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Teagasc fungicide trials in winter wheat have given a yield response of 3.0-5.0 t/ha with a good margin over fungicide costs and improved grain and straw quality.

A reasonable fungicide program will cost in the region of €190/ha. However this should be reduced by 20% for late sown crops, where disease pressure from Septoria and Eyespot is low and where disease resistant varieties are sown.

Integrated Pest Management (IPM) techniques should be used where possible. For more information on IPM visit: Integrated Pest Management

Septoria

  • Fungicides continue to provide good control but need careful management.
  • Triazoles continue to weaken against Septoria
  • SDHI’s remain fully effective against Septoria.
  • Variety, spray timing and drilling date are vital for good Septoria control.

Eyespot

  • Early drilled crops in a plough-based system are highest risk
  • Assess crops for visual symptoms at gs 31 and treat at the T1 timing
  • Average yield response to eyespot fungicides 0.4 t/ha (HGCA - high-risk sites)

Min-till crops have a lower risk due to antagonistic factors in the cereal stubble.

N.B. - Where eyespot has a history of being problematic in a field, a pre-drilling assessment is suggested. Rotation, variety resistance and drilling date can all be used to reduce the risk of eyespot in an integrated management approach.

2015 Winter wheat spray timings, rationale & research results

T0

  • Yield response: NONE - helps better timing of T1
  • Timing: apply with PGR/onto leaf 4
  • Recommendations: 1.0 l/ha chlorothalonil (+/- strob for rust; morph for mildew)
  • Notes: No benefit from adding triazoles but increases risk of resistance occurring
  • Add a strob if rust is problematic or morpholine if mildew is prevalent.

T1

  • Yield response: (2012-2014 Teagasc experiments 0.5 t/ha)
  • Timing: Apply onto final leaf 3 fully emerged (~ gs 32 in 2015).
  • Recommendations: 1.0 l/ha chlorothalonil + 80-100 % (SDHI + triazole mix)
  • Notes: Assess for eyespot and mildew also at this timing

T2

  • Yield response: (2012-2014 Teagasc experiments 1.7 t/ha)
  • Timing: Apply onto flag leaf fully emerged (~ gs 39). See table above
  • Recommendations: 1.0 l/ha chlorothalonil + 80 - 100 % (SDHI + triazole mix)
  • This is consistently the best paying spray in winter wheat trials

T3

  • Yield response: (2012-2014 Teagasc experiments 0.5 t/ha)
  • Timing: Apply at start of flowering.
  • Recommendations: Fusarium & Septoria active triazole (See table above).
  • The yield response can be low in low disease pressure years.

For further information see Steven Kildea’s presentation at the National Tillage Conference 2015 available from here

Winter Barley Disease Control

Recent Teagasc trials from 2010-2012 show that a 3 spray program (< gs 30, gs 31-32 & gs 39-45) gives the best response from fungicides.

The following graph is from trials carried out by Oak Park across the country in the last four years. It shows the yield response to different fungicide timings and spray combinations.

Key messages from the trial

  • Trials from 2010-2013 show that the three timings; < gs 30, gs 31-32 & gs 39-45 give the best response from fungicides.
  • The two fungicide applications (gs 31-32 and gs 39/45) gave the best response. However a higher yield response can be expected from the three fungicide applications where the disease challenge is high in early season.
  • Applying the final fungicide at gs 39/45 out preforms applying a fungicide at gs 59, whether as a single application or in as part of a fungicide program.
  • Waiting to apply the final fungicide until the head fully emerges gives a poor response to fungicides.

Tillering spray (T1): Early disease can cause tiller loss at a critical time for yield formation.

Spray crops with high levels of Rhyncho to protect new growth with a suitable product such as Prothioconazole (Proline) and include a non-Triazole as an anti-resistance strategy. A Tillering spray has given up to 0.33 t/ha response in SAC and Teagasc trials. Watch six row varieties and Hybrid varieties for brown rust at this early stage.

Stem extension (T2): A comprehensive fungicide mix should be applied during Stem Extension (gs 32-37). Best responses will be achieved when applying closer to gs 32. A PGR can be added to this timing

Flag leaf/booting (T3): At flag leaf to heading stage a broad-spectrum fungicide such as a Triazole + SDHI mixture would be appropriate. Include Chlorothalonil on all varieties.

Winter Oat Disease Control

T1: (gs 30-31) On clean crops the inclusion of a preventative mildewcide such as Talius or Flexity will give prolonged protection against mildew. Including a reduced rate Triazole such as Epoxiconazole/Tebuconazole will give some control Red Leather Leaf Disease and prevent rust development. This will also give further protection against mildew. Tocata/Capalo is triazole + curative and preventative mildewcides.

Suitable product mixes include:

  • Clean crops
    Talius 0.2L/ha (or Flexity 0.4L/ha)
  • Mildew > 5%
    Epoxiconazole 0.5L/ha + Corbel 0.5L/ha or Tern 0.5L/ha

T2: A robust fungicide mix targeting mildew and Crown Rust is required when applying the main plant growth regulator at gs 32-33. Suitable product mixes include:

  • Furlong 0.5-0.8L/ha + Talius 0.2L/ha (+ Corbel 0.25L/ha where mildew >5%)
  • Tocata 1.0-1.5L/ha
  • Jenton 1.0L/ha + Talius 0.2L/ha
  • Vertisan 1.3L/ha + Talius 0.15L/ha +/- Corbel or Tern 0.3L/ha
  • Frelizon 1.0L/ha + Talius 0.15L/ha +/- Corbel or Tern 0.3L/ha

T3: A robust fungicide mix targeting mildew and Crown Rust is required at late flag leaf to heading gs 39-59. Suitable product mixes are similar to those at T2 but rates can be tailored to the disease challenge.

Note: curative mildewcides include morpholines such as Corbel, Tern or Winger. Preventative mildewcide include Talius or Flexity.

Note: Treoris is not cleared for oats