Best practice management of spot type net blotch in barley and interaction with stubble management and head loss 2015-2017

2017

Research organisaton
Funding source

Trial details

Researcher(s) Trent Butcher, Garren Knell, Ashton Gray, Geoff Thomas
Year(s) 2017
Contributor ConsultAg
Trial location(s) Corrigin, WA
Best practice management of spot type net blotch in barley and interaction with stubble management and head loss 2015-2017 locations
Aims
  • Investigate the best practice foliar fungicide management for barley on barley rotations and STNB control in barley cv. Scope.
  • Better understand the interactions of STNB, stubble and fungicides on the impact of disease, yield and profitability of barley on barley rotations.
  • Investigate if higher levels of STNB are associated with head loss pre-harvest.
Key messages

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.

Lead research organisation ConsultAg
Host research organisation N/A
Trial funding source GRDC TAR00007,TAR00006
Related program Regional Cropping Solutions Network
Acknowledgments

This has been a collaborative project between ConsultAg and the Deparment of Primary Industries and Regional Development. In particular thanks must be given to Geoff Thomas from the Department of Primary Industries and Regional Development for assistance in disease severity assessments and statistical analysis. This ensured rigour and consistency of assessments to match standard practices.


Other trial partners DPIRD, CFIG
Download the trial report to view additional trial information

Method

Crop type Cereal: Barley
Treatment type(s)
  • Crop: Protection
  • Fungicide: Type
  • Fungicide: Timing
  • Fungicide: Application
  • Fungicide: Method
  • Stubble: Management
Trial type Experimental
Trial design Blocked, randomised and replicated
Sow rate or Target density Not specified
Sowing machinery Not specified
Plot size Not specified
Plot replication Not specified
Plot blocking Not specified
Plot randomisation Not specified
Paddock history Barley on Barley Rotation
Fertiliser Not specified
Herbicide Not specified
Insecticide Not specified
Fungicide Not specified
Pesticide Not specified
Soil amelioration Not specified
Seed treatment Not specified
Inoculant Not specified
Tillage Not specified
Other trial notes Not specified
Download the trial report to view additional method/treatment information

Trial results Table 1

@T1: 2017 Assessment Following Z32 Application (01-01-2017) @T2: 2017 Assessment Following Z37 Application (01-01-2017) @T3: 2017 Grain Yield (01-05-2017) @T4: 2016 flag leaf assessment (01-01-2016) @T5: 2016 flag-1 leaf assessment (01-01-2016) @T6: 2016 flag-2 leaf assessment (01-01-2016) @T7: 2016 flag-3 leaf assessment (01-01-2016)
# Treatment 1
Treatment 2
Disease Severity Z32 (% leaf area affected) Disease severity Z37 (% leaf area affected) Grain yield (t/ha) Disease severity flag leaf (% leaf area affected) Disease severity flag-1 (% leaf area affected) Disease Severity Flag-2 (% leaf area affected) Disease Severity Flag-3 (% leaf area affected)
1 Amistar (Z32) + Tilt (Z37) Tilt (Z32) 1.3 2.833 2.521 5.7 8.426 9.93
2 Tilt (Z32) + Tilt (Z37) Tilt (Z37) 1.7 2.667 1.563 2.813 4.237 6.881
3 Prosaro (Z32) + Tilt (Z37) Tilt (Z32) + Tilt (Z37) 1.7 2.917 1.34 1.85 3.137 5.066
4 Tilt (Z37) Prosaro (Z32) 1.9 2.622 3.789 7.338 11.575 12.348
5 Prosaro (Z37) Prosaro (Z37) 2.7 2.748 2.438 4.663 7.725 9.379
6 Tilt (Z32) Prosaro (Z32) + Tilt (Z37) 1.094 4.1 2.683 1.706 2.063 3.938 5.576
7 Amistar (Z32) Amistar (Z32) 1.125 4.3 2.547 3.625 6.138 8.537 11.168
8 Prosaro (Z32) Amistar (Z32) + Tilt (Z37) 1.984 5.2 2.685 1.413 2.675 3.537 5.316
9 Untreated Control Untreated Control 2.772 8 2.525 4.988 8.475 12.412 16.208
LSD 1.192@T1 1.358@T2 0.2161@T3 1.207@T4 1.049@T5 1.427@T6 2.217@T7
CV 9.7@T1 7@T2 8.4@T3

Grain yield t/ha


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Disease severity flag leaf % leaf area affected


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Disease severity flag-1 % leaf area affected


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Disease Severity Flag-2 % leaf area affected


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Disease Severity Flag-3 % leaf area affected


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Disease Severity Z32 % leaf area affected


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Disease severity Z37 % leaf area affected


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Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Corrigin, WA Not specified
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Corrigin, WA Sodosol
National soil grid Source
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties

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Climate

Corrigin WA 2017


Derived climate information
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BOM Data source CORRIGIN [2197] 10km proximity to trial site location


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Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.