Fungicide Performance in 2005

1
Fungicide Performance in 2005

• Dr. Tom McCabe
• BASIS Meeting
• October 2005

2
Resistance Shifts to Triazoles

• Is there a slow but continuous shift in Septoria
  tritici populations for all triazoles in
  N.Europe.
• In UK evidence suggests flattening in 2003-2005,
  how will it continue ? will it level off,
  increase linearly.
• Epoxi and other triazoles have lost some efficacy
  over a longer period of time, and it is believed
  that this is a shift in sensitivity.
• A key question here is what about the 1990s base
  figures

3
Preventing Resistance Shifts in Triazole
Fungicides

• FRAC recommend
• Limit the number of applications
• To use the full-recommended rates
• To mix fungicides with different modes of action
• Farm Practice
• Limit the number of applications to reduce cost
• To use appropriate rates to optimise returns
• To mix fungicides with different modes of action
  to optimise control and to increase spectrum of
  control

4
Sensitivity of Septoria tritici populations to
DMIs (triazoles) Summary

• Slight but continuous shift of sensitivity
  observed between 1991 and 2003, slight shift
  observed from 2003 to 2004 in England, France and
  Germany,
• No significant shift in last two years
• Sensitivity shifts are about the same for all
  triazoles and cross resistance exists between all
  triazoles for the majority of isolates.
  Interesting data on procloraz from France.
• Reduced rates of triazoles are believed to
  promote selection of the less sensitive part of
  populations hence field rates of triazoles
  should be kept high to give adequate disease
  control and to keep selection pressure low
• Triazoles should be mixed with a contact
  fungicide (e.g. chlorothalonil) to give more
  reliable disease control and to slow down further
  sensitivity shifts to triazoles

5
(No Transcript)
6
Performance of triazole mixtures in 2004 and 2005

• In 2004
• Epoxi Prothio outperformed epoxi alone
• Excellent yield responses to a GS 39 application

7
Disease Control for T2 Triazoles cv. Savannah
2004
8
Disease Control for T2 Triazoles cv. Savannah
2005
9
Disease Control for T2 Triazoles cv. Savannah
2005
10
Yield Response to T2 Triazoles cv. Savannah 2004
11
Yield Response to T2 Triazoles cv. Savannah 2005
12
Winter Wheat 2005T2 - Blarney
Septoria
Source Infield Blarney L2 Untreated, Septoria
100 inf yield 4.27 t/ha
13
Winter Wheat 2005T2 Across Sites
14
Winter Wheat 2005T2 Yield Response to
Fungicide
15
Winter Wheat 2005T2 Yield Response to
Fungicide avg. 3 trials
16
Yield Response to Fungicide UCD 2005 Two-spray
progs on cv. Tanker
17
Yield Response to Fungicide UCD 2005 Two-spray
progs on cv. Tanker
Average Yield Response to Bravo 0.38 t/ha (sig
5)
18
Fungicide Performance at GS 39 in 2005cv.
Einstein
19
Fungicide Performance at GS 39 in 2005cv.
Einstein
20
Fungicide Performance at GS 39 in 2005cv.
Einstein
21
Strob Response 2005 Trials

• Trial 1 Fungicide programme studies across
  four cultivars
• /- strob , 2 x 0.5 Amistar
• Trial 2 Fungicide programme studies incl.
  multiple low-dose strob approach
• Trial 3 Studies with Amistar Opti at T2
  combined with Menara or Opus
• Trial 4 Strob and Chlorothalonil strategies in
  a triazole-based programme

22
Trial 1. Fungicide Programme Studies across
Four Cultivars

• Four cultivars of varying Septoria tritici
  resistance with three fungicide programmes on
  each
• Savannah (4) , Richmond (4) , Einstein (6),
  Robigus (7)
• Three-spray fungicide programmes
• GS 32 , GS 39 , GS 60
• Standard Programme was triazole-based
• T1 Proline 0.5 l/ha
• T2 OpusBravo 0.51.0 l/ha1 / A1477Bravo
• T3 Proline 0.5 l/ha

23
Green Leaf Data for Strob and Non-strob Prog.s
(Avg. 4 Varieties)
24
Green Leaf Data for Strob and Non-strob Prog.s
(Avg. 4 Varieties)
25
Disease Control for Strob and Non-strob Prog.s
(cv. Savannah)
26
Disease Control for Strob and Non-strob Prog.s
(cv. Savannah)
27
CDCF 2005Grain Yield Response to Fungicide
Programmes 4 varieties
28
CDCF 2005Grain Yield Response to Fungicide
Programmes 4 varieties
29
CDCF 2005Grain Yield Response to Fungicide
Programmes 4 varieties
30
CDCF 2005Grain Yield Response to Fungicide
Programmes 4 varieties
31
CDCF 2005Grain Yield Response to Fungicide
Programmes 4 varieties
Yield response to triazole 0.7 t/ha Yield
response to triazolestrob 1.02 t/ha LSD 0.21
32
Trial 2. Fungicide Programme Studies on a
Septoria Resistant Cultivar - Robigus

• Four-spray fungicide programmes were tested
• Strob frequency of zero-four
• Strob dose of 0.5 to 2.0 Amistar (125 to 500g/ha)
• Fungicide timings
• GS 30 (21/4), 32 (14/5), GS 39 (2/6), GS 65
  (20/6)
• Standard Programme was triazole-based
• Tzero Bravo 1.0
• T1 OpusBravo 0.61.0
• T2 Opus 0.8
• T3 Proline 0.6

33
(No Transcript)
34
Yield Response to Strob on cv. Robigus
35
Trial 3. Fungicide Programme Studies with
Amistar Opti on cv. Richmond

• Three-four-spray fungicide programmes were tested
  
• Strob use at T2 and T3
• Amistar Opti dose of 1.25 2.5 applied
  once/twice
• Fungicide timings
• GS 30 (21/4), 32 (6/5), GS 39 (26/5), GS 65
  (22/6)
• MenaraBravo v OpusBravo
• 0.51.0 0.61.0

36
Yield Response to Amistar Opti on cv. Richmond
37
Performance of Amistar Opti as a Tzero 1
Septoria tritici Control
38
Performance of Amistar Opti as a Tzero 2 -
Green Leaf Retention
39
Conclusions on 2005 Trials

• Relatively high untreated fungicide yields
• Modest yield response to fungicide use
• Very good efficacy from triazole fungicides
• Chlorothalonil very consistent and valuable
  contribution to disease control and yield
  response
• Yield response to strob (2 x 0.5) 0.4 t/ha
• Difficult to get consistent response patterns to
  strob use within a fungicide programme

40
Data from Spring Barley Trials in 2005

• Relatively high early-season disease pressure in
  earlier drilled trials
• Moderate-low disease pressure from T2 onwards
  with earlier ripening of crops
• Good disease control generally with timing
  critical for rhynco control at T1
• Excellent control of ramularia at T2 in most
  situations

41
Data from Spring Barley Trials in 2005

• Net blotch resistance to strobs deteched in a no.
  of EU countries (F129L gene)
• Monitoring has indicated no presence of
  resistance to strobilurin fungicides in Ireland
  to date
• Net blotch control tested on cv. Lux in 2005
• Very good efficacy on net blotch from a range of
  fungicide programmes
• Reduced efficacy expected when resistance emerges

42
(No Transcript)