geraldton, Dalwallinu), where powdery mildew infection commenced during stem elongation, all tested seed dressing and in-furrow fungicides had significant impact on disease severity and incidence. At the one site (Geraldton) where powdery mildew was yield limiting, in-furrow and foliar fungicide treatments gave a significant yield response.

• At both Murtoa and Birchip Gairdner barley developed spot form of net blotch; however it was most evident at Murtoa where fungicide applications gave yield responses varying from minus 0.4% to 8.5% (0-0.38t/ha).
• At this site three treatments gave significant yield increases over the untreated controls.

2018

Soil moisture measurements were taken on the 24th of May 2013 to confirm whether there had been carryover moisture from season 2012 in the bare areas of the paddock (due to mice damage in 2012). Based on the soil moisture tests below, and with regard to the bared areas observed in the paddock, the area shaded blue was identified as the only area with a potential representation of the chemical fallow effect. So in regards to final crop yield, this is the only one that was used for continuous crop versus chemical fallow comparisons.

2019

It was observed on the 23rd of July for both the wheat and barley, continuous cropped plots, were less vigorous and weedier than the respective chemical fallowed plots. For the canola on this day the chemical fallowed plot has commenced flowering sooner than the continuous cropped canola plot. There was more purpling on the continuous cropped canola compared with the chemical fallow plots which was possibly a combination of nitrogen deficiency and herbicide damage from the chemical, Intervix. On the 23rd of July it was also observed no differences in vigour between continuous cropped chickpeas and albus lupins when compared with the respective chemical fallowed plots.

On the 31st of July it was observed that net blotch disease had infected the barley plots and needed spraying with fungicide.

On the 1st of December when the trial was harvested it was observed that the chemical fallowed albus lupins appeared to have more terminal pods when compared with the continuous cropped plot. On this day both canola plots showed symptoms of severe shedding. The continuous cropped canola plot was thinner and shorter compared the chemical fallow canola plot. For both the wheat and barley, the chemical fallowed plots were thicker than the respective continuous cropped plots.

• However, the influence of seedbed N application (50kg/ha N) was evident in the crop structure scores, producing 150-200 more shoots/m2 and producing higher readings when the crop sensor Greenseeker® was passed over the trial than the GS30 stem elongation timing or the zero nitrogen controls.
• Despite a relatively low soil nitrogen reserve at sowing (43 kg/ha N 0-100cm), there was no influence of nitrogen on yield.
• In a trial subject to low levels of spot form of net blotch (SFNB), there was no response to fungicide over the untreated.

Barley can be successfully grown on retained wheat stubble, but it is advisable to burn wheat stubble when growing wheat on wheat. If stubble is retained then Yellow Leaf Spot can be a devastating disease in a wet winter. The most important management practices when growing a cereal on cereal are as follows:

• Select paddocks with low numbers of grass weeds.
• Retain wheat stubble for barley, burn the stubble for wheat.
• Control summer weeds to ensure summer rainfall can be used by the crop.
• Use varieties with good disease resistance such as Silverstar or Krichauff.
• Disease - select paddocks with low disease pressure (monitor the previous crop) and DNA test the paddock prior to sowing.
•  Apply sufficient nitrogen for a good crop (soil test to know how much to apply).
• Barley on barley can lead to serious problems with leaf diseases such as net blotch.

• All cultivars gave their highest yield under higher fungicide and nitrogen input (High input management), but cultivars differed in their response to increasing input with Westminster being the least responsive (1.69t/ha increase from low to high input) and Oxford the most responsive (3.09t/ha).
• RGT Planet was the highest yielding cultivar, although its advantage over Westminster was only apparent at higher levels of input, under low input both yielded similarly.
• Disease control resulting from the later fungicide application at GS37 and GS59 was strongly implicated in the yield differences, particularly between low and standard input where there was no difference in N input.
• Disease (net form of net blotch) in Oxford was uncontrollable in this trial even under high input where yield was maximised.
• RGT Planet, RGT Conquest and Westminster showed no significant difference in grain protein across the three management levels, whilst the proteins of Granger and Oxford decreased as yield increased from low to high input.
• Granger and RGT Planet recorded the lowest grain screenings. There was no significant effect of management level on screenings with these two cultivars or Westminster.
• In contrast, Oxford and Conquest that gave the largest responses to higher input showed significant decreases in grain screenings as input was increased.
• The devastating effect of NFNB on Oxford in this HRZ environment was very evident in both yield and screening results. As later fungicide input was removed from the management program so was the yield with significant reductions in yield and increased screenings.
• Under the lowest input RGT Planet and Westminster were significantly higher yielding than other cultivars tested.
• Under the highest input RGT Planet was significantly higher yielding than all other cultivars tested and produced the highest gross margins at each management level.
• With the very high disease pressure in this trial, the higher fungicide input associated with the High Input management made this the most cost effective management program of the Crop Technology Centre trials.
• As a result of higher disease pressure unlike wheat (Protocol 1) higher inputs of fungicide were generally more cost effective in barley sown early, irrespective of cultivar.

Again the majority of individual treatment responses to fungicide are positive but not statistically significant, indicating that there is a
trend but it is small. Barley however, poses a dilemma in that the single spray options early and late do not optimise performance against early Scald and late leaf rust infection, as such it is difficult to avoid spraying twice if both diseases pose a threat. In addition, if the rate of both sprays are cut to a bare minimum the results are inferior in terms of disease control. Triazoles are generally not as effective against Scald and diseases such net blotch, by comparison to the rusts.

• Genetic mutations in the Septoria tritici blotch (STB) pathogen Zymoseptoria tritici can differentially influence the performance of triazole fungicides in the laboratory.
• There should continue to be a focus on the principles of an integrated disease management (IDM) approach to control diseases such as STB, using rotation, cultivar resistance, later sowing, and other aspects of cultural control to compliment fungicide control.
• New research on foliar fungicide indicates that the principal fungicides still give good in-field control of STB up to 30 days after application when applied at full label rates.
• There are significant differences in disease control amongst the different fungicide products and rates of application when monitored leaves are assessed more than 30 days after application.
• Single spray timings of foliar fungicide for control of STB made during the late tillering phase gave less effective disease control than applications made at first node (GS31). Spray application delayed until flag leaf gave the poorest control of STB but gave superior leaf rust control later in the season.

 • Reduced sensitivity of the Septoria tritici blotch (STB) pathogen Zymoseptoria tritici to triazole fungicides is likely to be an increasing problem, following the discovery of more resistant biotypes (R8 strain or Isoform 11) on the mainland in 2016.
• The presence of this strain and its proportion in the population will influence disease management strategies differentially.
• In Tasmania, early season disease control in the field with flutriafol (2017 trials) and tebuconazole (2016 trials) has been reduced by the more resistant biotypes of the pathogen, whilst on the mainland trial sites the activity of flutriafol appears to have been maintained in 2017 for the control of STB.
• The performance of a new SDHI based seed treatment and to a lesser extent fluquinconazole (Jockey) has been better than flutriafol in Tasmanian trials.
• Triazole/strobilurin mixtures based on epoxiconazole and azoxystrobin (e.g. Radial, Tazer Xpert), along with new as yet unregistered combinations of triazole & SDHI have given excellent control of STB.
• In 2016 the advantage of these products was evident in disease control and yield response in wheat but in 2017 the yield response to these products was similar to that observed with Opus and Prosaro (registered in wheat but not registered for STB control).
• Single spray timings of foliar fungicide for control of STB made during the tillering phase gave less effective disease control than applications made between GS31 – GS39.
• The most effective control of STB on a canopy leaf layer is achieved by applying fungicide to that leaf shortly after it has fully emerged but before infection becomes established.
• Where more than one fungicide is used in wheat avoid using the same triazole active ingredient twice in a season, irrespective of diseases to be controlled. If it is not possible ensure it is mixed with another mode of action (strobilurin) at one of the timings.
• Since strobilurins are at higher risk of resistance avoid using products containing these active ingredients more than once in a season.

• Dry conditions reduced the severity of septoria tritici blotch.
• Timing of fungicide application did not affect (p<0.05) grain yield or quality.
• Consider using seed or fertiliser fungicide treatment when grazing wheat early in the season.
• Multiple fungicide applications using different active groups will reduce the risk of fungicide resistance developing in Zymoseptoria tritici.
• Grazing can add feed value to the wheat crop and reduce disease pressure. 

Despite the prevalence of cereal leaf disease in the Wimmera in 2003, these sites were relatively clean. Low levels of spot form of net blotch (SFNB) were present at most sites.

• The 2013 Tamworth and 2014 Trangie environments were not conducive to high levels of seed markings, with all varieties having <5% tiger stripe/blotches.
• The later sown chickpeas had a lower incidence of seed markings in two of the three environments.
• The 2015 Tamworth experiment was conducive to seed markings for the first sowing date (SD1). In this case, the most susceptible commercial varieties were PBA PistolA and PBA BoundaryA, with 9.7% and 6.7% of individual seeds having tiger stripe/blotches respectively.
• All five kabuli varieties did not display any seed markings in any of the three environments.
• All desi varieties showed at least low levels of tiger stripe/blotch type markings in one or more of the three environments and two sowing dates

Conclusions

Time of sowing and variety influence the amount of seeds showing the tiger stripe/blotching type markings in chickpea. Kabuli chickpeas do not suffer from this defect. Desi chickpeas sown in mid-June at Tamworth and Trangie had a lower incidence of this type of seed marking. Research is ongoing to identify both the genetic basis and the environmental triggers of tiger stripe/blotch type markings in desi chickpeas to minimise any potential risk to the Australian chickpea industry.

• Zymoseptoria tritici and Pyrenophra tritici-repentis, the disease-causing pathogens of septoria tritici blotch (STB) and yellow leaf spot (YLS), can produce ascospores on wheat stubble regardless of their resistance status.
• Any infected wheat stubble has the ability to initiate an epidemic for up to 2 years.
• Reduce harvest cut height to limit Z. tritici colonising stubble.
• Excess harvest material must be removed from the paddock to produce a net reduction of Z. tritici inoculum.
• Minimise disease impacts by using an integrated approach to management.